diff --git a/AUTHORS b/AUTHORS
index 5c9ad9e..817b038 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -24,5 +24,5 @@ for use in the OpenSSL Toolkit (http://www.openssl.org/).
 
 Translations
 ------------
-Thanks to Per-Arne Christensen for the Norwegian translation of 
+Thanks to Per-Arne Christensen for the Norwegian translation of
 the GUI.
diff --git a/ChangeLog b/ChangeLog
index c189116..ddbe2b0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,11 +1,18 @@
 E-MailRelay Change Log
 ======================
 
-2.3 -> 2.3.1
-------------
-* Hourly log file rotation using "%h" (eg. "--log-file=log.%d.%h").
+2.3 -> 2.4
+----------
+* Multiple "--filter" and "--client-filter" options allowed.
 * TLS key and certificate files can be specified separately.
-* Fixed error handling for network client filters ("--client-filter=net:...") [bug-id #50].
+* Finer control when using "--anonymous" (eg. "--anonymous=server").
+* The "auth-config" options can distinguish between TLS and non-TLS authentication.
+* Hourly log file rotation using "%h" (eg. "--log-file=log.%d.%h").
+* Listening file descriptors can be inherited from the parent process (see "--interface").
+* Listening ports on Windows use exclusive binding.
+* The Linux event loop uses "epoll" by default rather than "select".
+* Some support for message routing (see NEWS).
+* Fix of error handling in network client filters ("--client-filter=net:...") [bug-id #50].
 
 2.2 -> 2.3
 ----------
diff --git a/Makefile.am b/Makefile.am
index 4b011a5..46285fb 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -61,7 +61,7 @@ EXTRA_DIST = \
 	winbuild.pl \
 	runperl.bat
 
-SUBDIRS = bin src etc doc debian test m4 bsd po
+SUBDIRS = bin src etc doc debian test m4 bsd po unity
 
 # work-round PKG_CHECK_MODULES if no pkg-config
 ACLOCAL_AMFLAGS = -I m4
@@ -76,6 +76,7 @@ RPM_ROOT ?= ${HOME}/rpmbuild
 ARCH ?= x86_64
 RPM=$(RPM_ROOT)/RPMS/$(ARCH)/emailrelay-$(VERSION)-1.$(ARCH).rpm
 TAR=emailrelay-$(VERSION).tar.gz
+ZIP=emailrelay-$(VERSION)-src.zip
 DEB=emailrelay_$(VERSION)_$(ARCH).deb
 
 .PHONY: strip
@@ -102,21 +103,25 @@ deb: $(DEB)
 
 $(DEB): dist
 	-mv emailrelay-$(VERSION) emailrelay-$(VERSION).old.$$$$ || true
-	tar xzf $(TAR)
+	tar -xzf $(TAR)
 	cd emailrelay-$(VERSION) && fakeroot debian/rules binary
 	mkdir emailrelay-$(VERSION)/debian/source
 
 .PHONY: deb-src
 deb-src: dist
 	-mv emailrelay-$(VERSION) emailrelay-$(VERSION).old.$$$$ || true
-	tar xzf $(TAR)
+	tar -xzf $(TAR)
 	mkdir emailrelay-$(VERSION)/debian/source
 	echo 1.0 > emailrelay-$(VERSION)/debian/source/format
 	dpkg-source --build emailrelay-$(VERSION)
 
 .PHONY: tidy
 tidy:
-	$(MAKE) -C src tidy
+	$(MAKE) -C unity tidy
+
+.PHONY: unitybuild
+unitybuild:
+	$(MAKE) -C unity programs
 
 .PHONY: format
 format:
@@ -130,3 +135,22 @@ cmake:
 	cd build && cmake -DCMAKE_MAKE_PROGRAM:FILEPATH=/usr/bin/make -DCMAKE_EXPORT_COMPILE_COMMANDS=ON ..
 	@echo now run make from the '"build"' directory
 
+.PHONY: tar
+tar: $(TAR)
+
+$(TAR):
+	$(MAKE) dist
+
+.PHONY: zip
+zip: $(ZIP)
+
+$(ZIP): $(TAR)
+	tar -xzf $(TAR)
+	sh -c "cd emailrelay-$(VERSION) && zip -r ../$(ZIP) ."
+
+.PHONY: mbedtls
+mbedtls:
+	test -d mbedtls || git clone https://salsa.debian.org/debian/mbedtls.git
+	make -C mbedtls/library WINDOWS=0
+	-@echo now run ./configure.sh
+
diff --git a/Makefile.in b/Makefile.in
index e24e46a..21684e5 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -406,13 +406,14 @@ EXTRA_DIST = \
 	winbuild.pl \
 	runperl.bat
 
-SUBDIRS = bin src etc doc debian test m4 bsd po
+SUBDIRS = bin src etc doc debian test m4 bsd po unity
 
 # work-round PKG_CHECK_MODULES if no pkg-config
 ACLOCAL_AMFLAGS = -I m4
 e_doc_DATA = COPYING AUTHORS INSTALL NEWS README ChangeLog
 RPM = $(RPM_ROOT)/RPMS/$(ARCH)/emailrelay-$(VERSION)-1.$(ARCH).rpm
 TAR = emailrelay-$(VERSION).tar.gz
+ZIP = emailrelay-$(VERSION)-src.zip
 DEB = emailrelay_$(VERSION)_$(ARCH).deb
 all: all-recursive
 
@@ -928,21 +929,25 @@ deb: $(DEB)
 
 $(DEB): dist
 	-mv emailrelay-$(VERSION) emailrelay-$(VERSION).old.$$$$ || true
-	tar xzf $(TAR)
+	tar -xzf $(TAR)
 	cd emailrelay-$(VERSION) && fakeroot debian/rules binary
 	mkdir emailrelay-$(VERSION)/debian/source
 
 .PHONY: deb-src
 deb-src: dist
 	-mv emailrelay-$(VERSION) emailrelay-$(VERSION).old.$$$$ || true
-	tar xzf $(TAR)
+	tar -xzf $(TAR)
 	mkdir emailrelay-$(VERSION)/debian/source
 	echo 1.0 > emailrelay-$(VERSION)/debian/source/format
 	dpkg-source --build emailrelay-$(VERSION)
 
 .PHONY: tidy
 tidy:
-	$(MAKE) -C src tidy
+	$(MAKE) -C unity tidy
+
+.PHONY: unitybuild
+unitybuild:
+	$(MAKE) -C unity programs
 
 .PHONY: format
 format:
@@ -956,6 +961,25 @@ cmake:
 	cd build && cmake -DCMAKE_MAKE_PROGRAM:FILEPATH=/usr/bin/make -DCMAKE_EXPORT_COMPILE_COMMANDS=ON ..
 	@echo now run make from the '"build"' directory
 
+.PHONY: tar
+tar: $(TAR)
+
+$(TAR):
+	$(MAKE) dist
+
+.PHONY: zip
+zip: $(ZIP)
+
+$(ZIP): $(TAR)
+	tar -xzf $(TAR)
+	sh -c "cd emailrelay-$(VERSION) && zip -r ../$(ZIP) ."
+
+.PHONY: mbedtls
+mbedtls:
+	test -d mbedtls || git clone https://salsa.debian.org/debian/mbedtls.git
+	make -C mbedtls/library WINDOWS=0
+	-@echo now run ./configure.sh
+
 # Tell versions [3.59,3.63) of GNU make to not export all variables.
 # Otherwise a system limit (for SysV at least) may be exceeded.
 .NOEXPORT:
diff --git a/NEWS b/NEWS
index 7a931e8..db9d9e9 100644
--- a/NEWS
+++ b/NEWS
@@ -1,7 +1,34 @@
 News
 ----
-Version 2.3 is a relatively minor release. The main functional change is to
-support unix domain sockets. Non-functional code changes include better
-separation of interface and implementation in the SMTP message store.
+Low-level changes include a rework of the event-loops. The Unix event loop
+defaults to an epoll() implementation.
 
-Version 2.3.1 is a point release principally to fix bug-id #50.
+The i18n of the main server (not the gui) has been extended somewhat by marking
+for translation the text of most C++ exceptions. This is only relevant if
+building "--with-gettext" and running with "--localedir".
+
+The "--anonyous" option has changed slightly in v2.4 so that it will now force
+the AUTH parameter on the MAIL command to be "AUTH=<>". Replace "--anonymous"
+with "--anonymous=vrfy,server,content" to keep the same behaviour as before.
+
+The "emailrelay-submit" utility's "--content" option no longer suppresses
+reading of the standard input stream; there is a new "--no-stdin" option
+instead. A dot on its own does not terminate the input any more, so use ^D or
+^Z to stop reading from the terminal. Header-only content with no body text is
+now permitted.
+
+Authentication using PAM no longer insists on TLS encryption because the
+"--server-auth-config" option can be used to disable password authentication
+over an unencypted connection.
+
+Limited support for routing is included. The envelope files have two new fields:
+ForwardTo and ForwardToAddress. A filter script can examine the message content
+and deposit the appropriate domain name and port number in the ForwardTo field.
+If the SMTP client sees a ForwardTo value then it runs the client-filter early
+allowing the client filter to do a DNS MX lookup of the ForwardTo value and
+deposit the address into the ForwardToAddress field. If the SMTP client sees a
+ForwardToAddress it will initiate a connection to that address to send the
+message. The client-filter is run a second time in the normal way once the SMTP
+session has been established. A connection to the main "--forward-to" address
+will always be made even if all the messages are routed elsewhere, and each
+routed connection will carry only one message.
diff --git a/README b/README
index 4dd9a75..03c048a 100644
--- a/README
+++ b/README
@@ -73,6 +73,30 @@ or run:
 
 	emailrelay --help --verbose
 
+Packages
+--------
+To install on Linux from a RPM or DEB package:
+
+	sudo $SHELL # or 'su'
+	rpm -i emailrelay*.rpm  # if RPM
+	dpkg -i emailrelay*.deb  # if DEB
+
+If your Linux system uses "systemd" then you should check the E-MailRelay
+configuration file "/etc/emailrelay.conf" is as you want it and then run:
+
+	systemctl enable emailrelay
+	systemctl start emailrelay
+	systemctl status emailrelay
+
+On other systems try these commands:
+
+	cp /usr/lib/emailrelay/init/emailrelay /etc/init.d/
+	update-rc.d emailrelay enable || rc-update add emailrelay
+	invoke-rc.d emailrelay start || service emailrelay start
+	tail /var/log/messages /var/log/syslog 2>/dev/null
+
+On Windows run the setup program.
+
 Documentation
 -------------
 The following documentation is provided:
@@ -87,7 +111,3 @@ The following documentation is provided:
 Source code documentation will be generated when building from source if
 "doxygen" is available.
 
-Feedback
---------
-Please feel free to e-mail the author at "mailto:graeme_walker@users.sourceforge.net".
-
diff --git a/README.md b/README.md
index 2016da9..1ba0df7 100644
--- a/README.md
+++ b/README.md
@@ -79,6 +79,30 @@ or run:
 
         emailrelay --help --verbose
 
+Packages
+--------
+To install on Linux from a RPM or DEB package:
+
+        sudo $SHELL # or 'su'
+        rpm -i emailrelay*.rpm  # if RPM
+        dpkg -i emailrelay*.deb  # if DEB
+
+If your Linux system uses `systemd` then you should check the E-MailRelay
+configuration file `/etc/emailrelay.conf` is as you want it and then run:
+
+        systemctl enable emailrelay
+        systemctl start emailrelay
+        systemctl status emailrelay
+
+On other systems try these commands:
+
+        cp /usr/lib/emailrelay/init/emailrelay /etc/init.d/
+        update-rc.d emailrelay enable || rc-update add emailrelay
+        invoke-rc.d emailrelay start || service emailrelay start
+        tail /var/log/messages /var/log/syslog 2>/dev/null
+
+On Windows run the setup program.
+
 Documentation
 -------------
 The following documentation is provided:
@@ -94,10 +118,6 @@ The following documentation is provided:
 Source code documentation will be generated when building from source if
 `doxygen` is available.
 
-Feedback
---------
-Please feel free to e-mail the author at `mailto:graeme_walker@users.sourceforge.net`.
-
 
 [POP]: https://en.wikipedia.org/wiki/Post_Office_Protocol
 [SMTP]: https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol
diff --git a/README.rst b/README.rst
index 052000f..7ae89f7 100644
--- a/README.rst
+++ b/README.rst
@@ -100,6 +100,36 @@ or run:
 
     emailrelay --help --verbose
 
+Packages
+========
+To install on Linux from a RPM or DEB package:
+
+::
+
+    sudo $SHELL # or 'su'
+    rpm -i emailrelay*.rpm  # if RPM
+    dpkg -i emailrelay*.deb  # if DEB
+
+If your Linux system uses *systemd* then you should check the E-MailRelay
+configuration file */etc/emailrelay.conf* is as you want it and then run:
+
+::
+
+    systemctl enable emailrelay
+    systemctl start emailrelay
+    systemctl status emailrelay
+
+On other systems try these commands:
+
+::
+
+    cp /usr/lib/emailrelay/init/emailrelay /etc/init.d/
+    update-rc.d emailrelay enable || rc-update add emailrelay
+    invoke-rc.d emailrelay start || service emailrelay start
+    tail /var/log/messages /var/log/syslog 2>/dev/null
+
+On Windows run the setup program.
+
 Documentation
 =============
 The following documentation is provided:
@@ -115,10 +145,6 @@ The following documentation is provided:
 Source code documentation will be generated when building from source if
 *doxygen* is available.
 
-Feedback
-========
-Please feel free to e-mail the author at *mailto:graeme_walker@users.sourceforge.net*.
-
 
 .. _POP: https://en.wikipedia.org/wiki/Post_Office_Protocol
 .. _SMTP: https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol
diff --git a/VERSION b/VERSION
index 2bf1c1c..6b4950e 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.3.1
+2.4
diff --git a/autogen.sh b/autogen.sh
old mode 100644
new mode 100755
diff --git a/bin/AutoMakeParser.pm b/bin/AutoMakeParser.pm
index 8dadd3b..b4ab35c 100644
--- a/bin/AutoMakeParser.pm
+++ b/bin/AutoMakeParser.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -40,6 +40,24 @@
 #  $makefile->our_libs('foo') ;
 #  $makefile->sys_libs('foo') ;
 #
+# Typical directories in a autoconf vpath build (see includes()):
+#
+#    project <-- $(top_srcdir)        <-------+-+ "base_to_top"
+#       |                                     | |
+#       +----src  <-- readall() base        --+ | <---+ base()
+#       |     |                                 |     |
+#       |     +-- sub1  <-- path()              | ----+
+#       |                                       |
+#       +----bin                                |
+#       |                                       |
+#       +--build <-- $(top_builddir)            |  <-- $(top_builddir)
+#            |                                  |
+#            +-- src                          --+  <--+ base()
+#                 |                                   |
+#                 +-- sub1  <-- c++ cwd         ------+
+#
+# See also ConfigStatus.pm.
+#
 
 use strict ;
 use FileHandle ;
@@ -104,11 +122,11 @@ sub depth
 	return $this->{m_depth} ;
 }
 
-sub top
+sub base
 {
 	# Returns the relative path up to the first readall()
-	# makefile, which might be different from $(top_srcdir).
-	# The returned value will be something like "../../../".
+	# makefile. The returned value will be something like
+	# "../../../". See also includes().
 	#
 	my ( $this ) = @_ ;
 	my $depth = $this->{m_depth} ;
@@ -237,46 +255,47 @@ sub _definitions_imp
 
 sub includes
 {
-	# Returns a list of include directories, so for example
-	# "-I$(top_srcdir)/one/two -I$(top_srcdir)/three"
-	# with the 'top_srcdir' variable defined as "." gives
-	# ("./one/two","./three").
+	# Returns a list of include directories derived from the
+	# AM_CPPFLAGS and CXXFLAGS macros. The returned list also
+	# optionally starts with the autoconf header directory,
+	# obtained by expanding top_srcdir.
 	#
-	# However, since the 'top_srcdir' expansion is fixed, and
-	# relative include paths need to vary through the source
-	# tree, a prefix parameter ('top') should be passed in as
-	# the current value for expanding "$(top_srcdir)". So then
-	# "-I$(top_srcdir)/one/two" becomes "<top>/./one/two".
-	# (Absolute paths do not get the 'top' prefixed by 'top'.)
+	# Include paths need to vary through the source tree,
+	# so a 'base' parameter is provided here which is used
+	# as a prefix for all relative paths from the AM_CPPFLAGS
+	# and CXXFLAGS expansions and as a suffix for the
+	# autoconf header directory.
 	#
-	# The "top()" method provides a candidate for the 'top'
-	# parameter but will only work if readall() started at the
-	# 'top_srcdir' directory and the 'top_srcdir' variable is
-	# defined as ".". Otherwise, a simple approach is to still
-	# use top() for the 'top' parameter but define the 'top_srcdir'
-	# variable as the difference between the readall() base and
-	# the actual 'top_srcdir' directory.
+	# For example, if CXXFLAGS is "-I$(top_srcdir)/src/sub"
+	# and top_srcdir is "." then includes(base()) will
+	# will yield ("./..",".././src/sub") for one makefile and
+	# ("./../..","../.././src/sub") for another.
 	#
-	my ( $this , $top , $full_paths , $no_top_dir ) = @_ ;
-	$top ||= "" ;
-	my $add_top = !$no_top_dir ;
-	my $real_top = simplepath( join( "/" , $this->value("top_srcdir") , $top ) ) ;
-	my @a = $this->_includes_imp( $top , "AM_CPPFLAGS" , $this->{m_vars} , $full_paths ) ;
-	my @b = $this->_includes_imp( $top , "CXXFLAGS" , $this->{m_vars} , $full_paths ) ;
-	my @c = ( $real_top && $add_top ) ? ( $real_top ) : () ;
+	# In practice the value for top_srcdir should be carefully
+	# chosen as some "base-to-top" relative path that makes things
+	# work correctly if readall() was not based at top_srcdir
+	# or when targeting vpath builds. See above.
+	#
+	my ( $this , $base , $full_paths , $no_autoconf_dir ) = @_ ;
+	$base ||= "" ;
+	my $add_autoconf_dir = !$no_autoconf_dir ;
+	my $autoconf_dir = simplepath( join( "/" , $this->value("top_srcdir") , $base ) ) ;
+	my @a = $this->_includes_imp( $base , "AM_CPPFLAGS" , $this->{m_vars} , $full_paths ) ;
+	my @b = $this->_includes_imp( $base , "CXXFLAGS" , $this->{m_vars} , $full_paths ) ;
+	my @c = ( $autoconf_dir && $add_autoconf_dir ) ? ( $autoconf_dir ) : () ;
 	my @incs = ( @c , @a , @b ) ;
 	return wantarray ? @incs : join(" ",@incs) ;
 }
 
 sub _includes_imp
 {
-	my ( $this , $top , $var , $vars , $full_paths ) = @_ ;
+	my ( $this , $base , $var , $vars , $full_paths ) = @_ ;
 	my $s = protect_quoted_spaces( simple_spaces( $vars->{$var} ) ) ;
 	$s =~ s/-I /-I/g ;
 	return
 		map { $full_paths?$this->fullpath($_):$_ }
 		map { simplepath($_) }
-		map { my $p=$_ ; ($top&&($p!~m;^/;))?join("/",$top,$p):$p }
+		map { my $p=$_ ; ($base&&($p!~m;^/;))?join("/",$base,$p):$p }
 		map { s/\t/ /g ; $_ }
 		map { s:-I:: ; $_ } grep { m/-I\S+/ }
 		split( " " , $s ) ;
diff --git a/bin/CompilationDatabase.pm b/bin/CompilationDatabase.pm
index dd1ad33..9e95724 100644
--- a/bin/CompilationDatabase.pm
+++ b/bin/CompilationDatabase.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -26,7 +26,9 @@
 # Synopsis:
 #
 #    use CompilationDatabase ;
-#    my $cdb = new CompilationDatabase( $src_dir , {WINDOWS=>0,...} , {top_srcdir=>'..'} , {} ) ;
+#    my @makefiles = AutoMakeParser::readall( ... ) ;
+#    my $cdb = new CompilationDatabase( \@makefiles , {full_paths=>1} ) ;
+#    my $cdb = new CompilationDatabase( $src_dir , {WINDOWS=>0,...} , {top_srcdir=>'..'} , {full_paths=>1} ) ;
 #    my @files = $cdb->list() ;
 #    my @stanzas = $cdb->stanzas() ;
 #    $cdb->print() ;
@@ -41,28 +43,50 @@ our $debug = 0 ;
 
 sub new
 {
-	my ( $classname , $base_makefile_dir , $switches , $ro_vars , $config ) = @_ ;
-	$AutoMakeParser::debug = 1 if $debug > 1 ;
-	$config ||= {} ;
-	$config->{test_mode} ||= 0 ;
-	$config->{full_paths} ||= 0 ;
-	my %me = (
-		m_base_dir => $base_makefile_dir ,
-		m_switches => $switches ,
-		m_ro_vars => $ro_vars ,
-		m_config => $config ,
-	) ;
-	return bless \%me , $classname ;
+	if( ref($_[1]) )
+	{
+		# Parses a set of makefiles as given by an array of Makefile
+		# objects obtained from AutoMakeParser::readall().
+		#
+		my ( $classname , $makefiles_ref , $config ) = @_ ;
+		$config ||= {} ;
+		$config->{test_mode} ||= 0 ;
+		$config->{full_paths} ||= 0 ;
+		my %me = (
+			m_makefiles => $makefiles_ref ,
+			m_config => $config ,
+		) ;
+		return bless \%me , $classname ;
+	}
+	else
+	{
+		# Finds makefiles under the given base directory and parses
+		# them. The switches and read-only expansion variables can
+		# be hard-coded or extracted from a config.status file
+		# (see ConfigStatus).
+		#
+		my ( $classname , $base_makefile_dir , $switches , $ro_vars , $config ) = @_ ;
+		$AutoMakeParser::debug = 1 if $debug > 1 ;
+		$config ||= {} ;
+		$config->{test_mode} ||= 0 ;
+		$config->{full_paths} ||= 0 ;
+		my @makefiles = AutoMakeParser::readall( $base_makefile_dir , $switches , $ro_vars ) ;
+		my %me = (
+			m_makefiles => \@makefiles ,
+			m_config => $config ,
+		) ;
+		return bless \%me , $classname ;
+	}
 }
 
 sub list
 {
+	# Returns a list of all the source files in all the makefiles found under base-dir.
 	my ( $this ) = @_ ;
 
 	my @list = () ;
 	my $verbose = $debug ;
-	my @makefiles = AutoMakeParser::readall( $this->{m_base_dir} , $this->{m_switches} , $this->{m_ro_vars} , $verbose ) ;
-	for my $m ( @makefiles )
+	for my $m ( @{$this->{m_makefiles}} )
 	{
 		my $sub_dir = File::Basename::dirname( $m->path() ) ;
 		for my $library ( $m->libraries() )
@@ -79,6 +103,7 @@ sub list
 
 sub print
 {
+	# Prints the complete compilation database json structure to stdout.
 	my ( $this ) = @_ ;
 	print "[\n" ;
 	print join( ",\n" , $this->stanzas() ) ;
@@ -87,14 +112,15 @@ sub print
 
 sub stanzas
 {
+	# Returns a list of separate compilation database stanzas for all the source files
+	# in all the makefiles found under base-dir.
 	my ( $this ) = @_ ;
 
-	my @makefiles = AutoMakeParser::readall( $this->{m_base_dir} , $this->{m_switches} , $this->{m_ro_vars} ) ;
 	my @output = () ;
-	for my $m ( @makefiles )
+	for my $m ( @{$this->{m_makefiles}} )
 	{
 		my $dir = File::Basename::dirname( $m->path() ) ;
-		my @includes = map { "-I$_" } $m->includes( $m->top() , undef , undef , $this->{m_config}->{full_paths} ) ;
+		my @includes = map { "-I$_" } $m->includes( $m->base() , undef , undef , $this->{m_config}->{full_paths} ) ;
 		my @definitions = map { "-D$_" } $m->definitions() ;
 		my @compile_options = $m->compile_options() ;
 		my @link_options = $m->link_options() ;
@@ -102,7 +128,7 @@ sub stanzas
 		if( $debug )
 		{
 			print "cdb: makefile=" , $m->path() , "\n" ;
-			print "cdb:  top=",$m->top(),"\n" ;
+			print "cdb:  base=",$m->base(),"\n" ;
 			print "cdb:  \@includes=" , join("|",@includes) , "\n" ;
 			print "cdb:  \@definitions=" , join("|",@definitions) , "\n" ;
 			print "cdb:  \@compile_options=" , join("|",@compile_options) , "\n" ;
diff --git a/bin/ConfigStatus.pm b/bin/ConfigStatus.pm
index f5ef715..bf27933 100644
--- a/bin/ConfigStatus.pm
+++ b/bin/ConfigStatus.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -23,7 +23,9 @@
 #
 # Synopsis:
 #  use ConfigStatus ;
-#  my $cs = new ConfigStatus( "config.status" ) ;
+#  my $cs = new ConfigStatus() ;
+#  my $cs = new ConfigStatus( "./config.status" ) ;
+#  my $cs = new ConfigStatus("") ; $cs->parse( "/tmp/config.status" ) ;
 #  my %vars = $cs->vars() ;
 #  my %switches = $cs->switches() ;
 #
@@ -42,6 +44,18 @@ sub new
 		m_vars => {} ,
 		m_switches => {} ,
 	} , $classname ;
+	if( !defined($filename) )
+	{
+		for my $dir ( "." , ".." , "../.." )
+		{
+			if( -e "$dir/config.status" )
+			{
+				$filename = "$dir/config.status" ;
+				last ;
+			}
+		}
+		$filename or die ;
+	}
 	$this->parse( $filename ) if $filename ;
 	return $this ;
 }
diff --git a/bin/Makefile.am b/bin/Makefile.am
index 2ed57f1..c8187c8 100644
--- a/bin/Makefile.am
+++ b/bin/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -19,6 +19,7 @@ example_scripts_static = \
 	emailrelay-bcc-check.pl \
 	emailrelay-check-ipaddress.js \
 	emailrelay-check-ipaddress.pl \
+	emailrelay-dkim-signer.pl \
 	emailrelay-ldap-verify.py \
 	emailrelay-multicast.sh \
 	emailrelay-rot13.pl \
@@ -52,6 +53,7 @@ work_scripts = \
 	make-format \
 	make2cmake \
 	make2cdb \
+	make2unity \
 	AutoMakeParser.pm \
 	CompilationDatabase.pm \
 	ConfigStatus.pm \
diff --git a/bin/Makefile.in b/bin/Makefile.in
index 9d94961..c72b31f 100644
--- a/bin/Makefile.in
+++ b/bin/Makefile.in
@@ -286,6 +286,7 @@ example_scripts_static = \
 	emailrelay-bcc-check.pl \
 	emailrelay-check-ipaddress.js \
 	emailrelay-check-ipaddress.pl \
+	emailrelay-dkim-signer.pl \
 	emailrelay-ldap-verify.py \
 	emailrelay-multicast.sh \
 	emailrelay-rot13.pl \
@@ -319,6 +320,7 @@ work_scripts = \
 	make-format \
 	make2cmake \
 	make2cdb \
+	make2unity \
 	AutoMakeParser.pm \
 	CompilationDatabase.pm \
 	ConfigStatus.pm \
diff --git a/bin/doxygen.sh b/bin/doxygen.sh
index d35f4ff..4e95a0d 100755
--- a/bin/doxygen.sh
+++ b/bin/doxygen.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/bin/emailrelay-bcc-check.pl b/bin/emailrelay-bcc-check.pl
index a549234..7bd338f 100755
--- a/bin/emailrelay-bcc-check.pl
+++ b/bin/emailrelay-bcc-check.pl
@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # Copying and distribution of this file, with or without modification,
 # are permitted in any medium without royalty provided the copyright
diff --git a/bin/emailrelay-deliver.sh.in b/bin/emailrelay-deliver.sh.in
old mode 100644
new mode 100755
index 09a3e1c..be92336
--- a/bin/emailrelay-deliver.sh.in
+++ b/bin/emailrelay-deliver.sh.in
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # Copying and distribution of this file, with or without modification,
 # are permitted in any medium without royalty provided the copyright
diff --git a/bin/emailrelay-dkim-signer.pl b/bin/emailrelay-dkim-signer.pl
new file mode 100755
index 0000000..2fd98a9
--- /dev/null
+++ b/bin/emailrelay-dkim-signer.pl
@@ -0,0 +1,65 @@
+#!/usr/bin/env perl
+#
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+# 
+# Copying and distribution of this file, with or without modification,
+# are permitted in any medium without royalty provided the copyright
+# notice and this notice are preserved.  This file is offered as-is,
+# without any warranty.
+# ===
+#
+# emailrelay-dkim-signer.pl
+#
+# An example E-MailRelay filter script for DKIM signing.
+#
+# To generate a key pair:
+#   $ openssl genrsa -out example.com.pk 2048
+#   $ openssl rsa -in example.com.pk -pubout -out example.com.pub
+#
+# Serve up the public key via DNS, eg:
+#   $ grep -v PUBLIC example.com.pub | tr -d '\n'
+#   upload default._domainkey TXT "p=Q8AMIIB...."
+#   $ nslookup -query=TXT default._domainkey.example.com
+#   text = "p=Q8AMIIB...."
+#
+# Test with spamassassin:
+#   $ c=`emailrelay-submit -v -s \`pwd\` -C DQo= -C aGVsbG8sIHdvcmxkIQ== -d -F -t -f me@example.com you@example.com`
+#   $ emailrelay-dkim-signer.pl $c
+#   $ spamassassin --debug=dkim --test-mode < $c
+#
+# Requires debian package 'libmail-dkim-perl'.
+#
+
+use strict ;
+use FileHandle ;
+use File::Copy ;
+use Mail::DKIM::Signer ;
+use Mail::DKIM::TextWrap ;
+
+$SIG{__DIE__} = sub { (my $e = join(" ",@_)) =~ s/\n/ /g ; print "<<error: $e>>\n" ; exit 99 } ;
+
+my $content = $ARGV[0] or die "usage error\n" ;
+my $fh = new FileHandle( $content ) or die "cannot open content file\n" ;
+
+my $dkim = new Mail::DKIM::Signer(
+	Algorithm => 'rsa-sha1' ,
+	Method => 'relaxed' ,
+	Domain => 'example.com' ,
+	Selector => 'default' , # => default._domainkey.example.com
+	KeyFile => '/etc/dkim/private/example.com.pk' ,
+	Headers => '' , # 'x-header:x-header2'
+);
+
+$dkim->load( $fh ) ; # includes CLOSE()
+$fh->close() or die ;
+
+my $signature = $dkim->signature->as_string() ;
+
+$fh = new FileHandle( $content.".tmp" , "w" ) or die ;
+print $fh $signature , "\r\n" ;
+$fh->flush() ;
+File::Copy::copy( $content , $fh ) or die ;
+$fh->close() or die ;
+File::Copy::move( $content.".tmp" , $content ) or die ;
+
+exit 0 ;
diff --git a/bin/emailrelay-edit-content.js b/bin/emailrelay-edit-content.js
index 2dae43f..a526ff5 100644
--- a/bin/emailrelay-edit-content.js
+++ b/bin/emailrelay-edit-content.js
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 // 
 // Copying and distribution of this file, with or without modification,
 // are permitted in any medium without royalty provided the copyright
diff --git a/bin/emailrelay-edit-envelope.js b/bin/emailrelay-edit-envelope.js
index 2393e97..d3463dd 100644
--- a/bin/emailrelay-edit-envelope.js
+++ b/bin/emailrelay-edit-envelope.js
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 // 
 // Copying and distribution of this file, with or without modification,
 // are permitted in any medium without royalty provided the copyright
diff --git a/bin/emailrelay-ldap-verify.py b/bin/emailrelay-ldap-verify.py
index 5333c85..dcbf26f 100755
--- a/bin/emailrelay-ldap-verify.py
+++ b/bin/emailrelay-ldap-verify.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2020-2021 <richardwvm@users.sourceforge.net>
+# Copyright (C) 2020-2022 <richardwvm@users.sourceforge.net>
 # 
 # Copying and distribution of this file, with or without modification,
 # are permitted in any medium without royalty provided the copyright
diff --git a/bin/emailrelay-multicast.sh b/bin/emailrelay-multicast.sh
index adf77df..06637ac 100755
--- a/bin/emailrelay-multicast.sh
+++ b/bin/emailrelay-multicast.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # Copying and distribution of this file, with or without modification,
 # are permitted in any medium without royalty provided the copyright
diff --git a/bin/emailrelay-notify.sh.in b/bin/emailrelay-notify.sh.in
old mode 100644
new mode 100755
index 6e7c029..d076cca
--- a/bin/emailrelay-notify.sh.in
+++ b/bin/emailrelay-notify.sh.in
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # Copying and distribution of this file, with or without modification,
 # are permitted in any medium without royalty provided the copyright
diff --git a/bin/emailrelay-resubmit.js b/bin/emailrelay-resubmit.js
index 2bae0c1..a4a0d5f 100644
--- a/bin/emailrelay-resubmit.js
+++ b/bin/emailrelay-resubmit.js
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 // 
 // Copying and distribution of this file, with or without modification,
 // are permitted in any medium without royalty provided the copyright
diff --git a/bin/emailrelay-resubmit.sh.in b/bin/emailrelay-resubmit.sh.in
old mode 100644
new mode 100755
index b675a68..1b516ee
--- a/bin/emailrelay-resubmit.sh.in
+++ b/bin/emailrelay-resubmit.sh.in
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # Copying and distribution of this file, with or without modification,
 # are permitted in any medium without royalty provided the copyright
diff --git a/bin/emailrelay-rot13.pl b/bin/emailrelay-rot13.pl
index 68159eb..6b1384b 100755
--- a/bin/emailrelay-rot13.pl
+++ b/bin/emailrelay-rot13.pl
@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # Copying and distribution of this file, with or without modification,
 # are permitted in any medium without royalty provided the copyright
diff --git a/bin/emailrelay-sendmail.pl b/bin/emailrelay-sendmail.pl
index 903f9b0..706e604 100755
--- a/bin/emailrelay-sendmail.pl
+++ b/bin/emailrelay-sendmail.pl
@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # Copying and distribution of this file, with or without modification,
 # are permitted in any medium without royalty provided the copyright
diff --git a/bin/emailrelay-service-install.js b/bin/emailrelay-service-install.js
index 63f57b6..2c5e6a0 100644
--- a/bin/emailrelay-service-install.js
+++ b/bin/emailrelay-service-install.js
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 // 
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/bin/emailrelay-set-from.js b/bin/emailrelay-set-from.js
index 55336b7..2b24293 100755
--- a/bin/emailrelay-set-from.js
+++ b/bin/emailrelay-set-from.js
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 // 
 // Copying and distribution of this file, with or without modification,
 // are permitted in any medium without royalty provided the copyright
diff --git a/bin/emailrelay-set-from.pl b/bin/emailrelay-set-from.pl
index f537a9a..71791b7 100755
--- a/bin/emailrelay-set-from.pl
+++ b/bin/emailrelay-set-from.pl
@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # Copying and distribution of this file, with or without modification,
 # are permitted in any medium without royalty provided the copyright
diff --git a/bin/emailrelay-submit.sh.in b/bin/emailrelay-submit.sh.in
old mode 100644
new mode 100755
index 96042f5..2a95484
--- a/bin/emailrelay-submit.sh.in
+++ b/bin/emailrelay-submit.sh.in
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # Copying and distribution of this file, with or without modification,
 # are permitted in any medium without royalty provided the copyright
diff --git a/bin/emailrelay.sh.in b/bin/emailrelay.sh.in
index 9451b36..5d3f952 100644
--- a/bin/emailrelay.sh.in
+++ b/bin/emailrelay.sh.in
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/bin/make-format b/bin/make-format
index 435d7d3..381868f 100755
--- a/bin/make-format
+++ b/bin/make-format
@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/bin/make-manifest.sh b/bin/make-manifest.sh
index 3b22e35..4658b86 100755
--- a/bin/make-manifest.sh
+++ b/bin/make-manifest.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/bin/make-setup.sh b/bin/make-setup.sh
index 3bb3fb3..8296375 100755
--- a/bin/make-setup.sh
+++ b/bin/make-setup.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/bin/make2cdb b/bin/make2cdb
index b098be2..5daf8f9 100755
--- a/bin/make2cdb
+++ b/bin/make2cdb
@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/bin/make2cmake b/bin/make2cmake
index 056588e..7514c81 100755
--- a/bin/make2cmake
+++ b/bin/make2cmake
@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -100,7 +100,7 @@ sub create_cmake_file
 	}
 
 	my $definitions = join( " " , $m->definitions() ) ;
-	my $includes = join( " " , "." , ".." , $m->includes($m->top()) ) ;
+	my $includes = join( " " , "." , ".." , $m->includes($m->base()) ) ;
 
 	my @libraries = $m->libraries() ;
 	for my $library ( @libraries )
diff --git a/bin/make2unity b/bin/make2unity
new file mode 100755
index 0000000..caf7e5b
--- /dev/null
+++ b/bin/make2unity
@@ -0,0 +1,171 @@
+#!/usr/bin/env perl
+#
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+# 
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# ===
+#
+# make2unity
+#
+# Generates "unity build" source files by parsing autoconf/automake
+# artifacts throughout the source tree. Also optionally creates a
+# compilation database ("compile_commands.json") for running
+# clang-tidy.
+#
+# usage:
+#   make2unity --out=<output> [options] <program>
+#   make2unity [options] [<program> [<program> ...]]
+#      --base=<dir>            -- base directory for makefile search
+#      --config-status=<file>  -- path of config.status file
+#      --out=<file>            -- output source file (if one <program>)
+#      --cdb                   -- create a compilation database
+#      --cdb-top=<dir>         -- top_srcdir (needed if --cdb)
+#      --cdb-cxx=<exe>         -- compiler (needed if --cdb)
+#
+# The <program> arguments are allowed to have a ".cpp" suffix.
+#
+# Eg:
+#     $ cd src
+#     $ ../bin/make2unity emailrelay.cpp
+#     $ g++ -pthread -I.... -c emailrelay.cpp
+#     $ g++ -pthread -o emailrelay emailrelay.o -lpam -lssl -lcrypto
+#
+
+use strict ;
+use warnings ;
+use FileHandle ;
+use File::Basename ;
+use Getopt::Long ;
+use Data::Dumper ;
+use lib dirname($0) ;
+use CompilationDatabase ;
+use ConfigStatus ;
+use AutoMakeParser ;
+$AutoMakeParser::debug = 0 ;
+
+my %opt = () ;
+GetOptions( \%opt , "out=s" , "cdb" , "cdb-cxx=s" , "cdb-top=s" , "base=s" , "config-status=s" ) or die "make2unity: usage error" ;
+die "make2unity: usage error" if scalar(@ARGV) == 0 ;
+die "make2unity: usage error" if ( $opt{out} && scalar(@ARGV) != 1 ) ;
+
+my $cfg_out = $opt{out} ;
+my $cfg_cdb = exists $opt{cdb} ;
+my $cfg_top_srcdir = $opt{'cdb-top'} ;
+my $cfg_base_dir = exists $opt{base} ? $opt{base} : File::Basename::dirname($0)."/../src" ;
+my $cfg_config_status = $opt{'config-status'} ;
+my @cfg_programs = @ARGV ;
+push @cfg_programs , "emailrelay" if !@cfg_programs ;
+my $cfg_cxx = $opt{'cdb-cxx'} || "/usr/bin/c++" ;
+
+my $cs = new ConfigStatus( $cfg_config_status ) ;
+my %switches = $cs->switches() ;
+my %vars = $cs->vars() ;
+
+$vars{top_srcdir} = "." ;
+$vars{top_builddir} = "." ;
+
+my @makefiles = AutoMakeParser::readall( $cfg_base_dir , \%switches , \%vars ) ;
+
+my $fh_cdb ;
+if( $cfg_cdb )
+{
+	$fh_cdb = new FileHandle( "compile_commands.json" , "w" ) or die ;
+	print $fh_cdb "[\n" ;
+}
+
+for my $cfg_program ( @cfg_programs )
+{
+	my $program = File::Basename::basename( $cfg_program , ".cpp" ) ;
+	my $out = $cfg_out ? $cfg_out : "${program}.cpp" ;
+
+	my $fh_out = new FileHandle( $out , "w" ) or die ;
+	print $fh_out "/* autogenerated by make2unity */\n" ;
+	my $stanza = undef ;
+	my %libs = () ;
+	my @out_lines = () ;
+	for my $m ( @makefiles )
+	{
+		my $dir = File::Basename::dirname( $m->path() ) ;
+		for my $p ( $m->programs() )
+		{
+			if( $p eq $program || ($p eq "$program.real") )
+			{
+				map { $libs{"lib".$_.".a"} = 1 } $m->our_libs( $p ) ;
+				push @out_lines , "/* exe [$dir] */\n" ;
+				print $fh_out "/* c++ -pthread".join(" -I ../",("",$m->includes("",0,0)))." -o $p $p.cpp ".join(" -l",("",$m->sys_libs($p)))." */\n" ;
+				for my $src ( $m->sources($p) )
+				{
+					push @out_lines , "#include \"$src\"\n" ;
+				}
+				$stanza = stanza( $program , $m ) ;
+			}
+		}
+	}
+	for my $m ( @makefiles )
+	{
+		my $dir = File::Basename::dirname( $m->path() ) ;
+
+		print $fh_out "/* lib [$dir] */\n" ;
+		for my $library ( $m->libraries() )
+		{
+			if( exists($libs{$library}) ) # ignore this library if not linked in to $program
+			{
+				for my $src ( $m->sources($library) )
+				{
+					print $fh_out "#include \"$src\"\n" ;
+				}
+			}
+			else
+			{
+				print $fh_out "/* (not linked) */\n" ;
+			}
+		}
+	}
+	print $fh_out @out_lines ; # (after all the library sources)
+	$fh_out->close() or die ;
+	print $fh_cdb $stanza , "\n" if ( $fh_cdb && defined($stanza) ) ;
+}
+
+if( $fh_cdb )
+{
+	print $fh_cdb "]\n" ;
+	$fh_cdb->close() or die ;
+}
+
+sub stanza
+{
+	my ( $program , $m ) = @_ ;
+
+	my $dir = cwd() ;
+	my $src = "$program.cpp" ;
+	my $autoconf_dir = "../src" ;
+	my $program_dir = File::Basename::dirname( $m->path() ) ;
+	my $moc_dir = "." ;
+	my @includes = ( $autoconf_dir , $program_dir , $moc_dir , $m->includes($cfg_top_srcdir,0,1) ) ;
+	my $includes = join( " -I" , ("",@includes) ) ;
+	my $options = $m->compile_options() ;
+	my $cmd = "$cfg_cxx $options $includes -c $program.cpp" ;
+
+	my $s = '{
+		 "directory" : "__DIR__" ,
+		 "command" : "__CMD__" ,
+		 "file" : "__SRC__" ,
+		},' ;
+	$s =~ s/\t//gm ;
+	$s =~ s/__DIR__/$dir/m ;
+	$s =~ s/__CMD__/$cmd/m ;
+	$s =~ s/__SRC__/$src/m ;
+	return $s ;
+}
+
diff --git a/bin/winbuild.pm b/bin/winbuild.pm
index 34a1d81..5992463 100644
--- a/bin/winbuild.pm
+++ b/bin/winbuild.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/bsd/Makefile.am b/bsd/Makefile.am
index 128c49e..638d6f6 100644
--- a/bsd/Makefile.am
+++ b/bsd/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
diff --git a/bsd/emailrelay-bsd.sh.in b/bsd/emailrelay-bsd.sh.in
index df41c24..a4b476c 100755
--- a/bsd/emailrelay-bsd.sh.in
+++ b/bsd/emailrelay-bsd.sh.in
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/configure b/configure
index d8daa73..dfa2ef0 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.69 for E-MailRelay 2.3.1.
+# Generated by GNU Autoconf 2.69 for E-MailRelay 2.4.
 #
 #
 # Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
@@ -577,8 +577,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='E-MailRelay'
 PACKAGE_TARNAME='emailrelay'
-PACKAGE_VERSION='2.3.1'
-PACKAGE_STRING='E-MailRelay 2.3.1'
+PACKAGE_VERSION='2.4'
+PACKAGE_STRING='E-MailRelay 2.4'
 PACKAGE_BUGREPORT=''
 PACKAGE_URL=''
 
@@ -636,8 +636,6 @@ e_icondir
 e_bsdinitdir
 e_initdir
 e_docdir
-GCONFIG_UDS_FALSE
-GCONFIG_UDS_TRUE
 GCONFIG_PAM_FALSE
 GCONFIG_PAM_TRUE
 GCONFIG_TLS_USE_NONE_FALSE
@@ -651,6 +649,10 @@ GCONFIG_TLS_USE_BOTH_TRUE
 GCONFIG_TLS_LIBS
 GCONFIG_GETTEXT_FALSE
 GCONFIG_GETTEXT_TRUE
+GCONFIG_DNSBL_FALSE
+GCONFIG_DNSBL_TRUE
+GCONFIG_UDS_FALSE
+GCONFIG_UDS_TRUE
 GCONFIG_WINDOWS_FALSE
 GCONFIG_WINDOWS_TRUE
 GCONFIG_TESTING_FALSE
@@ -799,13 +801,14 @@ enable_std_thread
 enable_testing
 enable_verbose
 enable_windows
+enable_uds
+enable_dnsbl
 with_doxygen
 with_gettext
 with_man2html
 with_openssl
 with_mbedtls
 with_pam
-with_uds
 '
       ac_precious_vars='build_alias
 host_alias
@@ -1375,7 +1378,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures E-MailRelay 2.3.1 to adapt to many kinds of systems.
+\`configure' configures E-MailRelay 2.4 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1442,7 +1445,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of E-MailRelay 2.3.1:";;
+     short | recursive ) echo "Configuration of E-MailRelay 2.4:";;
    esac
   cat <<\_ACEOF
 
@@ -1462,7 +1465,7 @@ Optional Features:
   --enable-bsd            enable building for bsd (default auto)
   --enable-debug          enable extra debug messages at compile-time (default
                           no)
-  --enable-epoll          enable epoll (default no)
+  --enable-epoll          enable epoll (default auto)
   --enable-gui            enable configuration gui (requires Qt) (default
                           auto)
   --enable-install-hook   enable fixing up the start/stop configuration file
@@ -1475,6 +1478,8 @@ Optional Features:
   --enable-testing        enable make check tests (default yes)
   --enable-verbose        enable verbose logging (default yes)
   --enable-windows        enable building for windows (default auto)
+  --enable-uds            enable unix domain sockets (default auto)
+  --enable-dnsbl          enable DNSBL (default yes)
 
 Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
@@ -1487,7 +1492,6 @@ Optional Packages:
   --with-openssl          use openssl for tls layer (default auto)
   --with-mbedtls          use mbedtls for tls layer (default auto)
   --with-pam              use linux pam for authentication (default auto)
-  --with-uds              enable unix domain sockets (default auto)
 
 Some influential environment variables:
   CC          C compiler command
@@ -1575,7 +1579,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-E-MailRelay configure 2.3.1
+E-MailRelay configure 2.4
 generated by GNU Autoconf 2.69
 
 Copyright (C) 2012 Free Software Foundation, Inc.
@@ -2011,7 +2015,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by E-MailRelay $as_me 2.3.1, which was
+It was created by E-MailRelay $as_me 2.4, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   $ $0 $@
@@ -2876,7 +2880,7 @@ fi
 
 # Define the identity of the package.
  PACKAGE='emailrelay'
- VERSION='2.3.1'
+ VERSION='2.4'
 
 
 # Some tools Automake needs.
@@ -7283,6 +7287,61 @@ $as_echo "#define GCONFIG_HAVE_IFNAMETOLUID 0" >>confdefs.h
 
 	fi
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for ifreq ifr_index" >&5
+$as_echo_n "checking for ifreq ifr_index... " >&6; }
+if ${gconfig_cv_ifindex+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+	cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+			#ifdef _WIN32
+				#include <winsock2.h>
+				#include <windows.h>
+				#include <ws2tcpip.h>
+				#include <iphlpapi.h>
+			#else
+				#include <sys/types.h>
+				#include <sys/socket.h>
+				#include <arpa/inet.h>
+				#include <net/if.h>
+				#include <sys/ioctl.h>
+			#endif
+			struct ifreq req ;
+			int i = 0 ;
+
+int
+main ()
+{
+
+			(void) ioctl( i , SIOCGIFINDEX , &req , sizeof(req) );
+			i = req.ifr_ifindex ;
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  gconfig_cv_ifindex=yes
+else
+  gconfig_cv_ifindex=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gconfig_cv_ifindex" >&5
+$as_echo "$gconfig_cv_ifindex" >&6; }
+	if test "$gconfig_cv_ifindex" = "yes" ; then
+
+$as_echo "#define GCONFIG_HAVE_IFINDEX 1" >>confdefs.h
+
+	else
+
+$as_echo "#define GCONFIG_HAVE_IFINDEX 0" >>confdefs.h
+
+	fi
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for gai_strerror()" >&5
 $as_echo_n "checking for gai_strerror()... " >&6; }
 if ${gconfig_cv_gaistrerror+:} false; then :
@@ -7380,6 +7439,55 @@ $as_echo "#define GCONFIG_HAVE_UDS 0" >>confdefs.h
 
 	fi
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for unix domain sockets" >&5
+$as_echo_n "checking for unix domain sockets... " >&6; }
+if ${gconfig_cv_uds_len+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+	cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+			#include <sys/types.h>
+			#include <sys/socket.h>
+			#include <sys/un.h>
+			struct sockaddr_un a ;
+
+int
+main ()
+{
+
+			a.sun_len = 2U ;
+			a.sun_family = AF_UNIX | PF_UNIX ;
+			a.sun_path[0] = '\0' ;
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  gconfig_cv_uds_len=yes
+else
+  gconfig_cv_uds_len=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gconfig_cv_uds_len" >&5
+$as_echo "$gconfig_cv_uds_len" >&6; }
+	if test "$gconfig_cv_uds_len" = "yes"
+	then
+
+$as_echo "#define GCONFIG_HAVE_UDS_LEN 1" >>confdefs.h
+
+	else
+
+$as_echo "#define GCONFIG_HAVE_UDS_LEN 0" >>confdefs.h
+
+	fi
+
+
+
 
 
 
@@ -8039,6 +8147,7 @@ main ()
 {
 
 			errno_t e = _sopen_s(&fd,"foo",_O_WRONLY,_SH_DENYNO,_S_IWRITE) ;
+			if( e ) return 1 ;
 
   ;
   return 0;
@@ -8954,7 +9063,7 @@ if ${gconfig_cv_qt_build+:} false; then :
   $as_echo_n "(cached) " >&6
 else
 
-	if test "$gconfig_have_qt" = "yes"
+	if test "$gconfig_have_qt" = "yes" -a "$enable_gui" != "no"
 	then
 		gconfig_save_LIBS="$LIBS"
 		gconfig_save_CXXFLAGS="$CXXFLAGS"
@@ -9207,7 +9316,6 @@ $as_echo "#define GCONFIG_HAVE_MBEDTLS_NET_H 0" >>confdefs.h
 	fi
 
 
-
 # Check whether --enable-bsd was given.
 if test "${enable_bsd+set}" = set; then :
   enableval=$enable_bsd;
@@ -9245,7 +9353,7 @@ if test "${enable_epoll+set}" = set; then :
 fi
 
 
-	if test "$enable_epoll" = "yes"
+	if test "$enable_epoll" != "no"
 	then
 		if test "$gconfig_cv_epoll" = "no"
 		then
@@ -9479,6 +9587,66 @@ else
 fi
 
 
+# Check whether --enable-uds was given.
+if test "${enable_uds+set}" = set; then :
+  enableval=$enable_uds;
+fi
+
+
+
+	if test "$enable_uds" = "no"
+	then
+		 if false; then
+  GCONFIG_UDS_TRUE=
+  GCONFIG_UDS_FALSE='#'
+else
+  GCONFIG_UDS_TRUE='#'
+  GCONFIG_UDS_FALSE=
+fi
+
+	else
+		if test "$enable_uds" = "yes" -a "$gconfig_cv_uds" = "no"
+		then
+			{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: forcing use of unix domain sockets even though not detected" >&5
+$as_echo "$as_me: WARNING: forcing use of unix domain sockets even though not detected" >&2;}
+		fi
+		 if true; then
+  GCONFIG_UDS_TRUE=
+  GCONFIG_UDS_FALSE='#'
+else
+  GCONFIG_UDS_TRUE='#'
+  GCONFIG_UDS_FALSE=
+fi
+
+	fi
+
+# Check whether --enable-dnsbl was given.
+if test "${enable_dnsbl+set}" = set; then :
+  enableval=$enable_dnsbl;
+fi
+
+
+	if test "$enable_dnsbl" = "no"
+	then
+		 if false; then
+  GCONFIG_DNSBL_TRUE=
+  GCONFIG_DNSBL_FALSE='#'
+else
+  GCONFIG_DNSBL_TRUE='#'
+  GCONFIG_DNSBL_FALSE=
+fi
+
+	else
+		 if true; then
+  GCONFIG_DNSBL_TRUE=
+  GCONFIG_DNSBL_FALSE='#'
+else
+  GCONFIG_DNSBL_TRUE='#'
+  GCONFIG_DNSBL_FALSE=
+fi
+
+	fi
+
 
 
 # Check whether --with-doxygen was given.
@@ -9505,11 +9673,7 @@ if test "${with_gettext+set}" = set; then :
 fi
 
 
-	if test "$with_gettext" = "no"
-	then
-		gconfig_cv_gettext="no"
-	:
-	elif test "$with_gettext" = "yes"
+	if test "$with_gettext" = "yes"
 	then
 		if test "$gconfig_cv_gettext" = "no"
 		then
@@ -9517,6 +9681,8 @@ fi
 $as_echo "$as_me: WARNING: forcing use of gettext even though not detected" >&2;}
 			gconfig_cv_gettext="yes"
 		fi
+	else
+		gconfig_cv_gettext="no"
 	fi
 
 	if test "$gconfig_cv_gettext" = "yes" ; then
@@ -9627,7 +9793,7 @@ fi
 		GCONFIG_TLS_LIBS=""
 	fi
 
-	if test "$gconfig_ssl_use_none" = "yes" -a "$with_openssl" != "no"
+	if test "$gconfig_ssl_use_none" = "yes"
 	then
 		gconfig_warnings="$gconfig_warnings openssl/mbedtls_transport_layer_security"
 	fi
@@ -10014,40 +10180,6 @@ fi
 
 
 
-# Check whether --with-uds was given.
-if test "${with_uds+set}" = set; then :
-  withval=$with_uds;
-fi
-
-
-
-	if test "$with_uds" = "no"
-	then
-		 if false; then
-  GCONFIG_UDS_TRUE=
-  GCONFIG_UDS_FALSE='#'
-else
-  GCONFIG_UDS_TRUE='#'
-  GCONFIG_UDS_FALSE=
-fi
-
-	else
-		if test "$with_uds" = "yes" -a "$gconfig_cv_uds" = "no"
-		then
-			{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: forcing use of unix domain sockets even though not detected" >&5
-$as_echo "$as_me: WARNING: forcing use of unix domain sockets even though not detected" >&2;}
-		fi
-		 if true; then
-  GCONFIG_UDS_TRUE=
-  GCONFIG_UDS_FALSE='#'
-else
-  GCONFIG_UDS_TRUE='#'
-  GCONFIG_UDS_FALSE=
-fi
-
-	fi
-
-
 
 	if test "$e_libexecdir" = ""
 	then
@@ -10124,7 +10256,7 @@ fi
 
 
 
-ac_config_files="$ac_config_files Makefile src/Makefile src/glib/Makefile src/gssl/Makefile src/gnet/Makefile src/gauth/Makefile src/gsmtp/Makefile src/gpop/Makefile src/main/Makefile src/main/icon/Makefile src/win32/Makefile src/gui/Makefile bin/Makefile doc/Makefile etc/Makefile test/Makefile test/certificates/Makefile m4/Makefile bsd/Makefile debian/Makefile po/Makefile"
+ac_config_files="$ac_config_files Makefile src/Makefile src/glib/Makefile src/gssl/Makefile src/gnet/Makefile src/gauth/Makefile src/gsmtp/Makefile src/gpop/Makefile src/main/Makefile src/main/icon/Makefile src/win32/Makefile src/gui/Makefile bin/Makefile doc/Makefile etc/Makefile test/Makefile test/certificates/Makefile m4/Makefile bsd/Makefile debian/Makefile po/Makefile unity/Makefile"
 
 cat >confcache <<\_ACEOF
 # This file is a shell script that caches the results of configure
@@ -10299,6 +10431,22 @@ if test -z "${GCONFIG_WINDOWS_TRUE}" && test -z "${GCONFIG_WINDOWS_FALSE}"; then
   as_fn_error $? "conditional \"GCONFIG_WINDOWS\" was never defined.
 Usually this means the macro was only invoked conditionally." "$LINENO" 5
 fi
+if test -z "${GCONFIG_UDS_TRUE}" && test -z "${GCONFIG_UDS_FALSE}"; then
+  as_fn_error $? "conditional \"GCONFIG_UDS\" was never defined.
+Usually this means the macro was only invoked conditionally." "$LINENO" 5
+fi
+if test -z "${GCONFIG_UDS_TRUE}" && test -z "${GCONFIG_UDS_FALSE}"; then
+  as_fn_error $? "conditional \"GCONFIG_UDS\" was never defined.
+Usually this means the macro was only invoked conditionally." "$LINENO" 5
+fi
+if test -z "${GCONFIG_DNSBL_TRUE}" && test -z "${GCONFIG_DNSBL_FALSE}"; then
+  as_fn_error $? "conditional \"GCONFIG_DNSBL\" was never defined.
+Usually this means the macro was only invoked conditionally." "$LINENO" 5
+fi
+if test -z "${GCONFIG_DNSBL_TRUE}" && test -z "${GCONFIG_DNSBL_FALSE}"; then
+  as_fn_error $? "conditional \"GCONFIG_DNSBL\" was never defined.
+Usually this means the macro was only invoked conditionally." "$LINENO" 5
+fi
 if test -z "${GCONFIG_GETTEXT_TRUE}" && test -z "${GCONFIG_GETTEXT_FALSE}"; then
   as_fn_error $? "conditional \"GCONFIG_GETTEXT\" was never defined.
 Usually this means the macro was only invoked conditionally." "$LINENO" 5
@@ -10323,14 +10471,6 @@ if test -z "${GCONFIG_PAM_TRUE}" && test -z "${GCONFIG_PAM_FALSE}"; then
   as_fn_error $? "conditional \"GCONFIG_PAM\" was never defined.
 Usually this means the macro was only invoked conditionally." "$LINENO" 5
 fi
-if test -z "${GCONFIG_UDS_TRUE}" && test -z "${GCONFIG_UDS_FALSE}"; then
-  as_fn_error $? "conditional \"GCONFIG_UDS\" was never defined.
-Usually this means the macro was only invoked conditionally." "$LINENO" 5
-fi
-if test -z "${GCONFIG_UDS_TRUE}" && test -z "${GCONFIG_UDS_FALSE}"; then
-  as_fn_error $? "conditional \"GCONFIG_UDS\" was never defined.
-Usually this means the macro was only invoked conditionally." "$LINENO" 5
-fi
 
 : "${CONFIG_STATUS=./config.status}"
 ac_write_fail=0
@@ -10728,7 +10868,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by E-MailRelay $as_me 2.3.1, which was
+This file was extended by E-MailRelay $as_me 2.4, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -10794,7 +10934,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-E-MailRelay config.status 2.3.1
+E-MailRelay config.status 2.4
 configured by $0, generated by GNU Autoconf 2.69,
   with options \\"\$ac_cs_config\\"
 
@@ -10946,6 +11086,7 @@ do
     "bsd/Makefile") CONFIG_FILES="$CONFIG_FILES bsd/Makefile" ;;
     "debian/Makefile") CONFIG_FILES="$CONFIG_FILES debian/Makefile" ;;
     "po/Makefile") CONFIG_FILES="$CONFIG_FILES po/Makefile" ;;
+    "unity/Makefile") CONFIG_FILES="$CONFIG_FILES unity/Makefile" ;;
 
   *) as_fn_error $? "invalid argument: \`$ac_config_target'" "$LINENO" 5;;
   esac
diff --git a/configure.ac b/configure.ac
index ce310ba..0cf337a 100755
--- a/configure.ac
+++ b/configure.ac
@@ -1,4 +1,4 @@
-dnl Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+dnl Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 dnl 
 dnl This program is free software: you can redistribute it and/or modify
 dnl it under the terms of the GNU General Public License as published by
@@ -19,7 +19,7 @@ dnl
 dnl Process this file with autoconf to produce a configure script.
 dnl
 
-AC_INIT([E-MailRelay],[2.3.1],[],[emailrelay])
+AC_INIT([E-MailRelay],[2.4],[],[emailrelay])
 AC_CONFIG_SRCDIR([src/glib/gdef.h])
 AC_CONFIG_MACRO_DIR([m4])
 AM_INIT_AUTOMAKE([no-define])
@@ -71,18 +71,13 @@ GCONFIG_FN_QT_BUILD
 GCONFIG_FN_TLS_OPENSSL
 GCONFIG_FN_TLS_MBEDTLS
 
-dnl possibly enable full gettext support -- uncomment this after running
-dnl 'gettextize' and remove the other gettext lines below
-dnl
-dnl AM_GNU_GETTEXT([external])
-
 dnl "--enable-whatever"
 dnl
 AC_ARG_ENABLE([bsd],AS_HELP_STRING([--enable-bsd],[enable building for bsd (default auto)]))
 GCONFIG_FN_ENABLE_BSD
 AC_ARG_ENABLE([debug],AS_HELP_STRING([--enable-debug],[enable extra debug messages at compile-time (default no)]))
 GCONFIG_FN_ENABLE_DEBUG
-AC_ARG_ENABLE([epoll],AS_HELP_STRING([--enable-epoll],[enable epoll (default no)]))
+AC_ARG_ENABLE([epoll],AS_HELP_STRING([--enable-epoll],[enable epoll (default auto)]))
 GCONFIG_FN_ENABLE_EPOLL
 AC_ARG_ENABLE([gui],AS_HELP_STRING([--enable-gui],[enable configuration gui (requires Qt) (default auto)]))
 GCONFIG_FN_ENABLE_GUI
@@ -100,6 +95,10 @@ AC_ARG_ENABLE([verbose],AS_HELP_STRING([--enable-verbose],[enable verbose loggin
 GCONFIG_FN_ENABLE_VERBOSE
 AC_ARG_ENABLE([windows],AS_HELP_STRING([--enable-windows],[enable building for windows (default auto)]))
 GCONFIG_FN_ENABLE_WINDOWS
+AC_ARG_ENABLE([uds],AS_HELP_STRING([--enable-uds],[enable unix domain sockets (default auto)]))
+GCONFIG_FN_ENABLE_UDS
+AC_ARG_ENABLE([dnsbl],AS_HELP_STRING([--enable-dnsbl],[enable DNSBL (default yes)]))
+GCONFIG_FN_ENABLE_DNSBL
 
 dnl "--with-whatever"
 dnl
@@ -114,8 +113,6 @@ AC_ARG_WITH([mbedtls],AS_HELP_STRING([--with-mbedtls],[use mbedtls for tls layer
 GCONFIG_FN_TLS
 AC_ARG_WITH([pam],AS_HELP_STRING([--with-pam],[use linux pam for authentication (default auto)]))
 GCONFIG_FN_WITH_PAM
-AC_ARG_WITH([uds],AS_HELP_STRING([--with-uds],[enable unix domain sockets (default auto)]))
-GCONFIG_FN_WITH_UDS
 
 dnl directory tweaking -- define e_ prefixed directory variables
 dnl
@@ -124,7 +121,7 @@ GCONFIG_FN_SET_DIRECTORIES_E
 
 dnl generate files
 dnl
-AC_CONFIG_FILES([Makefile src/Makefile src/glib/Makefile src/gssl/Makefile src/gnet/Makefile src/gauth/Makefile src/gsmtp/Makefile src/gpop/Makefile src/main/Makefile src/main/icon/Makefile src/win32/Makefile src/gui/Makefile bin/Makefile doc/Makefile etc/Makefile test/Makefile test/certificates/Makefile m4/Makefile bsd/Makefile debian/Makefile po/Makefile])
+AC_CONFIG_FILES([Makefile src/Makefile src/glib/Makefile src/gssl/Makefile src/gnet/Makefile src/gauth/Makefile src/gsmtp/Makefile src/gpop/Makefile src/main/Makefile src/main/icon/Makefile src/win32/Makefile src/gui/Makefile bin/Makefile doc/Makefile etc/Makefile test/Makefile test/certificates/Makefile m4/Makefile bsd/Makefile debian/Makefile po/Makefile unity/Makefile])
 AC_OUTPUT
 
 dnl final warnings
diff --git a/configure.sh b/configure.sh
index 663ff2b..06b1932 100755
--- a/configure.sh
+++ b/configure.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -31,8 +31,8 @@
 #         -w64 cross-compile for windows 64-bit with mingw-w64
 #         -p   cross-compile for rpi
 #         -g   git-clone mbedtls and exit
-#
-# For systemd add "e_systemddir=/usr/lib/systemd/system".
+#         -S   force e_systemddir for systemd
+#         -X   suppress e_systemddir for systemd
 #
 # When cross-compiling with mbedtls the mbedtls source should be unpacked
 # into this base directory (see MBEDTLS_DIR below), or use '-g' to
@@ -42,6 +42,7 @@
 thisdir="`cd \`dirname $0\` && pwd`"
 
 usage="[-g] [{-d|-s <>}] [{-o|-w|-p}] -- <configure-args>"
+opt_systemd=0 ; if test "`systemctl is-system-running 2>/dev/null | sed 's/offline//'`" != "" ; then opt_systemd=1 ; fi
 while expr "x$1" : "x-" >/dev/null
 do
 	valued=0
@@ -54,6 +55,8 @@ do
 		w32) opt_mingw=1 ; opt_win=32 ;;
 		w64) opt_mingw=1 ; opt_win=64 ;;
 		p) opt_rpi=1 ;;
+		S) opt_systemd=1 ;;
+		X) opt_systemd=0 ;;
 		h) echo usage: `basename $0` $usage "..." ; $thisdir/configure --help=short ; exit 0 ;;
 		#\?) echo usage: `basename $0` $usage >&2 ; exit 2 ;;
 		*) opt_passthrough="$opt_passthrough $1" ;;
@@ -90,7 +93,7 @@ if test "0$opt_debug" -eq 1
 then
 	export CFLAGS="-O0 -g"
 	export CXXFLAGS="-O0 -g"
-	if expr "x$*" : '.*enable.debug' ; then : ; else enable_debug="--enable-debug" ; fi
+	if expr "x$*" : '.*enable.debug' >/dev/null ; then : ; else enable_debug="--enable-debug" ; fi
 :
 elif expr "x$*" : '.*enable.debug' >/dev/null
 then
@@ -241,6 +244,15 @@ then
 	$thisdir/configure $enable_debug $with_mbedtls \
 		--prefix=/opt/local --mandir=/opt/local/man $opt_passthrough "$@"
 :
+elif test "`uname`" = "Linux" -a "$opt_systemd" -eq 1
+then
+	export CXXFLAGS
+	export LDFLAGS
+	$thisdir/configure $enable_debug $with_mbedtls \
+		--prefix=/usr --libexecdir=/usr/lib --sysconfdir=/etc \
+		--localstatedir=/var e_systemddir=/usr/lib/systemd/system \
+		$opt_passthrough e_rundir=/run/emailrelay "$@"
+:
 elif test "`uname`" = "Linux"
 then
 	export CXXFLAGS
diff --git a/debian/Makefile.am b/debian/Makefile.am
index d030078..6f82903 100644
--- a/debian/Makefile.am
+++ b/debian/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
diff --git a/debian/changelog b/debian/changelog
index 95ebbd7..1369d70 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,16 +1,23 @@
-emailrelay (2.3.1) unstable; urgency=low
-  * Hourly log file rotation using "%h" (eg. "--log-file=log.%d.%h").
+emailrelay (2.4) unstable; urgency=low
+  * Multiple "--filter" and "--client-filter" options allowed.
   * TLS key and certificate files can be specified separately.
-  * Fixed error handling for network client filters ("--client-filter=net:...") [bug-id 50].
- -- maintainer graeme_walker <graeme_walker@users.sourceforge.net>  Thu, 30 Jun 2022 00:00:00 +0000
+  * Finer control when using "--anonymous" (eg. "--anonymous=server").
+  * The "auth-config" options can distinguish between TLS and non-TLS authentication.
+  * Hourly log file rotation using "%h" (eg. "--log-file=log.%d.%h").
+  * Listening file descriptors can be inherited from the parent process (see "--interface").
+  * Listening ports on Windows use exclusive binding.
+  * The Linux event loop uses "epoll" by default rather than "select".
+  * Some support for message routing (see NEWS).
+  * Fix of error handling in network client filters ("--client-filter=net:...") [bug-id #50].
+ -- maintainer graeme_walker <graeme_walker@users.sourceforge.net>  Fri, 28 Oct 2022 00:00:00 +0000
 
 emailrelay (2.3) unstable; urgency=low
   * Unix domain sockets supported (eg. "--interface=/tmp/smtp.s").
   * Windows event log not used for verbose logging (prefer "--log-file").
-  * New admin 'forward' command to trigger forwarding without waiting.
+  * New admin "forward" command to trigger forwarding without waiting.
   * Optional base64 encoding of passwords in secrets files ("plain:b").
   * Support for MbedTLS version 3.
- -- maintainer graeme_walker <graeme_walker@users.sourceforge.net>  Tue, 14 Feb 2022 00:00:00 +0000
+ -- maintainer graeme_walker <graeme_walker@users.sourceforge.net>  Sun, 10 Apr 2022 00:00:00 +0000
 
 emailrelay (2.2) unstable; urgency=low
   * Connections from IPv4 'private use' addresses are allowed by default (see "--remote-clients").
diff --git a/debian/control b/debian/control
index e91122b..3afe463 100644
--- a/debian/control
+++ b/debian/control
@@ -2,7 +2,7 @@ Source: emailrelay
 Section: mail
 Priority: optional
 Maintainer: Graeme Walker <graeme_walker@users.sourceforge.net>
-Build-Depends: debhelper (>= 9), autotools-dev
+Build-Depends: debhelper (>= 9), autotools-dev, libssl-dev, libpam0g-dev
 Standards-Version: 3.9.8
 Homepage: http://emailrelay.sourceforge.net
 
diff --git a/debian/copyright b/debian/copyright
index 3df7dc3..8096da7 100644
--- a/debian/copyright
+++ b/debian/copyright
@@ -1,6 +1,6 @@
 Copyright
 =========
-Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 
 Refer to the file COPYING (included), /usr/share/common-licenses/GPL-3, or
 <http://www.gnu.org/licenses/> for the terms of the GNU General Public License.
diff --git a/debian/emailrelay.init b/debian/emailrelay.init
index 1214ba3..a91f33d 100755
--- a/debian/emailrelay.init
+++ b/debian/emailrelay.init
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/debian/emailrelay.service b/debian/emailrelay.service
index 52a519e..a856af9 100644
--- a/debian/emailrelay.service
+++ b/debian/emailrelay.service
@@ -8,10 +8,9 @@ Wants=network-online.target
 Type=forking
 Restart=on-success
 KillMode=control-group
-ExecStart=/etc/init.d/emailrelay start
-ExecStop=/etc/init.d/emailrelay stop
+ExecStart=/usr/sbin/emailrelay --as-server --syslog --pid-file /run/emailrelay/emailrelay.pid /etc/emailrelay.conf
+ExecStop=/bin/kill -15 $MAINPID
 PIDFile=/run/emailrelay/emailrelay.pid
-SuccessExitStatus=0 143
 
 [Install]
 WantedBy=multi-user.target
diff --git a/debian/postinst b/debian/postinst
old mode 100644
new mode 100755
diff --git a/debian/postrm b/debian/postrm
old mode 100644
new mode 100755
diff --git a/debian/preinst b/debian/preinst
old mode 100644
new mode 100755
diff --git a/debian/prerm b/debian/prerm
old mode 100644
new mode 100755
diff --git a/doc/Makefile.am b/doc/Makefile.am
index e0b3fa5..c7d7217 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
diff --git a/doc/authentication.png b/doc/authentication.png
index 5ccc167..481b623 100644
Binary files a/doc/authentication.png and b/doc/authentication.png differ
diff --git a/doc/authentication.svg b/doc/authentication.svg
index fa89ddd..20917e8 100644
--- a/doc/authentication.svg
+++ b/doc/authentication.svg
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <!-- Created with Inkscape (http://www.inkscape.org/) -->
-<!-- Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
+<!-- Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
 
 <svg
    xmlns:dc="http://purl.org/dc/elements/1.1/"
diff --git a/doc/changelog.html b/doc/changelog.html
index b62db6c..95c635b 100644
--- a/doc/changelog.html
+++ b/doc/changelog.html
@@ -1,4 +1,4 @@
-<!DOCTYPE HTML PUBLIC "%-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
+<!DOCTYPE html>
 <html>
  <head>
   <title>E-MailRelay Change Log</title>
@@ -9,21 +9,28 @@
   <!-- index:0::::E-MailRelay Change Log -->
  <div class="div-main">
   <h1><a class="a-header" name="H_1">E-MailRelay Change Log</a></h1> <!-- index:1:H:E-MailRelay Change Log -->
-   <h2><a class="a-header" name="SH_1_0">2.3 -> 2.3.1</a></h2> <!-- index:2:SH:1:0:2.3 -> 2.3.1 -->
+   <h2><a class="a-header" name="SH_1_1">2.3 -> 2.4</a></h2> <!-- index:2:SH:1:1:2.3 -> 2.4 -->
     <ul>
-     <li>Hourly log file rotation using <em>%h</em> (eg. <em>--log-file=log.%d.%h</em>).</li>
+     <li>Multiple <em>--filter</em> and <em>--client-filter</em> options allowed.</li>
      <li>TLS key and certificate files can be specified separately.</li>
-     <li>Fixed error handling for network client filters (<em>--client-filter=net:...</em>) [bug-id #50].</li>
+     <li>Finer control when using <em>--anonymous</em> (eg. <em>--anonymous=server</em>).</li>
+     <li>The <em>auth-config</em> options can distinguish between TLS and non-TLS authentication.</li>
+     <li>Hourly log file rotation using <em>%h</em> (eg. <em>--log-file=log.%d.%h</em>).</li>
+     <li>Listening file descriptors can be inherited from the parent process (see <em>--interface</em>).</li>
+     <li>Listening ports on Windows use exclusive binding.</li>
+     <li>The Linux event loop uses <em>epoll</em> by default rather than <em>select</em>.</li>
+     <li>Some support for message routing (see NEWS).</li>
+     <li>Fix of error handling in network client filters (<em>--client-filter=net:...</em>) [bug-id #50].</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_1">2.2 -> 2.3</a></h2> <!-- index:2:SH:1:1:2.2 -> 2.3 -->
+   <h2><a class="a-header" name="SH_1_2">2.2 -> 2.3</a></h2> <!-- index:2:SH:1:2:2.2 -> 2.3 -->
     <ul>
-     <li>Unix domain sockets supported (eg. <em>--interface=/tmp/smtp.s</em>.</li>
+     <li>Unix domain sockets supported (eg. <em>--interface=/tmp/smtp.s</em>).</li>
      <li>Windows event log not used for verbose logging (prefer <em>--log-file</em>).</li>
      <li>New admin <em>forward</em> command to trigger forwarding without waiting.</li>
      <li>Optional base64 encoding of passwords in secrets files (<em>plain:b</em>).</li>
      <li>Support for MbedTLS version 3.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_2">2.1 -> 2.2</a></h2> <!-- index:2:SH:1:2:2.1 -> 2.2 -->
+   <h2><a class="a-header" name="SH_1_3">2.1 -> 2.2</a></h2> <!-- index:2:SH:1:3:2.1 -> 2.2 -->
     <ul>
      <li>Connections from IPv4 'private use' addresses are allowed by default (see <em>--remote-clients</em>).</li>
      <li>Interface names can be used with <em>--interface</em> (eg. <em>--interface=eth0</em>).</li>
@@ -39,7 +46,7 @@
      <li>Support for Windows XP restored when built with mingw-w64.</li>
      <li>C++ 2011 compiler is required.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_3">2.0.1 -> 2.1</a></h2> <!-- index:2:SH:1:3:2.0.1 -> 2.1 -->
+   <h2><a class="a-header" name="SH_1_4">2.0.1 -> 2.1</a></h2> <!-- index:2:SH:1:4:2.0.1 -> 2.1 -->
     <ul>
      <li>Backwards compatibility features for 1.9-to-2.0 transition removed.</li>
      <li>Better handling of too-many-connections on Windows.</li>
@@ -56,11 +63,11 @@
      <li>Certificate contents are not logged.</li>
      <li>Timestamp parts of spool filenames no longer limited to six digits.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_4">2.0 -> 2.0.1</a></h2> <!-- index:2:SH:1:4:2.0 -> 2.0.1 -->
+   <h2><a class="a-header" name="SH_1_5">2.0 -> 2.0.1</a></h2> <!-- index:2:SH:1:5:2.0 -> 2.0.1 -->
     <ul>
      <li>Make PLAIN client authentication work against servers with broken 334 responses.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_5">1.9.2 -> 2.0</a></h2> <!-- index:2:SH:1:5:1.9.2 -> 2.0 -->
+   <h2><a class="a-header" name="SH_1_6">1.9.2 -> 2.0</a></h2> <!-- index:2:SH:1:6:1.9.2 -> 2.0 -->
     <ul>
      <li>Improved IPv6 support, with IPv4 and IPv6 used independently at run-time (see <em>--interface</em>).</li>
      <li>Server process is not blocked during <em>--filter</em> or <em>--address-verifier</em> execution, if multi-threaded.</li>
@@ -91,7 +98,7 @@
      <li>C++ 2011 is preferred, and required for multi-threading.</li>
      <li>Support for very old versions of Windows is dropped.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_6">1.9.1 -> 1.9.2</a></h2> <!-- index:2:SH:1:6:1.9.1 -> 1.9.2 -->
+   <h2><a class="a-header" name="SH_1_7">1.9.1 -> 1.9.2</a></h2> <!-- index:2:SH:1:7:1.9.1 -> 1.9.2 -->
     <ul>
      <li>Fixed a leak in the event-loop garbage collection.</li>
      <li>A local hostname that fails to resolve is not an error.</li>
@@ -107,11 +114,11 @@
      <li>Qt4 or Qt5 selected by the <em>configure</em> script.</li>
      <li>Improved the RPM spec file.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_7">1.9 -> 1.9.1</a></h2> <!-- index:2:SH:1:7:1.9 -> 1.9.1 -->
+   <h2><a class="a-header" name="SH_1_8">1.9 -> 1.9.1</a></h2> <!-- index:2:SH:1:8:1.9 -> 1.9.1 -->
     <ul>
      <li>Updated OpenSSL from 1.0.1e to 1.0.1g in the Windows build.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_8">1.8.2 -> 1.9</a></h2> <!-- index:2:SH:1:8:1.8.2 -> 1.9 -->
+   <h2><a class="a-header" name="SH_1_9">1.8.2 -> 1.9</a></h2> <!-- index:2:SH:1:9:1.8.2 -> 1.9 -->
     <ul>
      <li>Added negotiated TLS/SSL for POP (ie. <em>STLS</em>).</li>
      <li>The first two fields in the secrets files are reordered (with backwards compatibility).</li>
@@ -136,17 +143,17 @@
      <li>Added Windows <em>--peer-lookup</em> option.</li>
      <li>Fix for MD5 code in 64-bit builds.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_9">1.8.1 -> 1.8.2</a></h2> <!-- index:2:SH:1:9:1.8.1 -> 1.8.2 -->
+   <h2><a class="a-header" name="SH_1_10">1.8.1 -> 1.8.2</a></h2> <!-- index:2:SH:1:10:1.8.1 -> 1.8.2 -->
     <ul>
      <li>Fix namespaces for gcc 3.4.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_10">1.8 -> 1.8.1</a></h2> <!-- index:2:SH:1:10:1.8 -> 1.8.1 -->
+   <h2><a class="a-header" name="SH_1_11">1.8 -> 1.8.1</a></h2> <!-- index:2:SH:1:11:1.8 -> 1.8.1 -->
     <ul>
      <li>Changed the definition of <em>--as-proxy</em> to use <em>--poll 0</em> rather than <em>--immediate</em> [bug-id 1961652].</li>
      <li>Fixed stalling bug when using server-side TLS/SSL (<em>--server-tls</em>) [bug-id 1961655].</li>
      <li>Improved Debian packaging for Linux (<em>make deb</em>).</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_11">1.7 -> 1.8</a></h2> <!-- index:2:SH:1:11:1.7 -> 1.8 -->
+   <h2><a class="a-header" name="SH_1_12">1.7 -> 1.8</a></h2> <!-- index:2:SH:1:12:1.7 -> 1.8 -->
     <ul>
      <li>Speed optimisations (as identified by KCachegrind/valgrind in KDevelop).</li>
      <li>Build-time size optimisations (eg. <em>./configure --disable-exec --enable-small-exceptions ...</em>).</li>
@@ -162,7 +169,7 @@
      <li>Improved native support for Mac OS X (10.5) with graphical installation from disk image.</li>
      <li>Compatibility with gcc 2.95 restored.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_12">1.6 -> 1.7</a></h2> <!-- index:2:SH:1:12:1.6 -> 1.7 -->
+   <h2><a class="a-header" name="SH_1_13">1.6 -> 1.7</a></h2> <!-- index:2:SH:1:13:1.6 -> 1.7 -->
     <ul>
      <li>TLS/SSL support for SMTP using OpenSSL (<em>./configure --with-openssl</em> with <em>--client-tls</em> and <em>--server-tls</em>).</li>
      <li>Authentication mechanism <em>PLAIN</em> added.</li>
@@ -170,7 +177,7 @@
      <li>Windows service wrapper has an <em>--uninstall</em> option.</li>
      <li>Windows installation GUI uninstalls the service before reinstalling it.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_13">1.5 -> 1.6</a></h2> <!-- index:2:SH:1:13:1.5 -> 1.6 -->
+   <h2><a class="a-header" name="SH_1_14">1.5 -> 1.6</a></h2> <!-- index:2:SH:1:14:1.5 -> 1.6 -->
     <ul>
      <li>GPLv3 licence (see <em>http://gplv3.fsf.org</em>).</li>
      <li>New <em>--prompt-timeout</em> switch for the timeout when waiting for the initial 220 prompt from the SMTP server.</li>
@@ -190,7 +197,7 @@
      <li>Experimental SpamAssassin spamc/spamd protocol support.</li>
      <li>Acceptance tests added to the distribution.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_14">1.4 -> 1.5</a></h2> <!-- index:2:SH:1:14:1.4 -> 1.5 -->
+   <h2><a class="a-header" name="SH_1_15">1.4 -> 1.5</a></h2> <!-- index:2:SH:1:15:1.4 -> 1.5 -->
     <ul>
      <li>New installation and configuration GUI using TrollTech Qt 4.x (<em>./configure --enable-gui</em>)</li>
      <li>Default address verifier accepts all addresses as valid and never treats them as local mailboxes.</li>
@@ -205,7 +212,7 @@
      <li>Documentation also created in docbook format (requires xmlto).</li>
      <li>Windows installation document revised.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_15">1.3.3 -> 1.4</a></h2> <!-- index:2:SH:1:15:1.3.3 -> 1.4 -->
+   <h2><a class="a-header" name="SH_1_16">1.3.3 -> 1.4</a></h2> <!-- index:2:SH:1:16:1.3.3 -> 1.4 -->
     <ul>
      <li>POP3 server (enable with <em>--pop</em>, disable at build-time with <em>./configure --disable-pop</em>).</li>
      <li>Fix for logging reentrancy bug (affects <em>./configure --enable-debug</em> with <em>--debug</em>).</li>
@@ -219,7 +226,7 @@
      <li>The <em>--dont-listen</em> switch is now <em>--no-smtp</em>.</li>
      <li>Better IPv6 support (Linux only).</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_16">1.3.2 -> 1.3.3</a></h2> <!-- index:2:SH:1:16:1.3.2 -> 1.3.3 -->
+   <h2><a class="a-header" name="SH_1_17">1.3.2 -> 1.3.3</a></h2> <!-- index:2:SH:1:17:1.3.2 -> 1.3.3 -->
     <ul>
      <li>No bind() for outgoing connections [bug-id 1051689].</li>
      <li>Updated rpm spec file [bug-id 1224850].</li>
@@ -228,21 +235,21 @@
      <li>Documentation of <em>auth</em> switches corrected.</li>
      <li>State-machine template type declaration modernised, possibly breaking older compilers.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_17">1.3.1 -> 1.3.2</a></h2> <!-- index:2:SH:1:17:1.3.1 -> 1.3.2 -->
+   <h2><a class="a-header" name="SH_1_18">1.3.1 -> 1.3.2</a></h2> <!-- index:2:SH:1:18:1.3.1 -> 1.3.2 -->
     <ul>
      <li>Fix for core dump when <em>--client-filter</em> pre-processing fails.</li>
      <li>Revised code structure to prepare for asynchronous pre-processing.</li>
      <li>Better diagnostics when pre-processor exec() fails.</li>
      <li>Better cleanup of empty and orphaned files.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_18">1.3 -> 1.3.1</a></h2> <!-- index:2:SH:1:18:1.3 -> 1.3.1 -->
+   <h2><a class="a-header" name="SH_1_19">1.3 -> 1.3.1</a></h2> <!-- index:2:SH:1:19:1.3 -> 1.3.1 -->
     <ul>
      <li>Windows resource leak from CreateProcess() fixed.</li>
      <li>Windows dialog box double-close fix.</li>
      <li>Some documentation for the <em>--scanner</em> switch.</li>
      <li>New usage patterns section in the user guide.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_19">1.2 -> 1.3</a></h2> <!-- index:2:SH:1:19:1.2 -> 1.3 -->
+   <h2><a class="a-header" name="SH_1_20">1.2 -> 1.3</a></h2> <!-- index:2:SH:1:20:1.2 -> 1.3 -->
     <ul>
      <li>Client protocol waits for a greeting from the server on startup [bug-id 842156].</li>
      <li>Fix for incorrect backslash normalisation on <em>--verifier</em> command-lines containing spaces [bug-id 890646].</li>
@@ -255,7 +262,7 @@
      <li>New switches for the <em>configure</em> script.</li>
      <li>More JavaScript example scripts.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_20">1.1.2 -> 1.2</a></h2> <!-- index:2:SH:1:20:1.1.2 -> 1.2 -->
+   <h2><a class="a-header" name="SH_1_21">1.1.2 -> 1.2</a></h2> <!-- index:2:SH:1:21:1.1.2 -> 1.2 -->
     <ul>
      <li>The <em>--filter</em> and <em>--verifier</em> arguments interpreted as command-lines; spaces in executable paths now need escaping.</li>
      <li>The <em>--interface</em> switch applies to outgoing connections too.</li>
@@ -264,7 +271,7 @@
      <li>Fix for dangling reference bug, seen after <em>quit</em> command on Windows.</li>
      <li>JavaScript examples in the documentation.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_21">1.1.1 -> 1.1.2</a></h2> <!-- index:2:SH:1:21:1.1.1 -> 1.1.2 -->
+   <h2><a class="a-header" name="SH_1_22">1.1.1 -> 1.1.2</a></h2> <!-- index:2:SH:1:22:1.1.1 -> 1.1.2 -->
     <ul>
      <li>Earlier check for un-bindable ports on startup, and later fork()ing [bug-id 776972].</li>
      <li>Resolved the file-descriptor kludge for <em>--verifier</em> on Windows.</li>
@@ -273,7 +280,7 @@
      <li>Pre-processor (<em>--filter</em>) program's standard output searched for a failure reason string.</li>
      <li>Undocumented <em>--scanner</em> switch added for asynchronous processing by a separate network server.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_22">1.1.0 -> 1.1.1</a></h2> <!-- index:2:SH:1:22:1.1.0 -> 1.1.1 -->
+   <h2><a class="a-header" name="SH_1_23">1.1.0 -> 1.1.1</a></h2> <!-- index:2:SH:1:23:1.1.0 -> 1.1.1 -->
     <ul>
      <li>Restored the fix for building with gcc2.96.</li>
      <li>Support for MinGW builds on Windows.</li>
@@ -283,7 +290,7 @@
      <li>Fix for <em>make install</em> when <em>man2html</em> is not available.</li>
      <li>Updated init script.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_23">1.0.2 -> 1.1.0</a></h2> <!-- index:2:SH:1:23:1.0.2 -> 1.1.0 -->
+   <h2><a class="a-header" name="SH_1_24">1.0.2 -> 1.1.0</a></h2> <!-- index:2:SH:1:24:1.0.2 -> 1.1.0 -->
     <ul>
      <li>In proxy mode unexpected client-side disconnects and timeouts do not leave <em>.bad</em> files [see also bug-id 659039].</li>
      <li>By default proxy mode does not interpret addresses for local delivery (<em>--postmaster</em>).</li>
@@ -298,14 +305,14 @@
      <li>Support for Sun WorkShop 5.0 added.</li>
      <li>Documentation overhaul.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_24">1.0.0 -> 1.0.2</a></h2> <!-- index:2:SH:1:24:1.0.0 -> 1.0.2 -->
+   <h2><a class="a-header" name="SH_1_25">1.0.0 -> 1.0.2</a></h2> <!-- index:2:SH:1:25:1.0.0 -> 1.0.2 -->
     <ul>
      <li>Support for trusted IP addresses, allowing certain clients to avoid authentication.</li>
      <li>Address verifier interface extended to include authentication information.</li>
      <li>New public mail relay section added to the user guide.</li>
      <li>Example verifier scripts etc. added to the reference guide.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_25">1.0.0 -> 1.0.1</a></h2> <!-- index:2:SH:1:25:1.0.0 -> 1.0.1 -->
+   <h2><a class="a-header" name="SH_1_26">1.0.0 -> 1.0.1</a></h2> <!-- index:2:SH:1:26:1.0.0 -> 1.0.1 -->
     <ul>
      <li>In proxy mode unexpected client-side disconnects and timeouts result in <em>.bad</em> files [bug-id 659039].</li>
      <li>Require successful <em>AUTH</em> before <em>MAIL FROM</em> when using <em>--server-auth</em>.</li>
@@ -318,7 +325,7 @@
      <li>Fix build when using gcc2.96 rather than gcc2.95 (1.0.0-pl1).</li>
      <li>Fix default spool directory in example scripts (1.0.0-pl1).</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_26">0.9.9 -> 1.0.0</a></h2> <!-- index:2:SH:1:26:0.9.9 -> 1.0.0 -->
+   <h2><a class="a-header" name="SH_1_27">0.9.9 -> 1.0.0</a></h2> <!-- index:2:SH:1:27:0.9.9 -> 1.0.0 -->
     <ul>
      <li>Briefer <em>--help</em> output; works with <em>--verbose</em>.</li>
      <li>Option to listen on a specific network interface (<em>--interface</em>).</li>
@@ -331,7 +338,7 @@
      <li>EHLO response parsing is now case-insensitive [bug-id 561522].</li>
      <li>Fewer missing-secrets warnings [bug-id 564987].</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_27">0.9.8 -> 0.9.9</a></h2> <!-- index:2:SH:1:27:0.9.8 -> 0.9.9 -->
+   <h2><a class="a-header" name="SH_1_28">0.9.8 -> 0.9.9</a></h2> <!-- index:2:SH:1:28:0.9.8 -> 0.9.9 -->
     <ul>
      <li>More flexible logging options (<em>--verbose</em> and <em>--debug</em> work better).</li>
      <li>File Hierarchy Standard (FHS) option for <em>configure</em> (<em>--enable-fhs</em>).</li>
@@ -347,14 +354,14 @@
      <li>Submit utility works under Windows. [rc2]</li>
      <li>Improved Windows project files. [rc2]</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_28">0.9.7 -> 0.9.8</a></h2> <!-- index:2:SH:1:28:0.9.7 -> 0.9.8 -->
+   <h2><a class="a-header" name="SH_1_29">0.9.7 -> 0.9.8</a></h2> <!-- index:2:SH:1:29:0.9.7 -> 0.9.8 -->
     <ul>
      <li>Fix for running pre-processor (<em>--filter</em>) as root.</li>
      <li>Ignore bogus <em>AUTH=LOGIN</em> lines in EHLO response.</li>
      <li>Submit utility improved to work with mutt.</li>
      <li>Installation of submit man page.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_29">0.9.6 -> 0.9.7</a></h2> <!-- index:2:SH:1:29:0.9.6 -> 0.9.7 -->
+   <h2><a class="a-header" name="SH_1_30">0.9.6 -> 0.9.7</a></h2> <!-- index:2:SH:1:30:0.9.6 -> 0.9.7 -->
     <ul>
      <li>CRAM-MD5 authentication mechanism added.</li>
      <li>Revoke root permissions at start up, and reclaim them when needed.</li>
@@ -370,7 +377,7 @@
      <li>Submission utility <em>emailrelay-submit</em> added.</li>
      <li>HTML4.0 compliant HTML documentation, using CSS.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_30">0.9.5 -> 0.9.6</a></h2> <!-- index:2:SH:1:30:0.9.5 -> 0.9.6 -->
+   <h2><a class="a-header" name="SH_1_31">0.9.5 -> 0.9.6</a></h2> <!-- index:2:SH:1:31:0.9.5 -> 0.9.6 -->
     <ul>
      <li>SMTP AUTHentication extension -- LOGIN mechanism only.</li>
      <li>Client-side protocol timeout.</li>
@@ -380,7 +387,7 @@
      <li>Multiple hard-coded listening addresses supported at compile-time.</li>
      <li>Fix for automatic reopening of stderr stream.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_31">0.9.4 -> 0.9.5</a></h2> <!-- index:2:SH:1:31:0.9.4 -> 0.9.5 -->
+   <h2><a class="a-header" name="SH_1_32">0.9.4 -> 0.9.5</a></h2> <!-- index:2:SH:1:32:0.9.4 -> 0.9.5 -->
     <p>
      Windows fixes and improvements...
     </p>
@@ -390,14 +397,14 @@
      <li>fix for content file deletion</li>
      <li>fix for directory iterator</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_32">0.9.3 -> 0.9.4</a></h2> <!-- index:2:SH:1:32:0.9.3 -> 0.9.4 -->
+   <h2><a class="a-header" name="SH_1_33">0.9.3 -> 0.9.4</a></h2> <!-- index:2:SH:1:33:0.9.3 -> 0.9.4 -->
     <ul>
      <li>Fixed memory leak when no <em>--log</em> switch.</li>
      <li>Windows build is more <em>gui</em> and less <em>command-line</em>.</li>
      <li><em>Info</em> command added to the administration interface.</li>
      <li>Doxygen files removed from binary RPM.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_33">0.9.2 -> 0.9.3</a></h2> <!-- index:2:SH:1:33:0.9.2 -> 0.9.3 -->
+   <h2><a class="a-header" name="SH_1_34">0.9.2 -> 0.9.3</a></h2> <!-- index:2:SH:1:34:0.9.2 -> 0.9.3 -->
     <ul>
      <li>Proxy mode (<em>--immediate</em> and <em>--as-proxy</em>).</li>
      <li>Message pre-processing (<em>--filter</em>).</li>
@@ -405,7 +412,7 @@
      <li>Improved notification script, with MIME encoding.</li>
      <li>Builds with old 2.91 version of gcc.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_34">0.9.1 -> 0.9.2</a></h2> <!-- index:2:SH:1:34:0.9.1 -> 0.9.2 -->
+   <h2><a class="a-header" name="SH_1_35">0.9.1 -> 0.9.2</a></h2> <!-- index:2:SH:1:35:0.9.1 -> 0.9.2 -->
     <ul>
      <li>Better autoconf detection.</li>
      <li>Workround for FreeBSD uname() feature.</li>
@@ -413,7 +420,7 @@
      <li>Fixed a benign directory iterator bug.</li>
      <li>Use of gcc's <em>exception</em> header.</li>
     </ul>
-   <h2><a class="a-header" name="SH_1_35">0.9 -> 0.9.1</a></h2> <!-- index:2:SH:1:35:0.9 -> 0.9.1 -->
+   <h2><a class="a-header" name="SH_1_36">0.9 -> 0.9.1</a></h2> <!-- index:2:SH:1:36:0.9 -> 0.9.1 -->
     <ul>
      <li>Improved documentation from doxygen.</li>
      <li>More complete use of namespaces.</li>
@@ -423,4 +430,4 @@
  </div> <!-- div-main -->
  </body>
 </html>
-<!-- Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
+<!-- Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
diff --git a/doc/changelog.md b/doc/changelog.md
index d8aed12..e0d6533 100644
--- a/doc/changelog.md
+++ b/doc/changelog.md
@@ -1,12 +1,19 @@
 E-MailRelay Change Log
 ======================
 
-2.3 -> 2.3.1
-------------
+2.3 -> 2.4
+----------
 
+* Multiple `--filter` and `--client-filter` options allowed.
+* [TLS][] key and certificate files can be specified separately.
+* Finer control when using `--anonymous` (eg. `--anonymous=server`).
+* The `auth-config` options can distinguish between TLS and non-TLS authentication.
 * Hourly log file rotation using `%h` (eg. `--log-file=log.%d.%h`).
-* TLS key and certificate files can be specified separately.
-* Fixed error handling for network client filters (`--client-filter=net:...`) [bug-id #50].
+* Listening file descriptors can be inherited from the parent process (see `--interface`).
+* Listening ports on Windows use exclusive binding.
+* The Linux event loop uses `epoll` by default rather than `select`.
+* Some support for message routing (see NEWS).
+* Fix of error handling in network client filters (`--client-filter=net:...`) [bug-id #50].
 
 2.2 -> 2.3
 ----------
@@ -22,7 +29,7 @@ E-MailRelay Change Log
 
 * Connections from IPv4 'private use' addresses are allowed by default (see `--remote-clients`).
 * Interface names can be used with `--interface` (eg. `--interface=eth0`).
-* New `--server-tls-connection` option for server-side implicit [TLS][].
+* New `--server-tls-connection` option for server-side implicit TLS.
 * New `--forward-to-some` option to permit some message recipients to be rejected.
 * New `--log-address` option to aid adaptive firewalling.
 * Dynamic log file rolling when using `--log-file=%d`.
diff --git a/doc/changelog.rst b/doc/changelog.rst
index b0ca93f..9ae4667 100644
--- a/doc/changelog.rst
+++ b/doc/changelog.rst
@@ -2,12 +2,19 @@
 E-MailRelay Change Log
 **********************
 
-2.3 -> 2.3.1
-============
+2.3 -> 2.4
+==========
 
+* Multiple *--filter* and *--client-filter* options allowed.
+* TLS_ key and certificate files can be specified separately.
+* Finer control when using *--anonymous* (eg. *--anonymous=server*).
+* The *auth-config* options can distinguish between TLS and non-TLS authentication.
 * Hourly log file rotation using *%h* (eg. *--log-file=log.%d.%h*).
-* TLS key and certificate files can be specified separately.
-* Fixed error handling for network client filters (*--client-filter=net:...*) [bug-id #50].
+* Listening file descriptors can be inherited from the parent process (see *--interface*).
+* Listening ports on Windows use exclusive binding.
+* The Linux event loop uses *epoll* by default rather than *select*.
+* Some support for message routing (see NEWS).
+* Fix of error handling in network client filters (\ *--client-filter=net:...*\ ) [bug-id #50].
 
 2.2 -> 2.3
 ==========
@@ -15,7 +22,7 @@ E-MailRelay Change Log
 * Unix domain sockets supported (eg. *--interface=/tmp/smtp.s*).
 * Windows event log not used for verbose logging (prefer *--log-file*).
 * New admin *forward* command to trigger forwarding without waiting.
-* Optional base64 encoding of passwords in secrets files (*plain:b*).
+* Optional base64 encoding of passwords in secrets files (\ *plain:b*\ ).
 * Support for MbedTLS version 3.
 
 2.1 -> 2.2
@@ -23,7 +30,7 @@ E-MailRelay Change Log
 
 * Connections from IPv4 'private use' addresses are allowed by default (see *--remote-clients*).
 * Interface names can be used with *--interface* (eg. *--interface=eth0*).
-* New *--server-tls-connection* option for server-side implicit TLS_.
+* New *--server-tls-connection* option for server-side implicit TLS.
 * New *--forward-to-some* option to permit some message recipients to be rejected.
 * New *--log-address* option to aid adaptive firewalling.
 * Dynamic log file rolling when using *--log-file=%d*.
diff --git a/doc/changelog.txt b/doc/changelog.txt
index c189116..ddbe2b0 100644
--- a/doc/changelog.txt
+++ b/doc/changelog.txt
@@ -1,11 +1,18 @@
 E-MailRelay Change Log
 ======================
 
-2.3 -> 2.3.1
-------------
-* Hourly log file rotation using "%h" (eg. "--log-file=log.%d.%h").
+2.3 -> 2.4
+----------
+* Multiple "--filter" and "--client-filter" options allowed.
 * TLS key and certificate files can be specified separately.
-* Fixed error handling for network client filters ("--client-filter=net:...") [bug-id #50].
+* Finer control when using "--anonymous" (eg. "--anonymous=server").
+* The "auth-config" options can distinguish between TLS and non-TLS authentication.
+* Hourly log file rotation using "%h" (eg. "--log-file=log.%d.%h").
+* Listening file descriptors can be inherited from the parent process (see "--interface").
+* Listening ports on Windows use exclusive binding.
+* The Linux event loop uses "epoll" by default rather than "select".
+* Some support for message routing (see NEWS).
+* Fix of error handling in network client filters ("--client-filter=net:...") [bug-id #50].
 
 2.2 -> 2.3
 ----------
diff --git a/doc/conf.py.sphinx b/doc/conf.py.sphinx
index d02c370..c8c852c 100644
--- a/doc/conf.py.sphinx
+++ b/doc/conf.py.sphinx
@@ -9,8 +9,8 @@ master_doc = 'index'
 project = u'E-MailRelay'
 copyright = u'2022, Graeme Walker'
 author = u'Graeme Walker'
-version = u'2.3'
-release = u'2.3'
+version = u'2.4'
+release = u'2.4'
 language = None
 today_fmt = '%Y-%m-%d'
 exclude_patterns = []
diff --git a/doc/developer.html b/doc/developer.html
index 38fdfa7..936d704 100644
--- a/doc/developer.html
+++ b/doc/developer.html
@@ -1,4 +1,4 @@
-<!DOCTYPE HTML PUBLIC "%-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
+<!DOCTYPE html>
 <html>
  <head>
   <title>E-MailRelay Developer Guide</title>
@@ -8,7 +8,7 @@
  <body>
   <!-- index:0::::E-MailRelay Developer Guide -->
  <div class="div-main">
-  <h1><a class="a-header" name="H_1">E-MailRelay Developer Guide</a></h1> <!-- index:1:H:1::E-MailRelay Developer Guide -->
+  <h1><a class="a-header" name="H_1">E-MailRelay Developer Guide</a></h1> <!-- index:1:H:E-MailRelay Developer Guide -->
    <h2><a class="a-header" name="SH_1_1">Principles</a></h2> <!-- index:2:SH:1:1:Principles -->
     <p>
      The main principles in the design of E-MailRelay can be summarised as:
@@ -102,34 +102,31 @@
     <p>
      The main C++ libraries in the E-MailRelay code base are as follows:
     </p>
-
-    <dl>
-     <dt><em>glib</em></dt>
+   <h3><a class="a-header"><em>glib</em></a></h3>
       <dd>
        Low-level classes for file-system abstraction, date and time representation,
        string utility functions, logging, command line parsing etc.
       </dd>
-     <dt><em>gssl</em></dt>
+   <h3><a class="a-header"><em>gssl</em></a></h3>
       <dd>
        A thin layer over the third-party TLS libraries.
       </dd>
-     <dt><em>gnet</em></dt>
+   <h3><a class="a-header"><em>gnet</em></a></h3>
       <dd>
        Network and event-loop classes.
       </dd>
-     <dt><em>gauth</em></dt>
+   <h3><a class="a-header"><em>gauth</em></a></h3>
       <dd>
        Implements various authentication mechanisms.
       </dd>
-     <dt><em>gsmtp</em></dt>
+   <h3><a class="a-header"><em>gsmtp</em></a></h3>
       <dd>
        SMTP protocol and message-store classes.
       </dd>
-     <dt><em>gpop</em></dt>
+   <h3><a class="a-header"><em>gpop</em></a></h3>
       <dd>
        POP3 protocol classes.
       </dd>
-    </dl>
     <p>
      All of these libraries are portable between Unix-like systems and Windows.
     </p>
@@ -353,10 +350,10 @@
 
     <div class="div-footer">
      <p>
-      Copyright (C) 2001-2021 Graeme Walker
+      Copyright (C) 2001-2022 Graeme Walker
      </p>
     </div><!-- div-footer -->
  </div> <!-- div-main -->
  </body>
 </html>
-<!-- Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
+<!-- Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
diff --git a/doc/developer.md b/doc/developer.md
index cb71df7..ba8796c 100644
--- a/doc/developer.md
+++ b/doc/developer.md
@@ -77,28 +77,33 @@ Module structure
 ----------------
 The main C++ libraries in the E-MailRelay code base are as follows:
 
-*   `glib`
+### "glib" ###
 
     Low-level classes for file-system abstraction, date and time representation,
     string utility functions, logging, command line parsing etc.
 
-*   `gssl`
+
+### "gssl" ###
 
     A thin layer over the third-party TLS libraries.
 
-*   `gnet`
+
+### "gnet" ###
 
     Network and event-loop classes.
 
-*   `gauth`
+
+### "gauth" ###
 
     Implements various authentication mechanisms.
 
-*   `gsmtp`
+
+### "gsmtp" ###
 
     SMTP protocol and message-store classes.
 
-*   `gpop`
+
+### "gpop" ###
 
     POP3 protocol classes.
 
@@ -287,4 +292,4 @@ Use `./configure --help` to see a complete list of options.
 [TLS]: https://en.wikipedia.org/wiki/Transport_Layer_Security
 
 _____________________________________
-Copyright (C) 2001-2021 Graeme Walker
+Copyright (C) 2001-2022 Graeme Walker
diff --git a/doc/developer.rst b/doc/developer.rst
index 6ce8960..3476901 100644
--- a/doc/developer.rst
+++ b/doc/developer.rst
@@ -77,30 +77,17 @@ required.
 Module structure
 ================
 The main C++ libraries in the E-MailRelay code base are as follows:
-
-*   \ *glib*\
-
     Low-level classes for file-system abstraction, date and time representation,
     string utility functions, logging, command line parsing etc.
 
-*   \ *gssl*\
-
     A thin layer over the third-party TLS libraries.
 
-*   \ *gnet*\
-
     Network and event-loop classes.
 
-*   \ *gauth*\
-
     Implements various authentication mechanisms.
 
-*   \ *gsmtp*\
-
     SMTP protocol and message-store classes.
 
-*   \ *gpop*\
-
     POP3 protocol classes.
 
 All of these libraries are portable between Unix-like systems and Windows.
@@ -290,4 +277,4 @@ Use *./configure --help* to see a complete list of options.
 .. _SMTP: https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol
 .. _TLS: https://en.wikipedia.org/wiki/Transport_Layer_Security
 
-.. footer:: Copyright (C) 2001-2021 Graeme Walker
+.. footer:: Copyright (C) 2001-2022 Graeme Walker
diff --git a/doc/developer.txt b/doc/developer.txt
index 7300eee..d476384 100644
--- a/doc/developer.txt
+++ b/doc/developer.txt
@@ -275,4 +275,4 @@ Use "./configure --help" to see a complete list of options.
 
 
 _____________________________________
-Copyright (C) 2001-2021 Graeme Walker
+Copyright (C) 2001-2022 Graeme Walker
diff --git a/doc/doxygen-missing.html b/doc/doxygen-missing.html
index 6083393..2d4a467 100644
--- a/doc/doxygen-missing.html
+++ b/doc/doxygen-missing.html
@@ -1,4 +1,4 @@
-<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
+<!DOCTYPE html>
 <html>
  <head>
   <title>E-MailRelay source code documentation missing</title>
@@ -11,4 +11,4 @@
   </div>
  </body>
 </html>
-<!-- Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
+<!-- Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
diff --git a/doc/doxygen.cfg.in b/doc/doxygen.cfg.in
index 1660393..20ca8bb 100644
--- a/doc/doxygen.cfg.in
+++ b/doc/doxygen.cfg.in
@@ -838,51 +838,7 @@ INPUT_ENCODING         = UTF-8
 # *.m, *.markdown, *.md, *.mm, *.dox, *.py, *.pyw, *.f90, *.f95, *.f03, *.f08,
 # *.f, *.for, *.tcl, *.vhd, *.vhdl, *.ucf, *.qsf and *.ice.
 
-FILE_PATTERNS          = *.c \
-                         *.cc \
-                         *.cxx \
-                         *.cpp \
-                         *.c++ \
-                         *.java \
-                         *.ii \
-                         *.ixx \
-                         *.ipp \
-                         *.i++ \
-                         *.inl \
-                         *.idl \
-                         *.ddl \
-                         *.odl \
-                         *.h \
-                         *.hh \
-                         *.hxx \
-                         *.hpp \
-                         *.h++ \
-                         *.cs \
-                         *.d \
-                         *.php \
-                         *.php4 \
-                         *.php5 \
-                         *.phtml \
-                         *.inc \
-                         *.m \
-                         *.markdown \
-                         *.md \
-                         *.mm \
-                         *.dox \
-                         *.py \
-                         *.pyw \
-                         *.f90 \
-                         *.f95 \
-                         *.f03 \
-                         *.f08 \
-                         *.f \
-                         *.for \
-                         *.tcl \
-                         *.vhd \
-                         *.vhdl \
-                         *.ucf \
-                         *.qsf \
-                         *.ice
+FILE_PATTERNS = *.h *.cpp
 
 # The RECURSIVE tag can be used to specify whether or not subdirectories should
 # be searched for input files as well.
@@ -913,7 +869,7 @@ EXCLUDE_SYMLINKS       = NO
 # Note that the wildcards are matched against the file with absolute path, so to
 # exclude all test directories for example use the pattern */test/*
 
-EXCLUDE_PATTERNS = *_none* *_win32* *_basic* *_mac* *_mbedtls* *_ipv4* *_ip.cpp *_both* *_epoll*
+EXCLUDE_PATTERNS = *handles.h *_*cpp
 
 # The EXCLUDE_SYMBOLS tag can be used to specify one or more symbol names
 # (namespaces, classes, functions, etc.) that should be excluded from the
diff --git a/doc/emailrelay-doxygen.css b/doc/emailrelay-doxygen.css
index c95eb12..73f47c1 100644
--- a/doc/emailrelay-doxygen.css
+++ b/doc/emailrelay-doxygen.css
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+  Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 */
 
 /*
diff --git a/doc/emailrelay-filter-copy.1 b/doc/emailrelay-filter-copy.1
index c5f7e29..40f87e6 100644
--- a/doc/emailrelay-filter-copy.1
+++ b/doc/emailrelay-filter-copy.1
@@ -1,4 +1,4 @@
-.\" Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+.\" Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 .\" 
 .\" This program is free software: you can redistribute it and/or modify
 .\" it under the terms of the GNU General Public License as published by
@@ -47,7 +47,7 @@ forwarding.
 When using
 .I "-d"
 all envelope files in the spool directory are copied to all
-sub-directories. This should be used after using
+sub-directories. This can be used after
 .B emailrelay-submit
 has deposited an envelope file into the main spool
 directory, or perhaps periodically from cron.
diff --git a/doc/emailrelay-man.html b/doc/emailrelay-man.html
index d07cb10..a67f6a8 100644
--- a/doc/emailrelay-man.html
+++ b/doc/emailrelay-man.html
@@ -1,5 +1,4 @@
-
-<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
+<!DOCTYPE html>
 <HTML><HEAD><TITLE>Man page of EMAILRELAY</TITLE>
 </HEAD><BODY>
 <H1>EMAILRELAY</H1>
@@ -67,23 +66,10 @@ disconnects.
 <A NAME="lbAE">&nbsp;</A>
 <H2>OPTIONS</H2>
 
+<A NAME="lbAF">&nbsp;</A>
+<H3>Basic options</H3>
+
 <DL COMPACT>
-<DT><B>--address-verifier </B><I>&lt;program&gt;</I>
-
-<DD>
-Runs the specified external program to verify a message recipent's e-mail address. A network verifier can be specified as <I>net:&lt;transport-address&gt;</I>.
-<DT><B>-a, --admin </B><I>&lt;admin-port&gt;</I>
-
-<DD>
-Enables an administration interface on the specified listening port number. Use telnet or something similar to connect. The administration interface can be used to trigger forwarding of spooled mail messages if the <I>--forward-to</I> option is used.
-<DT><B>-Q, --admin-terminate</B>
-
-<DD>
-Enables the <I>terminate</I> command in the administration interface.
-<DT><B>-A, --anonymous</B>
-
-<DD>
-Disables the server's SMTP VRFY command, sends less verbose SMTP responses and SMTP greeting, and stops <I>Received</I> lines being added to mail message content files.
 <DT><B>-q, --as-client </B><I>&lt;host:port&gt;</I>
 
 <DD>
@@ -96,6 +82,155 @@ This is equivalent to <I>--log</I>, <I>--close-stderr</I>, <I>--forward-on-disco
 
 <DD>
 This is equivalent to <I>--log</I> and <I>--close-stderr</I>. It is a convenient way of running a background storage daemon that accepts mail messages and spools them. Use <I>--log</I> instead of <I>--as-server</I> to keep standard error stream open.
+<DT><B>-s, --spool-dir </B><I>&lt;dir&gt;</I>
+
+<DD>
+Specifies the directory used for holding mail messages that have been received but not yet forwarded.
+<DT><B>-h, --help</B>
+
+<DD>
+Displays help text and then exits. Use with <I>--verbose</I> for more complete output.
+<DT><B>-V, --version</B>
+
+<DD>
+Displays version information and then exits.
+</DL>
+<A NAME="lbAG">&nbsp;</A>
+<H3>SMTP client options</H3>
+
+<DL COMPACT>
+<DT><B>-f, --forward</B>
+
+<DD>
+Causes spooled mail messages to be forwarded when the program first starts.
+<DT><B>-1, --forward-on-disconnect</B>
+
+<DD>
+Causes spooled mail messages to be forwarded whenever a SMTP client connection disconnects.
+<DT><B>-o, --forward-to </B><I>&lt;host:port&gt;</I>
+
+<DD>
+Specifies the transport address of the remote SMTP server that spooled mail messages are forwarded to.
+<DT><B>-O, --poll </B><I>&lt;period&gt;</I>
+
+<DD>
+Causes forwarding of spooled mail messages to happen at regular intervals (with the time given in seconds).
+<DT><B>-Y, --client-filter </B><I>&lt;program&gt;</I>
+
+<DD>
+Runs the specified external filter program whenever a mail message is forwarded. The filter is passed the name of the message file in the spool directory so that it can edit it as required. A network filter can be specified as <I>net:&lt;tcp-address&gt;</I> and prefixes of <I>spam:</I>, <I>spam-edit:</I> and <I>exit:</I> are also allowed. The <I>spam:</I> and <I>spam-edit:</I> prefixes require a SpamAssassin daemon to be running. For store-and-forward applications the <I>--filter</I> option is normally more useful than <I>--client-filter</I>.
+<DT><B>-6, --client-interface </B><I>&lt;ip-address&gt;</I>
+
+<DD>
+Specifies the IP network address to be used to bind the local end of outgoing SMTP connections. By default the address will depend on the routing tables in the normal way. Use <I>0.0.0.0</I> to use only IPv4 addresses returned from DNS lookups of the <I>--forward-to</I> address, or <I>::</I> for IPv6.
+<DT><B>-U, --connection-timeout </B><I>&lt;time&gt;</I>
+
+<DD>
+Specifies a timeout (in seconds) for establishing a TCP connection to remote SMTP servers. The default is 40 seconds.
+<DT><B>--idle-timeout </B><I>&lt;time&gt;</I>
+
+<DD>
+Specifies a timeout (in seconds) for receiving network traffic from remote SMTP and POP clients. The default is 60 seconds.
+<DT><B>-T, --response-timeout </B><I>&lt;time&gt;</I>
+
+<DD>
+Specifies a timeout (in seconds) for getting responses from remote SMTP servers. The default is 60 seconds.
+<DT><B>--forward-to-some</B>
+
+<DD>
+Allow forwarding to continue even if some recipient addresses on an e-mail envelope are rejected by the remote server.
+<DT><B>-m, --immediate</B>
+
+<DD>
+Causes mail messages to be forwarded as they are received, even before they have been accepted. This can be used to do proxying without store-and-forward, but in practice clients tend to to time out while waiting for their mail message to be accepted.
+</DL>
+<A NAME="lbAH">&nbsp;</A>
+<H3>SMTP server options</H3>
+
+<DL COMPACT>
+<DT><B>-p, --port </B><I>&lt;port&gt;</I>
+
+<DD>
+Sets the port number used for listening for incoming SMTP connections.
+<DT><B>-r, --remote-clients</B>
+
+<DD>
+Allows incoming connections from addresses that are not local. The default behaviour is to reject connections that are not local in order to prevent accidental exposure to the public internet, although a firewall should also be used. Local address ranges are defined in RFC-1918, RFC-6890 etc.
+<DT><B>--address-verifier </B><I>&lt;program&gt;</I>
+
+<DD>
+Runs the specified external program to verify a message recipent's e-mail address. A network verifier can be specified as <I>net:&lt;tcp-address&gt;</I>.
+<DT><B>-A, --anonymous, --anonymous=</B><I>&lt;scope&gt;</I>
+
+<DD>
+Disables the server's SMTP VRFY command, sends less verbose SMTP greeting and responses, stops <I>Received</I> lines being added to mail message content files, and stops the SMTP client protocol adding <I>AUTH=</I> to the <I>MAIL</I> command. For finer control use a comma-separated list of things to anonymise: <I>vrfy</I>, <I>server</I>, <I>content</I> and/or <I>client</I>, eg. <I>--anonymous</I>=server,content.
+<DT><B>--dnsbl </B><I>&lt;config&gt;</I>
+
+<DD>
+Specifies a list of DNSBL servers that are used to reject SMTP connections from blocked addresses. The configuration string is made up of comma-separated fields: the DNS server's transport address, a timeout in milliseconds, a rejection threshold, and then the list of DNSBL servers.
+<DT><B>-D, --domain </B><I>&lt;fqdn&gt;</I>
+
+<DD>
+Specifies the network name that is used in SMTP EHLO commands, <I>Received</I> lines, and for generating authentication challenges. The default is derived from a DNS lookup of the local hostname.
+<DT><B>-z, --filter </B><I>&lt;program&gt;</I>
+
+<DD>
+Runs the specified external filter program whenever a mail message is stored. The filter is passed the name of the message file in the spool directory so that it can edit it as required. The mail message is rejected if the filter program terminates with an exit code between 1 and 99. Use <I>net:&lt;tcp-address&gt;</I> to communicate with a filter daemon over the network, or <I>spam:&lt;tcp-address&gt;</I> for a spamassassin spamd daemon to accept or reject mail messages, or <I>spam-edit:&lt;tcp-address&gt;</I> to have spamassassin edit the message content without rejecting it, or <I>exit:&lt;number&gt;</I> to emulate a filter program that just exits.
+<DT><B>-W, --filter-timeout </B><I>&lt;time&gt;</I>
+
+<DD>
+Specifies a timeout (in seconds) for running a <I>--filter</I> program. The default is 60 seconds.
+<DT><B>-I, --interface </B><I>&lt;ip-address-list&gt;</I>
+
+<DD>
+Specifies the IP network addresses or interface names used to bind listening ports. By default listening ports for incoming SMTP, POP and administration connections will bind the 'any' address for IPv4 and for IPv6, ie. <I>0.0.0.0</I> and <I>::</I>. Multiple addresses can be specified by using the option more than once or by using a comma-separated list. Use a prefix of <I>smtp=</I>, <I>pop=</I> or <I>admin=</I> on addresses that should apply only to those types of listening port. Any link-local IPv6 addresses must include a zone name or scope id.  Interface names can be used instead of addresses, in which case all the addresses associated with that interface at startup will used for listening. When an interface name is decorated with a <I>-ipv4</I> or <I>-ipv6</I> suffix only their IPv4 or IPv6 addresses will be used (eg. <I>ppp0-ipv4</I>).  To inherit listening file descriptors from the parent process on unix use a syntax like this: <I>--interface</I>=smtp=fd#3,smtp=fd#4,pop=fd#5.
+<DT><B>-w, --prompt-timeout </B><I>&lt;time&gt;</I>
+
+<DD>
+Specifies a timeout (in seconds) for getting the initial prompt from a remote SMTP server. If no prompt is received after this time then the SMTP dialog goes ahead without it.
+<DT><B>-M, --size </B><I>&lt;bytes&gt;</I>
+
+<DD>
+Limits the size of mail messages that can be submitted over SMTP.
+</DL>
+<A NAME="lbAI">&nbsp;</A>
+<H3>POP server options</H3>
+
+<DL COMPACT>
+<DT><B>-B, --pop</B>
+
+<DD>
+Enables the POP server, listening by default on port 110, providing access to spooled mail messages. Negotiated TLS using the POP <I>STLS</I> command will be enabled if the <I>--server-tls</I> option is also given.
+<DT><B>-J, --pop-by-name</B>
+
+<DD>
+Modifies the spool directory used by the POP server to be a sub-directory with the same name as the POP authentication user-id. This allows multiple POP clients to read the spooled mail messages without interfering with each other, particularly when also using <I>--pop-no-delete</I>. Content files can stay in the main spool directory with only the envelope files copied into user-specific sub-directories. The <I>emailrelay-filter-copy</I> program is a convenient way of doing this when run via <I>--filter</I>.
+<DT><B>-G, --pop-no-delete</B>
+
+<DD>
+Disables the POP DELE command so that the command appears to succeed but mail messages are not deleted from the spool directory.
+<DT><B>-E, --pop-port </B><I>&lt;port&gt;</I>
+
+<DD>
+Sets the POP server's listening port number.
+</DL>
+<A NAME="lbAJ">&nbsp;</A>
+<H3>Admin server options</H3>
+
+<DL COMPACT>
+<DT><B>-a, --admin </B><I>&lt;port&gt;</I>
+
+<DD>
+Enables an administration interface on the specified listening port number. Use telnet or something similar to connect. The administration interface can be used to trigger forwarding of spooled mail messages if the <I>--forward-to</I> option is used.
+<DT><B>-Q, --admin-terminate</B>
+
+<DD>
+Enables the <I>terminate</I> command in the administration interface.
+</DL>
+<A NAME="lbAK">&nbsp;</A>
+<H3>Authentication options</H3>
+
+<DL COMPACT>
 <DT><B>-C, --client-auth </B><I>&lt;file&gt;</I>
 
 <DD>
@@ -103,15 +238,24 @@ Enables SMTP client authentication with the remote server, using the client acco
 <DT><B>--client-auth-config </B><I>&lt;config&gt;</I>
 
 <DD>
-Configures the SMTP client authentication module using a semicolon-separated list of configuration items. Each item is a single-character key, followed by a colon and then a comma-separated list. A 'm' character introduces an ordered list of authentication mechanisms, and an 'x' is used for blocklisted mechanisms.
-<DT><B>-Y, --client-filter </B><I>&lt;program&gt;</I>
+Configures the SMTP client authentication module using a semicolon-separated list of configuration items. Each item is a single-character key, followed by a colon and then a comma-separated list. A 'm' character introduces an ordered list of preferred authentication mechanisms and an 'x' introduces a list of mechanisms to avoid. An 'a' list and a 'd' list can be used similarly to prefer and avoid certain mechanisms once the session is encrypted with TLS.
+<DT><B>-S, --server-auth </B><I>&lt;file&gt;</I>
 
 <DD>
-Runs the specified external filter program whenever a mail message is forwarded. The filter is passed the name of the message file in the spool directory so that it can edit it as required. A network filter can be specified as <I>net:&lt;transport-address&gt;</I> and prefixes of <I>spam:</I>, <I>spam-edit:</I> and <I>exit:</I> are also allowed. The <I>spam:</I> and <I>spam-edit:</I> prefixes require a SpamAssassin daemon to be running. For store-and-forward applications the <I>--filter</I> option is normally more useful than <I>--client-filter</I>.
-<DT><B>-6, --client-interface </B><I>&lt;ip-address&gt;</I>
+Enables SMTP server authentication of remote SMTP clients. Account names and passwords are taken from the specified secrets file. The secrets file should contain lines that have four space-separated fields, starting with <I>server</I> in the first field; the second field is the password encoding (<I>plain</I> or <I>md5</I>), the third is the client user-id and the fourth is the password. The user-id is RFC-1891 xtext encoded, and the password is either xtext encoded or generated by <I>emailrelay-passwd</I>. A special value of <I>/pam</I> can be used for authentication using linux PAM.
+<DT><B>--server-auth-config </B><I>&lt;config&gt;</I>
 
 <DD>
-Specifies the IP network address to be used to bind the local end of outgoing SMTP connections. By default the address will depend on the routing tables in the normal way. Use <I>0.0.0.0</I> to use only IPv4 addresses returned from DNS lookups of the <I>--forward-to</I> address, or <I>::</I> for IPv6.
+Configures the SMTP server authentication module using a semicolon-separated list of configuration items. Each item is a single-character key, followed by a colon and then a comma-separated list. A 'm' character introduces an ordered list of allowed authentication mechanisms and an 'x' introduces a list of mechanisms to deny. An 'a' list and a 'd' list can be used similarly to allow and deny mechanisms once the session is encrypted with TLS. In typical usage you might have an empty allow list for an unencrypted session and a single preferred mechanism once encrypted, <I>m:;a:plain</I>.
+<DT><B>-F, --pop-auth </B><I>&lt;file&gt;</I>
+
+<DD>
+Specifies a file containing valid POP account details. The file format is the same as for the SMTP server secrets file, ie. lines starting with <I>server</I>, with user-id and password in the third and fourth fields. A special value of <I>/pam</I> can be used for authentication using linux PAM.
+</DL>
+<A NAME="lbAL">&nbsp;</A>
+<H3>TLS options</H3>
+
+<DL COMPACT>
 <DT><B>-j, --client-tls</B>
 
 <DD>
@@ -140,158 +284,6 @@ Enables verification of the remote SMTP server's certificate against any of the
 
 <DD>
 Enables verification of the CNAME within the remote SMTP server's certificate.
-<DT><B>-e, --close-stderr</B>
-
-<DD>
-Causes the standard error stream to be closed soon after start-up. This is useful when operating as a background daemon and it is therefore implied by <I>--as-server</I> and <I>--as-proxy</I>.
-<DT><B>-U, --connection-timeout </B><I>&lt;time&gt;</I>
-
-<DD>
-Specifies a timeout (in seconds) for establishing a TCP connection to remote SMTP servers. The default is 40 seconds.
-<DT><B>-g, --debug</B>
-
-<DD>
-Enables debug level logging, if built in. Debug messages are usually only useful when cross-referenced with the source code and they may expose plaintext passwords and mail message content.
-<DT><B>--dnsbl </B><I>&lt;config&gt;</I>
-
-<DD>
-Specifies a list of DNSBL servers that are used to reject SMTP connections from blocked addresses. The configuration string is made up of comma-separated fields: the DNS server's transport address, a timeout in milliseconds, a rejection threshold, and then the list of DNSBL servers.
-<DT><B>-D, --domain </B><I>&lt;fqdn&gt;</I>
-
-<DD>
-Specifies the network name that is used in SMTP EHLO commands, <I>Received</I> lines, and for generating authentication challenges. The default is derived from a DNS lookup of the local hostname.
-<DT><B>-x, --dont-serve</B>
-
-<DD>
-Disables all network serving, including SMTP, POP and administration interfaces. The program will terminate as soon as any initial forwarding is complete.
-<DT><B>-z, --filter </B><I>&lt;program&gt;</I>
-
-<DD>
-Runs the specified external filter program whenever a mail message is stored. The filter is passed the name of the message file in the spool directory so that it can edit it as required. The mail message is rejected if the filter program terminates with an exit code between 1 and 99. Use <I>net:&lt;transport-address&gt;</I> to communicate with a filter daemon over the network, or <I>spam:&lt;transport-address&gt;</I> for a spamassassin spamd daemon to accept or reject mail messages, or <I>spam-edit:&lt;transport-address&gt;</I> to have spamassassin edit the message content without rejecting it, or <I>exit:&lt;number&gt;</I> to emulate a filter program that just exits.
-<DT><B>-W, --filter-timeout </B><I>&lt;time&gt;</I>
-
-<DD>
-Specifies a timeout (in seconds) for running a <I>--filter</I> program. The default is 300 seconds.
-<DT><B>-f, --forward</B>
-
-<DD>
-Causes spooled mail messages to be forwarded when the program first starts.
-<DT><B>-1, --forward-on-disconnect</B>
-
-<DD>
-Causes spooled mail messages to be forwarded whenever a SMTP client connection disconnects.
-<DT><B>-o, --forward-to </B><I>&lt;host:port&gt;</I>
-
-<DD>
-Specifies the transport address of the remote SMTP server that is use for mail message forwarding.
-<DT><B>--forward-to-some</B>
-
-<DD>
-Allow forwarding to continue even if some recipient addresses on an e-mail envelope are rejected by the remote server.
-<DT><B>-h, --help</B>
-
-<DD>
-Displays help text and then exits. Use with <I>--verbose</I> for more complete output.
-<DT><B>-H, --hidden</B>
-
-<DD>
-Windows only. Hides the application window and disables all message boxes, overriding any <I>--show</I> option. This is useful when running as a windows service.
-<DT><B>--idle-timeout </B><I>&lt;time&gt;</I>
-
-<DD>
-Specifies a timeout (in seconds) for receiving network traffic from remote SMTP and POP clients. The default is 1800 seconds.
-<DT><B>-m, --immediate</B>
-
-<DD>
-Causes mail messages to be forwarded as they are received, even before they have been accepted. This can be used to do proxying without store-and-forward, but in practice clients tend to to time out while waiting for their mail message to be accepted.
-<DT><B>-I, --interface </B><I>&lt;ip-address-list&gt;</I>
-
-<DD>
-Specifies the IP network addresses or interface names used to bind listening ports. By default listening ports for incoming SMTP, POP and administration connections will bind the 'any' address for IPv4 and for IPv6, ie. <I>0.0.0.0</I> and <I>::</I>. Multiple addresses can be specified by using the option more than once or by using a comma-separated list. Use a prefix of <I>smtp=</I>, <I>pop=</I> or <I>admin=</I> on addresses that should apply only to those types of listening port. Any link-local IPv6 addresses must include a zone name or scope id.  Interface names can be used instead of addresses, in which case all the addresses associated with that interface at startup will used for listening. When an interface name is decorated with a <I>-ipv4</I> or <I>-ipv6</I> suffix only their IPv4 or IPv6 addresses will be used (eg. <I>ppp0-ipv4</I>).
-<DT><B>--localedir </B><I>&lt;dir&gt;</I>
-
-<DD>
-Enables localisation and specifies the locale base directory where message catalogues can be found. An empty directory can be used for the built-in default.
-<DT><B>-l, --log</B>
-
-<DD>
-Enables logging to the standard error stream and to the syslog. The <I>--close-stderr</I> and <I>--no-syslog</I> options can be used to disable output to standard error stream and the syslog separately. Note that <I>--as-server</I>, <I>--as-client</I> and <I>--as-proxy</I> imply <I>--log</I>, and <I>--as-server</I> and <I>--as-proxy</I> also imply <I>--close-stderr</I>.
-<DT><B>--log-address</B>
-
-<DD>
-Adds the network address of remote clients to the logging output.
-<DT><B>-N, --log-file </B><I>&lt;file&gt;</I>
-
-<DD>
-Redirects standard-error logging to the specified file. Logging to the log file is not affected by <I>--close-stderr</I>. The filename can include <I>%d</I> to get daily log files; the <I>%d</I> is replaced by the current date in the local timezone using a <I>YYYYMMDD</I> format.
-<DT><B>-L, --log-time</B>
-
-<DD>
-Adds a timestamp to the logging output using the local timezone.
-<DT><B>-t, --no-daemon</B>
-
-<DD>
-Disables the normal backgrounding at startup so that the program runs in the foreground, without forking or detaching from the terminal.  On Windows this disables the system tray icon so the program uses a normal window; when the window is closed the program terminates.
-<DT><B>-X, --no-smtp</B>
-
-<DD>
-Disables listening for incoming SMTP connections.
-<DT><B>-n, --no-syslog</B>
-
-<DD>
-Disables logging to the syslog. Note that <I>--as-client</I> implies <I>--no-syslog</I>.
-<DT><B>-i, --pid-file </B><I>&lt;pid-file&gt;</I>
-
-<DD>
-Causes the process-id to be written into the specified file when the program starts up, typically after it has become a background daemon.
-<DT><B>-O, --poll </B><I>&lt;period&gt;</I>
-
-<DD>
-Causes forwarding of spooled mail messages to happen at regular intervals (with the time given in seconds).
-<DT><B>-B, --pop</B>
-
-<DD>
-Enables the POP server listening, by default on port 110, providing access to spooled mail messages. Negotiated TLS using the POP <I>STLS</I> command will be enabled if the <I>--server-tls</I> option is also given.
-<DT><B>-F, --pop-auth </B><I>&lt;file&gt;</I>
-
-<DD>
-Specifies a file containing valid POP account details. The file format is the same as for the SMTP server secrets file, ie. lines starting with <I>server</I>, with user-id and password in the third and fourth fields. A special value of <I>/pam</I> can be used for authentication using linux PAM.
-<DT><B>-J, --pop-by-name</B>
-
-<DD>
-Modifies the spool directory used by the POP server to be a sub-directory with the same name as the POP authentication user-id. This allows multiple POP clients to read the spooled messages without interfering with each other, particularly when also using <I>--pop-no-delete</I>. Content files can stay in the main spool directory with only the envelope files copied into user-specific sub-directories. The <I>emailrelay-filter-copy</I> program is a convenient way of doing this when run via <I>--filter</I>.
-<DT><B>-G, --pop-no-delete</B>
-
-<DD>
-Disables the POP DELE command so that the command appears to succeed but mail messages are not deleted from the spool directory.
-<DT><B>-E, --pop-port </B><I>&lt;port&gt;</I>
-
-<DD>
-Sets the POP server's listening port number.
-<DT><B>-p, --port </B><I>&lt;port&gt;</I>
-
-<DD>
-Sets the port number used for listening for incoming SMTP connections.
-<DT><B>-w, --prompt-timeout </B><I>&lt;time&gt;</I>
-
-<DD>
-Specifies a timeout (in seconds) for getting the initial prompt from a remote SMTP server. If no prompt is received after this time then the SMTP dialog goes ahead without it.
-<DT><B>-r, --remote-clients</B>
-
-<DD>
-Allows incoming connections from addresses that are not local. The default behaviour is to reject connections that are not local in order to prevent accidental exposure to the public internet, although a firewall should also be used. Local address ranges are defined in RFC-1918, RFC-6890 etc.
-<DT><B>-T, --response-timeout </B><I>&lt;time&gt;</I>
-
-<DD>
-Specifies a timeout (in seconds) for getting responses from remote SMTP servers. The default is 1800 seconds.
-<DT><B>-S, --server-auth </B><I>&lt;file&gt;</I>
-
-<DD>
-Enables SMTP server authentication of remote SMTP clients. Account names and passwords are taken from the specified secrets file. The secrets file should contain lines that have four space-separated fields, starting with <I>server</I> in the first field; the second field is the password encoding (<I>plain</I> or <I>md5</I>), the third is the client user-id and the fourth is the password. The user-id is RFC-1891 xtext encoded, and the password is either xtext encoded or generated by <I>emailrelay-passwd</I>. A special value of <I>/pam</I> can be used for authentication using linux PAM.
-<DT><B>--server-auth-config </B><I>&lt;config&gt;</I>
-
-<DD>
-Configures the SMTP server authentication module using a semicolon-separated list of configuration items. Each item is a single-character key, followed by a colon and then a comma-separated list. A 'm' character introduces a preferred sub-set of the built-in authentication mechanisms, and an 'x' is used for blocklisted mechanisms.
 <DT><B>-K, --server-tls</B>
 
 <DD>
@@ -312,43 +304,93 @@ Makes the use of TLS mandatory for any incoming SMTP and POP connections. SMTP c
 
 <DD>
 Enables verification of remote SMTP and POP clients' certificates against any of the trusted CA certificates in the specified file or directory. In many use cases this should be a file containing just your self-signed root certificate. Specify <I>&lt;default&gt;</I> for the TLS library's default set of trusted CAs.
-<DT><B>-M, --size </B><I>&lt;bytes&gt;</I>
-
-<DD>
-Limits the size of mail messages that can be submitted over SMTP.
-<DT><B>-s, --spool-dir </B><I>&lt;dir&gt;</I>
-
-<DD>
-Specifies the directory used for holding mail messages that have been received but not yet forwarded.
-<DT><B>-k, --syslog, --syslog=</B><I>&lt;facility&gt;</I>
-
-<DD>
-When used with <I>--log</I> this option enables logging to the syslog even if the <I>--no-syslog</I> option is also used. This is typically used as a convenient override when using <I>--as-client</I>.
 <DT><B>-9, --tls-config </B><I>&lt;options&gt;</I>
 
 <DD>
 Selects and configures the low-level TLS library, using a comma-separated list of keywords. If OpenSSL and mbedTLS are both built in then keywords of <I>openssl</I> and <I>mbedtls</I> will select one or the other. Keywords like <I>tlsv1.0</I> can be used to set a minimum TLS protocol version, or <I>-tlsv1.2</I> to set a maximum version.
+</DL>
+<A NAME="lbAM">&nbsp;</A>
+<H3>Process options</H3>
+
+<DL COMPACT>
+<DT><B>-x, --dont-serve</B>
+
+<DD>
+Disables all network serving, including SMTP, POP and administration interfaces. The program will terminate as soon as any initial forwarding is complete.
+<DT><B>-H, --hidden</B>
+
+<DD>
+Windows only. Hides the application window and disables all message boxes, overriding any <I>--show</I> option. This is useful when running as a windows service.
+<DT><B>--localedir </B><I>&lt;dir&gt;</I>
+
+<DD>
+Enables localisation and specifies the locale base directory where message catalogues can be found. An empty directory can be used for the built-in default.
+<DT><B>-t, --no-daemon</B>
+
+<DD>
+Disables the normal backgrounding at startup so that the program runs in the foreground, without forking or detaching from the terminal.  On Windows this disables the system tray icon so the program uses a normal window; when the window is closed the program terminates.
+<DT><B>-X, --no-smtp</B>
+
+<DD>
+Disables listening for incoming SMTP connections.
+<DT><B>-i, --pid-file </B><I>&lt;path&gt;</I>
+
+<DD>
+Causes the process-id to be written into the specified file when the program starts up, typically after it has become a background daemon. The immediate parent directory is created if necessary.
 <DT><B>-u, --user </B><I>&lt;username&gt;</I>
 
 <DD>
-When started as root the program switches to a non-privileged effective user-id when idle. This option can be used to define the idle user-id and also the group ownership of new files and sockets. Specify <I>root</I> to  disable all user-id switching. Ignored on Windows.
+When started as root the program switches to a non-privileged effective user-id when idle. This option can be used to define the idle user-id and also the group ownership of new files and sockets. Specify <I>root</I> to disable all user-id switching. Ignored on Windows.
+</DL>
+<A NAME="lbAN">&nbsp;</A>
+<H3>Logging options</H3>
+
+<DL COMPACT>
 <DT><B>-v, --verbose</B>
 
 <DD>
 Enables more verbose logging when used with <I>--log</I>, and more verbose help when used with <I>--help</I>.
-<DT><B>-V, --version</B>
+<DT><B>-l, --log</B>
 
 <DD>
-Displays version information and then exits.
+Enables logging to the standard error stream and to the syslog. The <I>--close-stderr</I> and <I>--no-syslog</I> options can be used to disable output to standard error stream and the syslog separately. Note that <I>--as-server</I>, <I>--as-client</I> and <I>--as-proxy</I> imply <I>--log</I>, and <I>--as-server</I> and <I>--as-proxy</I> also imply <I>--close-stderr</I>.
+<DT><B>-g, --debug</B>
+
+<DD>
+Enables debug level logging, if built in. Debug messages are usually only useful when cross-referenced with the source code and they may expose plaintext passwords and mail message content.
+<DT><B>--log-address</B>
+
+<DD>
+Adds the network address of remote clients to the logging output.
+<DT><B>-N, --log-file </B><I>&lt;file&gt;</I>
+
+<DD>
+Redirects standard-error logging to the specified file. Logging to the log file is not affected by <I>--close-stderr</I>. The filename can include <I>%d</I> to get daily log files; the <I>%d</I> is replaced by the current date in the local timezone using a <I>YYYYMMDD</I> format.
+<DT><B>-L, --log-time</B>
+
+<DD>
+Adds a timestamp to the logging output using the local timezone.
+<DT><B>-n, --no-syslog</B>
+
+<DD>
+Disables logging to the syslog. Note that <I>--as-client</I> implies <I>--no-syslog</I>.
+<DT><B>-k, --syslog, --syslog=</B><I>&lt;facility&gt;</I>
+
+<DD>
+When used with <I>--log</I> this option enables logging to the syslog even if the <I>--no-syslog</I> option is also used. This is typically used as a convenient override when using <I>--as-client</I>.
+<DT><B>-e, --close-stderr</B>
+
+<DD>
+Causes the standard error stream to be closed soon after start-up. This is useful when operating as a background daemon and it is therefore implied by <I>--as-server</I> and <I>--as-proxy</I>.
 </DL>
-<A NAME="lbAF">&nbsp;</A>
+<A NAME="lbAO">&nbsp;</A>
 <H2>SEE ALSO</H2>
 
 <B><A HREF="../man1/emailrelay-submit.1.html">emailrelay-submit</A></B>(1),
 
 <B><A HREF="../man1/emailrelay-passwd.1.html">emailrelay-passwd</A></B>(1),
 
-<A NAME="lbAG">&nbsp;</A>
+<A NAME="lbAP">&nbsp;</A>
 <H2>AUTHOR</H2>
 
 Graeme Walker, mailto:<A HREF="mailto:graeme_walker@users.sourceforge.net">graeme_walker@users.sourceforge.net</A>
@@ -361,8 +403,19 @@ Graeme Walker, mailto:<A HREF="mailto:graeme_walker@users.sourceforge.net">graem
 <DT><A HREF="#lbAC">SYNOPSIS</A><DD>
 <DT><A HREF="#lbAD">DESCRIPTION</A><DD>
 <DT><A HREF="#lbAE">OPTIONS</A><DD>
-<DT><A HREF="#lbAF">SEE ALSO</A><DD>
-<DT><A HREF="#lbAG">AUTHOR</A><DD>
+<DL>
+<DT><A HREF="#lbAF">Basic options</A><DD>
+<DT><A HREF="#lbAG">SMTP client options</A><DD>
+<DT><A HREF="#lbAH">SMTP server options</A><DD>
+<DT><A HREF="#lbAI">POP server options</A><DD>
+<DT><A HREF="#lbAJ">Admin server options</A><DD>
+<DT><A HREF="#lbAK">Authentication options</A><DD>
+<DT><A HREF="#lbAL">TLS options</A><DD>
+<DT><A HREF="#lbAM">Process options</A><DD>
+<DT><A HREF="#lbAN">Logging options</A><DD>
+</DL>
+<DT><A HREF="#lbAO">SEE ALSO</A><DD>
+<DT><A HREF="#lbAP">AUTHOR</A><DD>
 </DL>
 <HR>
 This document was created by
@@ -370,3 +423,4 @@ This document was created by
 using the manual pages.<BR>
 </BODY>
 </HTML>
+<!-- Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
diff --git a/doc/emailrelay-passwd.1 b/doc/emailrelay-passwd.1
index 0ce6634..2a1fb30 100644
--- a/doc/emailrelay-passwd.1
+++ b/doc/emailrelay-passwd.1
@@ -1,4 +1,4 @@
-.\" Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+.\" Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 .\" 
 .\" This program is free software: you can redistribute it and/or modify
 .\" it under the terms of the GNU General Public License as published by
@@ -39,6 +39,21 @@ server md5 alice Oqng9/H7wAyKgbuqw5VzG1bNO6feqtblyiNEi6QuN5dH
 .br
 server md5 bob Ot6SDdGj23eWjdEuKICgN8Nj9z/Vx9IV3ISz9VvmnaUB
 .SH OPTIONS
+.TP
+.B \-H, --hash \fI<function>\fR
+Specifies the hash function, such as MD5 or SHA1. MD5 is the default, and a hash function of NONE does simple xtext encoding. Other hash function may or may not be available, depending on the build.
+.TP
+.B \-h, --help
+Shows help text and exits.
+.TP
+.B \-b, --base64
+The input password is interpreted as being base-64 encoded.
+.TP
+.B \-d, --dotted
+Generates a dotted decimal format, for backwards compatibility.
+.TP
+.B \-p, --password \fI<pwd>\fR
+Specifies the password to be hashed. Beware of leaking sensitive passwords via command-line history or the process-table when using this option.
 .SH SEE ALSO
 .BR emailrelay (1),
 .BR emailrelay-submit (1),
diff --git a/doc/emailrelay-submit.1 b/doc/emailrelay-submit.1
index 021fdce..7d04055 100644
--- a/doc/emailrelay-submit.1
+++ b/doc/emailrelay-submit.1
@@ -1,4 +1,4 @@
-.\" Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+.\" Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 .\" 
 .\" This program is free software: you can redistribute it and/or modify
 .\" it under the terms of the GNU General Public License as published by
@@ -33,6 +33,52 @@ spool directory.
 .LP
 The verbose option causes the path of the new content file
 to be printed.
+.SH OPTIONS
+.TP
+.B \-f, --from \fI<name>\fR
+Sets the envelope 'from' address.
+.TP
+.B \-h, --help
+Shows help text and exits.
+.TP
+.B \-s, --spool-dir \fI<dir>\fR
+Specifies the spool directory.
+.TP
+.B \-v, --verbose
+Prints the full path of the content file.
+.TP
+.B \-d, --content-date
+Adds a \fIDate:\fR content header if there is none.
+.TP
+.B \-F, --content-from
+Adds the envelope 'from' addresses as a \fIFrom:\fR content header.
+.TP
+.B \-t, --content-to
+Adds the envelope 'to' addresses as \fITo:\fR content headers.
+.TP
+.B \-c, --copy
+Copies the envelope file into all sub-directories of the main spool directory.
+.TP
+.B \-n, --filename
+Prints the name of the content file.
+.TP
+.B \-V, --version
+Prints the version number and exits.
+.TP
+.B \-a, --auth \fI<name>\fR
+Sets the authentication value in the envelope file.
+.TP
+.B \-C, --content \fI<base64>\fR
+Sets a line of content. This can be a header line, a blank line or a line of the body text. The first blank line separates headers  from the body. The option value should be base64 encoded.
+.TP
+.B \-i, --from-auth-in \fI<name>\fR
+Sets the 'from-auth-in' value in the envelope file.
+.TP
+.B \-o, --from-auth-out \fI<name>\fR
+Sets the 'from-auth-out' value in the envelope file.
+.TP
+.B \-N, --no-stdin
+Ignores the standard-input. Typically used with \fI\fR\fI--content\fR\fI\fR.
 .SH SEE ALSO
 .BR emailrelay (1),
 .BR emailrelay-passwd (1)
diff --git a/doc/emailrelay.1 b/doc/emailrelay.1
index b4d099c..94e8a1d 100644
--- a/doc/emailrelay.1
+++ b/doc/emailrelay.1
@@ -1,4 +1,4 @@
-.\" Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+.\" Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 .\" 
 .\" This program is free software: you can redistribute it and/or modify
 .\" it under the terms of the GNU General Public License as published by
@@ -51,18 +51,7 @@ In this mode all e-mail messages are spooled temporarily while the
 client is connected and forwarded as soon as the client
 disconnects.
 .SH OPTIONS
-.TP
-.B --address-verifier \fI<program>\fR
-Runs the specified external program to verify a message recipent's e-mail address. A network verifier can be specified as \fInet:<transport-address>\fR.
-.TP
-.B \-a, --admin \fI<admin-port>\fR
-Enables an administration interface on the specified listening port number. Use telnet or something similar to connect. The administration interface can be used to trigger forwarding of spooled mail messages if the \fI--forward-to\fR option is used.
-.TP
-.B \-Q, --admin-terminate
-Enables the \fIterminate\fR command in the administration interface.
-.TP
-.B \-A, --anonymous
-Disables the server's SMTP VRFY command, sends less verbose SMTP responses and SMTP greeting, and stops \fIReceived\fR lines being added to mail message content files.
+.SS Basic options
 .TP
 .B \-q, --as-client \fI<host:port>\fR
 This is equivalent to \fI--log\fR, \fI--no-syslog\fR, \fI--no-daemon\fR, \fI--dont-serve\fR, \fI--forward\fR and \fI--forward-to\fR. It is a convenient way of running a forwarding agent that forwards spooled mail messages and then terminates.
@@ -73,17 +62,119 @@ This is equivalent to \fI--log\fR, \fI--close-stderr\fR, \fI--forward-on-disconn
 .B \-d, --as-server
 This is equivalent to \fI--log\fR and \fI--close-stderr\fR. It is a convenient way of running a background storage daemon that accepts mail messages and spools them. Use \fI--log\fR instead of \fI--as-server\fR to keep standard error stream open.
 .TP
+.B \-s, --spool-dir \fI<dir>\fR
+Specifies the directory used for holding mail messages that have been received but not yet forwarded.
+.TP
+.B \-h, --help
+Displays help text and then exits. Use with \fI--verbose\fR for more complete output.
+.TP
+.B \-V, --version
+Displays version information and then exits.
+.SS SMTP client options
+.TP
+.B \-f, --forward
+Causes spooled mail messages to be forwarded when the program first starts.
+.TP
+.B \-1, --forward-on-disconnect
+Causes spooled mail messages to be forwarded whenever a SMTP client connection disconnects.
+.TP
+.B \-o, --forward-to \fI<host:port>\fR
+Specifies the transport address of the remote SMTP server that spooled mail messages are forwarded to.
+.TP
+.B \-O, --poll \fI<period>\fR
+Causes forwarding of spooled mail messages to happen at regular intervals (with the time given in seconds).
+.TP
+.B \-Y, --client-filter \fI<program>\fR
+Runs the specified external filter program whenever a mail message is forwarded. The filter is passed the name of the message file in the spool directory so that it can edit it as required. A network filter can be specified as \fInet:<tcp-address>\fR and prefixes of \fIspam:\fR, \fIspam-edit:\fR and \fIexit:\fR are also allowed. The \fIspam:\fR and \fIspam-edit:\fR prefixes require a SpamAssassin daemon to be running. For store-and-forward applications the \fI--filter\fR option is normally more useful than \fI--client-filter\fR.
+.TP
+.B \-6, --client-interface \fI<ip-address>\fR
+Specifies the IP network address to be used to bind the local end of outgoing SMTP connections. By default the address will depend on the routing tables in the normal way. Use \fI0.0.0.0\fR to use only IPv4 addresses returned from DNS lookups of the \fI--forward-to\fR address, or \fI::\fR for IPv6.
+.TP
+.B \-U, --connection-timeout \fI<time>\fR
+Specifies a timeout (in seconds) for establishing a TCP connection to remote SMTP servers. The default is 40 seconds.
+.TP
+.B --idle-timeout \fI<time>\fR
+Specifies a timeout (in seconds) for receiving network traffic from remote SMTP and POP clients. The default is 60 seconds.
+.TP
+.B \-T, --response-timeout \fI<time>\fR
+Specifies a timeout (in seconds) for getting responses from remote SMTP servers. The default is 60 seconds.
+.TP
+.B --forward-to-some
+Allow forwarding to continue even if some recipient addresses on an e-mail envelope are rejected by the remote server.
+.TP
+.B \-m, --immediate
+Causes mail messages to be forwarded as they are received, even before they have been accepted. This can be used to do proxying without store-and-forward, but in practice clients tend to to time out while waiting for their mail message to be accepted.
+.SS SMTP server options
+.TP
+.B \-p, --port \fI<port>\fR
+Sets the port number used for listening for incoming SMTP connections.
+.TP
+.B \-r, --remote-clients
+Allows incoming connections from addresses that are not local. The default behaviour is to reject connections that are not local in order to prevent accidental exposure to the public internet, although a firewall should also be used. Local address ranges are defined in RFC-1918, RFC-6890 etc.
+.TP
+.B --address-verifier \fI<program>\fR
+Runs the specified external program to verify a message recipent's e-mail address. A network verifier can be specified as \fInet:<tcp-address>\fR.
+.TP
+.B \-A, --anonymous, --anonymous=\fI<scope>\fR
+Disables the server's SMTP VRFY command, sends less verbose SMTP greeting and responses, stops \fIReceived\fR lines being added to mail message content files, and stops the SMTP client protocol adding \fIAUTH=\fR to the \fIMAIL\fR command. For finer control use a comma-separated list of things to anonymise: \fIvrfy\fR, \fIserver\fR, \fIcontent\fR and/or \fIclient\fR, eg. \fI--anonymous\fR=server,content.
+.TP
+.B --dnsbl \fI<config>\fR
+Specifies a list of DNSBL servers that are used to reject SMTP connections from blocked addresses. The configuration string is made up of comma-separated fields: the DNS server's transport address, a timeout in milliseconds, a rejection threshold, and then the list of DNSBL servers.
+.TP
+.B \-D, --domain \fI<fqdn>\fR
+Specifies the network name that is used in SMTP EHLO commands, \fIReceived\fR lines, and for generating authentication challenges. The default is derived from a DNS lookup of the local hostname.
+.TP
+.B \-z, --filter \fI<program>\fR
+Runs the specified external filter program whenever a mail message is stored. The filter is passed the name of the message file in the spool directory so that it can edit it as required. The mail message is rejected if the filter program terminates with an exit code between 1 and 99. Use \fInet:<tcp-address>\fR to communicate with a filter daemon over the network, or \fIspam:<tcp-address>\fR for a spamassassin spamd daemon to accept or reject mail messages, or \fIspam-edit:<tcp-address>\fR to have spamassassin edit the message content without rejecting it, or \fIexit:<number>\fR to emulate a filter program that just exits.
+.TP
+.B \-W, --filter-timeout \fI<time>\fR
+Specifies a timeout (in seconds) for running a \fI--filter\fR program. The default is 60 seconds.
+.TP
+.B \-I, --interface \fI<ip-address-list>\fR
+Specifies the IP network addresses or interface names used to bind listening ports. By default listening ports for incoming SMTP, POP and administration connections will bind the 'any' address for IPv4 and for IPv6, ie. \fI0.0.0.0\fR and \fI::\fR. Multiple addresses can be specified by using the option more than once or by using a comma-separated list. Use a prefix of \fIsmtp=\fR, \fIpop=\fR or \fIadmin=\fR on addresses that should apply only to those types of listening port. Any link-local IPv6 addresses must include a zone name or scope id.  Interface names can be used instead of addresses, in which case all the addresses associated with that interface at startup will used for listening. When an interface name is decorated with a \fI-ipv4\fR or \fI-ipv6\fR suffix only their IPv4 or IPv6 addresses will be used (eg. \fIppp0-ipv4\fR).  To inherit listening file descriptors from the parent process on unix use a syntax like this: \fI--interface\fR=smtp=fd#3,smtp=fd#4,pop=fd#5.
+.TP
+.B \-w, --prompt-timeout \fI<time>\fR
+Specifies a timeout (in seconds) for getting the initial prompt from a remote SMTP server. If no prompt is received after this time then the SMTP dialog goes ahead without it.
+.TP
+.B \-M, --size \fI<bytes>\fR
+Limits the size of mail messages that can be submitted over SMTP.
+.SS POP server options
+.TP
+.B \-B, --pop
+Enables the POP server, listening by default on port 110, providing access to spooled mail messages. Negotiated TLS using the POP \fISTLS\fR command will be enabled if the \fI--server-tls\fR option is also given.
+.TP
+.B \-J, --pop-by-name
+Modifies the spool directory used by the POP server to be a sub-directory with the same name as the POP authentication user-id. This allows multiple POP clients to read the spooled mail messages without interfering with each other, particularly when also using \fI--pop-no-delete\fR. Content files can stay in the main spool directory with only the envelope files copied into user-specific sub-directories. The \fIemailrelay-filter-copy\fR program is a convenient way of doing this when run via \fI--filter\fR.
+.TP
+.B \-G, --pop-no-delete
+Disables the POP DELE command so that the command appears to succeed but mail messages are not deleted from the spool directory.
+.TP
+.B \-E, --pop-port \fI<port>\fR
+Sets the POP server's listening port number.
+.SS Admin server options
+.TP
+.B \-a, --admin \fI<port>\fR
+Enables an administration interface on the specified listening port number. Use telnet or something similar to connect. The administration interface can be used to trigger forwarding of spooled mail messages if the \fI--forward-to\fR option is used.
+.TP
+.B \-Q, --admin-terminate
+Enables the \fIterminate\fR command in the administration interface.
+.SS Authentication options
+.TP
 .B \-C, --client-auth \fI<file>\fR
 Enables SMTP client authentication with the remote server, using the client account details taken from the specified secrets file. The secrets file should normally contain one line that starts with \fIclient\fR and that line should have between four and five space-separated fields; the second field is the password encoding (\fIplain\fR or \fImd5\fR), the third is the user-id and the fourth is the password. The user-id is RFC-1891 xtext encoded, and the password is either xtext encoded or generated by \fIemailrelay-passwd\fR. If the remote server does not support SMTP authentication then the SMTP connection will fail.
 .TP
 .B --client-auth-config \fI<config>\fR
-Configures the SMTP client authentication module using a semicolon-separated list of configuration items. Each item is a single-character key, followed by a colon and then a comma-separated list. A 'm' character introduces an ordered list of authentication mechanisms, and an 'x' is used for blocklisted mechanisms.
+Configures the SMTP client authentication module using a semicolon-separated list of configuration items. Each item is a single-character key, followed by a colon and then a comma-separated list. A 'm' character introduces an ordered list of preferred authentication mechanisms and an 'x' introduces a list of mechanisms to avoid. An 'a' list and a 'd' list can be used similarly to prefer and avoid certain mechanisms once the session is encrypted with TLS.
 .TP
-.B \-Y, --client-filter \fI<program>\fR
-Runs the specified external filter program whenever a mail message is forwarded. The filter is passed the name of the message file in the spool directory so that it can edit it as required. A network filter can be specified as \fInet:<transport-address>\fR and prefixes of \fIspam:\fR, \fIspam-edit:\fR and \fIexit:\fR are also allowed. The \fIspam:\fR and \fIspam-edit:\fR prefixes require a SpamAssassin daemon to be running. For store-and-forward applications the \fI--filter\fR option is normally more useful than \fI--client-filter\fR.
+.B \-S, --server-auth \fI<file>\fR
+Enables SMTP server authentication of remote SMTP clients. Account names and passwords are taken from the specified secrets file. The secrets file should contain lines that have four space-separated fields, starting with \fIserver\fR in the first field; the second field is the password encoding (\fIplain\fR or \fImd5\fR), the third is the client user-id and the fourth is the password. The user-id is RFC-1891 xtext encoded, and the password is either xtext encoded or generated by \fIemailrelay-passwd\fR. A special value of \fI/pam\fR can be used for authentication using linux PAM.
 .TP
-.B \-6, --client-interface \fI<ip-address>\fR
-Specifies the IP network address to be used to bind the local end of outgoing SMTP connections. By default the address will depend on the routing tables in the normal way. Use \fI0.0.0.0\fR to use only IPv4 addresses returned from DNS lookups of the \fI--forward-to\fR address, or \fI::\fR for IPv6.
+.B --server-auth-config \fI<config>\fR
+Configures the SMTP server authentication module using a semicolon-separated list of configuration items. Each item is a single-character key, followed by a colon and then a comma-separated list. A 'm' character introduces an ordered list of allowed authentication mechanisms and an 'x' introduces a list of mechanisms to deny. An 'a' list and a 'd' list can be used similarly to allow and deny mechanisms once the session is encrypted with TLS. In typical usage you might have an empty allow list for an unencrypted session and a single preferred mechanism once encrypted, \fIm:;a:plain\fR.
+.TP
+.B \-F, --pop-auth \fI<file>\fR
+Specifies a file containing valid POP account details. The file format is the same as for the SMTP server secrets file, ie. lines starting with \fIserver\fR, with user-id and password in the third and fourth fields. A special value of \fI/pam\fR can be used for authentication using linux PAM.
+.SS TLS options
 .TP
 .B \-j, --client-tls
 Enables negotiated TLS for outgoing SMTP connections; the SMTP STARTTLS command will be issued if the remote server supports it.
@@ -106,120 +197,6 @@ Enables verification of the remote SMTP server's certificate against any of the
 .B --client-tls-verify-name \fI<cname>\fR
 Enables verification of the CNAME within the remote SMTP server's certificate.
 .TP
-.B \-e, --close-stderr
-Causes the standard error stream to be closed soon after start-up. This is useful when operating as a background daemon and it is therefore implied by \fI--as-server\fR and \fI--as-proxy\fR.
-.TP
-.B \-U, --connection-timeout \fI<time>\fR
-Specifies a timeout (in seconds) for establishing a TCP connection to remote SMTP servers. The default is 40 seconds.
-.TP
-.B \-g, --debug
-Enables debug level logging, if built in. Debug messages are usually only useful when cross-referenced with the source code and they may expose plaintext passwords and mail message content.
-.TP
-.B --dnsbl \fI<config>\fR
-Specifies a list of DNSBL servers that are used to reject SMTP connections from blocked addresses. The configuration string is made up of comma-separated fields: the DNS server's transport address, a timeout in milliseconds, a rejection threshold, and then the list of DNSBL servers.
-.TP
-.B \-D, --domain \fI<fqdn>\fR
-Specifies the network name that is used in SMTP EHLO commands, \fIReceived\fR lines, and for generating authentication challenges. The default is derived from a DNS lookup of the local hostname.
-.TP
-.B \-x, --dont-serve
-Disables all network serving, including SMTP, POP and administration interfaces. The program will terminate as soon as any initial forwarding is complete.
-.TP
-.B \-z, --filter \fI<program>\fR
-Runs the specified external filter program whenever a mail message is stored. The filter is passed the name of the message file in the spool directory so that it can edit it as required. The mail message is rejected if the filter program terminates with an exit code between 1 and 99. Use \fInet:<transport-address>\fR to communicate with a filter daemon over the network, or \fIspam:<transport-address>\fR for a spamassassin spamd daemon to accept or reject mail messages, or \fIspam-edit:<transport-address>\fR to have spamassassin edit the message content without rejecting it, or \fIexit:<number>\fR to emulate a filter program that just exits.
-.TP
-.B \-W, --filter-timeout \fI<time>\fR
-Specifies a timeout (in seconds) for running a \fI--filter\fR program. The default is 300 seconds.
-.TP
-.B \-f, --forward
-Causes spooled mail messages to be forwarded when the program first starts.
-.TP
-.B \-1, --forward-on-disconnect
-Causes spooled mail messages to be forwarded whenever a SMTP client connection disconnects.
-.TP
-.B \-o, --forward-to \fI<host:port>\fR
-Specifies the transport address of the remote SMTP server that is use for mail message forwarding.
-.TP
-.B --forward-to-some
-Allow forwarding to continue even if some recipient addresses on an e-mail envelope are rejected by the remote server.
-.TP
-.B \-h, --help
-Displays help text and then exits. Use with \fI--verbose\fR for more complete output.
-.TP
-.B \-H, --hidden
-Windows only. Hides the application window and disables all message boxes, overriding any \fI--show\fR option. This is useful when running as a windows service.
-.TP
-.B --idle-timeout \fI<time>\fR
-Specifies a timeout (in seconds) for receiving network traffic from remote SMTP and POP clients. The default is 1800 seconds.
-.TP
-.B \-m, --immediate
-Causes mail messages to be forwarded as they are received, even before they have been accepted. This can be used to do proxying without store-and-forward, but in practice clients tend to to time out while waiting for their mail message to be accepted.
-.TP
-.B \-I, --interface \fI<ip-address-list>\fR
-Specifies the IP network addresses or interface names used to bind listening ports. By default listening ports for incoming SMTP, POP and administration connections will bind the 'any' address for IPv4 and for IPv6, ie. \fI0.0.0.0\fR and \fI::\fR. Multiple addresses can be specified by using the option more than once or by using a comma-separated list. Use a prefix of \fIsmtp=\fR, \fIpop=\fR or \fIadmin=\fR on addresses that should apply only to those types of listening port. Any link-local IPv6 addresses must include a zone name or scope id.  Interface names can be used instead of addresses, in which case all the addresses associated with that interface at startup will used for listening. When an interface name is decorated with a \fI-ipv4\fR or \fI-ipv6\fR suffix only their IPv4 or IPv6 addresses will be used (eg. \fIppp0-ipv4\fR).
-.TP
-.B --localedir \fI<dir>\fR
-Enables localisation and specifies the locale base directory where message catalogues can be found. An empty directory can be used for the built-in default.
-.TP
-.B \-l, --log
-Enables logging to the standard error stream and to the syslog. The \fI--close-stderr\fR and \fI--no-syslog\fR options can be used to disable output to standard error stream and the syslog separately. Note that \fI--as-server\fR, \fI--as-client\fR and \fI--as-proxy\fR imply \fI--log\fR, and \fI--as-server\fR and \fI--as-proxy\fR also imply \fI--close-stderr\fR.
-.TP
-.B --log-address
-Adds the network address of remote clients to the logging output.
-.TP
-.B \-N, --log-file \fI<file>\fR
-Redirects standard-error logging to the specified file. Logging to the log file is not affected by \fI--close-stderr\fR. The filename can include \fI%d\fR to get daily log files; the \fI%d\fR is replaced by the current date in the local timezone using a \fIYYYYMMDD\fR format.
-.TP
-.B \-L, --log-time
-Adds a timestamp to the logging output using the local timezone.
-.TP
-.B \-t, --no-daemon
-Disables the normal backgrounding at startup so that the program runs in the foreground, without forking or detaching from the terminal.  On Windows this disables the system tray icon so the program uses a normal window; when the window is closed the program terminates.
-.TP
-.B \-X, --no-smtp
-Disables listening for incoming SMTP connections.
-.TP
-.B \-n, --no-syslog
-Disables logging to the syslog. Note that \fI--as-client\fR implies \fI--no-syslog\fR.
-.TP
-.B \-i, --pid-file \fI<pid-file>\fR
-Causes the process-id to be written into the specified file when the program starts up, typically after it has become a background daemon.
-.TP
-.B \-O, --poll \fI<period>\fR
-Causes forwarding of spooled mail messages to happen at regular intervals (with the time given in seconds).
-.TP
-.B \-B, --pop
-Enables the POP server listening, by default on port 110, providing access to spooled mail messages. Negotiated TLS using the POP \fISTLS\fR command will be enabled if the \fI--server-tls\fR option is also given.
-.TP
-.B \-F, --pop-auth \fI<file>\fR
-Specifies a file containing valid POP account details. The file format is the same as for the SMTP server secrets file, ie. lines starting with \fIserver\fR, with user-id and password in the third and fourth fields. A special value of \fI/pam\fR can be used for authentication using linux PAM.
-.TP
-.B \-J, --pop-by-name
-Modifies the spool directory used by the POP server to be a sub-directory with the same name as the POP authentication user-id. This allows multiple POP clients to read the spooled messages without interfering with each other, particularly when also using \fI--pop-no-delete\fR. Content files can stay in the main spool directory with only the envelope files copied into user-specific sub-directories. The \fIemailrelay-filter-copy\fR program is a convenient way of doing this when run via \fI--filter\fR.
-.TP
-.B \-G, --pop-no-delete
-Disables the POP DELE command so that the command appears to succeed but mail messages are not deleted from the spool directory.
-.TP
-.B \-E, --pop-port \fI<port>\fR
-Sets the POP server's listening port number.
-.TP
-.B \-p, --port \fI<port>\fR
-Sets the port number used for listening for incoming SMTP connections.
-.TP
-.B \-w, --prompt-timeout \fI<time>\fR
-Specifies a timeout (in seconds) for getting the initial prompt from a remote SMTP server. If no prompt is received after this time then the SMTP dialog goes ahead without it.
-.TP
-.B \-r, --remote-clients
-Allows incoming connections from addresses that are not local. The default behaviour is to reject connections that are not local in order to prevent accidental exposure to the public internet, although a firewall should also be used. Local address ranges are defined in RFC-1918, RFC-6890 etc.
-.TP
-.B \-T, --response-timeout \fI<time>\fR
-Specifies a timeout (in seconds) for getting responses from remote SMTP servers. The default is 1800 seconds.
-.TP
-.B \-S, --server-auth \fI<file>\fR
-Enables SMTP server authentication of remote SMTP clients. Account names and passwords are taken from the specified secrets file. The secrets file should contain lines that have four space-separated fields, starting with \fIserver\fR in the first field; the second field is the password encoding (\fIplain\fR or \fImd5\fR), the third is the client user-id and the fourth is the password. The user-id is RFC-1891 xtext encoded, and the password is either xtext encoded or generated by \fIemailrelay-passwd\fR. A special value of \fI/pam\fR can be used for authentication using linux PAM.
-.TP
-.B --server-auth-config \fI<config>\fR
-Configures the SMTP server authentication module using a semicolon-separated list of configuration items. Each item is a single-character key, followed by a colon and then a comma-separated list. A 'm' character introduces a preferred sub-set of the built-in authentication mechanisms, and an 'x' is used for blocklisted mechanisms.
-.TP
 .B \-K, --server-tls
 Enables TLS for incoming SMTP and POP connections. SMTP clients can then request TLS encryption by issuing the STARTTLS command. The \fI--server-tls-certificate\fR option must be used to define the server certificate.
 .TP
@@ -235,26 +212,58 @@ Makes the use of TLS mandatory for any incoming SMTP and POP connections. SMTP c
 .B --server-tls-verify \fI<ca-list>\fR
 Enables verification of remote SMTP and POP clients' certificates against any of the trusted CA certificates in the specified file or directory. In many use cases this should be a file containing just your self-signed root certificate. Specify \fI<default>\fR for the TLS library's default set of trusted CAs.
 .TP
-.B \-M, --size \fI<bytes>\fR
-Limits the size of mail messages that can be submitted over SMTP.
-.TP
-.B \-s, --spool-dir \fI<dir>\fR
-Specifies the directory used for holding mail messages that have been received but not yet forwarded.
-.TP
-.B \-k, --syslog, --syslog=\fI<facility>\fR
-When used with \fI--log\fR this option enables logging to the syslog even if the \fI--no-syslog\fR option is also used. This is typically used as a convenient override when using \fI--as-client\fR.
-.TP
 .B \-9, --tls-config \fI<options>\fR
 Selects and configures the low-level TLS library, using a comma-separated list of keywords. If OpenSSL and mbedTLS are both built in then keywords of \fIopenssl\fR and \fImbedtls\fR will select one or the other. Keywords like \fItlsv1.0\fR can be used to set a minimum TLS protocol version, or \fI-tlsv1.2\fR to set a maximum version.
+.SS Process options
+.TP
+.B \-x, --dont-serve
+Disables all network serving, including SMTP, POP and administration interfaces. The program will terminate as soon as any initial forwarding is complete.
+.TP
+.B \-H, --hidden
+Windows only. Hides the application window and disables all message boxes, overriding any \fI--show\fR option. This is useful when running as a windows service.
+.TP
+.B --localedir \fI<dir>\fR
+Enables localisation and specifies the locale base directory where message catalogues can be found. An empty directory can be used for the built-in default.
+.TP
+.B \-t, --no-daemon
+Disables the normal backgrounding at startup so that the program runs in the foreground, without forking or detaching from the terminal.  On Windows this disables the system tray icon so the program uses a normal window; when the window is closed the program terminates.
+.TP
+.B \-X, --no-smtp
+Disables listening for incoming SMTP connections.
+.TP
+.B \-i, --pid-file \fI<path>\fR
+Causes the process-id to be written into the specified file when the program starts up, typically after it has become a background daemon. The immediate parent directory is created if necessary.
 .TP
 .B \-u, --user \fI<username>\fR
-When started as root the program switches to a non-privileged effective user-id when idle. This option can be used to define the idle user-id and also the group ownership of new files and sockets. Specify \fIroot\fR to  disable all user-id switching. Ignored on Windows.
+When started as root the program switches to a non-privileged effective user-id when idle. This option can be used to define the idle user-id and also the group ownership of new files and sockets. Specify \fIroot\fR to disable all user-id switching. Ignored on Windows.
+.SS Logging options
 .TP
 .B \-v, --verbose
 Enables more verbose logging when used with \fI--log\fR, and more verbose help when used with \fI--help\fR.
 .TP
-.B \-V, --version
-Displays version information and then exits.
+.B \-l, --log
+Enables logging to the standard error stream and to the syslog. The \fI--close-stderr\fR and \fI--no-syslog\fR options can be used to disable output to standard error stream and the syslog separately. Note that \fI--as-server\fR, \fI--as-client\fR and \fI--as-proxy\fR imply \fI--log\fR, and \fI--as-server\fR and \fI--as-proxy\fR also imply \fI--close-stderr\fR.
+.TP
+.B \-g, --debug
+Enables debug level logging, if built in. Debug messages are usually only useful when cross-referenced with the source code and they may expose plaintext passwords and mail message content.
+.TP
+.B --log-address
+Adds the network address of remote clients to the logging output.
+.TP
+.B \-N, --log-file \fI<file>\fR
+Redirects standard-error logging to the specified file. Logging to the log file is not affected by \fI--close-stderr\fR. The filename can include \fI%d\fR to get daily log files; the \fI%d\fR is replaced by the current date in the local timezone using a \fIYYYYMMDD\fR format.
+.TP
+.B \-L, --log-time
+Adds a timestamp to the logging output using the local timezone.
+.TP
+.B \-n, --no-syslog
+Disables logging to the syslog. Note that \fI--as-client\fR implies \fI--no-syslog\fR.
+.TP
+.B \-k, --syslog, --syslog=\fI<facility>\fR
+When used with \fI--log\fR this option enables logging to the syslog even if the \fI--no-syslog\fR option is also used. This is typically used as a convenient override when using \fI--as-client\fR.
+.TP
+.B \-e, --close-stderr
+Causes the standard error stream to be closed soon after start-up. This is useful when operating as a background daemon and it is therefore implied by \fI--as-server\fR and \fI--as-proxy\fR.
 .SH SEE ALSO
 .BR emailrelay-submit (1),
 .BR emailrelay-passwd (1),
diff --git a/doc/emailrelay.css b/doc/emailrelay.css
index abb354b..d4350f8 100644
--- a/doc/emailrelay.css
+++ b/doc/emailrelay.css
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+  Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 */
 
 /*
@@ -26,6 +26,12 @@ h2
 	color: #09c ;
 }
 
+h3
+{
+	font-size: smaller ;
+	color: #09c ;
+}
+
 div.div-main
 {
 	margin-left: 10% ;
diff --git a/doc/forwardto.png b/doc/forwardto.png
index 00a36f2..da6265e 100644
Binary files a/doc/forwardto.png and b/doc/forwardto.png differ
diff --git a/doc/forwardto.svg b/doc/forwardto.svg
index 308041f..4281755 100644
--- a/doc/forwardto.svg
+++ b/doc/forwardto.svg
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <!-- Created with Inkscape (http://www.inkscape.org/) -->
-<!-- Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
+<!-- Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
 
 <svg
    xmlns:dc="http://purl.org/dc/elements/1.1/"
diff --git a/doc/index.html b/doc/index.html
index 7ae4a97..abefc6d 100644
--- a/doc/index.html
+++ b/doc/index.html
@@ -1,4 +1,4 @@
-<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
+<!DOCTYPE html>
 <html>
  <head>
   <title>E-MailRelay index</title>
@@ -20,4 +20,4 @@
    </div>
  </body>
 </html>
-<!-- Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
+<!-- Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
diff --git a/doc/make-website b/doc/make-website
index 509f4a4..cd92584 100755
--- a/doc/make-website
+++ b/doc/make-website
@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -175,11 +175,11 @@ sub make_mainpage_md
 		my $line_number = 0 ;
 		while( $line_number < $lines )
 		{
-			my $line = @lines[$line_number++] ;
-			my $next_line = @lines[$line_number] ;
+			my $line = $lines[$line_number++] ;
+			my $next_line = $lines[$line_number] ;
 			if( $next_line =~ m/^=====+$/ )
 			{
-				@lines[$line_number] = undef ;
+				$lines[$line_number] = undef ;
 				$line =~ s/E-MailRelay // ;
 				( my $id = basename($fname) . "_$line" ) =~ s/[- '?.]/_/g ;
 				print $fh "\\section $id $line\n" ;
@@ -191,14 +191,14 @@ sub make_mainpage_md
 			}
 			elsif( $next_line =~ m/^-----+$/ )
 			{
-				@lines[$line_number] = undef ;
+				$lines[$line_number] = undef ;
 				$line =~ s/^E-MailRelay // ;
 				( my $id = basename($fname) . "_$line" ) =~ s/[- '?.]/_/g ;
 				print $fh "\\subsection $id $line\n" ;
 			}
 			elsif( $line =~ m/^______+$/ )
 			{
-				@lines[$line_number] = undef ; # no footer text
+				$lines[$line_number] = undef ; # no footer text
 			}
 			elsif( defined($line) )
 			{
@@ -262,15 +262,15 @@ sub make_pages_md
 		my $line_number = 0 ;
 		while( $line_number < $lines )
 		{
-			my $line = @lines[$line_number++] ;
-			my $next_line = @lines[$line_number] ;
+			my $line = $lines[$line_number++] ;
+			my $next_line = $lines[$line_number] ;
 			if( $next_line =~ m/^=====+$/ )
 			{
-				@lines[$line_number] = undef ;
+				$lines[$line_number] = undef ;
 			}
 			elsif( $next_line =~ m/^---+$/ )
 			{
-				@lines[$line_number] = undef ;
+				$lines[$line_number] = undef ;
 				( my $id = "changelog_$line" ) =~ s/[- '?.>]/_/g ;
 				print $fh_out "\\section $id $line\n" ;
 			}
diff --git a/doc/man2html-missing.html b/doc/man2html-missing.html
index e768508..df9fcad 100644
--- a/doc/man2html-missing.html
+++ b/doc/man2html-missing.html
@@ -1,4 +1,4 @@
-<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
+<!DOCTYPE html>
 <html>
  <head>
   <title>E-MailRelay man page unavailable</title>
@@ -12,4 +12,4 @@
   </div>
  </body>
 </html>
-<!-- Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
+<!-- Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
diff --git a/doc/readme.html b/doc/readme.html
index 0022786..46708bc 100644
--- a/doc/readme.html
+++ b/doc/readme.html
@@ -1,4 +1,4 @@
-<!DOCTYPE HTML PUBLIC "%-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
+<!DOCTYPE html>
 <html>
  <head>
   <title>E-MailRelay Readme</title>
@@ -8,7 +8,7 @@
  <body>
   <!-- index:0::::E-MailRelay Readme -->
  <div class="div-main">
-  <h1><a class="a-header" name="H_1">E-MailRelay Readme</a></h1> <!-- index:1:H:1::E-MailRelay Readme -->
+  <h1><a class="a-header" name="H_1">E-MailRelay Readme</a></h1> <!-- index:1:H:E-MailRelay Readme -->
    <h2><a class="a-header" name="SH_1_1">Abstract</a></h2> <!-- index:2:SH:1:1:Abstract -->
     <p>
      E-MailRelay is an e-mail store-and-forward message transfer agent and proxy
@@ -132,7 +132,43 @@
       <div class="div-pre">
        <pre>emailrelay --help --verbose</pre>
       </div><!-- div-pre -->
-   <h2><a class="a-header" name="SH_1_3">Documentation</a></h2> <!-- index:2:SH:1:3:Documentation -->
+   <h2><a class="a-header" name="SH_1_3">Packages</a></h2> <!-- index:2:SH:1:3:Packages -->
+    <p>
+     To install on Linux from a RPM or DEB package:
+    </p>
+
+      <div class="div-pre">
+       <pre>sudo $SHELL # or 'su'
+rpm -i emailrelay*.rpm  # if RPM
+dpkg -i emailrelay*.deb  # if DEB
+</pre>
+      </div><!-- div-pre -->
+    <p>
+     If your Linux system uses <em>systemd</em> then you should check the E-MailRelay
+     configuration file <em>/etc/emailrelay.conf</em> is as you want it and then run:
+    </p>
+
+      <div class="div-pre">
+       <pre>systemctl enable emailrelay
+systemctl start emailrelay
+systemctl status emailrelay
+</pre>
+      </div><!-- div-pre -->
+    <p>
+     On other systems try these commands:
+    </p>
+
+      <div class="div-pre">
+       <pre>cp /usr/lib/emailrelay/init/emailrelay /etc/init.d/
+update-rc.d emailrelay enable || rc-update add emailrelay
+invoke-rc.d emailrelay start || service emailrelay start
+tail /var/log/messages /var/log/syslog 2&gt;/dev/null
+</pre>
+      </div><!-- div-pre -->
+    <p>
+     On Windows run the setup program.
+    </p>
+   <h2><a class="a-header" name="SH_1_4">Documentation</a></h2> <!-- index:2:SH:1:4:Documentation -->
     <p>
      The following documentation is provided:
     </p>
@@ -150,12 +186,8 @@
      Source code documentation will be generated when building from source if
      <em>doxygen</em> is available.
     </p>
-   <h2><a class="a-header" name="SH_1_4">Feedback</a></h2> <!-- index:2:SH:1:4:Feedback -->
-    <p>
-     Please feel free to e-mail the author at <em>mailto:graeme_walker@users.sourceforge.net</em>.
-    </p>
 
  </div> <!-- div-main -->
  </body>
 </html>
-<!-- Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
+<!-- Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
diff --git a/doc/readme.md b/doc/readme.md
index 2016da9..1ba0df7 100644
--- a/doc/readme.md
+++ b/doc/readme.md
@@ -79,6 +79,30 @@ or run:
 
         emailrelay --help --verbose
 
+Packages
+--------
+To install on Linux from a RPM or DEB package:
+
+        sudo $SHELL # or 'su'
+        rpm -i emailrelay*.rpm  # if RPM
+        dpkg -i emailrelay*.deb  # if DEB
+
+If your Linux system uses `systemd` then you should check the E-MailRelay
+configuration file `/etc/emailrelay.conf` is as you want it and then run:
+
+        systemctl enable emailrelay
+        systemctl start emailrelay
+        systemctl status emailrelay
+
+On other systems try these commands:
+
+        cp /usr/lib/emailrelay/init/emailrelay /etc/init.d/
+        update-rc.d emailrelay enable || rc-update add emailrelay
+        invoke-rc.d emailrelay start || service emailrelay start
+        tail /var/log/messages /var/log/syslog 2>/dev/null
+
+On Windows run the setup program.
+
 Documentation
 -------------
 The following documentation is provided:
@@ -94,10 +118,6 @@ The following documentation is provided:
 Source code documentation will be generated when building from source if
 `doxygen` is available.
 
-Feedback
---------
-Please feel free to e-mail the author at `mailto:graeme_walker@users.sourceforge.net`.
-
 
 [POP]: https://en.wikipedia.org/wiki/Post_Office_Protocol
 [SMTP]: https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol
diff --git a/doc/readme.rst b/doc/readme.rst
index 052000f..7ae89f7 100644
--- a/doc/readme.rst
+++ b/doc/readme.rst
@@ -100,6 +100,36 @@ or run:
 
     emailrelay --help --verbose
 
+Packages
+========
+To install on Linux from a RPM or DEB package:
+
+::
+
+    sudo $SHELL # or 'su'
+    rpm -i emailrelay*.rpm  # if RPM
+    dpkg -i emailrelay*.deb  # if DEB
+
+If your Linux system uses *systemd* then you should check the E-MailRelay
+configuration file */etc/emailrelay.conf* is as you want it and then run:
+
+::
+
+    systemctl enable emailrelay
+    systemctl start emailrelay
+    systemctl status emailrelay
+
+On other systems try these commands:
+
+::
+
+    cp /usr/lib/emailrelay/init/emailrelay /etc/init.d/
+    update-rc.d emailrelay enable || rc-update add emailrelay
+    invoke-rc.d emailrelay start || service emailrelay start
+    tail /var/log/messages /var/log/syslog 2>/dev/null
+
+On Windows run the setup program.
+
 Documentation
 =============
 The following documentation is provided:
@@ -115,10 +145,6 @@ The following documentation is provided:
 Source code documentation will be generated when building from source if
 *doxygen* is available.
 
-Feedback
-========
-Please feel free to e-mail the author at *mailto:graeme_walker@users.sourceforge.net*.
-
 
 .. _POP: https://en.wikipedia.org/wiki/Post_Office_Protocol
 .. _SMTP: https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol
diff --git a/doc/readme.txt b/doc/readme.txt
index 4dd9a75..03c048a 100644
--- a/doc/readme.txt
+++ b/doc/readme.txt
@@ -73,6 +73,30 @@ or run:
 
 	emailrelay --help --verbose
 
+Packages
+--------
+To install on Linux from a RPM or DEB package:
+
+	sudo $SHELL # or 'su'
+	rpm -i emailrelay*.rpm  # if RPM
+	dpkg -i emailrelay*.deb  # if DEB
+
+If your Linux system uses "systemd" then you should check the E-MailRelay
+configuration file "/etc/emailrelay.conf" is as you want it and then run:
+
+	systemctl enable emailrelay
+	systemctl start emailrelay
+	systemctl status emailrelay
+
+On other systems try these commands:
+
+	cp /usr/lib/emailrelay/init/emailrelay /etc/init.d/
+	update-rc.d emailrelay enable || rc-update add emailrelay
+	invoke-rc.d emailrelay start || service emailrelay start
+	tail /var/log/messages /var/log/syslog 2>/dev/null
+
+On Windows run the setup program.
+
 Documentation
 -------------
 The following documentation is provided:
@@ -87,7 +111,3 @@ The following documentation is provided:
 Source code documentation will be generated when building from source if
 "doxygen" is available.
 
-Feedback
---------
-Please feel free to e-mail the author at "mailto:graeme_walker@users.sourceforge.net".
-
diff --git a/doc/reference.html b/doc/reference.html
index 3fd5136..cfc3724 100644
--- a/doc/reference.html
+++ b/doc/reference.html
@@ -15,36 +15,10 @@
     </p>
 
       <div class="div-pre">
-       <pre>emailrelay [&lt;option&gt; [&lt;option&gt; ...]] [&lt;config-file&gt;]
-</pre>
+       <pre>emailrelay [&lt;option&gt; [&lt;option&gt; ...]] [&lt;config-file&gt;]</pre>
       </div><!-- div-pre -->
-    <p>
-     where &lt;option&gt; is:
-    </p>
-
+   <h3><a class="a-header">Basic options</a></h3>
     <dl>
-     <dt>--address-verifier &lt;program&gt;</dt>
-      <dd>
-       Runs the specified external program to verify a message recipent's e-mail
-       address. A network verifier can be specified as <em>net:<transport-address></em>.
-      </dd>
-     <dt>--admin &lt;admin-port&gt; (-a)</dt>
-      <dd>
-       Enables an administration interface on the specified listening port number.
-       Use telnet or something similar to connect. The administration interface
-       can be used to trigger forwarding of spooled mail messages if the
-       <em>--forward-to</em> option is used.
-      </dd>
-     <dt>--admin-terminate (-Q)</dt>
-      <dd>
-       Enables the <em>terminate</em> command in the administration interface.
-      </dd>
-     <dt>--anonymous (-A)</dt>
-      <dd>
-       Disables the server's SMTP VRFY command, sends less verbose SMTP responses
-       and SMTP greeting, and stops <em>Received</em> lines being added to mail message
-       content files.
-      </dd>
      <dt>--as-client &lt;host:port&gt; (-q)</dt>
       <dd>
        This is equivalent to <em>--log</em>, <em>--no-syslog</em>, <em>--no-daemon</em>, <em>--dont-serve</em>,
@@ -65,6 +39,215 @@
        them. Use <em>--log</em> instead of <em>--as-server</em> to keep standard error stream
        open.
       </dd>
+     <dt>--spool-dir &lt;dir&gt; (-s)</dt>
+      <dd>
+       Specifies the directory used for holding mail messages that have been
+       received but not yet forwarded.
+      </dd>
+     <dt>--help (-h)</dt>
+      <dd>
+       Displays help text and then exits. Use with <em>--verbose</em> for more complete
+       output.
+      </dd>
+     <dt>--version (-V)</dt>
+      <dd>
+       Displays version information and then exits.
+      </dd>
+    </dl>
+   <h3><a class="a-header">SMTP client options</a></h3>
+    <dl>
+     <dt>--forward (-f)</dt>
+      <dd>
+       Causes spooled mail messages to be forwarded when the program first starts.
+      </dd>
+     <dt>--forward-on-disconnect (-1)</dt>
+      <dd>
+       Causes spooled mail messages to be forwarded whenever a SMTP client
+       connection disconnects.
+      </dd>
+     <dt>--forward-to &lt;host:port&gt; (-o)</dt>
+      <dd>
+       Specifies the transport address of the remote SMTP server that spooled mail
+       messages are forwarded to.
+      </dd>
+     <dt>--poll &lt;period&gt; (-O)</dt>
+      <dd>
+       Causes forwarding of spooled mail messages to happen at regular intervals
+       (with the time given in seconds).
+      </dd>
+     <dt>--client-filter &lt;program&gt; (-Y)</dt>
+      <dd>
+       Runs the specified external filter program whenever a mail message is
+       forwarded. The filter is passed the name of the message file in the spool
+       directory so that it can edit it as required. A network filter can be
+       specified as <em>net:<tcp-address></em> and prefixes of <em>spam:</em>, <em>spam-edit:</em> and
+       <em>exit:</em> are also allowed. The <em>spam:</em> and <em>spam-edit:</em> prefixes require a
+       SpamAssassin daemon to be running. For store-and-forward applications the
+       <em>--filter</em> option is normally more useful than <em>--client-filter</em>.
+      </dd>
+     <dt>--client-interface &lt;ip-address&gt; (-6)</dt>
+      <dd>
+       Specifies the IP network address to be used to bind the local end of outgoing
+       SMTP connections. By default the address will depend on the routing tables
+       in the normal way. Use <em>0.0.0.0</em> to use only IPv4 addresses returned from
+       DNS lookups of the <em>--forward-to</em> address, or <em>::</em> for IPv6.
+      </dd>
+     <dt>--connection-timeout &lt;time&gt; (-U)</dt>
+      <dd>
+       Specifies a timeout (in seconds) for establishing a TCP connection to remote
+       SMTP servers. The default is 40 seconds.
+      </dd>
+     <dt>--idle-timeout &lt;time&gt;</dt>
+      <dd>
+       Specifies a timeout (in seconds) for receiving network traffic from remote
+       SMTP and POP clients. The default is 60 seconds.
+      </dd>
+     <dt>--response-timeout &lt;time&gt; (-T)</dt>
+      <dd>
+       Specifies a timeout (in seconds) for getting responses from remote SMTP
+       servers. The default is 60 seconds.
+      </dd>
+     <dt>--forward-to-some</dt>
+      <dd>
+       Allow forwarding to continue even if some recipient addresses on an e-mail
+       envelope are rejected by the remote server.
+      </dd>
+     <dt>--immediate (-m)</dt>
+      <dd>
+       Causes mail messages to be forwarded as they are received, even before they
+       have been accepted. This can be used to do proxying without
+       store-and-forward, but in practice clients tend to to time out while
+       waiting for their mail message to be accepted.
+      </dd>
+    </dl>
+   <h3><a class="a-header">SMTP server options</a></h3>
+    <dl>
+     <dt>--port &lt;port&gt; (-p)</dt>
+      <dd>
+       Sets the port number used for listening for incoming SMTP connections.
+      </dd>
+     <dt>--remote-clients (-r)</dt>
+      <dd>
+       Allows incoming connections from addresses that are not local. The default
+       behaviour is to reject connections that are not local in order to prevent
+       accidental exposure to the public internet, although a firewall should also
+       be used. Local address ranges are defined in RFC-1918, RFC-6890 etc.
+      </dd>
+     <dt>--address-verifier &lt;program&gt;</dt>
+      <dd>
+       Runs the specified external program to verify a message recipent's e-mail
+       address. A network verifier can be specified as <em>net:<tcp-address></em>.
+      </dd>
+     <dt>--anonymous[=&lt;scope&gt;] (-A)</dt>
+      <dd>
+       Disables the server's SMTP VRFY command, sends less verbose SMTP greeting and
+       responses, stops <em>Received</em> lines being added to mail message content
+       files, and stops the SMTP client protocol adding <em>AUTH=</em> to the <em>MAIL</em>
+       command. For finer control use a comma-separated list of things to
+       anonymise: <em>vrfy</em>, <em>server</em>, <em>content</em> and/or <em>client</em>, eg.
+       <em>--anonymous</em>=server,content.
+      </dd>
+     <dt>--dnsbl &lt;config&gt;</dt>
+      <dd>
+       Specifies a list of DNSBL servers that are used to reject SMTP connections
+       from blocked addresses. The configuration string is made up of
+       comma-separated fields: the DNS server's transport address, a timeout in
+       milliseconds, a rejection threshold, and then the list of DNSBL servers.
+      </dd>
+     <dt>--domain &lt;fqdn&gt; (-D)</dt>
+      <dd>
+       Specifies the network name that is used in SMTP EHLO commands, <em>Received</em>
+       lines, and for generating authentication challenges. The default is derived
+       from a DNS lookup of the local hostname.
+      </dd>
+     <dt>--filter &lt;program&gt; (-z)</dt>
+      <dd>
+       Runs the specified external filter program whenever a mail message is stored.
+       The filter is passed the name of the message file in the spool directory so
+       that it can edit it as required. The mail message is rejected if the filter
+       program terminates with an exit code between 1 and 99. Use
+       <em>net:<tcp-address></em> to communicate with a filter daemon over the network,
+       or <em>spam:<tcp-address></em> for a spamassassin spamd daemon to accept or reject
+       mail messages, or <em>spam-edit:<tcp-address></em> to have spamassassin edit the
+       message content without rejecting it, or <em>exit:<number></em> to emulate a
+       filter program that just exits.
+      </dd>
+     <dt>--filter-timeout &lt;time&gt; (-W)</dt>
+      <dd>
+       Specifies a timeout (in seconds) for running a <em>--filter</em> program. The
+       default is 60 seconds.
+      </dd>
+     <dt>--interface &lt;ip-address-list&gt; (-I)</dt>
+      <dd>
+       Specifies the IP network addresses or interface names used to bind listening
+       ports. By default listening ports for incoming SMTP, POP and administration
+       connections will bind the 'any' address for IPv4 and for IPv6, ie.
+       <em>0.0.0.0</em> and <em>::</em>. Multiple addresses can be specified by using the option
+       more than once or by using a comma-separated list. Use a prefix of <em>smtp=</em>,
+       <em>pop=</em> or <em>admin=</em> on addresses that should apply only to those types of
+       listening port. Any link-local IPv6 addresses must include a zone name or
+       scope id.  Interface names can be used instead of addresses, in which case
+       all the addresses associated with that interface at startup will used for
+       listening. When an interface name is decorated with a <em>-ipv4</em> or <em>-ipv6</em>
+       suffix only their IPv4 or IPv6 addresses will be used (eg. <em>ppp0-ipv4</em>).
+       To inherit listening file descriptors from the parent process on unix use a
+       syntax like this: <em>--interface</em>=smtp=fd#3,smtp=fd#4,pop=fd#5.
+      </dd>
+     <dt>--prompt-timeout &lt;time&gt; (-w)</dt>
+      <dd>
+       Specifies a timeout (in seconds) for getting the initial prompt from a remote
+       SMTP server. If no prompt is received after this time then the SMTP dialog
+       goes ahead without it.
+      </dd>
+     <dt>--size &lt;bytes&gt; (-M)</dt>
+      <dd>
+       Limits the size of mail messages that can be submitted over SMTP.
+      </dd>
+    </dl>
+   <h3><a class="a-header">POP server options</a></h3>
+    <dl>
+     <dt>--pop (-B)</dt>
+      <dd>
+       Enables the POP server, listening by default on port 110, providing access to
+       spooled mail messages. Negotiated TLS using the POP <em>STLS</em> command will be
+       enabled if the <em>--server-tls</em> option is also given.
+      </dd>
+     <dt>--pop-by-name (-J)</dt>
+      <dd>
+       Modifies the spool directory used by the POP server to be a sub-directory
+       with the same name as the POP authentication user-id. This allows multiple
+       POP clients to read the spooled mail messages without interfering with each
+       other, particularly when also using <em>--pop-no-delete</em>. Content files can
+       stay in the main spool directory with only the envelope files copied into
+       user-specific sub-directories. The <em>emailrelay-filter-copy</em> program is a
+       convenient way of doing this when run via <em>--filter</em>.
+      </dd>
+     <dt>--pop-no-delete (-G)</dt>
+      <dd>
+       Disables the POP DELE command so that the command appears to succeed but mail
+       messages are not deleted from the spool directory.
+      </dd>
+     <dt>--pop-port &lt;port&gt; (-E)</dt>
+      <dd>
+       Sets the POP server's listening port number.
+      </dd>
+    </dl>
+   <h3><a class="a-header">Admin server options</a></h3>
+    <dl>
+     <dt>--admin &lt;port&gt; (-a)</dt>
+      <dd>
+       Enables an administration interface on the specified listening port number.
+       Use telnet or something similar to connect. The administration interface
+       can be used to trigger forwarding of spooled mail messages if the
+       <em>--forward-to</em> option is used.
+      </dd>
+     <dt>--admin-terminate (-Q)</dt>
+      <dd>
+       Enables the <em>terminate</em> command in the administration interface.
+      </dd>
+    </dl>
+   <h3><a class="a-header">Authentication options</a></h3>
+    <dl>
      <dt>--client-auth &lt;file&gt; (-C)</dt>
       <dd>
        Enables SMTP client authentication with the remote server, using the client
@@ -82,27 +265,43 @@
        Configures the SMTP client authentication module using a semicolon-separated
        list of configuration items. Each item is a single-character key, followed
        by a colon and then a comma-separated list. A 'm' character introduces an
-       ordered list of authentication mechanisms, and an 'x' is used for
-       blocklisted mechanisms.
+       ordered list of preferred authentication mechanisms and an 'x' introduces a
+       list of mechanisms to avoid. An 'a' list and a 'd' list can be used
+       similarly to prefer and avoid certain mechanisms once the session is
+       encrypted with TLS.
       </dd>
-     <dt>--client-filter &lt;program&gt; (-Y)</dt>
+     <dt>--server-auth &lt;file&gt; (-S)</dt>
       <dd>
-       Runs the specified external filter program whenever a mail message is
-       forwarded. The filter is passed the name of the message file in the spool
-       directory so that it can edit it as required. A network filter can be
-       specified as <em>net:<transport-address></em> and prefixes of <em>spam:</em>,
-       <em>spam-edit:</em> and <em>exit:</em> are also allowed. The <em>spam:</em> and <em>spam-edit:</em>
-       prefixes require a SpamAssassin daemon to be running. For store-and-forward
-       applications the <em>--filter</em> option is normally more useful than
-       <em>--client-filter</em>.
+       Enables SMTP server authentication of remote SMTP clients. Account names and
+       passwords are taken from the specified secrets file. The secrets file
+       should contain lines that have four space-separated fields, starting with
+       <em>server</em> in the first field; the second field is the password encoding
+       (<em>plain</em> or <em>md5</em>), the third is the client user-id and the fourth is the
+       password. The user-id is RFC-1891 xtext encoded, and the password is either
+       xtext encoded or generated by <em>emailrelay-passwd</em>. A special value of
+       <em>/pam</em> can be used for authentication using linux PAM.
       </dd>
-     <dt>--client-interface &lt;ip-address&gt; (-6)</dt>
+     <dt>--server-auth-config &lt;config&gt;</dt>
       <dd>
-       Specifies the IP network address to be used to bind the local end of outgoing
-       SMTP connections. By default the address will depend on the routing tables
-       in the normal way. Use <em>0.0.0.0</em> to use only IPv4 addresses returned from
-       DNS lookups of the <em>--forward-to</em> address, or <em>::</em> for IPv6.
+       Configures the SMTP server authentication module using a semicolon-separated
+       list of configuration items. Each item is a single-character key, followed
+       by a colon and then a comma-separated list. A 'm' character introduces an
+       ordered list of allowed authentication mechanisms and an 'x' introduces a
+       list of mechanisms to deny. An 'a' list and a 'd' list can be used
+       similarly to allow and deny mechanisms once the session is encrypted with
+       TLS. In typical usage you might have an empty allow list for an unencrypted
+       session and a single preferred mechanism once encrypted, <em>m:;a:plain</em>.
       </dd>
+     <dt>--pop-auth &lt;file&gt; (-F)</dt>
+      <dd>
+       Specifies a file containing valid POP account details. The file format is the
+       same as for the SMTP server secrets file, ie. lines starting with <em>server</em>,
+       with user-id and password in the third and fourth fields. A special value
+       of <em>/pam</em> can be used for authentication using linux PAM.
+      </dd>
+    </dl>
+   <h3><a class="a-header">TLS options</a></h3>
+    <dl>
      <dt>--client-tls (-j)</dt>
       <dd>
        Enables negotiated TLS for outgoing SMTP connections; the SMTP STARTTLS
@@ -112,8 +311,8 @@
       <dd>
        Defines the TLS certificate file when acting as a SMTP client. This file must
        contain the client's private key and certificate chain using the PEM file
-       format. Alternatively, use this option twice with the first one specifying 
-       the key file and the second the certificate file. Keep the file permissions 
+       format. Alternatively, use this option twice with the first one specifying
+       the key file and the second the certificate file. Keep the file permissions
        tight to avoid accidental exposure of the private key.
       </dd>
      <dt>--client-tls-connection (-b)</dt>
@@ -138,7 +337,7 @@
        Enables verification of the remote SMTP server's certificate against any of
        the trusted CA certificates in the specified file or directory. In many use
        cases this should be a file containing just your self-signed root
-       certificate. Specify <em>&lt;default&gt;</em> for the TLS library's default set of
+       certificate. Specify <em><default></em> for the TLS library's default set of
        trusted CAs.
       </dd>
      <dt>--client-tls-verify-name &lt;cname&gt;</dt>
@@ -146,243 +345,6 @@
        Enables verification of the CNAME within the remote SMTP server's
        certificate.
       </dd>
-     <dt>--close-stderr (-e)</dt>
-      <dd>
-       Causes the standard error stream to be closed soon after start-up. This is
-       useful when operating as a background daemon and it is therefore implied by
-       <em>--as-server</em> and <em>--as-proxy</em>.
-      </dd>
-     <dt>--connection-timeout &lt;time&gt; (-U)</dt>
-      <dd>
-       Specifies a timeout (in seconds) for establishing a TCP connection to remote
-       SMTP servers. The default is 40 seconds.
-      </dd>
-     <dt>--debug (-g)</dt>
-      <dd>
-       Enables debug level logging, if built in. Debug messages are usually only
-       useful when cross-referenced with the source code and they may expose
-       plaintext passwords and mail message content.
-      </dd>
-     <dt>--dnsbl &lt;config&gt;</dt>
-      <dd>
-       Specifies a list of DNSBL servers that are used to reject SMTP connections
-       from blocked addresses. The configuration string is made up of
-       comma-separated fields: the DNS server's transport address, a timeout in
-       milliseconds, a rejection threshold, and then the list of DNSBL servers.
-      </dd>
-     <dt>--domain &lt;fqdn&gt; (-D)</dt>
-      <dd>
-       Specifies the network name that is used in SMTP EHLO commands, <em>Received</em>
-       lines, and for generating authentication challenges. The default is derived
-       from a DNS lookup of the local hostname.
-      </dd>
-     <dt>--dont-serve (-x)</dt>
-      <dd>
-       Disables all network serving, including SMTP, POP and administration
-       interfaces. The program will terminate as soon as any initial forwarding is
-       complete.
-      </dd>
-     <dt>--filter &lt;program&gt; (-z)</dt>
-      <dd>
-       Runs the specified external filter program whenever a mail message is stored.
-       The filter is passed the name of the message file in the spool directory so
-       that it can edit it as required. The mail message is rejected if the filter
-       program terminates with an exit code between 1 and 99. Use
-       <em>net:<transport-address></em> to communicate with a filter daemon over the
-       network, or <em>spam:<transport-address></em> for a spamassassin spamd daemon to
-       accept or reject mail messages, or <em>spam-edit:<transport-address></em> to have
-       spamassassin edit the message content without rejecting it, or
-       <em>exit:<number></em> to emulate a filter program that just exits.
-      </dd>
-     <dt>--filter-timeout &lt;time&gt; (-W)</dt>
-      <dd>
-       Specifies a timeout (in seconds) for running a <em>--filter</em> program. The
-       default is 300 seconds.
-      </dd>
-     <dt>--forward (-f)</dt>
-      <dd>
-       Causes spooled mail messages to be forwarded when the program first starts.
-      </dd>
-     <dt>--forward-on-disconnect (-1)</dt>
-      <dd>
-       Causes spooled mail messages to be forwarded whenever a SMTP client
-       connection disconnects.
-      </dd>
-     <dt>--forward-to &lt;host:port&gt; (-o)</dt>
-      <dd>
-       Specifies the transport address of the remote SMTP server that is use for
-       mail message forwarding.
-      </dd>
-     <dt>--forward-to-some</dt>
-      <dd>
-       Allow forwarding to continue even if some recipient addresses on an e-mail
-       envelope are rejected by the remote server.
-      </dd>
-     <dt>--help (-h)</dt>
-      <dd>
-       Displays help text and then exits. Use with <em>--verbose</em> for more complete
-       output.
-      </dd>
-     <dt>--hidden (-H)</dt>
-      <dd>
-       Windows only. Hides the application window and disables all message boxes,
-       overriding any <em>--show</em> option. This is useful when running as a windows
-       service.
-      </dd>
-     <dt>--idle-timeout &lt;time&gt;</dt>
-      <dd>
-       Specifies a timeout (in seconds) for receiving network traffic from remote
-       SMTP and POP clients. The default is 1800 seconds.
-      </dd>
-     <dt>--immediate (-m)</dt>
-      <dd>
-       Causes mail messages to be forwarded as they are received, even before they
-       have been accepted. This can be used to do proxying without
-       store-and-forward, but in practice clients tend to to time out while
-       waiting for their mail message to be accepted.
-      </dd>
-     <dt>--interface &lt;ip-address-list&gt; (-I)</dt>
-      <dd>
-       Specifies the IP network addresses or interface names used to bind listening
-       ports. By default listening ports for incoming SMTP, POP and administration
-       connections will bind the 'any' address for IPv4 and for IPv6, ie.
-       <em>0.0.0.0</em> and <em>::</em>. Multiple addresses can be specified by using the option
-       more than once or by using a comma-separated list. Use a prefix of <em>smtp=</em>,
-       <em>pop=</em> or <em>admin=</em> on addresses that should apply only to those types of
-       listening port. Any link-local IPv6 addresses must include a zone name or
-       scope id.  Interface names can be used instead of addresses, in which case
-       all the addresses associated with that interface at startup will used for
-       listening. When an interface name is decorated with a <em>-ipv4</em> or <em>-ipv6</em>
-       suffix only their IPv4 or IPv6 addresses will be used (eg. <em>ppp0-ipv4</em>).
-      </dd>
-     <dt>--localedir &lt;dir&gt;</dt>
-      <dd>
-       Enables localisation and specifies the locale base directory where message
-       catalogues can be found. An empty directory can be used for the built-in
-       default.
-      </dd>
-     <dt>--log (-l)</dt>
-      <dd>
-       Enables logging to the standard error stream and to the syslog. The
-       <em>--close-stderr</em> and <em>--no-syslog</em> options can be used to disable output to
-       standard error stream and the syslog separately. Note that <em>--as-server</em>,
-       <em>--as-client</em> and <em>--as-proxy</em> imply <em>--log</em>, and <em>--as-server</em> and
-       <em>--as-proxy</em> also imply <em>--close-stderr</em>.
-      </dd>
-     <dt>--log-address</dt>
-      <dd>
-       Adds the network address of remote clients to the logging output.
-      </dd>
-     <dt>--log-file &lt;file&gt; (-N)</dt>
-      <dd>
-       Redirects standard-error logging to the specified file. Logging to the log
-       file is not affected by <em>--close-stderr</em>. The filename can include <em>%d</em> to
-       get daily log files; the <em>%d</em> is replaced by the current date in the local
-       timezone using a <em>YYYYMMDD</em> format.
-      </dd>
-     <dt>--log-time (-L)</dt>
-      <dd>
-       Adds a timestamp to the logging output using the local timezone.
-      </dd>
-     <dt>--no-daemon (-t)</dt>
-      <dd>
-       Disables the normal backgrounding at startup so that the program runs in the
-       foreground, without forking or detaching from the terminal.  On Windows
-       this disables the system tray icon so the program uses a normal window;
-       when the window is closed the program terminates.
-      </dd>
-     <dt>--no-smtp (-X)</dt>
-      <dd>
-       Disables listening for incoming SMTP connections.
-      </dd>
-     <dt>--no-syslog (-n)</dt>
-      <dd>
-       Disables logging to the syslog. Note that <em>--as-client</em> implies
-       <em>--no-syslog</em>.
-      </dd>
-     <dt>--pid-file &lt;pid-file&gt; (-i)</dt>
-      <dd>
-       Causes the process-id to be written into the specified file when the program
-       starts up, typically after it has become a background daemon.
-      </dd>
-     <dt>--poll &lt;period&gt; (-O)</dt>
-      <dd>
-       Causes forwarding of spooled mail messages to happen at regular intervals
-       (with the time given in seconds).
-      </dd>
-     <dt>--pop (-B)</dt>
-      <dd>
-       Enables the POP server listening, by default on port 110, providing access to
-       spooled mail messages. Negotiated TLS using the POP <em>STLS</em> command will be
-       enabled if the <em>--server-tls</em> option is also given.
-      </dd>
-     <dt>--pop-auth &lt;file&gt; (-F)</dt>
-      <dd>
-       Specifies a file containing valid POP account details. The file format is the
-       same as for the SMTP server secrets file, ie. lines starting with <em>server</em>,
-       with user-id and password in the third and fourth fields. A special value
-       of <em>/pam</em> can be used for authentication using linux PAM.
-      </dd>
-     <dt>--pop-by-name (-J)</dt>
-      <dd>
-       Modifies the spool directory used by the POP server to be a sub-directory
-       with the same name as the POP authentication user-id. This allows multiple
-       POP clients to read the spooled messages without interfering with each
-       other, particularly when also using <em>--pop-no-delete</em>. Content files can
-       stay in the main spool directory with only the envelope files copied into
-       user-specific sub-directories. The <em>emailrelay-filter-copy</em> program is a
-       convenient way of doing this when run via <em>--filter</em>.
-      </dd>
-     <dt>--pop-no-delete (-G)</dt>
-      <dd>
-       Disables the POP DELE command so that the command appears to succeed but mail
-       messages are not deleted from the spool directory.
-      </dd>
-     <dt>--pop-port &lt;port&gt; (-E)</dt>
-      <dd>
-       Sets the POP server's listening port number.
-      </dd>
-     <dt>--port &lt;port&gt; (-p)</dt>
-      <dd>
-       Sets the port number used for listening for incoming SMTP connections.
-      </dd>
-     <dt>--prompt-timeout &lt;time&gt; (-w)</dt>
-      <dd>
-       Specifies a timeout (in seconds) for getting the initial prompt from a remote
-       SMTP server. If no prompt is received after this time then the SMTP dialog
-       goes ahead without it.
-      </dd>
-     <dt>--remote-clients (-r)</dt>
-      <dd>
-       Allows incoming connections from addresses that are not local. The default
-       behaviour is to reject connections that are not local in order to prevent
-       accidental exposure to the public internet, although a firewall should also
-       be used. Local address ranges are defined in RFC-1918, RFC-6890 etc.
-      </dd>
-     <dt>--response-timeout &lt;time&gt; (-T)</dt>
-      <dd>
-       Specifies a timeout (in seconds) for getting responses from remote SMTP
-       servers. The default is 1800 seconds.
-      </dd>
-     <dt>--server-auth &lt;file&gt; (-S)</dt>
-      <dd>
-       Enables SMTP server authentication of remote SMTP clients. Account names and
-       passwords are taken from the specified secrets file. The secrets file
-       should contain lines that have four space-separated fields, starting with
-       <em>server</em> in the first field; the second field is the password encoding
-       (<em>plain</em> or <em>md5</em>), the third is the client user-id and the fourth is the
-       password. The user-id is RFC-1891 xtext encoded, and the password is either
-       xtext encoded or generated by <em>emailrelay-passwd</em>. A special value of
-       <em>/pam</em> can be used for authentication using linux PAM.
-      </dd>
-     <dt>--server-auth-config &lt;config&gt;</dt>
-      <dd>
-       Configures the SMTP server authentication module using a semicolon-separated
-       list of configuration items. Each item is a single-character key, followed
-       by a colon and then a comma-separated list. A 'm' character introduces a
-       preferred sub-set of the built-in authentication mechanisms, and an 'x' is
-       used for blocklisted mechanisms.
-      </dd>
      <dt>--server-tls (-K)</dt>
       <dd>
        Enables TLS for incoming SMTP and POP connections. SMTP clients can then
@@ -394,8 +356,8 @@
       <dd>
        Defines the TLS certificate file when acting as a SMTP or POP server. This
        file must contain the server's private key and certificate chain using the
-       PEM file format. Alternatively, use this option twice with the first one 
-       specifying the key file and the second the certificate file. Keep the file 
+       PEM file format. Alternatively, use this option twice with the first one
+       specifying the key file and the second the certificate file. Keep the file
        permissions tight to avoid accidental exposure of the private key.
       </dd>
      <dt>--server-tls-connection</dt>
@@ -414,24 +376,9 @@
        Enables verification of remote SMTP and POP clients' certificates against any
        of the trusted CA certificates in the specified file or directory. In many
        use cases this should be a file containing just your self-signed root
-       certificate. Specify <em>&lt;default&gt;</em> for the TLS library's default set of
+       certificate. Specify <em><default></em> for the TLS library's default set of
        trusted CAs.
       </dd>
-     <dt>--size &lt;bytes&gt; (-M)</dt>
-      <dd>
-       Limits the size of mail messages that can be submitted over SMTP.
-      </dd>
-     <dt>--spool-dir &lt;dir&gt; (-s)</dt>
-      <dd>
-       Specifies the directory used for holding mail messages that have been
-       received but not yet forwarded.
-      </dd>
-     <dt>--syslog[=&lt;facility&gt;] (-k)</dt>
-      <dd>
-       When used with <em>--log</em> this option enables logging to the syslog even if the
-       <em>--no-syslog</em> option is also used. This is typically used as a convenient
-       override when using <em>--as-client</em>.
-      </dd>
      <dt>--tls-config &lt;options&gt; (-9)</dt>
       <dd>
        Selects and configures the low-level TLS library, using a comma-separated
@@ -440,6 +387,44 @@
        <em>tlsv1.0</em> can be used to set a minimum TLS protocol version, or <em>-tlsv1.2</em>
        to set a maximum version.
       </dd>
+    </dl>
+   <h3><a class="a-header">Process options</a></h3>
+    <dl>
+     <dt>--dont-serve (-x)</dt>
+      <dd>
+       Disables all network serving, including SMTP, POP and administration
+       interfaces. The program will terminate as soon as any initial forwarding is
+       complete.
+      </dd>
+     <dt>--hidden (-H)</dt>
+      <dd>
+       Windows only. Hides the application window and disables all message boxes,
+       overriding any <em>--show</em> option. This is useful when running as a windows
+       service.
+      </dd>
+     <dt>--localedir &lt;dir&gt;</dt>
+      <dd>
+       Enables localisation and specifies the locale base directory where message
+       catalogues can be found. An empty directory can be used for the built-in
+       default.
+      </dd>
+     <dt>--no-daemon (-t)</dt>
+      <dd>
+       Disables the normal backgrounding at startup so that the program runs in the
+       foreground, without forking or detaching from the terminal.  On Windows
+       this disables the system tray icon so the program uses a normal window;
+       when the window is closed the program terminates.
+      </dd>
+     <dt>--no-smtp (-X)</dt>
+      <dd>
+       Disables listening for incoming SMTP connections.
+      </dd>
+     <dt>--pid-file &lt;path&gt; (-i)</dt>
+      <dd>
+       Causes the process-id to be written into the specified file when the program
+       starts up, typically after it has become a background daemon. The immediate
+       parent directory is created if necessary.
+      </dd>
      <dt>--user &lt;username&gt; (-u)</dt>
       <dd>
        When started as root the program switches to a non-privileged effective
@@ -447,14 +432,59 @@
        also the group ownership of new files and sockets. Specify <em>root</em> to
        disable all user-id switching. Ignored on Windows.
       </dd>
+    </dl>
+   <h3><a class="a-header">Logging options</a></h3>
+    <dl>
      <dt>--verbose (-v)</dt>
       <dd>
        Enables more verbose logging when used with <em>--log</em>, and more verbose help
        when used with <em>--help</em>.
       </dd>
-     <dt>--version (-V)</dt>
+     <dt>--log (-l)</dt>
       <dd>
-       Displays version information and then exits.
+       Enables logging to the standard error stream and to the syslog. The
+       <em>--close-stderr</em> and <em>--no-syslog</em> options can be used to disable output to
+       standard error stream and the syslog separately. Note that <em>--as-server</em>,
+       <em>--as-client</em> and <em>--as-proxy</em> imply <em>--log</em>, and <em>--as-server</em> and
+       <em>--as-proxy</em> also imply <em>--close-stderr</em>.
+      </dd>
+     <dt>--debug (-g)</dt>
+      <dd>
+       Enables debug level logging, if built in. Debug messages are usually only
+       useful when cross-referenced with the source code and they may expose
+       plaintext passwords and mail message content.
+      </dd>
+     <dt>--log-address</dt>
+      <dd>
+       Adds the network address of remote clients to the logging output.
+      </dd>
+     <dt>--log-file &lt;file&gt; (-N)</dt>
+      <dd>
+       Redirects standard-error logging to the specified file. Logging to the log
+       file is not affected by <em>--close-stderr</em>. The filename can include <em>%d</em> to
+       get daily log files; the <em>%d</em> is replaced by the current date in the local
+       timezone using a <em>YYYYMMDD</em> format.
+      </dd>
+     <dt>--log-time (-L)</dt>
+      <dd>
+       Adds a timestamp to the logging output using the local timezone.
+      </dd>
+     <dt>--no-syslog (-n)</dt>
+      <dd>
+       Disables logging to the syslog. Note that <em>--as-client</em> implies
+       <em>--no-syslog</em>.
+      </dd>
+     <dt>--syslog[=&lt;facility&gt;] (-k)</dt>
+      <dd>
+       When used with <em>--log</em> this option enables logging to the syslog even if the
+       <em>--no-syslog</em> option is also used. This is typically used as a convenient
+       override when using <em>--as-client</em>.
+      </dd>
+     <dt>--close-stderr (-e)</dt>
+      <dd>
+       Causes the standard error stream to be closed soon after start-up. This is
+       useful when operating as a background daemon and it is therefore implied by
+       <em>--as-server</em> and <em>--as-proxy</em>.
       </dd>
     </dl>
     <p>
@@ -906,7 +936,7 @@ server plain carol my+20password
     </p>
 
       <div class="div-pre">
-       <pre>$ openssl req -x509 -nodes -subj "/CN=$USER" -newkey rsa:2048 -keyout emailrelay.pem  -out emailrelay.pem
+       <pre>$ openssl req -x509 -noenc -subj "/CN=$USER" -newkey rsa:2048 -keyout emailrelay.pem  -out emailrelay.pem
 </pre>
       </div><!-- div-pre -->
     <p>
@@ -957,21 +987,15 @@ server plain carol my+20password
 
       <div class="div-pre">
        <pre>auth requisite pam_unix.so nullok_secure
-session required pam_permit.so
-account required pam_permit.so
-password required pam_deny.so
 </pre>
       </div><!-- div-pre -->
     <p>
      With this configuration the E-MailRelay server will use normal unix system
      account names and passwords to authenticate remote clients. On some systems
      this will require special permissioning to allow the E-MailRelay server to
-     read the shadow password database.
-    </p>
-
-    <p>
-     When using PAM authentication E-MailRelay requires that remote clients
-     establish an encrypted session using TLS before authentication can proceed.
+     read the shadow password database, so run the server as <em>root</em> and also add the
+     <em>--user=root</em> command-line option to make sure that the process's effective
+     user-id stays as <em>root</em> while it accesses the PAM system.
     </p>
    <h2><a class="a-header" name="SH_1_8">IP addresses</a></h2> <!-- index:2:SH:1:8:IP addresses -->
     <p>
@@ -1413,9 +1437,7 @@ catch( e )
     <p>
      The following are some security issues that have been taken into consideration:
     </p>
-
-    <dl>
-     <dt>Effective userid</dt>
+   <h3><a class="a-header">Effective userid</a></h3>
       <dd>
        Suid privileges are revoked at start-up, switching the effective
        userid/groupid to be the real userid/groupid values. If started as <em>root</em>
@@ -1427,32 +1449,32 @@ catch( e )
        groupid, so that new files have group ownership corresponding to the
        <em>daemon</em> user.
       </dd>
-     <dt>Execution environment</dt>
+   <h3><a class="a-header">Execution environment</a></h3>
       <dd>
        The external filter programs are run with an almost empty set of environment
        variables (<em>PATH</em> and <em>IFS</em>), and with no open file descriptors other than
        <em>stdin</em> and <em>stderr</em> open onto <em>/dev/null</em>, and <em>stdout</em> open onto a pipe.
       </dd>
-     <dt>Umask</dt>
+   <h3><a class="a-header">Umask</a></h3>
       <dd>
-       The program runs for most of the time with a <em>umask</em> of 177, switching to 117
+       The program runs for most of the time with a <em>umask</em> of 077, switching to 007
        when creating spool files.
       </dd>
-     <dt>Remote clients</dt>
+   <h3><a class="a-header">Remote clients</a></h3>
       <dd>
        By default connections will be rejected if they come from remote machines.
       </dd>
-     <dt>Remote configuration</dt>
+   <h3><a class="a-header">Remote configuration</a></h3>
       <dd>
        No configuration parameters can be changed through the administrative
        interface.
       </dd>
-     <dt>Use of exec() and system()</dt>
+   <h3><a class="a-header">Use of exec() and system()</a></h3>
       <dd>
        No exec(), system() or popen() calls are used other than execve() to spawn the
        mail filter and/or address verifier.
       </dd>
-     <dt>File permissions</dt>
+   <h3><a class="a-header">File permissions</a></h3>
       <dd>
        After a normal installation the spool directory is has ownership of
        <em>root.daemon</em> with permissions of <em>-rwxrwxr-x</em> and messages files are created
@@ -1464,7 +1486,7 @@ catch( e )
        spool directory, and the files created end up owned by the submitter but with
        group ownership of <em>daemon</em>.
       </dd>
-     <dt>Logging</dt>
+   <h3><a class="a-header">Logging</a></h3>
       <dd>
        Logging output is conditioned so that ANSI escape sequences cannot appear
        in the log.
@@ -1472,17 +1494,16 @@ catch( e )
        Passwords and message content are not logged (except if using the <em>--debug</em>
        option at run time with debug logging enabled at build time).
       </dd>
-     <dt>Information leakage</dt>
+   <h3><a class="a-header">Information leakage</a></h3>
       <dd>
        The <em>--anonymous</em> option can be used to reduce the amount of information
        leaked to remote clients.
       </dd>
-     <dt>Mandatory encryption</dt>
+   <h3><a class="a-header">Mandatory encryption</a></h3>
       <dd>
        When using PAM for authentication all clients are required to use
        TLS/SSL encryption.
       </dd>
-    </dl>
     <p>
      Security issues which relate to the SMTP protocol itself are beyond the scope
      of this document, but RFC-2821 makes the following observation: "SMTP mail is
@@ -1551,7 +1572,39 @@ E-MailRelay&gt; quit
      An E-MailRelay <em>--filter</em> script can be used to reject messages with incorrect
      <em>Bcc:</em> headers, and an example script is included.
     </p>
-   <h2><a class="a-header" name="SH_1_16">Files and directories</a></h2> <!-- index:2:SH:1:16:Files and directories -->
+   <h2><a class="a-header" name="SH_1_16">Routing</a></h2> <!-- index:2:SH:1:16:Routing -->
+    <p>
+     E-MailRelay does not normally do any routing of e-mail messages; they are
+     all forwarded to a fixed <em>smarthost</em> address given by the <em>--forward-to</em> or
+     <em>--as-client</em> command-line options.
+    </p>
+
+    <p>
+     However, each message envelope file contains a <em>ForwardToAddress</em> field that
+     can be populated by filter scripts in order to route the message to some other
+     server.
+    </p>
+
+    <p>
+     If the <em>ForwardTo</em> field has any non-empty value then E-MailRelay runs its
+     client filter early to allow the client filter script to set or update the
+     <em>ForwardToAddress</em> before the outgoing connection is made. (The client filter is
+     run a second time as normal once the connection is made and the SMTP session has
+     been established.)
+    </p>
+
+    <p>
+     Typically a <em>--filter</em> script would be used to examine the message content and
+     populate the <em>ForwardTo</em> field, then a <em>--client-filter</em> script would use
+     the <em>ForwardTo</em> value to populate the <em>ForwardToAddress</em> field with an up-to-date
+     forwarding address.
+    </p>
+
+    <p>
+     Note that a successful connection to the smarthost is required even if a message
+     is routed elsewhere.
+    </p>
+   <h2><a class="a-header" name="SH_1_17">Files and directories</a></h2> <!-- index:2:SH:1:17:Files and directories -->
     <p>
      On Unix-like systems E-MailRelay installs by default under <em>/usr/local</em>, but
      binary distributions will probably have been built to install elsewhere.
@@ -1611,10 +1664,10 @@ E-MailRelay&gt; quit
 
     <div class="div-footer">
      <p>
-      Copyright (C) 2001-2021 Graeme Walker
+      Copyright (C) 2001-2022 Graeme Walker
      </p>
     </div><!-- div-footer -->
  </div> <!-- div-main -->
  </body>
 </html>
-<!-- Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
+<!-- Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
diff --git a/doc/reference.md b/doc/reference.md
index 1f1eda4..7a57d80 100644
--- a/doc/reference.md
+++ b/doc/reference.md
@@ -7,29 +7,7 @@ The `emailrelay` program supports the following command-line usage:
 
         emailrelay [<option> [<option> ...]] [<config-file>]
 
-where &lt;option&gt; is:
-
-*   \-\-address-verifier &lt;program&gt;
-
-    Runs the specified external program to verify a message recipent's e-mail
-    address. A network verifier can be specified as `net:<transport-address>`.
-
-*   \-\-admin &lt;admin-port&gt; (-a)
-
-    Enables an administration interface on the specified listening port number.
-    Use telnet or something similar to connect. The administration interface
-    can be used to trigger forwarding of spooled mail messages if the
-    `--forward-to` option is used.
-
-*   \-\-admin-terminate (-Q)
-
-    Enables the `terminate` command in the administration interface.
-
-*   \-\-anonymous (-A)
-
-    Disables the server's [SMTP][] VRFY command, sends less verbose SMTP responses
-    and SMTP greeting, and stops `Received` lines being added to mail message
-    content files.
+### Basic options ###
 
 *   \-\-as-client &lt;host:port&gt; (-q)
 
@@ -51,6 +29,215 @@ where &lt;option&gt; is:
     them. Use `--log` instead of `--as-server` to keep standard error stream
     open.
 
+*   \-\-spool-dir &lt;dir&gt; (-s)
+
+    Specifies the directory used for holding mail messages that have been
+    received but not yet forwarded.
+
+*   \-\-help (-h)
+
+    Displays help text and then exits. Use with `--verbose` for more complete
+    output.
+
+*   \-\-version (-V)
+
+    Displays version information and then exits.
+
+
+### [SMTP][] client options ###
+
+*   \-\-forward (-f)
+
+    Causes spooled mail messages to be forwarded when the program first starts.
+
+*   \-\-forward-on-disconnect (-1)
+
+    Causes spooled mail messages to be forwarded whenever a SMTP client
+    connection disconnects.
+
+*   \-\-forward-to &lt;host:port&gt; (-o)
+
+    Specifies the transport address of the remote SMTP server that spooled mail
+    messages are forwarded to.
+
+*   \-\-poll &lt;period&gt; (-O)
+
+    Causes forwarding of spooled mail messages to happen at regular intervals
+    (with the time given in seconds).
+
+*   \-\-client-filter &lt;program&gt; (-Y)
+
+    Runs the specified external filter program whenever a mail message is
+    forwarded. The filter is passed the name of the message file in the spool
+    directory so that it can edit it as required. A network filter can be
+    specified as `net:<tcp-address>` and prefixes of `spam:`, `spam-edit:` and
+    `exit:` are also allowed. The `spam:` and `spam-edit:` prefixes require a
+    SpamAssassin daemon to be running. For store-and-forward applications the
+    `--filter` option is normally more useful than `--client-filter`.
+
+*   \-\-client-interface &lt;ip-address&gt; (-6)
+
+    Specifies the IP network address to be used to bind the local end of outgoing
+    SMTP connections. By default the address will depend on the routing tables
+    in the normal way. Use `0.0.0.0` to use only IPv4 addresses returned from
+    DNS lookups of the `--forward-to` address, or `::` for IPv6.
+
+*   \-\-connection-timeout &lt;time&gt; (-U)
+
+    Specifies a timeout (in seconds) for establishing a TCP connection to remote
+    SMTP servers. The default is 40 seconds.
+
+*   \-\-idle-timeout &lt;time&gt;
+
+    Specifies a timeout (in seconds) for receiving network traffic from remote
+    SMTP and [POP][] clients. The default is 60 seconds.
+
+*   \-\-response-timeout &lt;time&gt; (-T)
+
+    Specifies a timeout (in seconds) for getting responses from remote SMTP
+    servers. The default is 60 seconds.
+
+*   \-\-forward-to-some
+
+    Allow forwarding to continue even if some recipient addresses on an e-mail
+    envelope are rejected by the remote server.
+
+*   \-\-immediate (-m)
+
+    Causes mail messages to be forwarded as they are received, even before they
+    have been accepted. This can be used to do proxying without
+    store-and-forward, but in practice clients tend to to time out while
+    waiting for their mail message to be accepted.
+
+
+### SMTP server options ###
+
+*   \-\-port &lt;port&gt; (-p)
+
+    Sets the port number used for listening for incoming SMTP connections.
+
+*   \-\-remote-clients (-r)
+
+    Allows incoming connections from addresses that are not local. The default
+    behaviour is to reject connections that are not local in order to prevent
+    accidental exposure to the public internet, although a firewall should also
+    be used. Local address ranges are defined in [RFC-1918][], RFC-6890 etc.
+
+*   \-\-address-verifier &lt;program&gt;
+
+    Runs the specified external program to verify a message recipent's e-mail
+    address. A network verifier can be specified as `net:<tcp-address>`.
+
+*   \-\-anonymous[=&lt;scope&gt;] (-A)
+
+    Disables the server's SMTP VRFY command, sends less verbose SMTP greeting and
+    responses, stops `Received` lines being added to mail message content
+    files, and stops the SMTP client protocol adding `AUTH=` to the `MAIL`
+    command. For finer control use a comma-separated list of things to
+    anonymise: `vrfy`, `server`, `content` and/or `client`, eg.
+    `--anonymous`=server,content.
+
+*   \-\-dnsbl &lt;config&gt;
+
+    Specifies a list of [DNSBL][] servers that are used to reject SMTP connections
+    from blocked addresses. The configuration string is made up of
+    comma-separated fields: the DNS server's transport address, a timeout in
+    milliseconds, a rejection threshold, and then the list of DNSBL servers.
+
+*   \-\-domain &lt;fqdn&gt; (-D)
+
+    Specifies the network name that is used in SMTP EHLO commands, `Received`
+    lines, and for generating authentication challenges. The default is derived
+    from a DNS lookup of the local hostname.
+
+*   \-\-filter &lt;program&gt; (-z)
+
+    Runs the specified external filter program whenever a mail message is stored.
+    The filter is passed the name of the message file in the spool directory so
+    that it can edit it as required. The mail message is rejected if the filter
+    program terminates with an exit code between 1 and 99. Use
+    `net:<tcp-address>` to communicate with a filter daemon over the network,
+    or `spam:<tcp-address>` for a spamassassin spamd daemon to accept or reject
+    mail messages, or `spam-edit:<tcp-address>` to have spamassassin edit the
+    message content without rejecting it, or `exit:<number>` to emulate a
+    filter program that just exits.
+
+*   \-\-filter-timeout &lt;time&gt; (-W)
+
+    Specifies a timeout (in seconds) for running a `--filter` program. The
+    default is 60 seconds.
+
+*   \-\-interface &lt;ip-address-list&gt; (-I)
+
+    Specifies the IP network addresses or interface names used to bind listening
+    ports. By default listening ports for incoming SMTP, POP and administration
+    connections will bind the 'any' address for IPv4 and for IPv6, ie.
+    `0.0.0.0` and `::`. Multiple addresses can be specified by using the option
+    more than once or by using a comma-separated list. Use a prefix of `smtp=`,
+    `pop=` or `admin=` on addresses that should apply only to those types of
+    listening port. Any link-local IPv6 addresses must include a zone name or
+    scope id.  Interface names can be used instead of addresses, in which case
+    all the addresses associated with that interface at startup will used for
+    listening. When an interface name is decorated with a `-ipv4` or `-ipv6`
+    suffix only their IPv4 or IPv6 addresses will be used (eg. `ppp0-ipv4`).
+    To inherit listening file descriptors from the parent process on unix use a
+    syntax like this: `--interface`=smtp=fd#3,smtp=fd#4,pop=fd#5.
+
+*   \-\-prompt-timeout &lt;time&gt; (-w)
+
+    Specifies a timeout (in seconds) for getting the initial prompt from a remote
+    SMTP server. If no prompt is received after this time then the SMTP dialog
+    goes ahead without it.
+
+*   \-\-size &lt;bytes&gt; (-M)
+
+    Limits the size of mail messages that can be submitted over SMTP.
+
+
+### POP server options ###
+
+*   \-\-pop (-B)
+
+    Enables the POP server, listening by default on port 110, providing access to
+    spooled mail messages. Negotiated [TLS][] using the POP `STLS` command will be
+    enabled if the `--server-tls` option is also given.
+
+*   \-\-pop-by-name (-J)
+
+    Modifies the spool directory used by the POP server to be a sub-directory
+    with the same name as the POP authentication user-id. This allows multiple
+    POP clients to read the spooled mail messages without interfering with each
+    other, particularly when also using `--pop-no-delete`. Content files can
+    stay in the main spool directory with only the envelope files copied into
+    user-specific sub-directories. The `emailrelay-filter-copy` program is a
+    convenient way of doing this when run via `--filter`.
+
+*   \-\-pop-no-delete (-G)
+
+    Disables the POP DELE command so that the command appears to succeed but mail
+    messages are not deleted from the spool directory.
+
+*   \-\-pop-port &lt;port&gt; (-E)
+
+    Sets the POP server's listening port number.
+
+
+### Admin server options ###
+
+*   \-\-admin &lt;port&gt; (-a)
+
+    Enables an administration interface on the specified listening port number.
+    Use telnet or something similar to connect. The administration interface
+    can be used to trigger forwarding of spooled mail messages if the
+    `--forward-to` option is used.
+
+*   \-\-admin-terminate (-Q)
+
+    Enables the `terminate` command in the administration interface.
+
+
+### Authentication options ###
+
 *   \-\-client-auth &lt;file&gt; (-C)
 
     Enables SMTP client authentication with the remote server, using the client
@@ -68,38 +255,54 @@ where &lt;option&gt; is:
     Configures the SMTP client authentication module using a semicolon-separated
     list of configuration items. Each item is a single-character key, followed
     by a colon and then a comma-separated list. A 'm' character introduces an
-    ordered list of authentication mechanisms, and an 'x' is used for
-    blocklisted mechanisms.
+    ordered list of preferred authentication mechanisms and an 'x' introduces a
+    list of mechanisms to avoid. An 'a' list and a 'd' list can be used
+    similarly to prefer and avoid certain mechanisms once the session is
+    encrypted with TLS.
 
-*   \-\-client-filter &lt;program&gt; (-Y)
+*   \-\-server-auth &lt;file&gt; (-S)
 
-    Runs the specified external filter program whenever a mail message is
-    forwarded. The filter is passed the name of the message file in the spool
-    directory so that it can edit it as required. A network filter can be
-    specified as `net:<transport-address>` and prefixes of `spam:`,
-    `spam-edit:` and `exit:` are also allowed. The `spam:` and `spam-edit:`
-    prefixes require a SpamAssassin daemon to be running. For store-and-forward
-    applications the `--filter` option is normally more useful than
-    `--client-filter`.
+    Enables SMTP server authentication of remote SMTP clients. Account names and
+    passwords are taken from the specified secrets file. The secrets file
+    should contain lines that have four space-separated fields, starting with
+    `server` in the first field; the second field is the password encoding
+    (`plain` or `md5`), the third is the client user-id and the fourth is the
+    password. The user-id is [RFC-1891][] xtext encoded, and the password is either
+    xtext encoded or generated by `emailrelay-passwd`. A special value of
+    `/pam` can be used for authentication using linux [PAM][].
 
-*   \-\-client-interface &lt;ip-address&gt; (-6)
+*   \-\-server-auth-config &lt;config&gt;
 
-    Specifies the IP network address to be used to bind the local end of outgoing
-    SMTP connections. By default the address will depend on the routing tables
-    in the normal way. Use `0.0.0.0` to use only IPv4 addresses returned from
-    DNS lookups of the `--forward-to` address, or `::` for IPv6.
+    Configures the SMTP server authentication module using a semicolon-separated
+    list of configuration items. Each item is a single-character key, followed
+    by a colon and then a comma-separated list. A 'm' character introduces an
+    ordered list of allowed authentication mechanisms and an 'x' introduces a
+    list of mechanisms to deny. An 'a' list and a 'd' list can be used
+    similarly to allow and deny mechanisms once the session is encrypted with
+    TLS. In typical usage you might have an empty allow list for an unencrypted
+    session and a single preferred mechanism once encrypted, `m:;a:plain`.
+
+*   \-\-pop-auth &lt;file&gt; (-F)
+
+    Specifies a file containing valid POP account details. The file format is the
+    same as for the SMTP server secrets file, ie. lines starting with `server`,
+    with user-id and password in the third and fourth fields. A special value
+    of `/pam` can be used for authentication using linux PAM.
+
+
+### TLS options ###
 
 *   \-\-client-tls (-j)
 
-    Enables negotiated [TLS][] for outgoing SMTP connections; the SMTP STARTTLS
+    Enables negotiated TLS for outgoing SMTP connections; the SMTP STARTTLS
     command will be issued if the remote server supports it.
 
 *   \-\-client-tls-certificate &lt;pem-file&gt;
 
     Defines the TLS certificate file when acting as a SMTP client. This file must
     contain the client's private key and certificate chain using the PEM file
-    format. Alternatively, use this option twice with the first one specifying 
-    the key file and the second the certificate file. Keep the file permissions 
+    format. Alternatively, use this option twice with the first one specifying
+    the key file and the second the certificate file. Keep the file permissions
     tight to avoid accidental exposure of the private key.
 
 *   \-\-client-tls-connection (-b)
@@ -132,243 +335,6 @@ where &lt;option&gt; is:
     Enables verification of the CNAME within the remote SMTP server's
     certificate.
 
-*   \-\-close-stderr (-e)
-
-    Causes the standard error stream to be closed soon after start-up. This is
-    useful when operating as a background daemon and it is therefore implied by
-    `--as-server` and `--as-proxy`.
-
-*   \-\-connection-timeout &lt;time&gt; (-U)
-
-    Specifies a timeout (in seconds) for establishing a TCP connection to remote
-    SMTP servers. The default is 40 seconds.
-
-*   \-\-debug (-g)
-
-    Enables debug level logging, if built in. Debug messages are usually only
-    useful when cross-referenced with the source code and they may expose
-    plaintext passwords and mail message content.
-
-*   \-\-dnsbl &lt;config&gt;
-
-    Specifies a list of [DNSBL][] servers that are used to reject SMTP connections
-    from blocked addresses. The configuration string is made up of
-    comma-separated fields: the DNS server's transport address, a timeout in
-    milliseconds, a rejection threshold, and then the list of DNSBL servers.
-
-*   \-\-domain &lt;fqdn&gt; (-D)
-
-    Specifies the network name that is used in SMTP EHLO commands, `Received`
-    lines, and for generating authentication challenges. The default is derived
-    from a DNS lookup of the local hostname.
-
-*   \-\-dont-serve (-x)
-
-    Disables all network serving, including SMTP, [POP][] and administration
-    interfaces. The program will terminate as soon as any initial forwarding is
-    complete.
-
-*   \-\-filter &lt;program&gt; (-z)
-
-    Runs the specified external filter program whenever a mail message is stored.
-    The filter is passed the name of the message file in the spool directory so
-    that it can edit it as required. The mail message is rejected if the filter
-    program terminates with an exit code between 1 and 99. Use
-    `net:<transport-address>` to communicate with a filter daemon over the
-    network, or `spam:<transport-address>` for a spamassassin spamd daemon to
-    accept or reject mail messages, or `spam-edit:<transport-address>` to have
-    spamassassin edit the message content without rejecting it, or
-    `exit:<number>` to emulate a filter program that just exits.
-
-*   \-\-filter-timeout &lt;time&gt; (-W)
-
-    Specifies a timeout (in seconds) for running a `--filter` program. The
-    default is 300 seconds.
-
-*   \-\-forward (-f)
-
-    Causes spooled mail messages to be forwarded when the program first starts.
-
-*   \-\-forward-on-disconnect (-1)
-
-    Causes spooled mail messages to be forwarded whenever a SMTP client
-    connection disconnects.
-
-*   \-\-forward-to &lt;host:port&gt; (-o)
-
-    Specifies the transport address of the remote SMTP server that is use for
-    mail message forwarding.
-
-*   \-\-forward-to-some
-
-    Allow forwarding to continue even if some recipient addresses on an e-mail
-    envelope are rejected by the remote server.
-
-*   \-\-help (-h)
-
-    Displays help text and then exits. Use with `--verbose` for more complete
-    output.
-
-*   \-\-hidden (-H)
-
-    Windows only. Hides the application window and disables all message boxes,
-    overriding any `--show` option. This is useful when running as a windows
-    service.
-
-*   \-\-idle-timeout &lt;time&gt;
-
-    Specifies a timeout (in seconds) for receiving network traffic from remote
-    SMTP and POP clients. The default is 1800 seconds.
-
-*   \-\-immediate (-m)
-
-    Causes mail messages to be forwarded as they are received, even before they
-    have been accepted. This can be used to do proxying without
-    store-and-forward, but in practice clients tend to to time out while
-    waiting for their mail message to be accepted.
-
-*   \-\-interface &lt;ip-address-list&gt; (-I)
-
-    Specifies the IP network addresses or interface names used to bind listening
-    ports. By default listening ports for incoming SMTP, POP and administration
-    connections will bind the 'any' address for IPv4 and for IPv6, ie.
-    `0.0.0.0` and `::`. Multiple addresses can be specified by using the option
-    more than once or by using a comma-separated list. Use a prefix of `smtp=`,
-    `pop=` or `admin=` on addresses that should apply only to those types of
-    listening port. Any link-local IPv6 addresses must include a zone name or
-    scope id.  Interface names can be used instead of addresses, in which case
-    all the addresses associated with that interface at startup will used for
-    listening. When an interface name is decorated with a `-ipv4` or `-ipv6`
-    suffix only their IPv4 or IPv6 addresses will be used (eg. `ppp0-ipv4`).
-
-*   \-\-localedir &lt;dir&gt;
-
-    Enables localisation and specifies the locale base directory where message
-    catalogues can be found. An empty directory can be used for the built-in
-    default.
-
-*   \-\-log (-l)
-
-    Enables logging to the standard error stream and to the syslog. The
-    `--close-stderr` and `--no-syslog` options can be used to disable output to
-    standard error stream and the syslog separately. Note that `--as-server`,
-    `--as-client` and `--as-proxy` imply `--log`, and `--as-server` and
-    `--as-proxy` also imply `--close-stderr`.
-
-*   \-\-log-address
-
-    Adds the network address of remote clients to the logging output.
-
-*   \-\-log-file &lt;file&gt; (-N)
-
-    Redirects standard-error logging to the specified file. Logging to the log
-    file is not affected by `--close-stderr`. The filename can include `%d` to
-    get daily log files; the `%d` is replaced by the current date in the local
-    timezone using a `YYYYMMDD` format.
-
-*   \-\-log-time (-L)
-
-    Adds a timestamp to the logging output using the local timezone.
-
-*   \-\-no-daemon (-t)
-
-    Disables the normal backgrounding at startup so that the program runs in the
-    foreground, without forking or detaching from the terminal.  On Windows
-    this disables the system tray icon so the program uses a normal window;
-    when the window is closed the program terminates.
-
-*   \-\-no-smtp (-X)
-
-    Disables listening for incoming SMTP connections.
-
-*   \-\-no-syslog (-n)
-
-    Disables logging to the syslog. Note that `--as-client` implies
-    `--no-syslog`.
-
-*   \-\-pid-file &lt;pid-file&gt; (-i)
-
-    Causes the process-id to be written into the specified file when the program
-    starts up, typically after it has become a background daemon.
-
-*   \-\-poll &lt;period&gt; (-O)
-
-    Causes forwarding of spooled mail messages to happen at regular intervals
-    (with the time given in seconds).
-
-*   \-\-pop (-B)
-
-    Enables the POP server listening, by default on port 110, providing access to
-    spooled mail messages. Negotiated TLS using the POP `STLS` command will be
-    enabled if the `--server-tls` option is also given.
-
-*   \-\-pop-auth &lt;file&gt; (-F)
-
-    Specifies a file containing valid POP account details. The file format is the
-    same as for the SMTP server secrets file, ie. lines starting with `server`,
-    with user-id and password in the third and fourth fields. A special value
-    of `/pam` can be used for authentication using linux [PAM][].
-
-*   \-\-pop-by-name (-J)
-
-    Modifies the spool directory used by the POP server to be a sub-directory
-    with the same name as the POP authentication user-id. This allows multiple
-    POP clients to read the spooled messages without interfering with each
-    other, particularly when also using `--pop-no-delete`. Content files can
-    stay in the main spool directory with only the envelope files copied into
-    user-specific sub-directories. The `emailrelay-filter-copy` program is a
-    convenient way of doing this when run via `--filter`.
-
-*   \-\-pop-no-delete (-G)
-
-    Disables the POP DELE command so that the command appears to succeed but mail
-    messages are not deleted from the spool directory.
-
-*   \-\-pop-port &lt;port&gt; (-E)
-
-    Sets the POP server's listening port number.
-
-*   \-\-port &lt;port&gt; (-p)
-
-    Sets the port number used for listening for incoming SMTP connections.
-
-*   \-\-prompt-timeout &lt;time&gt; (-w)
-
-    Specifies a timeout (in seconds) for getting the initial prompt from a remote
-    SMTP server. If no prompt is received after this time then the SMTP dialog
-    goes ahead without it.
-
-*   \-\-remote-clients (-r)
-
-    Allows incoming connections from addresses that are not local. The default
-    behaviour is to reject connections that are not local in order to prevent
-    accidental exposure to the public internet, although a firewall should also
-    be used. Local address ranges are defined in [RFC-1918][], RFC-6890 etc.
-
-*   \-\-response-timeout &lt;time&gt; (-T)
-
-    Specifies a timeout (in seconds) for getting responses from remote SMTP
-    servers. The default is 1800 seconds.
-
-*   \-\-server-auth &lt;file&gt; (-S)
-
-    Enables SMTP server authentication of remote SMTP clients. Account names and
-    passwords are taken from the specified secrets file. The secrets file
-    should contain lines that have four space-separated fields, starting with
-    `server` in the first field; the second field is the password encoding
-    (`plain` or `md5`), the third is the client user-id and the fourth is the
-    password. The user-id is [RFC-1891][] xtext encoded, and the password is either
-    xtext encoded or generated by `emailrelay-passwd`. A special value of
-    `/pam` can be used for authentication using linux PAM.
-
-*   \-\-server-auth-config &lt;config&gt;
-
-    Configures the SMTP server authentication module using a semicolon-separated
-    list of configuration items. Each item is a single-character key, followed
-    by a colon and then a comma-separated list. A 'm' character introduces a
-    preferred sub-set of the built-in authentication mechanisms, and an 'x' is
-    used for blocklisted mechanisms.
-
 *   \-\-server-tls (-K)
 
     Enables TLS for incoming SMTP and POP connections. SMTP clients can then
@@ -380,8 +346,8 @@ where &lt;option&gt; is:
 
     Defines the TLS certificate file when acting as a SMTP or POP server. This
     file must contain the server's private key and certificate chain using the
-    PEM file format. Alternatively, use this option twice with the first one 
-    specifying the key file and the second the certificate file. Keep the file 
+    PEM file format. Alternatively, use this option twice with the first one
+    specifying the key file and the second the certificate file. Keep the file
     permissions tight to avoid accidental exposure of the private key.
 
 *   \-\-server-tls-connection
@@ -403,21 +369,6 @@ where &lt;option&gt; is:
     certificate. Specify `<default>` for the TLS library's default set of
     trusted CAs.
 
-*   \-\-size &lt;bytes&gt; (-M)
-
-    Limits the size of mail messages that can be submitted over SMTP.
-
-*   \-\-spool-dir &lt;dir&gt; (-s)
-
-    Specifies the directory used for holding mail messages that have been
-    received but not yet forwarded.
-
-*   \-\-syslog[=&lt;facility&gt;] (-k)
-
-    When used with `--log` this option enables logging to the syslog even if the
-    `--no-syslog` option is also used. This is typically used as a convenient
-    override when using `--as-client`.
-
 *   \-\-tls-config &lt;options&gt; (-9)
 
     Selects and configures the low-level TLS library, using a comma-separated
@@ -426,6 +377,44 @@ where &lt;option&gt; is:
     `tlsv1.0` can be used to set a minimum TLS protocol version, or `-tlsv1.2`
     to set a maximum version.
 
+
+### Process options ###
+
+*   \-\-dont-serve (-x)
+
+    Disables all network serving, including SMTP, POP and administration
+    interfaces. The program will terminate as soon as any initial forwarding is
+    complete.
+
+*   \-\-hidden (-H)
+
+    Windows only. Hides the application window and disables all message boxes,
+    overriding any `--show` option. This is useful when running as a windows
+    service.
+
+*   \-\-localedir &lt;dir&gt;
+
+    Enables localisation and specifies the locale base directory where message
+    catalogues can be found. An empty directory can be used for the built-in
+    default.
+
+*   \-\-no-daemon (-t)
+
+    Disables the normal backgrounding at startup so that the program runs in the
+    foreground, without forking or detaching from the terminal.  On Windows
+    this disables the system tray icon so the program uses a normal window;
+    when the window is closed the program terminates.
+
+*   \-\-no-smtp (-X)
+
+    Disables listening for incoming SMTP connections.
+
+*   \-\-pid-file &lt;path&gt; (-i)
+
+    Causes the process-id to be written into the specified file when the program
+    starts up, typically after it has become a background daemon. The immediate
+    parent directory is created if necessary.
+
 *   \-\-user &lt;username&gt; (-u)
 
     When started as root the program switches to a non-privileged effective
@@ -433,14 +422,59 @@ where &lt;option&gt; is:
     also the group ownership of new files and sockets. Specify `root` to
     disable all user-id switching. Ignored on Windows.
 
+
+### Logging options ###
+
 *   \-\-verbose (-v)
 
     Enables more verbose logging when used with `--log`, and more verbose help
     when used with `--help`.
 
-*   \-\-version (-V)
+*   \-\-log (-l)
 
-    Displays version information and then exits.
+    Enables logging to the standard error stream and to the syslog. The
+    `--close-stderr` and `--no-syslog` options can be used to disable output to
+    standard error stream and the syslog separately. Note that `--as-server`,
+    `--as-client` and `--as-proxy` imply `--log`, and `--as-server` and
+    `--as-proxy` also imply `--close-stderr`.
+
+*   \-\-debug (-g)
+
+    Enables debug level logging, if built in. Debug messages are usually only
+    useful when cross-referenced with the source code and they may expose
+    plaintext passwords and mail message content.
+
+*   \-\-log-address
+
+    Adds the network address of remote clients to the logging output.
+
+*   \-\-log-file &lt;file&gt; (-N)
+
+    Redirects standard-error logging to the specified file. Logging to the log
+    file is not affected by `--close-stderr`. The filename can include `%d` to
+    get daily log files; the `%d` is replaced by the current date in the local
+    timezone using a `YYYYMMDD` format.
+
+*   \-\-log-time (-L)
+
+    Adds a timestamp to the logging output using the local timezone.
+
+*   \-\-no-syslog (-n)
+
+    Disables logging to the syslog. Note that `--as-client` implies
+    `--no-syslog`.
+
+*   \-\-syslog[=&lt;facility&gt;] (-k)
+
+    When used with `--log` this option enables logging to the syslog even if the
+    `--no-syslog` option is also used. This is typically used as a convenient
+    override when using `--as-client`.
+
+*   \-\-close-stderr (-e)
+
+    Causes the standard error stream to be closed soon after start-up. This is
+    useful when operating as a background daemon and it is therefore implied by
+    `--as-server` and `--as-proxy`.
 
 A configuration file can be used to provide additional options; put each
 option on a separate line, use the long option names but without the double
@@ -777,7 +811,7 @@ key.
 This OpenSSL command can be used to create a self-signed certificate file
 suitable for testing:
 
-        $ openssl req -x509 -nodes -subj "/CN=$USER" -newkey rsa:2048 -keyout emailrelay.pem  -out emailrelay.pem
+        $ openssl req -x509 -noenc -subj "/CN=$USER" -newkey rsa:2048 -keyout emailrelay.pem  -out emailrelay.pem
 
 TLS performs encryption to prevent eavesdropping, but it does not necessarily
 do authentication to prevent man-in-the-middle attacks. For full TLS
@@ -814,17 +848,13 @@ normally involves creating a file `/etc/pam.d/emailrelay` containing something
 like the following:
 
         auth requisite pam_unix.so nullok_secure
-        session required pam_permit.so
-        account required pam_permit.so
-        password required pam_deny.so
 
 With this configuration the E-MailRelay server will use normal unix system
 account names and passwords to authenticate remote clients. On some systems
 this will require special permissioning to allow the E-MailRelay server to
-read the shadow password database.
-
-When using PAM authentication E-MailRelay requires that remote clients
-establish an encrypted session using TLS before authentication can proceed.
+read the shadow password database, so run the server as `root` and also add the
+`--user=root` command-line option to make sure that the process's effective
+user-id stays as `root` while it accesses the PAM system.
 
 IP addresses
 ------------
@@ -1135,7 +1165,7 @@ Security issues
 ---------------
 The following are some security issues that have been taken into consideration:
 
-*   Effective userid
+### Effective userid ###
 
     Suid privileges are revoked at start-up, switching the effective
     userid/groupid to be the real userid/groupid values. If started as `root`
@@ -1147,57 +1177,66 @@ The following are some security issues that have been taken into consideration:
     groupid, so that new files have group ownership corresponding to the
     `daemon` user.
 
-*   Execution environment
+
+### Execution environment ###
 
     The external filter programs are run with an almost empty set of environment
     variables (`PATH` and `IFS`), and with no open file descriptors other than
     `stdin` and `stderr` open onto `/dev/null`, and `stdout` open onto a pipe.
 
-*   Umask
 
-    The program runs for most of the time with a `umask` of 177, switching to 117
+### Umask ###
+
+    The program runs for most of the time with a `umask` of 077, switching to 007
     when creating spool files.
 
-*   Remote clients
+
+### Remote clients ###
 
     By default connections will be rejected if they come from remote machines.
 
-*   Remote configuration
+
+### Remote configuration ###
 
     No configuration parameters can be changed through the administrative
     interface.
 
-*   Use of exec() and system()
+
+### Use of exec() and system() ###
 
     No exec(), system() or popen() calls are used other than execve() to spawn the
     mail filter and/or address verifier.
 
-*   File permissions
+
+### File permissions ###
 
     After a normal installation the spool directory is has ownership of
     `root.daemon` with permissions of `-rwxrwxr-x` and messages files are created
     with permissions of `-rw-rw----`. This allows normal users to list messages
     files but not read them.
-    
+
     The `emailrelay-submit` program is given group ownership of `daemon` with its
     group set-user-id flag set. This allows it to create message files in the
     spool directory, and the files created end up owned by the submitter but with
     group ownership of `daemon`.
 
-*   Logging
+
+### Logging ###
 
     Logging output is conditioned so that ANSI escape sequences cannot appear
     in the log.
-    
+
     Passwords and message content are not logged (except if using the `--debug`
     option at run time with debug logging enabled at build time).
 
-*   Information leakage
+
+### Information leakage ###
 
     The `--anonymous` option can be used to reduce the amount of information
     leaked to remote clients.
 
-*   Mandatory encryption
+
+### Mandatory encryption ###
 
     When using PAM for authentication all clients are required to use
     TLS/SSL encryption.
@@ -1253,6 +1292,30 @@ and `Cc` message recipients.
 An E-MailRelay `--filter` script can be used to reject messages with incorrect
 `Bcc:` headers, and an example script is included.
 
+Routing
+-------
+E-MailRelay does not normally do any routing of e-mail messages; they are
+all forwarded to a fixed `smarthost` address given by the `--forward-to` or
+`--as-client` command-line options.
+
+However, each message envelope file contains a `ForwardToAddress` field that
+can be populated by filter scripts in order to route the message to some other
+server.
+
+If the `ForwardTo` field has any non-empty value then E-MailRelay runs its
+client filter early to allow the client filter script to set or update the
+`ForwardToAddress` before the outgoing connection is made. (The client filter is
+run a second time as normal once the connection is made and the SMTP session has
+been established.)
+
+Typically a `--filter` script would be used to examine the message content and
+populate the `ForwardTo` field, then a `--client-filter` script would use
+the `ForwardTo` value to populate the `ForwardToAddress` field with an up-to-date
+forwarding address.
+
+Note that a successful connection to the smarthost is required even if a message
+is routed elsewhere.
+
 Files and directories
 ---------------------
 On Unix-like systems E-MailRelay installs by default under `/usr/local`, but
@@ -1314,4 +1377,4 @@ and these default to `%ProgramFiles%/E-MailRelay` for programs and
 [TLS]: https://en.wikipedia.org/wiki/Transport_Layer_Security
 
 _____________________________________
-Copyright (C) 2001-2021 Graeme Walker
+Copyright (C) 2001-2022 Graeme Walker
diff --git a/doc/reference.rst b/doc/reference.rst
index 80b303f..8a7978b 100644
--- a/doc/reference.rst
+++ b/doc/reference.rst
@@ -10,30 +10,6 @@ The *emailrelay* program supports the following command-line usage:
 
     emailrelay [<option> [<option> ...]] [<config-file>]
 
-where \<option\> is:
-
-*   --address-verifier \<program\>
-
-    Runs the specified external program to verify a message recipent's e-mail
-    address. A network verifier can be specified as *net:<transport-address>*.
-
-*   --admin \<admin-port\> (-a)
-
-    Enables an administration interface on the specified listening port number.
-    Use telnet or something similar to connect. The administration interface
-    can be used to trigger forwarding of spooled mail messages if the
-    *--forward-to* option is used.
-
-*   --admin-terminate (-Q)
-
-    Enables the *terminate* command in the administration interface.
-
-*   --anonymous (-A)
-
-    Disables the server's SMTP_ VRFY command, sends less verbose SMTP responses
-    and SMTP greeting, and stops *Received* lines being added to mail message
-    content files.
-
 *   --as-client \<host:port\> (-q)
 
     This is equivalent to *--log*, *--no-syslog*, *--no-daemon*, *--dont-serve*,
@@ -54,6 +30,205 @@ where \<option\> is:
     them. Use *--log* instead of *--as-server* to keep standard error stream
     open.
 
+*   --spool-dir \<dir\> (-s)
+
+    Specifies the directory used for holding mail messages that have been
+    received but not yet forwarded.
+
+*   --help (-h)
+
+    Displays help text and then exits. Use with *--verbose* for more complete
+    output.
+
+*   --version (-V)
+
+    Displays version information and then exits.
+
+
+*   --forward (-f)
+
+    Causes spooled mail messages to be forwarded when the program first starts.
+
+*   --forward-on-disconnect (-1)
+
+    Causes spooled mail messages to be forwarded whenever a SMTP_ client
+    connection disconnects.
+
+*   --forward-to \<host:port\> (-o)
+
+    Specifies the transport address of the remote SMTP server that spooled mail
+    messages are forwarded to.
+
+*   --poll \<period\> (-O)
+
+    Causes forwarding of spooled mail messages to happen at regular intervals
+    (with the time given in seconds).
+
+*   --client-filter \<program\> (-Y)
+
+    Runs the specified external filter program whenever a mail message is
+    forwarded. The filter is passed the name of the message file in the spool
+    directory so that it can edit it as required. A network filter can be
+    specified as *net:<tcp-address>* and prefixes of *spam:*, *spam-edit:* and
+    *exit:* are also allowed. The *spam:* and *spam-edit:* prefixes require a
+    SpamAssassin daemon to be running. For store-and-forward applications the
+    *--filter* option is normally more useful than *--client-filter*.
+
+*   --client-interface \<ip-address\> (-6)
+
+    Specifies the IP network address to be used to bind the local end of outgoing
+    SMTP connections. By default the address will depend on the routing tables
+    in the normal way. Use *0.0.0.0* to use only IPv4 addresses returned from
+    DNS lookups of the *--forward-to* address, or *::* for IPv6.
+
+*   --connection-timeout \<time\> (-U)
+
+    Specifies a timeout (in seconds) for establishing a TCP connection to remote
+    SMTP servers. The default is 40 seconds.
+
+*   --idle-timeout \<time\>
+
+    Specifies a timeout (in seconds) for receiving network traffic from remote
+    SMTP and POP_ clients. The default is 60 seconds.
+
+*   --response-timeout \<time\> (-T)
+
+    Specifies a timeout (in seconds) for getting responses from remote SMTP
+    servers. The default is 60 seconds.
+
+*   --forward-to-some
+
+    Allow forwarding to continue even if some recipient addresses on an e-mail
+    envelope are rejected by the remote server.
+
+*   --immediate (-m)
+
+    Causes mail messages to be forwarded as they are received, even before they
+    have been accepted. This can be used to do proxying without
+    store-and-forward, but in practice clients tend to to time out while
+    waiting for their mail message to be accepted.
+
+
+*   --port \<port\> (-p)
+
+    Sets the port number used for listening for incoming SMTP connections.
+
+*   --remote-clients (-r)
+
+    Allows incoming connections from addresses that are not local. The default
+    behaviour is to reject connections that are not local in order to prevent
+    accidental exposure to the public internet, although a firewall should also
+    be used. Local address ranges are defined in RFC-1918_, RFC-6890 etc.
+
+*   --address-verifier \<program\>
+
+    Runs the specified external program to verify a message recipent's e-mail
+    address. A network verifier can be specified as *net:<tcp-address>*.
+
+*   --anonymous[=\<scope\>] (-A)
+
+    Disables the server's SMTP VRFY command, sends less verbose SMTP greeting and
+    responses, stops *Received* lines being added to mail message content
+    files, and stops the SMTP client protocol adding *AUTH=* to the *MAIL*
+    command. For finer control use a comma-separated list of things to
+    anonymise: *vrfy*, *server*, *content* and/or *client*, eg.
+    \ *--anonymous*\ =server,content.
+
+*   --dnsbl \<config\>
+
+    Specifies a list of DNSBL_ servers that are used to reject SMTP connections
+    from blocked addresses. The configuration string is made up of
+    comma-separated fields: the DNS server's transport address, a timeout in
+    milliseconds, a rejection threshold, and then the list of DNSBL servers.
+
+*   --domain \<fqdn\> (-D)
+
+    Specifies the network name that is used in SMTP EHLO commands, *Received*
+    lines, and for generating authentication challenges. The default is derived
+    from a DNS lookup of the local hostname.
+
+*   --filter \<program\> (-z)
+
+    Runs the specified external filter program whenever a mail message is stored.
+    The filter is passed the name of the message file in the spool directory so
+    that it can edit it as required. The mail message is rejected if the filter
+    program terminates with an exit code between 1 and 99. Use
+    *net:<tcp-address>* to communicate with a filter daemon over the network,
+    or *spam:<tcp-address>* for a spamassassin spamd daemon to accept or reject
+    mail messages, or *spam-edit:<tcp-address>* to have spamassassin edit the
+    message content without rejecting it, or *exit:<number>* to emulate a
+    filter program that just exits.
+
+*   --filter-timeout \<time\> (-W)
+
+    Specifies a timeout (in seconds) for running a *--filter* program. The
+    default is 60 seconds.
+
+*   --interface \<ip-address-list\> (-I)
+
+    Specifies the IP network addresses or interface names used to bind listening
+    ports. By default listening ports for incoming SMTP, POP and administration
+    connections will bind the 'any' address for IPv4 and for IPv6, ie.
+    *0.0.0.0* and *::*. Multiple addresses can be specified by using the option
+    more than once or by using a comma-separated list. Use a prefix of *smtp=*,
+    *pop=* or *admin=* on addresses that should apply only to those types of
+    listening port. Any link-local IPv6 addresses must include a zone name or
+    scope id.  Interface names can be used instead of addresses, in which case
+    all the addresses associated with that interface at startup will used for
+    listening. When an interface name is decorated with a *-ipv4* or *-ipv6*
+    suffix only their IPv4 or IPv6 addresses will be used (eg. *ppp0-ipv4*).
+    To inherit listening file descriptors from the parent process on unix use a
+    syntax like this: *--interface*=smtp=fd#3,smtp=fd#4,pop=fd#5.
+
+*   --prompt-timeout \<time\> (-w)
+
+    Specifies a timeout (in seconds) for getting the initial prompt from a remote
+    SMTP server. If no prompt is received after this time then the SMTP dialog
+    goes ahead without it.
+
+*   --size \<bytes\> (-M)
+
+    Limits the size of mail messages that can be submitted over SMTP.
+
+
+*   --pop (-B)
+
+    Enables the POP server, listening by default on port 110, providing access to
+    spooled mail messages. Negotiated TLS_ using the POP *STLS* command will be
+    enabled if the *--server-tls* option is also given.
+
+*   --pop-by-name (-J)
+
+    Modifies the spool directory used by the POP server to be a sub-directory
+    with the same name as the POP authentication user-id. This allows multiple
+    POP clients to read the spooled mail messages without interfering with each
+    other, particularly when also using *--pop-no-delete*. Content files can
+    stay in the main spool directory with only the envelope files copied into
+    user-specific sub-directories. The *emailrelay-filter-copy* program is a
+    convenient way of doing this when run via *--filter*.
+
+*   --pop-no-delete (-G)
+
+    Disables the POP DELE command so that the command appears to succeed but mail
+    messages are not deleted from the spool directory.
+
+*   --pop-port \<port\> (-E)
+
+    Sets the POP server's listening port number.
+
+
+*   --admin \<port\> (-a)
+
+    Enables an administration interface on the specified listening port number.
+    Use telnet or something similar to connect. The administration interface
+    can be used to trigger forwarding of spooled mail messages if the
+    *--forward-to* option is used.
+
+*   --admin-terminate (-Q)
+
+    Enables the *terminate* command in the administration interface.
+
+
 *   --client-auth \<file\> (-C)
 
     Enables SMTP client authentication with the remote server, using the client
@@ -71,38 +246,52 @@ where \<option\> is:
     Configures the SMTP client authentication module using a semicolon-separated
     list of configuration items. Each item is a single-character key, followed
     by a colon and then a comma-separated list. A 'm' character introduces an
-    ordered list of authentication mechanisms, and an 'x' is used for
-    blocklisted mechanisms.
+    ordered list of preferred authentication mechanisms and an 'x' introduces a
+    list of mechanisms to avoid. An 'a' list and a 'd' list can be used
+    similarly to prefer and avoid certain mechanisms once the session is
+    encrypted with TLS.
 
-*   --client-filter \<program\> (-Y)
+*   --server-auth \<file\> (-S)
 
-    Runs the specified external filter program whenever a mail message is
-    forwarded. The filter is passed the name of the message file in the spool
-    directory so that it can edit it as required. A network filter can be
-    specified as *net:<transport-address>* and prefixes of *spam:*,
-    *spam-edit:* and *exit:* are also allowed. The *spam:* and *spam-edit:*
-    prefixes require a SpamAssassin daemon to be running. For store-and-forward
-    applications the *--filter* option is normally more useful than
-    \ *--client-filter*\ .
+    Enables SMTP server authentication of remote SMTP clients. Account names and
+    passwords are taken from the specified secrets file. The secrets file
+    should contain lines that have four space-separated fields, starting with
+    *server* in the first field; the second field is the password encoding
+    (*plain* or *md5*), the third is the client user-id and the fourth is the
+    password. The user-id is RFC-1891_ xtext encoded, and the password is either
+    xtext encoded or generated by *emailrelay-passwd*. A special value of
+    */pam* can be used for authentication using linux PAM_.
 
-*   --client-interface \<ip-address\> (-6)
+*   --server-auth-config \<config\>
+
+    Configures the SMTP server authentication module using a semicolon-separated
+    list of configuration items. Each item is a single-character key, followed
+    by a colon and then a comma-separated list. A 'm' character introduces an
+    ordered list of allowed authentication mechanisms and an 'x' introduces a
+    list of mechanisms to deny. An 'a' list and a 'd' list can be used
+    similarly to allow and deny mechanisms once the session is encrypted with
+    TLS. In typical usage you might have an empty allow list for an unencrypted
+    session and a single preferred mechanism once encrypted, *m:;a:plain*.
+
+*   --pop-auth \<file\> (-F)
+
+    Specifies a file containing valid POP account details. The file format is the
+    same as for the SMTP server secrets file, ie. lines starting with *server*,
+    with user-id and password in the third and fourth fields. A special value
+    of */pam* can be used for authentication using linux PAM.
 
-    Specifies the IP network address to be used to bind the local end of outgoing
-    SMTP connections. By default the address will depend on the routing tables
-    in the normal way. Use *0.0.0.0* to use only IPv4 addresses returned from
-    DNS lookups of the *--forward-to* address, or *::* for IPv6.
 
 *   --client-tls (-j)
 
-    Enables negotiated TLS_ for outgoing SMTP connections; the SMTP STARTTLS
+    Enables negotiated TLS for outgoing SMTP connections; the SMTP STARTTLS
     command will be issued if the remote server supports it.
 
 *   --client-tls-certificate \<pem-file\>
 
     Defines the TLS certificate file when acting as a SMTP client. This file must
     contain the client's private key and certificate chain using the PEM file
-    format. Alternatively, use this option twice with the first one specifying 
-    the key file and the second the certificate file. Keep the file permissions 
+    format. Alternatively, use this option twice with the first one specifying
+    the key file and the second the certificate file. Keep the file permissions
     tight to avoid accidental exposure of the private key.
 
 *   --client-tls-connection (-b)
@@ -127,7 +316,7 @@ where \<option\> is:
     Enables verification of the remote SMTP server's certificate against any of
     the trusted CA certificates in the specified file or directory. In many use
     cases this should be a file containing just your self-signed root
-    certificate. Specify *\<default\>* for the TLS library's default set of
+    certificate. Specify *<default>* for the TLS library's default set of
     trusted CAs.
 
 *   --client-tls-verify-name \<cname\>
@@ -135,243 +324,6 @@ where \<option\> is:
     Enables verification of the CNAME within the remote SMTP server's
     certificate.
 
-*   --close-stderr (-e)
-
-    Causes the standard error stream to be closed soon after start-up. This is
-    useful when operating as a background daemon and it is therefore implied by
-    *--as-server* and *--as-proxy*.
-
-*   --connection-timeout \<time\> (-U)
-
-    Specifies a timeout (in seconds) for establishing a TCP connection to remote
-    SMTP servers. The default is 40 seconds.
-
-*   --debug (-g)
-
-    Enables debug level logging, if built in. Debug messages are usually only
-    useful when cross-referenced with the source code and they may expose
-    plaintext passwords and mail message content.
-
-*   --dnsbl \<config\>
-
-    Specifies a list of DNSBL_ servers that are used to reject SMTP connections
-    from blocked addresses. The configuration string is made up of
-    comma-separated fields: the DNS server's transport address, a timeout in
-    milliseconds, a rejection threshold, and then the list of DNSBL servers.
-
-*   --domain \<fqdn\> (-D)
-
-    Specifies the network name that is used in SMTP EHLO commands, *Received*
-    lines, and for generating authentication challenges. The default is derived
-    from a DNS lookup of the local hostname.
-
-*   --dont-serve (-x)
-
-    Disables all network serving, including SMTP, POP_ and administration
-    interfaces. The program will terminate as soon as any initial forwarding is
-    complete.
-
-*   --filter \<program\> (-z)
-
-    Runs the specified external filter program whenever a mail message is stored.
-    The filter is passed the name of the message file in the spool directory so
-    that it can edit it as required. The mail message is rejected if the filter
-    program terminates with an exit code between 1 and 99. Use
-    *net:<transport-address>* to communicate with a filter daemon over the
-    network, or *spam:<transport-address>* for a spamassassin spamd daemon to
-    accept or reject mail messages, or *spam-edit:<transport-address>* to have
-    spamassassin edit the message content without rejecting it, or
-    *exit:<number>* to emulate a filter program that just exits.
-
-*   --filter-timeout \<time\> (-W)
-
-    Specifies a timeout (in seconds) for running a *--filter* program. The
-    default is 300 seconds.
-
-*   --forward (-f)
-
-    Causes spooled mail messages to be forwarded when the program first starts.
-
-*   --forward-on-disconnect (-1)
-
-    Causes spooled mail messages to be forwarded whenever a SMTP client
-    connection disconnects.
-
-*   --forward-to \<host:port\> (-o)
-
-    Specifies the transport address of the remote SMTP server that is use for
-    mail message forwarding.
-
-*   --forward-to-some
-
-    Allow forwarding to continue even if some recipient addresses on an e-mail
-    envelope are rejected by the remote server.
-
-*   --help (-h)
-
-    Displays help text and then exits. Use with *--verbose* for more complete
-    output.
-
-*   --hidden (-H)
-
-    Windows only. Hides the application window and disables all message boxes,
-    overriding any *--show* option. This is useful when running as a windows
-    service.
-
-*   --idle-timeout \<time\>
-
-    Specifies a timeout (in seconds) for receiving network traffic from remote
-    SMTP and POP clients. The default is 1800 seconds.
-
-*   --immediate (-m)
-
-    Causes mail messages to be forwarded as they are received, even before they
-    have been accepted. This can be used to do proxying without
-    store-and-forward, but in practice clients tend to to time out while
-    waiting for their mail message to be accepted.
-
-*   --interface \<ip-address-list\> (-I)
-
-    Specifies the IP network addresses or interface names used to bind listening
-    ports. By default listening ports for incoming SMTP, POP and administration
-    connections will bind the 'any' address for IPv4 and for IPv6, ie.
-    *0.0.0.0* and *::*. Multiple addresses can be specified by using the option
-    more than once or by using a comma-separated list. Use a prefix of *smtp=*,
-    *pop=* or *admin=* on addresses that should apply only to those types of
-    listening port. Any link-local IPv6 addresses must include a zone name or
-    scope id.  Interface names can be used instead of addresses, in which case
-    all the addresses associated with that interface at startup will used for
-    listening. When an interface name is decorated with a *-ipv4* or *-ipv6*
-    suffix only their IPv4 or IPv6 addresses will be used (eg. *ppp0-ipv4*).
-
-*   --localedir \<dir\>
-
-    Enables localisation and specifies the locale base directory where message
-    catalogues can be found. An empty directory can be used for the built-in
-    default.
-
-*   --log (-l)
-
-    Enables logging to the standard error stream and to the syslog. The
-    *--close-stderr* and *--no-syslog* options can be used to disable output to
-    standard error stream and the syslog separately. Note that *--as-server*,
-    *--as-client* and *--as-proxy* imply *--log*, and *--as-server* and
-    *--as-proxy* also imply *--close-stderr*.
-
-*   --log-address
-
-    Adds the network address of remote clients to the logging output.
-
-*   --log-file \<file\> (-N)
-
-    Redirects standard-error logging to the specified file. Logging to the log
-    file is not affected by *--close-stderr*. The filename can include *%d* to
-    get daily log files; the *%d* is replaced by the current date in the local
-    timezone using a *YYYYMMDD* format.
-
-*   --log-time (-L)
-
-    Adds a timestamp to the logging output using the local timezone.
-
-*   --no-daemon (-t)
-
-    Disables the normal backgrounding at startup so that the program runs in the
-    foreground, without forking or detaching from the terminal.  On Windows
-    this disables the system tray icon so the program uses a normal window;
-    when the window is closed the program terminates.
-
-*   --no-smtp (-X)
-
-    Disables listening for incoming SMTP connections.
-
-*   --no-syslog (-n)
-
-    Disables logging to the syslog. Note that *--as-client* implies
-    \ *--no-syslog*\ .
-
-*   --pid-file \<pid-file\> (-i)
-
-    Causes the process-id to be written into the specified file when the program
-    starts up, typically after it has become a background daemon.
-
-*   --poll \<period\> (-O)
-
-    Causes forwarding of spooled mail messages to happen at regular intervals
-    (with the time given in seconds).
-
-*   --pop (-B)
-
-    Enables the POP server listening, by default on port 110, providing access to
-    spooled mail messages. Negotiated TLS using the POP *STLS* command will be
-    enabled if the *--server-tls* option is also given.
-
-*   --pop-auth \<file\> (-F)
-
-    Specifies a file containing valid POP account details. The file format is the
-    same as for the SMTP server secrets file, ie. lines starting with *server*,
-    with user-id and password in the third and fourth fields. A special value
-    of */pam* can be used for authentication using linux PAM_.
-
-*   --pop-by-name (-J)
-
-    Modifies the spool directory used by the POP server to be a sub-directory
-    with the same name as the POP authentication user-id. This allows multiple
-    POP clients to read the spooled messages without interfering with each
-    other, particularly when also using *--pop-no-delete*. Content files can
-    stay in the main spool directory with only the envelope files copied into
-    user-specific sub-directories. The *emailrelay-filter-copy* program is a
-    convenient way of doing this when run via *--filter*.
-
-*   --pop-no-delete (-G)
-
-    Disables the POP DELE command so that the command appears to succeed but mail
-    messages are not deleted from the spool directory.
-
-*   --pop-port \<port\> (-E)
-
-    Sets the POP server's listening port number.
-
-*   --port \<port\> (-p)
-
-    Sets the port number used for listening for incoming SMTP connections.
-
-*   --prompt-timeout \<time\> (-w)
-
-    Specifies a timeout (in seconds) for getting the initial prompt from a remote
-    SMTP server. If no prompt is received after this time then the SMTP dialog
-    goes ahead without it.
-
-*   --remote-clients (-r)
-
-    Allows incoming connections from addresses that are not local. The default
-    behaviour is to reject connections that are not local in order to prevent
-    accidental exposure to the public internet, although a firewall should also
-    be used. Local address ranges are defined in RFC-1918_, RFC-6890 etc.
-
-*   --response-timeout \<time\> (-T)
-
-    Specifies a timeout (in seconds) for getting responses from remote SMTP
-    servers. The default is 1800 seconds.
-
-*   --server-auth \<file\> (-S)
-
-    Enables SMTP server authentication of remote SMTP clients. Account names and
-    passwords are taken from the specified secrets file. The secrets file
-    should contain lines that have four space-separated fields, starting with
-    *server* in the first field; the second field is the password encoding
-    (*plain* or *md5*), the third is the client user-id and the fourth is the
-    password. The user-id is RFC-1891_ xtext encoded, and the password is either
-    xtext encoded or generated by *emailrelay-passwd*. A special value of
-    */pam* can be used for authentication using linux PAM.
-
-*   --server-auth-config \<config\>
-
-    Configures the SMTP server authentication module using a semicolon-separated
-    list of configuration items. Each item is a single-character key, followed
-    by a colon and then a comma-separated list. A 'm' character introduces a
-    preferred sub-set of the built-in authentication mechanisms, and an 'x' is
-    used for blocklisted mechanisms.
-
 *   --server-tls (-K)
 
     Enables TLS for incoming SMTP and POP connections. SMTP clients can then
@@ -383,8 +335,8 @@ where \<option\> is:
 
     Defines the TLS certificate file when acting as a SMTP or POP server. This
     file must contain the server's private key and certificate chain using the
-    PEM file format. Alternatively, use this option twice with the first one 
-    specifying the key file and the second the certificate file. Keep the file 
+    PEM file format. Alternatively, use this option twice with the first one
+    specifying the key file and the second the certificate file. Keep the file
     permissions tight to avoid accidental exposure of the private key.
 
 *   --server-tls-connection
@@ -403,24 +355,9 @@ where \<option\> is:
     Enables verification of remote SMTP and POP clients' certificates against any
     of the trusted CA certificates in the specified file or directory. In many
     use cases this should be a file containing just your self-signed root
-    certificate. Specify *\<default\>* for the TLS library's default  set of
+    certificate. Specify *<default>* for the TLS library's default set of
     trusted CAs.
 
-*   --size \<bytes\> (-M)
-
-    Limits the size of mail messages that can be submitted over SMTP.
-
-*   --spool-dir \<dir\> (-s)
-
-    Specifies the directory used for holding mail messages that have been
-    received but not yet forwarded.
-
-*   --syslog[=\<facility\>] (-k)
-
-    When used with *--log* this option enables logging to the syslog even if the
-    *--no-syslog* option is also used. This is typically used as a convenient
-    override when using *--as-client*.
-
 *   --tls-config \<options\> (-9)
 
     Selects and configures the low-level TLS library, using a comma-separated
@@ -429,6 +366,42 @@ where \<option\> is:
     *tlsv1.0* can be used to set a minimum TLS protocol version, or *-tlsv1.2*
     to set a maximum version.
 
+
+*   --dont-serve (-x)
+
+    Disables all network serving, including SMTP, POP and administration
+    interfaces. The program will terminate as soon as any initial forwarding is
+    complete.
+
+*   --hidden (-H)
+
+    Windows only. Hides the application window and disables all message boxes,
+    overriding any *--show* option. This is useful when running as a windows
+    service.
+
+*   --localedir \<dir\>
+
+    Enables localisation and specifies the locale base directory where message
+    catalogues can be found. An empty directory can be used for the built-in
+    default.
+
+*   --no-daemon (-t)
+
+    Disables the normal backgrounding at startup so that the program runs in the
+    foreground, without forking or detaching from the terminal.  On Windows
+    this disables the system tray icon so the program uses a normal window;
+    when the window is closed the program terminates.
+
+*   --no-smtp (-X)
+
+    Disables listening for incoming SMTP connections.
+
+*   --pid-file \<path\> (-i)
+
+    Causes the process-id to be written into the specified file when the program
+    starts up, typically after it has become a background daemon. The immediate
+    parent directory is created if necessary.
+
 *   --user \<username\> (-u)
 
     When started as root the program switches to a non-privileged effective
@@ -436,14 +409,57 @@ where \<option\> is:
     also the group ownership of new files and sockets. Specify *root* to
     disable all user-id switching. Ignored on Windows.
 
+
 *   --verbose (-v)
 
     Enables more verbose logging when used with *--log*, and more verbose help
     when used with *--help*.
 
-*   --version (-V)
+*   --log (-l)
 
-    Displays version information and then exits.
+    Enables logging to the standard error stream and to the syslog. The
+    *--close-stderr* and *--no-syslog* options can be used to disable output to
+    standard error stream and the syslog separately. Note that *--as-server*,
+    *--as-client* and *--as-proxy* imply *--log*, and *--as-server* and
+    *--as-proxy* also imply *--close-stderr*.
+
+*   --debug (-g)
+
+    Enables debug level logging, if built in. Debug messages are usually only
+    useful when cross-referenced with the source code and they may expose
+    plaintext passwords and mail message content.
+
+*   --log-address
+
+    Adds the network address of remote clients to the logging output.
+
+*   --log-file \<file\> (-N)
+
+    Redirects standard-error logging to the specified file. Logging to the log
+    file is not affected by *--close-stderr*. The filename can include *%d* to
+    get daily log files; the *%d* is replaced by the current date in the local
+    timezone using a *YYYYMMDD* format.
+
+*   --log-time (-L)
+
+    Adds a timestamp to the logging output using the local timezone.
+
+*   --no-syslog (-n)
+
+    Disables logging to the syslog. Note that *--as-client* implies
+    \ *--no-syslog*\ .
+
+*   --syslog[=\<facility\>] (-k)
+
+    When used with *--log* this option enables logging to the syslog even if the
+    *--no-syslog* option is also used. This is typically used as a convenient
+    override when using *--as-client*.
+
+*   --close-stderr (-e)
+
+    Causes the standard error stream to be closed soon after start-up. This is
+    useful when operating as a background daemon and it is therefore implied by
+    *--as-server* and *--as-proxy*.
 
 A configuration file can be used to provide additional options; put each
 option on a separate line, use the long option names but without the double
@@ -800,7 +816,7 @@ suitable for testing:
 
 ::
 
-    $ openssl req -x509 -nodes -subj "/CN=$USER" -newkey rsa:2048 -keyout emailrelay.pem  -out emailrelay.pem
+    $ openssl req -x509 -noenc -subj "/CN=$USER" -newkey rsa:2048 -keyout emailrelay.pem  -out emailrelay.pem
 
 TLS performs encryption to prevent eavesdropping, but it does not necessarily
 do authentication to prevent man-in-the-middle attacks. For full TLS
@@ -839,17 +855,13 @@ like the following:
 ::
 
     auth requisite pam_unix.so nullok_secure
-    session required pam_permit.so
-    account required pam_permit.so
-    password required pam_deny.so
 
 With this configuration the E-MailRelay server will use normal unix system
 account names and passwords to authenticate remote clients. On some systems
 this will require special permissioning to allow the E-MailRelay server to
-read the shadow password database.
-
-When using PAM authentication E-MailRelay requires that remote clients
-establish an encrypted session using TLS before authentication can proceed.
+read the shadow password database, so run the server as *root* and also add the
+*--user=root* command-line option to make sure that the process's effective
+user-id stays as *root* while it accesses the PAM system.
 
 IP addresses
 ============
@@ -1207,9 +1219,6 @@ checked.
 Security issues
 ===============
 The following are some security issues that have been taken into consideration:
-
-*   Effective userid
-
     Suid privileges are revoked at start-up, switching the effective
     userid/groupid to be the real userid/groupid values. If started as *root*
     then the effective userid/groupid are switched at start-up to those of user
@@ -1220,33 +1229,21 @@ The following are some security issues that have been taken into consideration:
     groupid, so that new files have group ownership corresponding to the
     *daemon* user.
 
-*   Execution environment
-
     The external filter programs are run with an almost empty set of environment
     variables (*PATH* and *IFS*), and with no open file descriptors other than
     *stdin* and *stderr* open onto */dev/null*, and *stdout* open onto a pipe.
 
-*   Umask
-
-    The program runs for most of the time with a *umask* of 177, switching to 117
+    The program runs for most of the time with a *umask* of 077, switching to 007
     when creating spool files.
 
-*   Remote clients
-
     By default connections will be rejected if they come from remote machines.
 
-*   Remote configuration
-
     No configuration parameters can be changed through the administrative
     interface.
 
-*   Use of exec() and system()
-
     No exec(), system() or popen() calls are used other than execve() to spawn the
     mail filter and/or address verifier.
 
-*   File permissions
-
     After a normal installation the spool directory is has ownership of
     *root.daemon* with permissions of *-rwxrwxr-x* and messages files are created
     with permissions of *-rw-rw----*. This allows normal users to list messages
@@ -1257,21 +1254,15 @@ The following are some security issues that have been taken into consideration:
     spool directory, and the files created end up owned by the submitter but with
     group ownership of *daemon*.
 
-*   Logging
-
     Logging output is conditioned so that ANSI escape sequences cannot appear
     in the log.
 
     Passwords and message content are not logged (except if using the *--debug*
     option at run time with debug logging enabled at build time).
 
-*   Information leakage
-
     The *--anonymous* option can be used to reduce the amount of information
     leaked to remote clients.
 
-*   Mandatory encryption
-
     When using PAM for authentication all clients are required to use
     TLS/SSL encryption.
 
@@ -1328,6 +1319,30 @@ and *Cc* message recipients.
 An E-MailRelay *--filter* script can be used to reject messages with incorrect
 *Bcc:* headers, and an example script is included.
 
+Routing
+=======
+E-MailRelay does not normally do any routing of e-mail messages; they are
+all forwarded to a fixed *smarthost* address given by the *--forward-to* or
+*--as-client* command-line options.
+
+However, each message envelope file contains a *ForwardToAddress* field that
+can be populated by filter scripts in order to route the message to some other
+server.
+
+If the *ForwardTo* field has any non-empty value then E-MailRelay runs its
+client filter early to allow the client filter script to set or update the
+*ForwardToAddress* before the outgoing connection is made. (The client filter is
+run a second time as normal once the connection is made and the SMTP session has
+been established.)
+
+Typically a *--filter* script would be used to examine the message content and
+populate the *ForwardTo* field, then a *--client-filter* script would use
+the *ForwardTo* value to populate the *ForwardToAddress* field with an up-to-date
+forwarding address.
+
+Note that a successful connection to the smarthost is required even if a message
+is routed elsewhere.
+
 Files and directories
 =====================
 On Unix-like systems E-MailRelay installs by default under */usr/local*, but
@@ -1391,4 +1406,4 @@ and these default to *%ProgramFiles%/E-MailRelay* for programs and
 .. _SOCKS: https://en.wikipedia.org/wiki/SOCKS
 .. _TLS: https://en.wikipedia.org/wiki/Transport_Layer_Security
 
-.. footer:: Copyright (C) 2001-2021 Graeme Walker
+.. footer:: Copyright (C) 2001-2022 Graeme Walker
diff --git a/doc/reference.txt b/doc/reference.txt
index b1f2787..f4c8148 100644
--- a/doc/reference.txt
+++ b/doc/reference.txt
@@ -7,193 +7,117 @@ The "emailrelay" program supports the following command-line usage:
 
 	emailrelay [<option> [<option> ...]] [<config-file>]
 
-where <option> is:
+# Basic options
 
-# --address-verifier <program>
-  Runs the specified external program to verify a message recipent's e-mail
-  address. A network verifier can be specified as "net:<transport-address>".
-
-# --admin <admin-port> (-a)
-  Enables an administration interface on the specified listening port number.
-  Use telnet or something similar to connect. The administration interface
-  can be used to trigger forwarding of spooled mail messages if the
-  "--forward-to" option is used.
-
-# --admin-terminate (-Q)
-  Enables the "terminate" command in the administration interface.
-
-# --anonymous (-A)
-  Disables the server's SMTP VRFY command, sends less verbose SMTP responses
-  and SMTP greeting, and stops "Received" lines being added to mail message
-  content files.
-
-# --as-client <host:port> (-q)
+* --as-client <host:port> (-q)
   This is equivalent to "--log", "--no-syslog", "--no-daemon", "--dont-serve",
   "--forward" and "--forward-to". It is a convenient way of running a
   forwarding agent that forwards spooled mail messages and then terminates.
-
-# --as-proxy <host:port> (-y)
+* --as-proxy <host:port> (-y)
   This is equivalent to "--log", "--close-stderr", "--forward-on-disconnect"
   and "--forward-to". It is a convenient way of running a store-and-forward
   daemon. Use "--log", "--forward-on-disconnect" and "--forward-to" instead
   of "--as-proxy" to keep the standard error stream open.
-
-# --as-server (-d)
+* --as-server (-d)
   This is equivalent to "--log" and "--close-stderr". It is a convenient way of
   running a background storage daemon that accepts mail messages and spools
   them. Use "--log" instead of "--as-server" to keep standard error stream
   open.
+* --spool-dir <dir> (-s)
+  Specifies the directory used for holding mail messages that have been
+  received but not yet forwarded.
+* --help (-h)
+  Displays help text and then exits. Use with "--verbose" for more complete
+  output.
+* --version (-V)
+  Displays version information and then exits.
 
-# --client-auth <file> (-C)
-  Enables SMTP client authentication with the remote server, using the client
-  account details taken from the specified secrets file. The secrets file
-  should normally contain one line that starts with "client" and that line
-  should have between four and five space-separated fields; the second field
-  is the password encoding ("plain" or "md5"), the third is the user-id and
-  the fourth is the password. The user-id is RFC-1891 xtext encoded, and the
-  password is either xtext encoded or generated by "emailrelay-passwd". If
-  the remote server does not support SMTP authentication then the SMTP
-  connection will fail.
+# SMTP client options
 
-# --client-auth-config <config>
-  Configures the SMTP client authentication module using a semicolon-separated
-  list of configuration items. Each item is a single-character key, followed
-  by a colon and then a comma-separated list. A 'm' character introduces an
-  ordered list of authentication mechanisms, and an 'x' is used for
-  blocklisted mechanisms.
-
-# --client-filter <program> (-Y)
+* --forward (-f)
+  Causes spooled mail messages to be forwarded when the program first starts.
+* --forward-on-disconnect (-1)
+  Causes spooled mail messages to be forwarded whenever a SMTP client
+  connection disconnects.
+* --forward-to <host:port> (-o)
+  Specifies the transport address of the remote SMTP server that spooled mail
+  messages are forwarded to.
+* --poll <period> (-O)
+  Causes forwarding of spooled mail messages to happen at regular intervals
+  (with the time given in seconds).
+* --client-filter <program> (-Y)
   Runs the specified external filter program whenever a mail message is
   forwarded. The filter is passed the name of the message file in the spool
   directory so that it can edit it as required. A network filter can be
-  specified as "net:<transport-address>" and prefixes of "spam:",
-  "spam-edit:" and "exit:" are also allowed. The "spam:" and "spam-edit:"
-  prefixes require a SpamAssassin daemon to be running. For store-and-forward
-  applications the "--filter" option is normally more useful than
-  "--client-filter".
-
-# --client-interface <ip-address> (-6)
+  specified as "net:<tcp-address>" and prefixes of "spam:", "spam-edit:" and
+  "exit:" are also allowed. The "spam:" and "spam-edit:" prefixes require a
+  SpamAssassin daemon to be running. For store-and-forward applications the
+  "--filter" option is normally more useful than "--client-filter".
+* --client-interface <ip-address> (-6)
   Specifies the IP network address to be used to bind the local end of outgoing
   SMTP connections. By default the address will depend on the routing tables
   in the normal way. Use "0.0.0.0" to use only IPv4 addresses returned from
   DNS lookups of the "--forward-to" address, or "::" for IPv6.
-
-# --client-tls (-j)
-  Enables negotiated TLS for outgoing SMTP connections; the SMTP STARTTLS
-  command will be issued if the remote server supports it.
-
-# --client-tls-certificate <pem-file>
-  Defines the TLS certificate file when acting as a SMTP client. This file must
-  contain the client's private key and certificate chain using the PEM file
-  format. Alternatively, use this option twice with the first one specifying
-  the key file and the second the certificate file. Keep the file permissions
-  tight to avoid accidental exposure of the private key.
-
-# --client-tls-connection (-b)
-  Enables the use of a TLS tunnel for outgoing SMTP connections. This is for
-  SMTP over TLS (SMTPS), not TLS negotiated within SMTP using STARTTLS.
-
-# --client-tls-required
-  Makes the use of TLS mandatory for outgoing SMTP connections. The SMTP
-  STARTTLS command will be used before mail messages are sent out. If the
-  remote server does not allow STARTTLS then the SMTP connection will fail.
-
-# --client-tls-server-name <hostname>
-  Defines the target server hostname in the TLS handshake. With
-  "--client-tls-connection" this can be used for SNI, allowing the remote
-  server to adopt an appropriate identity.
-
-# --client-tls-verify <ca-list>
-  Enables verification of the remote SMTP server's certificate against any of
-  the trusted CA certificates in the specified file or directory. In many use
-  cases this should be a file containing just your self-signed root
-  certificate. Specify "<default>" for the TLS library's default set of
-  trusted CAs.
-
-# --client-tls-verify-name <cname>
-  Enables verification of the CNAME within the remote SMTP server's
-  certificate.
-
-# --close-stderr (-e)
-  Causes the standard error stream to be closed soon after start-up. This is
-  useful when operating as a background daemon and it is therefore implied by
-  "--as-server" and "--as-proxy".
-
-# --connection-timeout <time> (-U)
+* --connection-timeout <time> (-U)
   Specifies a timeout (in seconds) for establishing a TCP connection to remote
   SMTP servers. The default is 40 seconds.
-
-# --debug (-g)
-  Enables debug level logging, if built in. Debug messages are usually only
-  useful when cross-referenced with the source code and they may expose
-  plaintext passwords and mail message content.
-
-# --dnsbl <config>
-  Specifies a list of DNSBL servers that are used to reject SMTP connections
-  from blocked addresses. The configuration string is made up of
-  comma-separated fields: the DNS server's transport address, a timeout in
-  milliseconds, a rejection threshold, and then the list of DNSBL servers.
-
-# --domain <fqdn> (-D)
-  Specifies the network name that is used in SMTP EHLO commands, "Received"
-  lines, and for generating authentication challenges. The default is derived
-  from a DNS lookup of the local hostname.
-
-# --dont-serve (-x)
-  Disables all network serving, including SMTP, POP and administration
-  interfaces. The program will terminate as soon as any initial forwarding is
-  complete.
-
-# --filter <program> (-z)
-  Runs the specified external filter program whenever a mail message is stored.
-  The filter is passed the name of the message file in the spool directory so
-  that it can edit it as required. The mail message is rejected if the filter
-  program terminates with an exit code between 1 and 99. Use
-  "net:<transport-address>" to communicate with a filter daemon over the
-  network, or "spam:<transport-address>" for a spamassassin spamd daemon to
-  accept or reject mail messages, or "spam-edit:<transport-address>" to have
-  spamassassin edit the message content without rejecting it, or
-  "exit:<number>" to emulate a filter program that just exits.
-
-# --filter-timeout <time> (-W)
-  Specifies a timeout (in seconds) for running a "--filter" program. The
-  default is 300 seconds.
-
-# --forward (-f)
-  Causes spooled mail messages to be forwarded when the program first starts.
-
-# --forward-on-disconnect (-1)
-  Causes spooled mail messages to be forwarded whenever a SMTP client
-  connection disconnects.
-
-# --forward-to <host:port> (-o)
-  Specifies the transport address of the remote SMTP server that is use for
-  mail message forwarding.
-
-# --forward-to-some
+* --idle-timeout <time>
+  Specifies a timeout (in seconds) for receiving network traffic from remote
+  SMTP and POP clients. The default is 60 seconds.
+* --response-timeout <time> (-T)
+  Specifies a timeout (in seconds) for getting responses from remote SMTP
+  servers. The default is 60 seconds.
+* --forward-to-some
   Allow forwarding to continue even if some recipient addresses on an e-mail
   envelope are rejected by the remote server.
-
-# --help (-h)
-  Displays help text and then exits. Use with "--verbose" for more complete
-  output.
-
-# --hidden (-H)
-  Windows only. Hides the application window and disables all message boxes,
-  overriding any "--show" option. This is useful when running as a windows
-  service.
-
-# --idle-timeout <time>
-  Specifies a timeout (in seconds) for receiving network traffic from remote
-  SMTP and POP clients. The default is 1800 seconds.
-
-# --immediate (-m)
+* --immediate (-m)
   Causes mail messages to be forwarded as they are received, even before they
   have been accepted. This can be used to do proxying without
   store-and-forward, but in practice clients tend to to time out while
   waiting for their mail message to be accepted.
 
-# --interface <ip-address-list> (-I)
+# SMTP server options
+
+* --port <port> (-p)
+  Sets the port number used for listening for incoming SMTP connections.
+* --remote-clients (-r)
+  Allows incoming connections from addresses that are not local. The default
+  behaviour is to reject connections that are not local in order to prevent
+  accidental exposure to the public internet, although a firewall should also
+  be used. Local address ranges are defined in RFC-1918, RFC-6890 etc.
+* --address-verifier <program>
+  Runs the specified external program to verify a message recipent's e-mail
+  address. A network verifier can be specified as "net:<tcp-address>".
+* --anonymous[=<scope>] (-A)
+  Disables the server's SMTP VRFY command, sends less verbose SMTP greeting and
+  responses, stops "Received" lines being added to mail message content
+  files, and stops the SMTP client protocol adding "AUTH=" to the "MAIL"
+  command. For finer control use a comma-separated list of things to
+  anonymise: "vrfy", "server", "content" and/or "client", eg.
+  "--anonymous"=server,content.
+* --dnsbl <config>
+  Specifies a list of DNSBL servers that are used to reject SMTP connections
+  from blocked addresses. The configuration string is made up of
+  comma-separated fields: the DNS server's transport address, a timeout in
+  milliseconds, a rejection threshold, and then the list of DNSBL servers.
+* --domain <fqdn> (-D)
+  Specifies the network name that is used in SMTP EHLO commands, "Received"
+  lines, and for generating authentication challenges. The default is derived
+  from a DNS lookup of the local hostname.
+* --filter <program> (-z)
+  Runs the specified external filter program whenever a mail message is stored.
+  The filter is passed the name of the message file in the spool directory so
+  that it can edit it as required. The mail message is rejected if the filter
+  program terminates with an exit code between 1 and 99. Use
+  "net:<tcp-address>" to communicate with a filter daemon over the network,
+  or "spam:<tcp-address>" for a spamassassin spamd daemon to accept or reject
+  mail messages, or "spam-edit:<tcp-address>" to have spamassassin edit the
+  message content without rejecting it, or "exit:<number>" to emulate a
+  filter program that just exits.
+* --filter-timeout <time> (-W)
+  Specifies a timeout (in seconds) for running a "--filter" program. The
+  default is 60 seconds.
+* --interface <ip-address-list> (-I)
   Specifies the IP network addresses or interface names used to bind listening
   ports. By default listening ports for incoming SMTP, POP and administration
   connections will bind the 'any' address for IPv4 and for IPv6, ie.
@@ -205,98 +129,66 @@ where <option> is:
   all the addresses associated with that interface at startup will used for
   listening. When an interface name is decorated with a "-ipv4" or "-ipv6"
   suffix only their IPv4 or IPv6 addresses will be used (eg. "ppp0-ipv4").
+  To inherit listening file descriptors from the parent process on unix use a
+  syntax like this: "--interface"=smtp=fd#3,smtp=fd#4,pop=fd#5.
+* --prompt-timeout <time> (-w)
+  Specifies a timeout (in seconds) for getting the initial prompt from a remote
+  SMTP server. If no prompt is received after this time then the SMTP dialog
+  goes ahead without it.
+* --size <bytes> (-M)
+  Limits the size of mail messages that can be submitted over SMTP.
 
-# --localedir <dir>
-  Enables localisation and specifies the locale base directory where message
-  catalogues can be found. An empty directory can be used for the built-in
-  default.
+# POP server options
 
-# --log (-l)
-  Enables logging to the standard error stream and to the syslog. The
-  "--close-stderr" and "--no-syslog" options can be used to disable output to
-  standard error stream and the syslog separately. Note that "--as-server",
-  "--as-client" and "--as-proxy" imply "--log", and "--as-server" and
-  "--as-proxy" also imply "--close-stderr".
-
-# --log-address
-  Adds the network address of remote clients to the logging output.
-
-# --log-file <file> (-N)
-  Redirects standard-error logging to the specified file. Logging to the log
-  file is not affected by "--close-stderr". The filename can include "%d" to
-  get daily log files; the "%d" is replaced by the current date in the local
-  timezone using a "YYYYMMDD" format.
-
-# --log-time (-L)
-  Adds a timestamp to the logging output using the local timezone.
-
-# --no-daemon (-t)
-  Disables the normal backgrounding at startup so that the program runs in the
-  foreground, without forking or detaching from the terminal.  On Windows
-  this disables the system tray icon so the program uses a normal window;
-  when the window is closed the program terminates.
-
-# --no-smtp (-X)
-  Disables listening for incoming SMTP connections.
-
-# --no-syslog (-n)
-  Disables logging to the syslog. Note that "--as-client" implies
-  "--no-syslog".
-
-# --pid-file <pid-file> (-i)
-  Causes the process-id to be written into the specified file when the program
-  starts up, typically after it has become a background daemon.
-
-# --poll <period> (-O)
-  Causes forwarding of spooled mail messages to happen at regular intervals
-  (with the time given in seconds).
-
-# --pop (-B)
-  Enables the POP server listening, by default on port 110, providing access to
+* --pop (-B)
+  Enables the POP server, listening by default on port 110, providing access to
   spooled mail messages. Negotiated TLS using the POP "STLS" command will be
   enabled if the "--server-tls" option is also given.
-
-# --pop-auth <file> (-F)
-  Specifies a file containing valid POP account details. The file format is the
-  same as for the SMTP server secrets file, ie. lines starting with "server",
-  with user-id and password in the third and fourth fields. A special value
-  of "/pam" can be used for authentication using linux PAM.
-
-# --pop-by-name (-J)
+* --pop-by-name (-J)
   Modifies the spool directory used by the POP server to be a sub-directory
   with the same name as the POP authentication user-id. This allows multiple
-  POP clients to read the spooled messages without interfering with each
+  POP clients to read the spooled mail messages without interfering with each
   other, particularly when also using "--pop-no-delete". Content files can
   stay in the main spool directory with only the envelope files copied into
   user-specific sub-directories. The "emailrelay-filter-copy" program is a
   convenient way of doing this when run via "--filter".
-
-# --pop-no-delete (-G)
+* --pop-no-delete (-G)
   Disables the POP DELE command so that the command appears to succeed but mail
   messages are not deleted from the spool directory.
-
-# --pop-port <port> (-E)
+* --pop-port <port> (-E)
   Sets the POP server's listening port number.
 
-# --port <port> (-p)
-  Sets the port number used for listening for incoming SMTP connections.
+# Admin server options
 
-# --prompt-timeout <time> (-w)
-  Specifies a timeout (in seconds) for getting the initial prompt from a remote
-  SMTP server. If no prompt is received after this time then the SMTP dialog
-  goes ahead without it.
+* --admin <port> (-a)
+  Enables an administration interface on the specified listening port number.
+  Use telnet or something similar to connect. The administration interface
+  can be used to trigger forwarding of spooled mail messages if the
+  "--forward-to" option is used.
+* --admin-terminate (-Q)
+  Enables the "terminate" command in the administration interface.
 
-# --remote-clients (-r)
-  Allows incoming connections from addresses that are not local. The default
-  behaviour is to reject connections that are not local in order to prevent
-  accidental exposure to the public internet, although a firewall should also
-  be used. Local address ranges are defined in RFC-1918, RFC-6890 etc.
+# Authentication options
 
-# --response-timeout <time> (-T)
-  Specifies a timeout (in seconds) for getting responses from remote SMTP
-  servers. The default is 1800 seconds.
-
-# --server-auth <file> (-S)
+* --client-auth <file> (-C)
+  Enables SMTP client authentication with the remote server, using the client
+  account details taken from the specified secrets file. The secrets file
+  should normally contain one line that starts with "client" and that line
+  should have between four and five space-separated fields; the second field
+  is the password encoding ("plain" or "md5"), the third is the user-id and
+  the fourth is the password. The user-id is RFC-1891 xtext encoded, and the
+  password is either xtext encoded or generated by "emailrelay-passwd". If
+  the remote server does not support SMTP authentication then the SMTP
+  connection will fail.
+* --client-auth-config <config>
+  Configures the SMTP client authentication module using a semicolon-separated
+  list of configuration items. Each item is a single-character key, followed
+  by a colon and then a comma-separated list. A 'm' character introduces an
+  ordered list of preferred authentication mechanisms and an 'x' introduces a
+  list of mechanisms to avoid. An 'a' list and a 'd' list can be used
+  similarly to prefer and avoid certain mechanisms once the session is
+  encrypted with TLS.
+* --server-auth <file> (-S)
   Enables SMTP server authentication of remote SMTP clients. Account names and
   passwords are taken from the specified secrets file. The secrets file
   should contain lines that have four space-separated fields, starting with
@@ -305,74 +197,149 @@ where <option> is:
   password. The user-id is RFC-1891 xtext encoded, and the password is either
   xtext encoded or generated by "emailrelay-passwd". A special value of
   "/pam" can be used for authentication using linux PAM.
-
-# --server-auth-config <config>
+* --server-auth-config <config>
   Configures the SMTP server authentication module using a semicolon-separated
   list of configuration items. Each item is a single-character key, followed
-  by a colon and then a comma-separated list. A 'm' character introduces a
-  preferred sub-set of the built-in authentication mechanisms, and an 'x' is
-  used for blocklisted mechanisms.
+  by a colon and then a comma-separated list. A 'm' character introduces an
+  ordered list of allowed authentication mechanisms and an 'x' introduces a
+  list of mechanisms to deny. An 'a' list and a 'd' list can be used
+  similarly to allow and deny mechanisms once the session is encrypted with
+  TLS. In typical usage you might have an empty allow list for an unencrypted
+  session and a single preferred mechanism once encrypted, "m:;a:plain".
+* --pop-auth <file> (-F)
+  Specifies a file containing valid POP account details. The file format is the
+  same as for the SMTP server secrets file, ie. lines starting with "server",
+  with user-id and password in the third and fourth fields. A special value
+  of "/pam" can be used for authentication using linux PAM.
 
-# --server-tls (-K)
+# TLS options
+
+* --client-tls (-j)
+  Enables negotiated TLS for outgoing SMTP connections; the SMTP STARTTLS
+  command will be issued if the remote server supports it.
+* --client-tls-certificate <pem-file>
+  Defines the TLS certificate file when acting as a SMTP client. This file must
+  contain the client's private key and certificate chain using the PEM file
+  format. Alternatively, use this option twice with the first one specifying
+  the key file and the second the certificate file. Keep the file permissions
+  tight to avoid accidental exposure of the private key.
+* --client-tls-connection (-b)
+  Enables the use of a TLS tunnel for outgoing SMTP connections. This is for
+  SMTP over TLS (SMTPS), not TLS negotiated within SMTP using STARTTLS.
+* --client-tls-required
+  Makes the use of TLS mandatory for outgoing SMTP connections. The SMTP
+  STARTTLS command will be used before mail messages are sent out. If the
+  remote server does not allow STARTTLS then the SMTP connection will fail.
+* --client-tls-server-name <hostname>
+  Defines the target server hostname in the TLS handshake. With
+  "--client-tls-connection" this can be used for SNI, allowing the remote
+  server to adopt an appropriate identity.
+* --client-tls-verify <ca-list>
+  Enables verification of the remote SMTP server's certificate against any of
+  the trusted CA certificates in the specified file or directory. In many use
+  cases this should be a file containing just your self-signed root
+  certificate. Specify "<default>" for the TLS library's default set of
+  trusted CAs.
+* --client-tls-verify-name <cname>
+  Enables verification of the CNAME within the remote SMTP server's
+  certificate.
+* --server-tls (-K)
   Enables TLS for incoming SMTP and POP connections. SMTP clients can then
   request TLS encryption by issuing the STARTTLS command. The
   "--server-tls-certificate" option must be used to define the server
   certificate.
-
-# --server-tls-certificate <pem-file>
+* --server-tls-certificate <pem-file>
   Defines the TLS certificate file when acting as a SMTP or POP server. This
   file must contain the server's private key and certificate chain using the
   PEM file format. Alternatively, use this option twice with the first one
   specifying the key file and the second the certificate file. Keep the file
   permissions tight to avoid accidental exposure of the private key.
-
-# --server-tls-connection
+* --server-tls-connection
   Enables SMTP over TLS when acting as an SMTP server. This is for SMTP over
   TLS (SMTPS), not TLS negotiated within SMTP using STARTTLS.
-
-# --server-tls-required
+* --server-tls-required
   Makes the use of TLS mandatory for any incoming SMTP and POP connections.
   SMTP clients must use the STARTTLS command to establish a TLS session
   before they can issue SMTP AUTH or SMTP MAIL-TO commands.
-
-# --server-tls-verify <ca-list>
+* --server-tls-verify <ca-list>
   Enables verification of remote SMTP and POP clients' certificates against any
   of the trusted CA certificates in the specified file or directory. In many
   use cases this should be a file containing just your self-signed root
   certificate. Specify "<default>" for the TLS library's default set of
   trusted CAs.
-
-# --size <bytes> (-M)
-  Limits the size of mail messages that can be submitted over SMTP.
-
-# --spool-dir <dir> (-s)
-  Specifies the directory used for holding mail messages that have been
-  received but not yet forwarded.
-
-# --syslog[=<facility>] (-k)
-  When used with "--log" this option enables logging to the syslog even if the
-  "--no-syslog" option is also used. This is typically used as a convenient
-  override when using "--as-client".
-
-# --tls-config <options> (-9)
+* --tls-config <options> (-9)
   Selects and configures the low-level TLS library, using a comma-separated
   list of keywords. If OpenSSL and mbedTLS are both built in then keywords of
   "openssl" and "mbedtls" will select one or the other. Keywords like
   "tlsv1.0" can be used to set a minimum TLS protocol version, or "-tlsv1.2"
   to set a maximum version.
 
-# --user <username> (-u)
+# Process options
+
+* --dont-serve (-x)
+  Disables all network serving, including SMTP, POP and administration
+  interfaces. The program will terminate as soon as any initial forwarding is
+  complete.
+* --hidden (-H)
+  Windows only. Hides the application window and disables all message boxes,
+  overriding any "--show" option. This is useful when running as a windows
+  service.
+* --localedir <dir>
+  Enables localisation and specifies the locale base directory where message
+  catalogues can be found. An empty directory can be used for the built-in
+  default.
+* --no-daemon (-t)
+  Disables the normal backgrounding at startup so that the program runs in the
+  foreground, without forking or detaching from the terminal.  On Windows
+  this disables the system tray icon so the program uses a normal window;
+  when the window is closed the program terminates.
+* --no-smtp (-X)
+  Disables listening for incoming SMTP connections.
+* --pid-file <path> (-i)
+  Causes the process-id to be written into the specified file when the program
+  starts up, typically after it has become a background daemon. The immediate
+  parent directory is created if necessary.
+* --user <username> (-u)
   When started as root the program switches to a non-privileged effective
   user-id when idle. This option can be used to define the idle user-id and
   also the group ownership of new files and sockets. Specify "root" to
   disable all user-id switching. Ignored on Windows.
 
-# --verbose (-v)
+# Logging options
+
+* --verbose (-v)
   Enables more verbose logging when used with "--log", and more verbose help
   when used with "--help".
-
-# --version (-V)
-  Displays version information and then exits.
+* --log (-l)
+  Enables logging to the standard error stream and to the syslog. The
+  "--close-stderr" and "--no-syslog" options can be used to disable output to
+  standard error stream and the syslog separately. Note that "--as-server",
+  "--as-client" and "--as-proxy" imply "--log", and "--as-server" and
+  "--as-proxy" also imply "--close-stderr".
+* --debug (-g)
+  Enables debug level logging, if built in. Debug messages are usually only
+  useful when cross-referenced with the source code and they may expose
+  plaintext passwords and mail message content.
+* --log-address
+  Adds the network address of remote clients to the logging output.
+* --log-file <file> (-N)
+  Redirects standard-error logging to the specified file. Logging to the log
+  file is not affected by "--close-stderr". The filename can include "%d" to
+  get daily log files; the "%d" is replaced by the current date in the local
+  timezone using a "YYYYMMDD" format.
+* --log-time (-L)
+  Adds a timestamp to the logging output using the local timezone.
+* --no-syslog (-n)
+  Disables logging to the syslog. Note that "--as-client" implies
+  "--no-syslog".
+* --syslog[=<facility>] (-k)
+  When used with "--log" this option enables logging to the syslog even if the
+  "--no-syslog" option is also used. This is typically used as a convenient
+  override when using "--as-client".
+* --close-stderr (-e)
+  Causes the standard error stream to be closed soon after start-up. This is
+  useful when operating as a background daemon and it is therefore implied by
+  "--as-server" and "--as-proxy".
 
 A configuration file can be used to provide additional options; put each
 option on a separate line, use the long option names but without the double
@@ -709,7 +676,7 @@ key.
 This OpenSSL command can be used to create a self-signed certificate file
 suitable for testing:
 
-	$ openssl req -x509 -nodes -subj "/CN=$USER" -newkey rsa:2048 -keyout emailrelay.pem  -out emailrelay.pem
+	$ openssl req -x509 -noenc -subj "/CN=$USER" -newkey rsa:2048 -keyout emailrelay.pem  -out emailrelay.pem
 
 TLS performs encryption to prevent eavesdropping, but it does not necessarily
 do authentication to prevent man-in-the-middle attacks. For full TLS
@@ -746,17 +713,13 @@ normally involves creating a file "/etc/pam.d/emailrelay" containing something
 like the following:
 
 	auth requisite pam_unix.so nullok_secure
-	session required pam_permit.so
-	account required pam_permit.so
-	password required pam_deny.so
 
 With this configuration the E-MailRelay server will use normal unix system
 account names and passwords to authenticate remote clients. On some systems
 this will require special permissioning to allow the E-MailRelay server to
-read the shadow password database.
-
-When using PAM authentication E-MailRelay requires that remote clients
-establish an encrypted session using TLS before authentication can proceed.
+read the shadow password database, so run the server as "root" and also add the
+"--user=root" command-line option to make sure that the process's effective
+user-id stays as "root" while it accesses the PAM system.
 
 IP addresses
 ------------
@@ -1076,7 +1039,7 @@ The following are some security issues that have been taken into consideration:
 
 # Umask
 
-  The program runs for most of the time with a "umask" of 177, switching to 117
+  The program runs for most of the time with a "umask" of 077, switching to 007
   when creating spool files.
 
 # Remote clients
@@ -1174,6 +1137,30 @@ and "Cc" message recipients.
 An E-MailRelay "--filter" script can be used to reject messages with incorrect
 "Bcc:" headers, and an example script is included.
 
+Routing
+-------
+E-MailRelay does not normally do any routing of e-mail messages; they are
+all forwarded to a fixed "smarthost" address given by the "--forward-to" or
+"--as-client" command-line options.
+
+However, each message envelope file contains a "ForwardToAddress" field that
+can be populated by filter scripts in order to route the message to some other
+server.
+
+If the "ForwardTo" field has any non-empty value then E-MailRelay runs its
+client filter early to allow the client filter script to set or update the
+"ForwardToAddress" before the outgoing connection is made. (The client filter is
+run a second time as normal once the connection is made and the SMTP session has
+been established.)
+
+Typically a "--filter" script would be used to examine the message content and
+populate the "ForwardTo" field, then a "--client-filter" script would use
+the "ForwardTo" value to populate the "ForwardToAddress" field with an up-to-date
+forwarding address.
+
+Note that a successful connection to the smarthost is required even if a message
+is routed elsewhere.
+
 Files and directories
 ---------------------
 On Unix-like systems E-MailRelay installs by default under "/usr/local", but
@@ -1218,4 +1205,4 @@ and these default to "%ProgramFiles%/E-MailRelay" for programs and
 
 
 _____________________________________
-Copyright (C) 2001-2021 Graeme Walker
+Copyright (C) 2001-2022 Graeme Walker
diff --git a/doc/serverclient.png b/doc/serverclient.png
index 4acec6d..eaeb258 100644
Binary files a/doc/serverclient.png and b/doc/serverclient.png differ
diff --git a/doc/serverclient.svg b/doc/serverclient.svg
index d261db0..1dafd68 100644
--- a/doc/serverclient.svg
+++ b/doc/serverclient.svg
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <!-- Created with Inkscape (http://www.inkscape.org/) -->
-<!-- Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
+<!-- Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
 
 <svg
    xmlns:dc="http://purl.org/dc/elements/1.1/"
diff --git a/doc/userguide.html b/doc/userguide.html
index 0d75fe1..472e375 100644
--- a/doc/userguide.html
+++ b/doc/userguide.html
@@ -1,4 +1,4 @@
-<!DOCTYPE HTML PUBLIC "%-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
+<!DOCTYPE html>
 <html>
  <head>
   <title>E-MailRelay User Guide</title>
@@ -8,7 +8,7 @@
  <body>
   <!-- index:0::::E-MailRelay User Guide -->
  <div class="div-main">
-  <h1><a class="a-header" name="H_1">E-MailRelay User Guide</a></h1> <!-- index:1:H:1::E-MailRelay User Guide -->
+  <h1><a class="a-header" name="H_1">E-MailRelay User Guide</a></h1> <!-- index:1:H:E-MailRelay User Guide -->
    <h2><a class="a-header" name="SH_1_1">What is it?</a></h2> <!-- index:2:SH:1:1:What is it? -->
     <p>
      E-MailRelay is an e-mail store-and-forward message transfer agent and proxy
@@ -44,9 +44,9 @@
     </p>
    <h2><a class="a-header" name="SH_1_2">What it's not</a></h2> <!-- index:2:SH:1:2:What it's not -->
     <p>
-     E-MailRelay does not do routing of individual messages; it is not a routing MTA.
-     It forwards all e-mail messages to a pre-configured SMTP server, regardless of
-     any message addressing or DNS redirects.
+     E-MailRelay does not normally do routing of individual messages; it is not a
+     routing MTA. It forwards all e-mail messages to a pre-configured SMTP server,
+     regardless of any message addressing or DNS redirects.
     </p>
    <h2><a class="a-header" name="SH_1_3">Why use it?</a></h2> <!-- index:2:SH:1:3:Why use it? -->
     <p>
@@ -447,32 +447,49 @@ exit 0</pre>
       </div><!-- div-pre -->
    <h2><a class="a-header" name="SH_1_14">Google mail</a></h2> <!-- index:2:SH:1:14:Google mail -->
     <p>
-     To send mail via Google mail's SMTP gateway you will need to create a client
-     secrets file containing your account details and also enable TLS support in
-     E-MailRelay by using the <em>--client-tls</em> option.
+     To send mail via Google mail's SMTP gateway you will need to obtain a new
+     <em>application password</em> from Google. Log in to your Google account and look for
+     the account's security settings and then <em>app passwords</em>. Create the password
+     for E-MailRelay as application type <em>other</em>.
     </p>
 
     <p>
-     The secrets file should contain one line of text something like this:
+     Then you need to create a client secrets file for E-MailRelay containing your
+     account name and the new application password. You may already have this file
+     on Windows as <em>C:\ProgramData\E-MailRelay\emailrelay.auth</em>.
+    </p>
+
+    <p>
+     You should edit the file to contain one <em>client</em> line, something like this:
     </p>
 
       <div class="div-pre">
-       <pre>client plain myname@gmail.com my+20password
+       <pre>client plain myname@gmail.com myapppassword
 </pre>
       </div><!-- div-pre -->
     <p>
-     If your password contains a space, equals or plus sign, or any control
-     character then you will need to replace those characters with their
-     corresponding hexadecimal ascii value, something like <em>+20</em> or <em>+2B</em>.
+     Then change the E-MailRelay startup batch file or configuration file to refer
+     to your secrets file by using the <em>--client-auth</em> option. The <em>--as-proxy</em> or
+     <em>--forward-to</em> options should be set to <em>smtp.gmail.com:587</em> and you will also
+     need to add the <em>--client-tls</em> option to enable TLS encryption.
     </p>
 
     <p>
-     Refer to your secrets file by using <em>--client-auth</em> on the E-MailRelay
-     command-line, and also add in the <em>--client-tls</em> option:
+     On Windows the E-MailRelay startup batch file should contain something like this:
     </p>
 
       <div class="div-pre">
-       <pre>emailrelay --as-proxy=smtp.gmail.com:587 --client-tls --client-auth=/etc/emailrelay.auth ...</pre>
+       <pre>emailrelay --as-proxy=smtp.gmail.com:587 --client-tls --client-auth=C:/ProgramData/E-MailRelay/emailrelay.auth ...
+</pre>
+      </div><!-- div-pre -->
+    <p>
+     Or in a configration file like this:
+    </p>
+
+      <div class="div-pre">
+       <pre>forward-to smtp.gmail.com:587
+client-tls
+client-auth C:/ProgramData/E-MailRelay/emailrelay.auth</pre>
       </div><!-- div-pre -->
    <h2><a class="a-header" name="SH_1_15">Connection tunnelling</a></h2> <!-- index:2:SH:1:15:Connection tunnelling -->
     <p>
@@ -509,10 +526,10 @@ exit 0</pre>
 
     <div class="div-footer">
      <p>
-      Copyright (C) 2001-2021 Graeme Walker
+      Copyright (C) 2001-2022 Graeme Walker
      </p>
     </div><!-- div-footer -->
  </div> <!-- div-main -->
  </body>
 </html>
-<!-- Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
+<!-- Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
diff --git a/doc/userguide.md b/doc/userguide.md
index c74ff07..f9f5344 100644
--- a/doc/userguide.md
+++ b/doc/userguide.md
@@ -27,9 +27,9 @@ General Public License V3.
 
 What it's not
 -------------
-E-MailRelay does not do routing of individual messages; it is not a routing [MTA][].
-It forwards all e-mail messages to a pre-configured SMTP server, regardless of
-any message addressing or DNS redirects.
+E-MailRelay does not normally do routing of individual messages; it is not a
+routing [MTA][]. It forwards all e-mail messages to a pre-configured SMTP server,
+regardless of any message addressing or DNS redirects.
 
 Why use it?
 -----------
@@ -317,22 +317,33 @@ On Windows an equivalent batch script would be:
 
 Google mail
 -----------
-To send mail via Google mail's SMTP gateway you will need to create a client
-secrets file containing your account details and also enable [TLS][] support in
-E-MailRelay by using the `--client-tls` option.
+To send mail via Google mail's SMTP gateway you will need to obtain a new
+`application password` from Google. Log in to your Google account and look for
+the account's security settings and then `app passwords`. Create the password
+for E-MailRelay as application type `other`.
 
-The secrets file should contain one line of text something like this:
+Then you need to create a client secrets file for E-MailRelay containing your
+account name and the new application password. You may already have this file
+on Windows as `C:\ProgramData\E-MailRelay\emailrelay.auth`.
 
-        client plain myname@gmail.com my+20password
+You should edit the file to contain one `client` line, something like this:
 
-If your password contains a space, equals or plus sign, or any control
-character then you will need to replace those characters with their
-corresponding hexadecimal ascii value, something like `+20` or `+2B`.
+        client plain myname@gmail.com myapppassword
 
-Refer to your secrets file by using `--client-auth` on the E-MailRelay
-command-line, and also add in the `--client-tls` option:
+Then change the E-MailRelay startup batch file or configuration file to refer
+to your secrets file by using the `--client-auth` option. The `--as-proxy` or
+`--forward-to` options should be set to `smtp.gmail.com:587` and you will also
+need to add the `--client-tls` option to enable [TLS][] encryption.
 
-        emailrelay --as-proxy=smtp.gmail.com:587 --client-tls --client-auth=/etc/emailrelay.auth ...
+On Windows the E-MailRelay startup batch file should contain something like this:
+
+        emailrelay --as-proxy=smtp.gmail.com:587 --client-tls --client-auth=C:/ProgramData/E-MailRelay/emailrelay.auth ...
+
+Or in a configration file like this:
+
+        forward-to smtp.gmail.com:587
+        client-tls
+        client-auth C:/ProgramData/E-MailRelay/emailrelay.auth
 
 Connection tunnelling
 ---------------------
@@ -369,4 +380,4 @@ to `fail2ban`.
 [TLS]: https://en.wikipedia.org/wiki/Transport_Layer_Security
 
 _____________________________________
-Copyright (C) 2001-2021 Graeme Walker
+Copyright (C) 2001-2022 Graeme Walker
diff --git a/doc/userguide.rst b/doc/userguide.rst
index 504fe6b..9166652 100644
--- a/doc/userguide.rst
+++ b/doc/userguide.rst
@@ -30,9 +30,9 @@ General Public License V3.
 
 What it's not
 =============
-E-MailRelay does not do routing of individual messages; it is not a routing MTA_.
-It forwards all e-mail messages to a pre-configured SMTP server, regardless of
-any message addressing or DNS redirects.
+E-MailRelay does not normally do routing of individual messages; it is not a
+routing MTA_. It forwards all e-mail messages to a pre-configured SMTP server,
+regardless of any message addressing or DNS redirects.
 
 Why use it?
 ===========
@@ -354,26 +354,39 @@ On Windows an equivalent batch script would be:
 
 Google mail
 ===========
-To send mail via Google mail's SMTP gateway you will need to create a client
-secrets file containing your account details and also enable TLS_ support in
-E-MailRelay by using the *--client-tls* option.
+To send mail via Google mail's SMTP gateway you will need to obtain a new
+*application password* from Google. Log in to your Google account and look for
+the account's security settings and then *app passwords*. Create the password
+for E-MailRelay as application type *other*.
 
-The secrets file should contain one line of text something like this:
+Then you need to create a client secrets file for E-MailRelay containing your
+account name and the new application password. You may already have this file
+on Windows as *C:\\ProgramData\\E-MailRelay\\emailrelay.auth*.
+
+You should edit the file to contain one *client* line, something like this:
 
 ::
 
-    client plain myname@gmail.com my+20password
+    client plain myname@gmail.com myapppassword
 
-If your password contains a space, equals or plus sign, or any control
-character then you will need to replace those characters with their
-corresponding hexadecimal ascii value, something like *+20* or *+2B*.
+Then change the E-MailRelay startup batch file or configuration file to refer
+to your secrets file by using the *--client-auth* option. The *--as-proxy* or
+*--forward-to* options should be set to *smtp.gmail.com:587* and you will also
+need to add the *--client-tls* option to enable TLS_ encryption.
 
-Refer to your secrets file by using *--client-auth* on the E-MailRelay
-command-line, and also add in the *--client-tls* option:
+On Windows the E-MailRelay startup batch file should contain something like this:
 
 ::
 
-    emailrelay --as-proxy=smtp.gmail.com:587 --client-tls --client-auth=/etc/emailrelay.auth ...
+    emailrelay --as-proxy=smtp.gmail.com:587 --client-tls --client-auth=C:/ProgramData/E-MailRelay/emailrelay.auth ...
+
+Or in a configration file like this:
+
+::
+
+    forward-to smtp.gmail.com:587
+    client-tls
+    client-auth C:/ProgramData/E-MailRelay/emailrelay.auth
 
 Connection tunnelling
 =====================
@@ -412,4 +425,4 @@ to *fail2ban*.
 .. _SOCKS: https://en.wikipedia.org/wiki/SOCKS
 .. _TLS: https://en.wikipedia.org/wiki/Transport_Layer_Security
 
-.. footer:: Copyright (C) 2001-2021 Graeme Walker
+.. footer:: Copyright (C) 2001-2022 Graeme Walker
diff --git a/doc/userguide.txt b/doc/userguide.txt
index e276454..da776fc 100644
--- a/doc/userguide.txt
+++ b/doc/userguide.txt
@@ -27,9 +27,9 @@ General Public License V3.
 
 What it's not
 -------------
-E-MailRelay does not do routing of individual messages; it is not a routing MTA.
-It forwards all e-mail messages to a pre-configured SMTP server, regardless of
-any message addressing or DNS redirects.
+E-MailRelay does not normally do routing of individual messages; it is not a
+routing MTA. It forwards all e-mail messages to a pre-configured SMTP server,
+regardless of any message addressing or DNS redirects.
 
 Why use it?
 -----------
@@ -316,22 +316,33 @@ On Windows an equivalent batch script would be:
 
 Google mail
 -----------
-To send mail via Google mail's SMTP gateway you will need to create a client
-secrets file containing your account details and also enable TLS support in
-E-MailRelay by using the "--client-tls" option.
+To send mail via Google mail's SMTP gateway you will need to obtain a new
+"application password" from Google. Log in to your Google account and look for
+the account's security settings and then "app passwords". Create the password
+for E-MailRelay as application type "other".
 
-The secrets file should contain one line of text something like this:
+Then you need to create a client secrets file for E-MailRelay containing your
+account name and the new application password. You may already have this file
+on Windows as "C:\ProgramData\E-MailRelay\emailrelay.auth".
 
-	client plain myname@gmail.com my+20password
+You should edit the file to contain one "client" line, something like this:
 
-If your password contains a space, equals or plus sign, or any control
-character then you will need to replace those characters with their
-corresponding hexadecimal ascii value, something like "+20" or "+2B".
+	client plain myname@gmail.com myapppassword
 
-Refer to your secrets file by using "--client-auth" on the E-MailRelay
-command-line, and also add in the "--client-tls" option:
+Then change the E-MailRelay startup batch file or configuration file to refer
+to your secrets file by using the "--client-auth" option. The "--as-proxy" or
+"--forward-to" options should be set to "smtp.gmail.com:587" and you will also
+need to add the "--client-tls" option to enable TLS encryption.
 
-	emailrelay --as-proxy=smtp.gmail.com:587 --client-tls --client-auth=/etc/emailrelay.auth ...
+On Windows the E-MailRelay startup batch file should contain something like this:
+
+	emailrelay --as-proxy=smtp.gmail.com:587 --client-tls --client-auth=C:/ProgramData/E-MailRelay/emailrelay.auth ...
+
+Or in a configration file like this:
+
+	forward-to smtp.gmail.com:587
+	client-tls
+	client-auth C:/ProgramData/E-MailRelay/emailrelay.auth
 
 Connection tunnelling
 ---------------------
@@ -360,4 +371,4 @@ to "fail2ban".
 
 
 _____________________________________
-Copyright (C) 2001-2021 Graeme Walker
+Copyright (C) 2001-2022 Graeme Walker
diff --git a/doc/whatisit.png b/doc/whatisit.png
index 79ca895..d591d8b 100644
Binary files a/doc/whatisit.png and b/doc/whatisit.png differ
diff --git a/doc/whatisit.svg b/doc/whatisit.svg
index c51c362..c11e2ef 100644
--- a/doc/whatisit.svg
+++ b/doc/whatisit.svg
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <!-- Created with Inkscape (http://www.inkscape.org/) -->
-<!-- Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
+<!-- Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
 
 <svg
    xmlns:dc="http://purl.org/dc/elements/1.1/"
diff --git a/doc/windows.html b/doc/windows.html
index 8b39834..f04b69b 100644
--- a/doc/windows.html
+++ b/doc/windows.html
@@ -1,4 +1,4 @@
-<!DOCTYPE HTML PUBLIC "%-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
+<!DOCTYPE html>
 <html>
  <head>
   <title>E-MailRelay Windows</title>
@@ -8,7 +8,7 @@
  <body>
   <!-- index:0::::E-MailRelay Windows -->
  <div class="div-main">
-  <h1><a class="a-header" name="H_1">E-MailRelay Windows</a></h1> <!-- index:1:H:1::E-MailRelay Windows -->
+  <h1><a class="a-header" name="H_1">E-MailRelay Windows</a></h1> <!-- index:1:H:E-MailRelay Windows -->
    <h2><a class="a-header" name="SH_1_1">Setup program</a></h2> <!-- index:2:SH:1:1:Setup program -->
     <p>
      Installing E-MailRelay on Windows should be straightforward if you have the
@@ -45,9 +45,10 @@
     </p>
 
     <p>
-     Note that the <em>emailrelay-start.bat</em> file lives under <em>ProgramData</em>, and although
-     this might be a hidden directory you can still navigate there by right-clicking
-     on the E-MailRelay link under <em>Program Files</em> and selecting <em>Open file location</em>.
+     Note that the <em>emailrelay-start.bat</em> file lives under <em>ProgramData</em>, and
+     although this might be a hidden directory you can still navigate there by
+     right-clicking on the <em>E-MailRelay</em> link under <em>Program Files</em> and selecting
+     <em>Open file location</em>.
     </p>
    <h2><a class="a-header" name="SH_1_3">Configuration</a></h2> <!-- index:2:SH:1:3:Configuration -->
     <p>
@@ -200,10 +201,10 @@
 
     <div class="div-footer">
      <p>
-      Copyright (C) 2001-2021 Graeme Walker
+      Copyright (C) 2001-2022 Graeme Walker
      </p>
     </div><!-- div-footer -->
  </div> <!-- div-main -->
  </body>
 </html>
-<!-- Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
+<!-- Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
diff --git a/doc/windows.md b/doc/windows.md
index c617078..4eaaf2c 100644
--- a/doc/windows.md
+++ b/doc/windows.md
@@ -27,9 +27,10 @@ run the `emailrelay-start.bat` batch file to start the E-MailRelay server, and
 you should then see an icon appear in the Windows system tray under the "Show
 hidden icons" button.
 
-Note that the `emailrelay-start.bat` file lives under `ProgramData`, and although
-this might be a hidden directory you can still navigate there by right-clicking
-on the E-MailRelay link under `Program Files` and selecting `Open file location`.
+Note that the `emailrelay-start.bat` file lives under `ProgramData`, and
+although this might be a hidden directory you can still navigate there by
+right-clicking on the `E-MailRelay` link under `Program Files` and selecting
+`Open file location`.
 
 Configuration
 -------------
@@ -145,4 +146,4 @@ and `DATA`.
 [SMTP]: https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol
 
 _____________________________________
-Copyright (C) 2001-2021 Graeme Walker
+Copyright (C) 2001-2022 Graeme Walker
diff --git a/doc/windows.rst b/doc/windows.rst
index 0af1c98..89c14e2 100644
--- a/doc/windows.rst
+++ b/doc/windows.rst
@@ -28,9 +28,10 @@ run the *emailrelay-start.bat* batch file to start the E-MailRelay server, and
 you should then see an icon appear in the Windows system tray under the "Show
 hidden icons" button.
 
-Note that the *emailrelay-start.bat* file lives under *ProgramData*, and although
-this might be a hidden directory you can still navigate there by right-clicking
-on the E-MailRelay link under *Program Files* and selecting *Open file location*.
+Note that the *emailrelay-start.bat* file lives under *ProgramData*, and
+although this might be a hidden directory you can still navigate there by
+right-clicking on the *E-MailRelay* link under *Program Files* and selecting
+\ *Open file location*\ .
 
 Configuration
 =============
@@ -152,4 +153,4 @@ and *DATA*.
 
 .. _SMTP: https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol
 
-.. footer:: Copyright (C) 2001-2021 Graeme Walker
+.. footer:: Copyright (C) 2001-2022 Graeme Walker
diff --git a/doc/windows.txt b/doc/windows.txt
index aef49fb..21f6f95 100644
--- a/doc/windows.txt
+++ b/doc/windows.txt
@@ -141,4 +141,4 @@ and "DATA".
 
 
 _____________________________________
-Copyright (C) 2001-2021 Graeme Walker
+Copyright (C) 2001-2022 Graeme Walker
diff --git a/emailrelay.spec b/emailrelay.spec
index 6666ee1..cbd0711 100644
--- a/emailrelay.spec
+++ b/emailrelay.spec
@@ -1,12 +1,13 @@
 Summary: Simple e-mail message transfer agent and proxy using SMTP
 Name: emailrelay
-Version: 2.3
+Version: 2.4
 Release: 1
 License: GPL3
 Group: System Environment/Daemons
 URL: http://emailrelay.sourceforge.net
-Source: http://sourceforge.net/projects/emailrelay/files/emailrelay/2.3/emailrelay-2.3-src.tar.gz
+Source: http://sourceforge.net/projects/emailrelay/files/emailrelay/2.4/emailrelay-2.4-src.tar.gz
 BuildRoot: /tmp/emailrelay-install
+##BuildRequires: systemd-rpm-macros
 
 %description
 E-MailRelay is an e-mail store-and-forward message transfer agent and proxy
@@ -34,7 +35,7 @@ General Public License V3.
 %setup
 
 %build
-./configure --prefix=/usr --localstatedir=/var --libexecdir=/usr/lib --sysconfdir=/etc e_initdir=/etc/init.d e_systemddir=/usr/lib/systemd/system --without-doxygen --without-man2html --with-openssl --without-mbedtls --with-pam --disable-gui --disable-install-hook --disable-testing
+./configure --prefix=/usr --localstatedir=/var --libexecdir=/usr/lib --sysconfdir=/etc e_initdir=/usr/lib/emailrelay/init e_systemddir=/usr/lib/systemd/system --without-doxygen --without-man2html --with-openssl --without-mbedtls --with-pam --disable-gui --disable-install-hook --disable-testing
 make
 
 %install
@@ -42,11 +43,17 @@ make install-strip destdir=$RPM_BUILD_ROOT DESTDIR=$RPM_BUILD_ROOT
 test -f $RPM_BUILD_ROOT/etc/emailrelay.conf || cp $RPM_BUILD_ROOT/etc/emailrelay.conf.template $RPM_BUILD_ROOT/etc/emailrelay.conf || true
 
 %post
-test -x /etc/init.d/emailrelay && /etc/init.d/emailrelay setup || true
-test -x /sbin/chkconfig && cd /etc/init.d && /sbin/chkconfig --add emailrelay || true
+test -x /usr/lib/emailrelay/init/emailrelay && /usr/lib/emailrelay/init/emailrelay setup || true
+##%systemd_post emailrelay.service
+if test "$1" -eq 1 ; then systemctl --no-reload preset emailrelay.service &>/dev/null || true ; fi
 
 %preun
-test -x /sbin/chkconfig && /sbin/chkconfig --del emailrelay || true
+##%systemd_preun emailrelay.service
+if test "$1" -eq 0 ; then systemctl --no-reload disable --now emailrelay.service &>/dev/null || true ; fi
+
+%postun
+##%systemd_postun_with_restart emailrelay.service
+if test "$1" -ge 1 ; then systemctl try-restart emailrelay.service &>/dev/null || true ; fi
 
 %clean
 test "$RPM_BUILD_ROOT" = "/" || rm -rf "$RPM_BUILD_ROOT"
@@ -56,14 +63,16 @@ test "$RPM_BUILD_ROOT" = "/" || rm -rf "$RPM_BUILD_ROOT"
 /etc/emailrelay.auth.template
 %config /etc/emailrelay.conf
 /etc/emailrelay.conf.template
-/etc/init.d/emailrelay
 %config /etc/pam.d/emailrelay
 %dir /usr/lib/emailrelay
 %attr(2755, root, daemon) /usr/lib/emailrelay/emailrelay-filter-copy
 %dir /usr/lib/emailrelay/examples
 /usr/lib/emailrelay/examples/emailrelay
 /usr/lib/emailrelay/examples/emailrelay-bcc-check.pl
+/usr/lib/emailrelay/examples/emailrelay-check-ipaddress.js
+/usr/lib/emailrelay/examples/emailrelay-check-ipaddress.pl
 /usr/lib/emailrelay/examples/emailrelay-deliver.sh
+/usr/lib/emailrelay/examples/emailrelay-dkim-signer.pl
 /usr/lib/emailrelay/examples/emailrelay-fail2ban-filter
 /usr/lib/emailrelay/examples/emailrelay-fail2ban-jail
 /usr/lib/emailrelay/examples/emailrelay-ldap-verify.py
@@ -75,6 +84,7 @@ test "$RPM_BUILD_ROOT" = "/" || rm -rf "$RPM_BUILD_ROOT"
 /usr/lib/emailrelay/examples/emailrelay-set-from.js
 /usr/lib/emailrelay/examples/emailrelay-set-from.pl
 /usr/lib/emailrelay/examples/emailrelay-submit.sh
+/usr/lib/emailrelay/init/emailrelay
 /usr/lib/systemd/system/emailrelay.service
 /usr/sbin/emailrelay
 /usr/sbin/emailrelay-passwd
diff --git a/etc/Makefile.am b/etc/Makefile.am
index 725402b..d033c1e 100644
--- a/etc/Makefile.am
+++ b/etc/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -43,7 +43,7 @@ e_systemd_DATA = \
 emailrelay: emailrelay.pam
 	cp $(top_srcdir)/etc/emailrelay.pam $@
 
-do_sed = sed -e "s:__INIT_DIR__:$(e_initdir):g" -e "s:__RUN_DIR__:$(e_rundir):g"
+do_sed = sed -e "s:__INIT_DIR__:$(e_initdir):g" -e "s:__RUN_DIR__:$(e_rundir):g" -e "s:__SYSCONF_DIR__:$(e_sysconfdir):g" -e "s:__SBIN_DIR__:$(sbindir):g"
 
 emailrelay.service: emailrelay.service.in
 	$(do_sed) < $(srcdir)/emailrelay.service.in > emailrelay.service
diff --git a/etc/Makefile.in b/etc/Makefile.in
index a17ff42..9b533cd 100644
--- a/etc/Makefile.in
+++ b/etc/Makefile.in
@@ -302,7 +302,7 @@ e_examples_DATA = \
 e_systemd_DATA = \
 	emailrelay.service
 
-do_sed = sed -e "s:__INIT_DIR__:$(e_initdir):g" -e "s:__RUN_DIR__:$(e_rundir):g"
+do_sed = sed -e "s:__INIT_DIR__:$(e_initdir):g" -e "s:__RUN_DIR__:$(e_rundir):g" -e "s:__SYSCONF_DIR__:$(e_sysconfdir):g" -e "s:__SBIN_DIR__:$(sbindir):g"
 CLEANFILES = \
 	emailrelay \
 	emailrelay.service
diff --git a/etc/emailrelay.auth.template b/etc/emailrelay.auth.template
index efd3a75..cd60764 100644
--- a/etc/emailrelay.auth.template
+++ b/etc/emailrelay.auth.template
@@ -34,9 +34,9 @@
 #
 # Any unusual characters (including space, "=" and "+") in the "name" and
 # "password" fields should be encoded using the RFC-1891 "xtext" encoding
-# scheme so that they are representing as hexadecimal ascii as "+XX".
+# scheme so that they are represented as hexadecimal ascii as "+XX".
 #
-# Alternatively use "plain:b" instead of "plain" and then use Base64 encoding 
+# Alternatively use "plain:b" instead of "plain" and then use Base64 encoding
 # for the id and password.
 #
 # The "none" rows allow trusted IP addresses to bypass authentication.
diff --git a/etc/emailrelay.conf.template b/etc/emailrelay.conf.template
index 68662e2..3c1e67f 100644
--- a/etc/emailrelay.conf.template
+++ b/etc/emailrelay.conf.template
@@ -14,37 +14,8 @@
 # on the last line in the block.
 #
 
-# Name: address-verifier
-# Format: address-verifier <program>
-# Description: Runs the specified external program to verify a message
-# recipent's e-mail address. A network verifier can be specified as
-# "net:<transport-address>".
-#
-#address-verifier /usr/local/sbin/emailrelay-verifier.sh
-
-# Name: admin
-# Format: admin <admin-port>
-# Description: Enables an administration interface on the specified listening
-# port number. Use telnet or something similar to connect. The administration
-# interface can be used to trigger forwarding of spooled mail messages if the
-# "--forward-to" option is used.
-#
-#admin 587
-
-# Name: admin-terminate
-# Format: admin-terminate
-# Description: Enables the "terminate" command in the administration
-# interface.
-#
-#admin-terminate
-
-# Name: anonymous
-# Format: anonymous
-# Description: Disables the server's SMTP VRFY command, sends less verbose
-# SMTP responses and SMTP greeting, and stops "Received" lines being added to
-# mail message content files.
-#
-#anonymous
+# Basic options
+# -------------
 
 # Name: as-client
 # Format: as-client <host:port>
@@ -74,6 +45,273 @@
 #
 #as-server
 
+# Name: spool-dir
+# Format: spool-dir <dir>
+# Description: Specifies the directory used for holding mail messages that
+# have been received but not yet forwarded.
+#
+#spool-dir /var/spool/emailrelay
+
+# SMTP client options
+# -------------------
+
+# Name: forward
+# Format: forward
+# Description: Causes spooled mail messages to be forwarded when the program
+# first starts.
+#
+#forward
+
+# Name: forward-on-disconnect
+# Format: forward-on-disconnect
+# Description: Causes spooled mail messages to be forwarded whenever a SMTP
+# client connection disconnects.
+#
+#forward-on-disconnect
+
+# Name: forward-to
+# Format: forward-to <host:port>
+# Description: Specifies the transport address of the remote SMTP server that
+# spooled mail messages are forwarded to.
+#
+#forward-to smtp.example.com:25
+
+# Name: poll
+# Format: poll <period>
+# Description: Causes forwarding of spooled mail messages to happen at
+# regular intervals (with the time given in seconds).
+#
+#poll 60
+
+# Name: client-filter
+# Format: client-filter <program>
+# Description: Runs the specified external filter program whenever a mail
+# message is forwarded. The filter is passed the name of the message file in
+# the spool directory so that it can edit it as required. A network filter
+# can be specified as "net:<tcp-address>" and prefixes of "spam:",
+# "spam-edit:" and "exit:" are also allowed. The "spam:" and "spam-edit:"
+# prefixes require a SpamAssassin daemon to be running. For store-and-forward
+# applications the "--filter" option is normally more useful than
+# "--client-filter".
+#
+#client-filter /usr/local/sbin/emailrelay-client-filter
+
+# Name: client-interface
+# Format: client-interface <ip-address>
+# Description: Specifies the IP network address to be used to bind the local
+# end of outgoing SMTP connections. By default the address will depend on the
+# routing tables in the normal way. Use "0.0.0.0" to use only IPv4 addresses
+# returned from DNS lookups of the "--forward-to" address, or "::" for IPv6.
+#
+#client-interface 10.0.0.2
+
+# Name: connection-timeout
+# Format: connection-timeout <time>
+# Description: Specifies a timeout (in seconds) for establishing a TCP
+# connection to remote SMTP servers. The default is 40 seconds.
+#
+#connection-timeout 10
+
+# Name: idle-timeout
+# Format: idle-timeout <time>
+# Description: Specifies a timeout (in seconds) for receiving network traffic
+# from remote SMTP and POP clients. The default is 60 seconds.
+#
+#idle-timeout 2
+
+# Name: response-timeout
+# Format: response-timeout <time>
+# Description: Specifies a timeout (in seconds) for getting responses from
+# remote SMTP servers. The default is 60 seconds.
+#
+#response-timeout 2
+
+# Name: forward-to-some
+# Format: forward-to-some
+# Description: Allow forwarding to continue even if some recipient addresses
+# on an e-mail envelope are rejected by the remote server.
+#
+#forward-to-some
+
+# Name: immediate
+# Format: immediate
+# Description: Causes mail messages to be forwarded as they are received,
+# even before they have been accepted. This can be used to do proxying
+# without store-and-forward, but in practice clients tend to to time out
+# while waiting for their mail message to be accepted.
+#
+#immediate
+
+# SMTP server options
+# -------------------
+
+# Name: port
+# Format: port <port>
+# Description: Sets the port number used for listening for incoming SMTP
+# connections.
+#
+#port 587
+
+# Name: remote-clients
+# Format: remote-clients
+# Description: Allows incoming connections from addresses that are not local.
+# The default behaviour is to reject connections that are not local in order
+# to prevent accidental exposure to the public internet, although a firewall
+# should also be used. Local address ranges are defined in RFC-1918, RFC-6890
+# etc.
+#
+#remote-clients
+
+# Name: address-verifier
+# Format: address-verifier <program>
+# Description: Runs the specified external program to verify a message
+# recipent's e-mail address. A network verifier can be specified as
+# "net:<tcp-address>".
+#
+#address-verifier /usr/local/sbin/emailrelay-verifier.sh
+
+# Name: anonymous
+# Format: anonymous[=<scope>]
+# Description: Disables the server's SMTP VRFY command, sends less verbose
+# SMTP greeting and responses, stops "Received" lines being added to mail
+# message content files, and stops the SMTP client protocol adding "AUTH=" to
+# the "MAIL" command. For finer control use a comma-separated list of things
+# to anonymise: "vrfy", "server", "content" and/or "client", eg.
+# "--anonymous"=server,content.
+#
+#anonymous
+
+# Name: dnsbl
+# Format: dnsbl <config>
+# Description: Specifies a list of DNSBL servers that are used to reject SMTP
+# connections from blocked addresses. The configuration string is made up of
+# comma-separated fields: the DNS server's transport address, a timeout in
+# milliseconds, a rejection threshold, and then the list of DNSBL servers.
+#
+#dnsbl 1.1.1.1:53,1000,1,spam.dnsbl.example.com,block.dnsbl.example.com
+
+# Name: domain
+# Format: domain <fqdn>
+# Description: Specifies the network name that is used in SMTP EHLO commands,
+# "Received" lines, and for generating authentication challenges. The default
+# is derived from a DNS lookup of the local hostname.
+#
+#domain smtp.example.com
+
+# Name: filter
+# Format: filter <program>
+# Description: Runs the specified external filter program whenever a mail
+# message is stored. The filter is passed the name of the message file in the
+# spool directory so that it can edit it as required. The mail message is
+# rejected if the filter program terminates with an exit code between 1 and
+# 99. Use "net:<tcp-address>" to communicate with a filter daemon over the
+# network, or "spam:<tcp-address>" for a spamassassin spamd daemon to accept
+# or reject mail messages, or "spam-edit:<tcp-address>" to have spamassassin
+# edit the message content without rejecting it, or "exit:<number>" to
+# emulate a filter program that just exits.
+#
+#filter /usr/local/sbin/emailrelay-filter
+
+# Name: filter-timeout
+# Format: filter-timeout <time>
+# Description: Specifies a timeout (in seconds) for running a "--filter"
+# program. The default is 60 seconds.
+#
+#filter-timeout 10
+
+# Name: interface
+# Format: interface <ip-address-list>
+# Description: Specifies the IP network addresses or interface names used to
+# bind listening ports. By default listening ports for incoming SMTP, POP and
+# administration connections will bind the 'any' address for IPv4 and for
+# IPv6, ie. "0.0.0.0" and "::". Multiple addresses can be specified by using
+# the option more than once or by using a comma-separated list. Use a prefix
+# of "smtp=", "pop=" or "admin=" on addresses that should apply only to those
+# types of listening port. Any link-local IPv6 addresses must include a zone
+# name or scope id.  Interface names can be used instead of addresses, in
+# which case all the addresses associated with that interface at startup will
+# used for listening. When an interface name is decorated with a "-ipv4" or
+# "-ipv6" suffix only their IPv4 or IPv6 addresses will be used (eg.
+# "ppp0-ipv4").  To inherit listening file descriptors from the parent
+# process on unix use a syntax like this:
+# "--interface"=smtp=fd#3,smtp=fd#4,pop=fd#5.
+#
+#interface 127.0.0.1,smtp=eth0
+
+# Name: prompt-timeout
+# Format: prompt-timeout <time>
+# Description: Specifies a timeout (in seconds) for getting the initial
+# prompt from a remote SMTP server. If no prompt is received after this time
+# then the SMTP dialog goes ahead without it.
+#
+#prompt-timeout 3
+
+# Name: size
+# Format: size <bytes>
+# Description: Limits the size of mail messages that can be submitted over
+# SMTP.
+#
+#size 10000000
+
+# POP server options
+# ------------------
+
+# Name: pop
+# Format: pop
+# Description: Enables the POP server, listening by default on port 110,
+# providing access to spooled mail messages. Negotiated TLS using the POP
+# "STLS" command will be enabled if the "--server-tls" option is also given.
+#
+#pop
+
+# Name: pop-by-name
+# Format: pop-by-name
+# Description: Modifies the spool directory used by the POP server to be a
+# sub-directory with the same name as the POP authentication user-id. This
+# allows multiple POP clients to read the spooled mail messages without
+# interfering with each other, particularly when also using
+# "--pop-no-delete". Content files can stay in the main spool directory with
+# only the envelope files copied into user-specific sub-directories. The
+# "emailrelay-filter-copy" program is a convenient way of doing this when run
+# via "--filter".
+#
+#pop-by-name
+
+# Name: pop-no-delete
+# Format: pop-no-delete
+# Description: Disables the POP DELE command so that the command appears to
+# succeed but mail messages are not deleted from the spool directory.
+#
+#pop-no-delete
+
+# Name: pop-port
+# Format: pop-port <port>
+# Description: Sets the POP server's listening port number.
+#
+#pop-port 995
+
+# Admin server options
+# --------------------
+
+# Name: admin
+# Format: admin <port>
+# Description: Enables an administration interface on the specified listening
+# port number. Use telnet or something similar to connect. The administration
+# interface can be used to trigger forwarding of spooled mail messages if the
+# "--forward-to" option is used.
+#
+#admin 587
+
+# Name: admin-terminate
+# Format: admin-terminate
+# Description: Enables the "terminate" command in the administration
+# interface.
+#
+#admin-terminate
+
+# Authentication options
+# ----------------------
+
 # Name: client-auth
 # Format: client-auth <file>
 # Description: Enables SMTP client authentication with the remote server,
@@ -93,32 +331,52 @@
 # Description: Configures the SMTP client authentication module using a
 # semicolon-separated list of configuration items. Each item is a
 # single-character key, followed by a colon and then a comma-separated list.
-# A 'm' character introduces an ordered list of authentication mechanisms,
-# and an 'x' is used for blocklisted mechanisms.
+# A 'm' character introduces an ordered list of preferred authentication
+# mechanisms and an 'x' introduces a list of mechanisms to avoid. An 'a' list
+# and a 'd' list can be used similarly to prefer and avoid certain mechanisms
+# once the session is encrypted with TLS.
 #
 #client-auth-config m:cram-sha1,cram-md5
 
-# Name: client-filter
-# Format: client-filter <program>
-# Description: Runs the specified external filter program whenever a mail
-# message is forwarded. The filter is passed the name of the message file in
-# the spool directory so that it can edit it as required. A network filter
-# can be specified as "net:<transport-address>" and prefixes of "spam:",
-# "spam-edit:" and "exit:" are also allowed. The "spam:" and "spam-edit:"
-# prefixes require a SpamAssassin daemon to be running. For store-and-forward
-# applications the "--filter" option is normally more useful than
-# "--client-filter".
+# Name: server-auth
+# Format: server-auth <file>
+# Description: Enables SMTP server authentication of remote SMTP clients.
+# Account names and passwords are taken from the specified secrets file. The
+# secrets file should contain lines that have four space-separated fields,
+# starting with "server" in the first field; the second field is the password
+# encoding ("plain" or "md5"), the third is the client user-id and the fourth
+# is the password. The user-id is RFC-1891 xtext encoded, and the password is
+# either xtext encoded or generated by "emailrelay-passwd". A special value
+# of "/pam" can be used for authentication using linux PAM.
 #
-#client-filter /usr/local/sbin/emailrelay-client-filter
+#server-auth /etc/private/emailrelay.auth
 
-# Name: client-interface
-# Format: client-interface <ip-address>
-# Description: Specifies the IP network address to be used to bind the local
-# end of outgoing SMTP connections. By default the address will depend on the
-# routing tables in the normal way. Use "0.0.0.0" to use only IPv4 addresses
-# returned from DNS lookups of the "--forward-to" address, or "::" for IPv6.
+# Name: server-auth-config
+# Format: server-auth-config <config>
+# Description: Configures the SMTP server authentication module using a
+# semicolon-separated list of configuration items. Each item is a
+# single-character key, followed by a colon and then a comma-separated list.
+# A 'm' character introduces an ordered list of allowed authentication
+# mechanisms and an 'x' introduces a list of mechanisms to deny. An 'a' list
+# and a 'd' list can be used similarly to allow and deny mechanisms once the
+# session is encrypted with TLS. In typical usage you might have an empty
+# allow list for an unencrypted session and a single preferred mechanism once
+# encrypted, "m:;a:plain".
 #
-#client-interface 10.0.0.2
+#server-auth-config m:cram-sha256,cram-sha1
+
+# Name: pop-auth
+# Format: pop-auth <file>
+# Description: Specifies a file containing valid POP account details. The
+# file format is the same as for the SMTP server secrets file, ie. lines
+# starting with "server", with user-id and password in the third and fourth
+# fields. A special value of "/pam" can be used for authentication using
+# linux PAM.
+#
+#pop-auth /etc/private/emailrelay-pop.auth
+
+# TLS options
+# -----------
 
 # Name: client-tls
 # Format: client-tls
@@ -131,8 +389,9 @@
 # Format: client-tls-certificate <pem-file>
 # Description: Defines the TLS certificate file when acting as a SMTP client.
 # This file must contain the client's private key and certificate chain using
-# the PEM file format. Keep the file permissions tight to avoid accidental
-# exposure of the private key.
+# the PEM file format. Alternatively, use this option twice with the first
+# one specifying the key file and the second the certificate file. Keep the
+# file permissions tight to avoid accidental exposure of the private key.
 #
 #client-tls-certificate /etc/ssl/certs/emailrelay.pem
 
@@ -166,7 +425,8 @@
 # Description: Enables verification of the remote SMTP server's certificate
 # against any of the trusted CA certificates in the specified file or
 # directory. In many use cases this should be a file containing just your
-# self-signed root certificate.
+# self-signed root certificate. Specify "<default>" for the TLS library's
+# default set of trusted CAs.
 #
 #client-tls-verify /etc/ssl/certs/ca-certificates.crt
 
@@ -177,45 +437,63 @@
 #
 #client-tls-verify-name smtp.example.com
 
-# Name: close-stderr
-# Format: close-stderr
-# Description: Causes the standard error stream to be closed soon after
-# start-up. This is useful when operating as a backgroud daemon and it is
-# therefore implied by "--as-server" and "--as-proxy".
+# Name: server-tls
+# Format: server-tls
+# Description: Enables TLS for incoming SMTP and POP connections. SMTP
+# clients can then request TLS encryption by issuing the STARTTLS command.
+# The "--server-tls-certificate" option must be used to define the server
+# certificate.
 #
-#close-stderr
+#server-tls
 
-# Name: connection-timeout
-# Format: connection-timeout <time>
-# Description: Specifies a timeout (in seconds) for establishing a TCP
-# connection to remote SMTP servers. The default is 40 seconds.
+# Name: server-tls-certificate
+# Format: server-tls-certificate <pem-file>
+# Description: Defines the TLS certificate file when acting as a SMTP or POP
+# server. This file must contain the server's private key and certificate
+# chain using the PEM file format. Alternatively, use this option twice with
+# the first one specifying the key file and the second the certificate file.
+# Keep the file permissions tight to avoid accidental exposure of the private
+# key.
 #
-#connection-timeout 10
+#server-tls-certificate /etc/ssl/certs/emailrelay.pem
 
-# Name: debug
-# Format: debug
-# Description: Enables debug level logging, if built in. Debug messages are
-# usually only useful when cross-referenced with the source code and they may
-# expose plaintext passwords and mail message content.
+# Name: server-tls-connection
+# Format: server-tls-connection
+# Description: Enables SMTP over TLS when acting as an SMTP server. This is
+# for SMTP over TLS (SMTPS), not TLS negotiated within SMTP using STARTTLS.
 #
-#debug
+#server-tls-connection
 
-# Name: dnsbl
-# Format: dnsbl <config>
-# Description: Specifies a list of DNSBL servers that are used to reject SMTP
-# connections from blocked addresses. The configuration string is made up of
-# comma-separated fields: the DNS server's transport address, a timeout in
-# milliseconds, a rejection threshold, and then the list of DNSBL servers.
+# Name: server-tls-required
+# Format: server-tls-required
+# Description: Makes the use of TLS mandatory for any incoming SMTP and POP
+# connections. SMTP clients must use the STARTTLS command to establish a TLS
+# session before they can issue SMTP AUTH or SMTP MAIL-TO commands.
 #
-#dnsbl 1.1.1.1:53,1000,1,spam.dnsbl.example.com,block.dnsbl.example.com
+#server-tls-required
 
-# Name: domain
-# Format: domain <fqdn>
-# Description: Specifies the network name that is used in SMTP EHLO commands,
-# "Received" lines, and for generating authentication challenges. The default
-# is derived from a DNS lookup of the local hostname.
+# Name: server-tls-verify
+# Format: server-tls-verify <ca-list>
+# Description: Enables verification of remote SMTP and POP clients'
+# certificates against any of the trusted CA certificates in the specified
+# file or directory. In many use cases this should be a file containing just
+# your self-signed root certificate. Specify "<default>" for the TLS
+# library's default set of trusted CAs.
 #
-#domain smtp.example.com
+#server-tls-verify /etc/ssl/certs/ca-certificates.crt
+
+# Name: tls-config
+# Format: tls-config <options>
+# Description: Selects and configures the low-level TLS library, using a
+# comma-separated list of keywords. If OpenSSL and mbedTLS are both built in
+# then keywords of "openssl" and "mbedtls" will select one or the other.
+# Keywords like "tlsv1.0" can be used to set a minimum TLS protocol version,
+# or "-tlsv1.2" to set a maximum version.
+#
+#tls-config mbedtls,tlsv1.2
+
+# Process options
+# ---------------
 
 # Name: dont-serve
 # Format: dont-serve
@@ -225,96 +503,14 @@
 #
 #dont-serve
 
-# Name: filter
-# Format: filter <program>
-# Description: Runs the specified external filter program whenever a mail
-# message is stored. The filter is passed the name of the message file in the
-# spool directory so that it can edit it as required. The mail message is
-# rejected if the filter program terminates with an exit code between 1 and
-# 99. Use "net:<transport-address>" to communicate with a filter daemon over
-# the network, or "spam:<transport-address>" for a spamassassin spamd daemon
-# to accept or reject mail messages, or "spam-edit:<transport-address>" to
-# have spamassassin edit the message content without rejecting it, or
-# "exit:<number>" to emulate a filter program that just exits.
-#
-#filter /usr/local/sbin/emailrelay-filter
-
-# Name: filter-timeout
-# Format: filter-timeout <time>
-# Description: Specifies a timeout (in seconds) for running a "--filter"
-# program. The default is 300 seconds.
-#
-#filter-timeout 10
-
-# Name: forward
-# Format: forward
-# Description: Causes spooled mail messages to be forwarded when the program
-# first starts.
-#
-#forward
-
-# Name: forward-on-disconnect
-# Format: forward-on-disconnect
-# Description: Causes spooled mail messages to be forwarded whenever a SMTP
-# client connection disconnects.
-#
-#forward-on-disconnect
-
-# Name: forward-to
-# Format: forward-to <host:port>
-# Description: Specifies the transport address of the remote SMTP server that
-# is use for mail message forwarding.
-#
-#forward-to smtp.example.com:25
-
-# Name: forward-to-some
-# Format: forward-to-some
-# Description: Allow forwarding to continue even if some recipient addresses
-# on an e-mail envelope are rejected by the remote server.
-#
-#forward-to-some
-
 # Name: hidden
 # Format: hidden
 # Description: Windows only. Hides the application window and disables all
-# message boxes, overriding any "--show" option. This is useful when
-# running as a windows service.
+# message boxes, overriding any "--show" option. This is useful when running
+# as a windows service.
 #
 #hidden
 
-# Name: idle-timeout
-# Format: idle-timeout <time>
-# Description: Specifies a timeout (in seconds) for receiving network traffic
-# from remote SMTP and POP clients. The default is 1800 seconds.
-#
-#idle-timeout 2
-
-# Name: immediate
-# Format: immediate
-# Description: Causes mail messages to be forwarded as they are received,
-# even before they have been accepted. This can be used to do proxying
-# without store-and-forward, but in practice clients tend to to time out
-# while waiting for their mail message to be accepted.
-#
-#immediate
-
-# Name: interface
-# Format: interface <ip-address-list>
-# Description: Specifies the IP network addresses or interface names used to
-# bind listening ports. By default listening ports for incoming SMTP, POP and
-# administration connections will bind the 'any' address for IPv4 and for
-# IPv6, ie. "0.0.0.0" and "::". Multiple addresses can be specified by using
-# the option more than once or by using a comma-separated list. Use a prefix
-# of "smtp=", "pop=" or "admin=" on addresses that should apply only to those
-# types of listening port. Any link-local IPv6 addresses must include a zone
-# name or scope id.  Interface names can be used instead of addresses, in
-# which case all the addresses associated with that interface at startup will
-# used for listening. When an interface name is decorated with a "-ipv4" or
-# "-ipv6" suffix only their IPv4 or IPv6 addresses will be used (eg.
-# "ppp0-ipv4").
-#
-#interface 127.0.0.1,smtp=eth0
-
 # Name: localedir
 # Format: localedir <dir>
 # Description: Enables localisation and specifies the locale base directory
@@ -323,6 +519,48 @@
 #
 #localedir /opt/share/locale
 
+# Name: no-daemon
+# Format: no-daemon
+# Description: Disables the normal backgrounding at startup so that the
+# program runs in the foreground, without forking or detaching from the
+# terminal.  On Windows this disables the system tray icon so the program
+# uses a normal window; when the window is closed the program terminates.
+#
+#no-daemon
+
+# Name: no-smtp
+# Format: no-smtp
+# Description: Disables listening for incoming SMTP connections.
+#
+#no-smtp
+
+# Name: pid-file
+# Format: pid-file <path>
+# Description: Causes the process-id to be written into the specified file
+# when the program starts up, typically after it has become a background
+# daemon. The immediate parent directory is created if necessary.
+#
+#pid-file /run/emailrelay/emailrelay.pid
+
+# Name: user
+# Format: user <username>
+# Description: When started as root the program switches to a non-privileged
+# effective user-id when idle. This option can be used to define the idle
+# user-id and also the group ownership of new files and sockets. Specify
+# "root" to disable all user-id switching. Ignored on Windows.
+#
+#user nobody
+
+# Logging options
+# ---------------
+
+# Name: verbose
+# Format: verbose
+# Description: Enables more verbose logging when used with "--log", and more
+# verbose help when used with "--help".
+#
+#verbose
+
 # Name: log
 # Format: log
 # Description: Enables logging to the standard error stream and to the
@@ -333,6 +571,14 @@
 #
 #log
 
+# Name: debug
+# Format: debug
+# Description: Enables debug level logging, if built in. Debug messages are
+# usually only useful when cross-referenced with the source code and they may
+# expose plaintext passwords and mail message content.
+#
+#debug
+
 # Name: log-address
 # Format: log-address
 # Description: Adds the network address of remote clients to the logging
@@ -356,21 +602,6 @@
 #
 #log-time
 
-# Name: no-daemon
-# Format: no-daemon
-# Description: Disables the normal backgrounding at startup so that the
-# program runs in the foreground, without forking or detaching from the
-# terminal.  On Windows this disables the system tray icon so the program
-# uses a normal window; when the window is closed the program terminates.
-#
-#no-daemon
-
-# Name: no-smtp
-# Format: no-smtp
-# Description: Disables listening for incoming SMTP connections.
-#
-#no-smtp
-
 # Name: no-syslog
 # Format: no-syslog
 # Description: Disables logging to the syslog. Note that "--as-client"
@@ -378,176 +609,6 @@
 #
 #no-syslog
 
-# Name: pid-file
-# Format: pid-file <pid-file>
-# Description: Causes the process-id to be written into the specified file
-# when the program starts up, typically after it has become a backgroud
-# daemon.
-#
-#pid-file /run/emailrelay/emailrelay.pid
-
-# Name: poll
-# Format: poll <period>
-# Description: Causes forwarding of spooled mail messages to happen at
-# regular intervals (with the time given in seconds).
-#
-#poll 60
-
-# Name: pop
-# Format: pop
-# Description: Enables the POP server listening, by default on port 110,
-# providing access to spooled mail messages. Negotiated TLS using the POP
-# "STLS" command will be enabled if the "--server-tls" option is also given.
-#
-#pop
-
-# Name: pop-auth
-# Format: pop-auth <file>
-# Description: Specifies a file containing valid POP account details. The
-# file format is the same as for the SMTP server secrets file, ie. lines
-# starting with "server", with user-id and password in the third and fourth
-# fields. A special value of "/pam" can be used for authentication using
-# linux PAM.
-#
-#pop-auth /etc/private/emailrelay-pop.auth
-
-# Name: pop-by-name
-# Format: pop-by-name
-# Description: Modifies the spool directory used by the POP server to be a
-# sub-directory with the same name as the POP authentication user-id. This
-# allows multiple POP clients to read the spooled messages without
-# interfering with each other, particularly when also using
-# "--pop-no-delete". Content files can stay in the main spool directory with
-# only the envelope files copied into user-specific sub-directories. The
-# "emailrelay-filter-copy" program is a convenient way of doing this when run
-# via "--filter".
-#
-#pop-by-name
-
-# Name: pop-no-delete
-# Format: pop-no-delete
-# Description: Disables the POP DELE command so that the command appears to
-# succeed but mail messages are not deleted from the spool directory.
-#
-#pop-no-delete
-
-# Name: pop-port
-# Format: pop-port <port>
-# Description: Sets the POP server's listening port number.
-#
-#pop-port 995
-
-# Name: port
-# Format: port <port>
-# Description: Sets the port number used for listening for incoming SMTP
-# connections.
-#
-#port 587
-
-# Name: prompt-timeout
-# Format: prompt-timeout <time>
-# Description: Specifies a timeout (in seconds) for getting the initial
-# prompt from a remote SMTP server. If no prompt is received after this time
-# then the SMTP dialog goes ahead without it.
-#
-#prompt-timeout 3
-
-# Name: remote-clients
-# Format: remote-clients
-# Description: Allows incoming connections from addresses that are not local.
-# The default behaviour is to reject connections that are not local in order
-# to prevent accidental exposure to the public internet, although a firewall
-# should also be used. Local address ranges are defined in RFC-1918, RFC-6890
-# etc.
-#
-#remote-clients
-
-# Name: response-timeout
-# Format: response-timeout <time>
-# Description: Specifies a timeout (in seconds) for getting responses from
-# remote SMTP servers. The default is 1800 seconds.
-#
-#response-timeout 2
-
-# Name: server-auth
-# Format: server-auth <file>
-# Description: Enables SMTP server authentication of remote SMTP clients.
-# Account names and passwords are taken from the specified secrets file. The
-# secrets file should contain lines that have four space-separated fields,
-# starting with "server" in the first field; the second field is the password
-# encoding ("plain" or "md5"), the third is the client user-id and the fourth
-# is the password. The user-id is RFC-1891 xtext encoded, and the password is
-# either xtext encoded or generated by "emailrelay-passwd". A special value
-# of "/pam" can be used for authentication using linux PAM.
-#
-#server-auth /etc/private/emailrelay.auth
-
-# Name: server-auth-config
-# Format: server-auth-config <config>
-# Description: Configures the SMTP server authentication module using a
-# semicolon-separated list of configuration items. Each item is a
-# single-character key, followed by a colon and then a comma-separated list.
-# A 'm' character introduces a preferred sub-set of the built-in
-# authentication mechanisms, and an 'x' is used for blocklisted mechanisms.
-#
-#server-auth-config m:cram-sha256,cram-sha1
-
-# Name: server-tls
-# Format: server-tls
-# Description: Enables TLS for incoming SMTP and POP connections. SMTP
-# clients can then request TLS encryption by issuing the STARTTLS command.
-# The "--server-tls-certificate" option must be used to define the server
-# certificate.
-#
-#server-tls
-
-# Name: server-tls-certificate
-# Format: server-tls-certificate <pem-file>
-# Description: Defines the TLS certificate file when acting as a SMTP or POP
-# server. This file must contain the server's private key and certificate
-# chain using the PEM file format. Keep the file permissions tight to avoid
-# accidental exposure of the private key.
-#
-#server-tls-certificate /etc/ssl/certs/emailrelay.pem
-
-# Name: server-tls-connection
-# Format: server-tls-connection
-# Description: Enables SMTP over TLS when acting as an SMTP server. This is
-# for SMTP over TLS (SMTPS), not TLS negotiated within SMTP using STARTTLS.
-#
-#server-tls-connection
-
-# Name: server-tls-required
-# Format: server-tls-required
-# Description: Makes the use of TLS mandatory for any incoming SMTP and POP
-# connections. SMTP clients must use the STARTTLS command to establish a TLS
-# session before they can issue SMTP AUTH or SMTP MAIL-TO commands.
-#
-#server-tls-required
-
-# Name: server-tls-verify
-# Format: server-tls-verify <ca-list>
-# Description: Enables verification of remote SMTP and POP clients'
-# certificates against any of the trusted CA certificates in the specified
-# file or directory. In many use cases this should be a file containing just
-# your self-signed root certificate.
-#
-#server-tls-verify /etc/ssl/certs/ca-certificates.crt
-
-# Name: size
-# Format: size <bytes>
-# Description: Limits the size of mail messages that can be submitted over
-# SMTP.
-#
-#size 10000000
-
-# Name: spool-dir
-# Format: spool-dir <dir>
-# Description: Specifies the directory used for holding mail messages that
-# have been received but not yet forwarded.
-#
-#spool-dir /var/spool/emailrelay
-
 # Name: syslog
 # Format: syslog[=<facility>]
 # Description: When used with "--log" this option enables logging to the
@@ -556,29 +617,11 @@
 #
 #syslog
 
-# Name: tls-config
-# Format: tls-config <options>
-# Description: Selects and configures the low-level TLS library, using a
-# comma-separated list of keywords. If OpenSSL and mbedTLS are both built in
-# then keywords of "openssl" and "mbedtls" will select one or the other.
-# Keywords like "tlsv1.0" can be used to set a minimum TLS protocol version,
-# or "-tlsv1.2" to set a maximum version.
+# Name: close-stderr
+# Format: close-stderr
+# Description: Causes the standard error stream to be closed soon after
+# start-up. This is useful when operating as a background daemon and it is
+# therefore implied by "--as-server" and "--as-proxy".
 #
-#tls-config mbedtls,tlsv1.2
-
-# Name: user
-# Format: user <username>
-# Description: When started as root the program switches to a non-privileged
-# effective user-id when idle. This option can be used to define the idle
-# user-id and also the group ownership of new files and sockets. Specify
-# "root" to  disable all user-id switching. Ignored on Windows.
-#
-#user nobody
-
-# Name: verbose
-# Format: verbose
-# Description: Enables more verbose logging when used with "--log", and more
-# verbose help when used with "--help".
-#
-#verbose
+#close-stderr
 
diff --git a/etc/emailrelay.service.in b/etc/emailrelay.service.in
index fd08099..340bf89 100644
--- a/etc/emailrelay.service.in
+++ b/etc/emailrelay.service.in
@@ -8,10 +8,9 @@ Wants=network-online.target
 Type=forking
 Restart=on-success
 KillMode=control-group
-ExecStart=__INIT_DIR__/emailrelay start
-ExecStop=__INIT_DIR__/emailrelay stop
+ExecStart=__SBIN_DIR__/emailrelay --as-server --syslog --pid-file __RUN_DIR__/emailrelay.pid __SYSCONF_DIR__/emailrelay.conf
+ExecStop=/bin/kill -15 $MAINPID
 PIDFile=__RUN_DIR__/emailrelay.pid
-SuccessExitStatus=0 143
 
 [Install]
 WantedBy=multi-user.target
diff --git a/m4/Makefile.am b/m4/Makefile.am
index 8ed53ac..86cbb1b 100644
--- a/m4/Makefile.am
+++ b/m4/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
diff --git a/m4/acinclude.m4 b/m4/acinclude.m4
index 464dce2..6b12229 100644
--- a/m4/acinclude.m4
+++ b/m4/acinclude.m4
@@ -1,4 +1,4 @@
-dnl Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+dnl Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 dnl 
 dnl This program is free software: you can redistribute it and/or modify
 dnl it under the terms of the GNU General Public License as published by
@@ -134,8 +134,10 @@ AC_DEFUN([GCONFIG_FN_CHECK_NET],[
 	AC_REQUIRE([GCONFIG_FN_NETROUTE])
 	AC_REQUIRE([GCONFIG_FN_IFNAMETOINDEX])
 	AC_REQUIRE([GCONFIG_FN_IFNAMETOLUID])
+	AC_REQUIRE([GCONFIG_FN_IFINDEX])
 	AC_REQUIRE([GCONFIG_FN_GAISTRERROR])
 	AC_REQUIRE([GCONFIG_FN_UDS])
+	AC_REQUIRE([GCONFIG_FN_UDS_LEN])
 ])
 
 dnl GCONFIG_FN_CHECK_TYPES
@@ -341,14 +343,29 @@ AC_DEFUN([GCONFIG_FN_ENABLE_DEBUG],
 	fi
 ])
 
+dnl GCONFIG_FN_ENABLE_DNSBL
+dnl -----------------------
+dnl Enables DNSBL unless "--disable-dnsbl" is used.
+dnl Typically used after AC_ARG_ENABLE(dnsbl).
+dnl
+AC_DEFUN([GCONFIG_FN_ENABLE_DNSBL],
+[
+	if test "$enable_dnsbl" = "no"
+	then
+		AM_CONDITIONAL([GCONFIG_DNSBL],[false])
+	else
+		AM_CONDITIONAL([GCONFIG_DNSBL],[true])
+	fi
+])
+
 dnl GCONFIG_FN_ENABLE_EPOLL
 dnl -----------------------
-dnl Enables the epoll event-loop if "--enable-epoll" is used and epoll is
-dnl available. Typically used after GCONFIG_FN_EPOLL and AC_ARG_ENABLE(epoll).
+dnl Enables the epoll event-loop if epoll is available and "--disable-epoll"
+dnl is not used. Typically used after GCONFIG_FN_EPOLL and AC_ARG_ENABLE(epoll).
 dnl
 AC_DEFUN([GCONFIG_FN_ENABLE_EPOLL],
 [
-	if test "$enable_epoll" = "yes"
+	if test "$enable_epoll" != "no"
 	then
 		if test "$gconfig_cv_epoll" = "no"
 		then
@@ -440,42 +457,6 @@ AC_DEFUN([GCONFIG_FN_ENABLE_INTERFACE_NAMES],
 	AM_CONDITIONAL([GCONFIG_INTERFACE_NAMES],test "$enable_interface_names" != "no")
 ])
 
-dnl GCONFIG_FN_ENABLE_IPV6
-dnl ----------------------
-dnl Enables ipv6 if "--enable-ipv6" is used and ipv6 is available.
-dnl Typically used after GCONFIG_FN_IPV6 and AC_ARG_ENABLE(ipv6).
-dnl
-AC_DEFUN([GCONFIG_FN_ENABLE_IPV6],
-[
-	if test "$enable_ipv6" = "no"
-	then
-		gconfig_use_ipv6="no"
-	else
-		if test "$gconfig_cv_ipv6" = "no"
-		then
-			if test "$enable_ipv6" = "yes"
-			then
-				AC_MSG_WARN([ignoring --enable-ipv6])
-			fi
-			gconfig_use_ipv6="no"
-		else
-			gconfig_use_ipv6="yes"
-		fi
-	fi
-
-	if test "$enable_ipv6" != "no" -a "$gconfig_use_ipv6" = "no"
-	then
-		gconfig_warnings="$gconfig_warnings ipv6_ipv6_networking"
-	fi
-
-	if test "$gconfig_use_ipv6" = "yes" ; then
-		AC_DEFINE(GCONFIG_ENABLE_IPV6,1,[Define true to use IPv6])
-	else
-		AC_DEFINE(GCONFIG_ENABLE_IPV6,0,[Define true to use IPv6])
-	fi
-	AM_CONDITIONAL([GCONFIG_IPV6],test "$gconfig_use_ipv6" = "yes")
-])
-
 dnl GCONFIG_FN_ENABLE_MAC
 dnl ---------------------
 dnl Enables mac tweaks if "--enable-mac" is used. Typically used after
@@ -565,6 +546,27 @@ AC_DEFUN([GCONFIG_FN_ENABLE_WINDOWS],
 	AM_CONDITIONAL([GCONFIG_WINDOWS],test "$enable_windows" = "yes" -o "`uname -o 2>/dev/null`" = "Msys")
 ])
 
+dnl GCONFIG_FN_ENABLE_UDS
+dnl ---------------------
+dnl Enables unix domain sockets if detected unless "--disable-uds" is
+dnl used. Requires GCONFIG_FN_UDS to set gconfig_cv_uds.
+dnl Typically used after AC_ARG_ENABLE(uds).
+dnl
+AC_DEFUN([GCONFIG_FN_ENABLE_UDS],
+[
+	AC_REQUIRE([GCONFIG_FN_UDS])
+	if test "$enable_uds" = "no"
+	then
+		AM_CONDITIONAL([GCONFIG_UDS],[false])
+	else
+		if test "$enable_uds" = "yes" -a "$gconfig_cv_uds" = "no"
+		then
+			AC_MSG_WARN([forcing use of unix domain sockets even though not detected])
+		fi
+		AM_CONDITIONAL([GCONFIG_UDS],[true])
+	fi
+])
+
 dnl GCONFIG_FN_EPOLL
 dnl ----------------
 dnl Tests for linux epoll().
@@ -1068,6 +1070,44 @@ AC_DEFUN([GCONFIG_FN_IFNAMETOLUID],
 	fi
 ])
 
+dnl GCONFIG_FN_IFINDEX
+dnl ------------------
+dnl Tests for struct ifreq ifr_ifindex and SIOCGIFINDEX.
+dnl
+AC_DEFUN([GCONFIG_FN_IFINDEX],
+[AC_CACHE_CHECK([for ifreq ifr_index],[gconfig_cv_ifindex],
+[
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
+		[
+			[#ifdef _WIN32]
+				[#include <winsock2.h>]
+				[#include <windows.h>]
+				[#include <ws2tcpip.h>]
+				[#include <iphlpapi.h>]
+			[#else]
+				[#include <sys/types.h>]
+				[#include <sys/socket.h>]
+				[#include <arpa/inet.h>]
+				[#include <net/if.h>]
+				[#include <sys/ioctl.h>]
+			[#endif]
+			[struct ifreq req ;]
+			[int i = 0 ;]
+		],
+		[
+			[(void) ioctl( i , SIOCGIFINDEX , &req , sizeof(req) );]
+			[i = req.ifr_ifindex ;]
+		])],
+		gconfig_cv_ifindex=yes ,
+		gconfig_cv_ifindex=no )
+])
+	if test "$gconfig_cv_ifindex" = "yes" ; then
+		AC_DEFINE(GCONFIG_HAVE_IFINDEX,1,[Define true if struct ifreq has ifr_ifindex])
+	else
+		AC_DEFINE(GCONFIG_HAVE_IFINDEX,0,[Define true if struct ifreq has ifr_ifindex])
+	fi
+])
+
 dnl GCONFIG_FN_INET_NTOP
 dnl --------------------
 dnl Tests for inet_ntop().
@@ -1661,12 +1701,13 @@ AC_DEFUN([GCONFIG_FN_QT],
 dnl GCONFIG_FN_QT_BUILD
 dnl -------------------
 dnl Tests for successful Qt5 compilation if GCONFIG_FN_QT
-dnl has set gconfig_have_qt. Sets gconfig_qt_build.
+dnl has set gconfig_have_qt. Does nothing if --disable-gui.
+dnl Sets gconfig_qt_build.
 dnl
 AC_DEFUN([GCONFIG_FN_QT_BUILD],
 [AC_CACHE_CHECK([for QT compilation],[gconfig_cv_qt_build],
 [
-	if test "$gconfig_have_qt" = "yes"
+	if test "$gconfig_have_qt" = "yes" -a "$enable_gui" != "no"
 	then
 		gconfig_save_LIBS="$LIBS"
 		gconfig_save_CXXFLAGS="$CXXFLAGS"
@@ -2013,6 +2054,7 @@ AC_DEFUN([GCONFIG_FN_SOPEN_S],
 		],
 		[
 			[errno_t e = _sopen_s(&fd,"foo",_O_WRONLY,_SH_DENYNO,_S_IWRITE) ;]
+			[if( e ) return 1 ;]
 		])],
 		gconfig_cv_sopen_s=yes ,
 		gconfig_cv_sopen_s=no )
@@ -2279,7 +2321,7 @@ AC_DEFUN([GCONFIG_FN_TLS],
 		GCONFIG_TLS_LIBS=""
 	fi
 
-	if test "$gconfig_ssl_use_none" = "yes" -a "$with_openssl" != "no"
+	if test "$gconfig_ssl_use_none" = "yes"
 	then
 		gconfig_warnings="$gconfig_warnings openssl/mbedtls_transport_layer_security"
 	fi
@@ -2632,6 +2674,36 @@ AC_DEFUN([GCONFIG_FN_UDS],
 	fi
 ])
 
+dnl GCONFIG_FN_UDS_LEN
+dnl ------------------
+dnl Tests for BSD's 'sun_len' in 'sockaddr_un'.
+dnl
+AC_DEFUN([GCONFIG_FN_UDS_LEN],
+[AC_CACHE_CHECK([for unix domain sockets],[gconfig_cv_uds_len],
+[
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
+		[
+			[#include <sys/types.h>]
+			[#include <sys/socket.h>]
+			[#include <sys/un.h>]
+			[struct sockaddr_un a ;]
+		] ,
+		[
+			[a.sun_len = 2U ;]
+			[a.sun_family = AF_UNIX | PF_UNIX ;]
+			[a.sun_path[0] = '\0' ;]
+		])] ,
+		[gconfig_cv_uds_len=yes],
+		[gconfig_cv_uds_len=no])
+])
+	if test "$gconfig_cv_uds_len" = "yes"
+	then
+		AC_DEFINE(GCONFIG_HAVE_UDS_LEN,1,[Define true if sockaddr_un has a sun_len field])
+	else
+		AC_DEFINE(GCONFIG_HAVE_UDS_LEN,0,[Define true if sockaddr_un has a sun_len field])
+	fi
+])
+
 dnl GCONFIG_FN_WARNINGS
 dnl -------------------
 dnl Displays a summary warning.
@@ -2678,17 +2750,15 @@ dnl relevant library code. See also AM_GNU_GETTEXT.
 dnl
 AC_DEFUN([GCONFIG_FN_WITH_GETTEXT],
 [
-	if test "$with_gettext" = "no"
-	then
-		gconfig_cv_gettext="no"
-	:
-	elif test "$with_gettext" = "yes"
+	if test "$with_gettext" = "yes"
 	then
 		if test "$gconfig_cv_gettext" = "no"
 		then
 			AC_MSG_WARN([forcing use of gettext even though not detected])
 			gconfig_cv_gettext="yes"
 		fi
+	else
+		gconfig_cv_gettext="no"
 	fi
 
 	if test "$gconfig_cv_gettext" = "yes" ; then
@@ -2765,24 +2835,3 @@ AC_DEFUN([GCONFIG_FN_WITH_PAM],
 	AM_CONDITIONAL([GCONFIG_PAM],[test "$gconfig_use_pam" = "yes"])
 ])
 
-dnl GCONFIG_FN_WITH_UDS
-dnl -------------------
-dnl Enables unix domain sockets if detected unless "--without-uds" is
-dnl used. Requires GCONFIG_FN_UDS to set gconfig_cv_uds.
-dnl Typically used after AC_ARG_WITH(uds).
-dnl
-AC_DEFUN([GCONFIG_FN_WITH_UDS],
-[
-	AC_REQUIRE([GCONFIG_FN_UDS])
-	if test "$with_uds" = "no"
-	then
-		AM_CONDITIONAL([GCONFIG_UDS],[false])
-	else
-		if test "$with_uds" = "yes" -a "$gconfig_cv_uds" = "no"
-		then
-			AC_MSG_WARN([forcing use of unix domain sockets even though not detected])
-		fi
-		AM_CONDITIONAL([GCONFIG_UDS],[true])
-	fi
-])
-
diff --git a/po/Makefile.am b/po/Makefile.am
index 1681a44..db79372 100644
--- a/po/Makefile.am
+++ b/po/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -65,7 +65,7 @@ mo: emailrelay.$(LANG).mo
 
 emailrelay.pot:
 	@rm emailrelay.pot 2>/dev/null || true
-	xgettext -i --no-wrap --package-name=$(PACKAGE_NAME) --package-version=$(PACKAGE_VERSION) --c++ -o emailrelay.pot `find $(top_srcdir)/src -name *.cpp -o -name *.h | grep -v gui/`
+	cd $(top_srcdir)/src ; xgettext -i --no-wrap --keyword=txt --keyword=tx --package-name=$(PACKAGE_NAME) --package-version=$(PACKAGE_VERSION) --c++ --force-po -o ../po/emailrelay.pot `find . -name *.cpp -o -name *.h`
 
 emailrelay.$(LANG).mo: emailrelay.$(LANG).po
 	msgfmt -o $@ $<
diff --git a/po/Makefile.in b/po/Makefile.in
index f00a006..e65d74e 100644
--- a/po/Makefile.in
+++ b/po/Makefile.in
@@ -488,7 +488,7 @@ mo: emailrelay.$(LANG).mo
 
 emailrelay.pot:
 	@rm emailrelay.pot 2>/dev/null || true
-	xgettext -i --no-wrap --package-name=$(PACKAGE_NAME) --package-version=$(PACKAGE_VERSION) --c++ -o emailrelay.pot `find $(top_srcdir)/src -name *.cpp -o -name *.h | grep -v gui/`
+	cd $(top_srcdir)/src ; xgettext -i --no-wrap --keyword=txt --keyword=tx --package-name=$(PACKAGE_NAME) --package-version=$(PACKAGE_VERSION) --c++ --force-po -o ../po/emailrelay.pot `find . -name *.cpp -o -name *.h`
 
 emailrelay.$(LANG).mo: emailrelay.$(LANG).po
 	msgfmt -o $@ $<
diff --git a/po/Makevars b/po/Makevars
index a33a8d2..624a17f 100644
--- a/po/Makevars
+++ b/po/Makevars
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 3ed143c..7be6fb7 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -16,6 +16,7 @@
 ./src/main/serviceimp_none.cpp
 ./src/main/submit.cpp
 ./src/main/main.cpp
+./src/main/testrun.cpp
 ./src/main/configuration.cpp
 ./src/main/passwd.cpp
 ./src/main/news.cpp
@@ -53,6 +54,7 @@
 ./src/gsmtp/ginternalverifier.cpp
 ./src/gsmtp/gadminserver.cpp
 ./src/gsmtp/gspamfilter.cpp
+./src/gsmtp/gfilterchain.cpp
 ./src/gsmtp/gprotocolmessagestore.cpp
 ./src/gsmtp/gmessagestore_unix.cpp
 ./src/gsmtp/genvelope.cpp
@@ -63,9 +65,12 @@
 ./src/gsmtp/gfilterfactory.cpp
 ./src/gsmtp/gspamclient.cpp
 ./src/gsmtp/gexecutableverifier.cpp
+./src/glib/gconvert_unix.cpp
 ./src/glib/goptionmap.cpp
 ./src/glib/gpath.cpp
 ./src/glib/gfile.cpp
+./src/glib/ggettext_none.cpp
+./src/glib/gstringview.cpp
 ./src/glib/gprocess_unix.cpp
 ./src/glib/gidentity_unix.cpp
 ./src/glib/gexception.cpp
@@ -88,6 +93,7 @@
 ./src/glib/gmapfile.cpp
 ./src/glib/gstr.cpp
 ./src/glib/glogoutput.cpp
+./src/glib/gstringlist.cpp
 ./src/glib/gformat.cpp
 ./src/glib/garg.cpp
 ./src/glib/gmsg_unix.cpp
@@ -96,18 +102,22 @@
 ./src/glib/gexecutablecommand.cpp
 ./src/glib/gpidfile.cpp
 ./src/glib/gpam_none.cpp
+./src/glib/goptionsusage.cpp
 ./src/glib/gdirectory.cpp
 ./src/glib/goptionparser.cpp
+./src/glib/glogstream.cpp
 ./src/glib/gtest.cpp
 ./src/glib/gdatetime.cpp
 ./src/glib/gstringwrap.cpp
 ./src/glib/gexecutablecommand_unix.cpp
 ./src/glib/gdate.cpp
+./src/glib/goption.cpp
 ./src/glib/gmd5.cpp
 ./src/glib/gthread.cpp
 ./src/glib/glogoutput_unix.cpp
 ./src/glib/glog.cpp
 ./src/glib/gdaemon_unix.cpp
+./src/glib/ggettext_unix.cpp
 ./src/glib/gconvert.cpp
 ./src/glib/groot.cpp
 ./src/gnet/gmultiserver.cpp
@@ -120,12 +130,15 @@
 ./src/gnet/geventloop_epoll.cpp
 ./src/gnet/geventloop.cpp
 ./src/gnet/ginterfaces_common.cpp
+./src/gnet/geventloophandles.cpp
 ./src/gnet/gaddresslocal_unix.cpp
 ./src/gnet/gmonitor.cpp
+./src/gnet/gdnsbl_enabled.cpp
 ./src/gnet/ginterfaces_unix.cpp
 ./src/gnet/gclientptr.cpp
 ./src/gnet/geventhandler.cpp
 ./src/gnet/gfutureevent_unix.cpp
+./src/gnet/geventemitter.cpp
 ./src/gnet/glinestore.cpp
 ./src/gnet/gresolverfuture.cpp
 ./src/gnet/gtask.cpp
@@ -134,11 +147,11 @@
 ./src/gnet/glinebuffer.cpp
 ./src/gnet/gaddresslocal_none.cpp
 ./src/gnet/gsocket.cpp
+./src/gnet/gdnsbl_disabled.cpp
 ./src/gnet/glocal.cpp
 ./src/gnet/glocation.cpp
 ./src/gnet/gtimer.cpp
 ./src/gnet/gtimerlist.cpp
-./src/gnet/gaddress.cpp
 ./src/gnet/gsocket_unix.cpp
 ./src/gnet/geventloggingcontext.cpp
 ./src/gnet/gconnection.cpp
@@ -147,7 +160,7 @@
 ./src/gnet/gexceptionsource.cpp
 ./src/gnet/geventloop_select.cpp
 ./src/gnet/ginterfaces_none.cpp
-./src/gnet/geventhandlerlist.cpp
+./src/gnet/gaddress.cpp
 ./src/gnet/gdnsmessage.cpp
 ./src/gnet/gexceptionsink.cpp
 ./src/gnet/gdescriptor_unix.cpp
diff --git a/src/.clang-tidy b/src/.clang-tidy
index 2ddf287..adaeca5 100644
--- a/src/.clang-tidy
+++ b/src/.clang-tidy
@@ -1,60 +1,28 @@
 #
-# clang-tidy
+# clang-tidy-7
 #
-# Configuration for clang-tidy v11.
+# Configuration for clang-tidy v7.
 #
 Checks: "\
 bugprone-*,\
--bugprone-easily-swappable-parameters,\
--bugprone-throw-keyword-missing,\
--bugprone-macro-parentheses,\
--bugprone-branch-clone,\
+-bugprone-suspicious-include,\
 cert-*,\
 clang-diagnostic-*,\
 misc-*,\
--misc-macro-parentheses,\
--misc-noexcept-move-constructor,\
--misc-no-recursion,\
 cppcoreguidelines-*,\
 -cppcoreguidelines-pro-*,\
-cppcoreguidelines-pro-type-member-init,\
 -cppcoreguidelines-owning-memory,\
--cppcoreguidelines-avoid-magic-numbers,\
--cppcoreguidelines-macro-usage,\
--cppcoreguidelines-avoid-non-const-global-variables,\
--cppcoreguidelines-prefer-member-initializer,\
 modernize-*,\
 -modernize-avoid-bind,\
 -modernize-use-auto,\
--modernize-use-default-member-init,\
--modernize-return-braced-init-list,\
--modernize-pass-by-value,\
--modernize-raw-string-literal,\
--modernize-use-trailing-return-type,\
 performance-*,\
--performance-unnecessary-value-param,\
 readability-*,\
--readability-function-cognitive-complexity,\
--readability-qualified-auto,\
--readability-simplify-boolean-expr,\
--readability-else-after-return,\
--readability-inconsistent-declaration-parameter-name,\
--readability-implicit-bool-conversion,\
--readability-implicit-bool-cast,\
--readability-named-parameter,\
--readability-braces-around-statements,\
--readability-convert-member-functions-to-static,\
--readability-redundant-access-specifiers,\
--readability-make-member-function-const,\
--readability-magic-numbers,\
+-readability-*,\
 "
 
 CheckOptions:
   - key: cppcoreguidelines-special-member-functions.AllowSoleDefaultDtor
     value: '1'
-  - key: misc-non-private-member-variables-in-classes.IgnoreClassesWithAllMemberVariablesBeingPublic
-    value: '1'
   - key: cppcoreguidelines-pro-type-member-init.IgnoreArrays
     value: '1'
 
-HeaderFilterRegex: '(gauth|glib|gnet|gpop|gsmtp|gssl|main)/.*'
diff --git a/src/Makefile.am b/src/Makefile.am
index 9206777..fa02dd9 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -24,7 +24,7 @@ TIDY ?= clang-tidy
 .PHONY: cdb
 cdb: compile_commands.json
 
-compile_commands.json:
+compile_commands.json: Makefile
 	@chmod +x $(top_srcdir)/bin/make2cdb || true
 	$(top_srcdir)/bin/make2cdb > $@.tmp && mv $@.tmp $@
 
diff --git a/src/Makefile.in b/src/Makefile.in
index 9fceef5..1bf6299 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -644,7 +644,7 @@ TIDY ?= clang-tidy
 .PHONY: cdb
 cdb: compile_commands.json
 
-compile_commands.json:
+compile_commands.json: Makefile
 	@chmod +x $(top_srcdir)/bin/make2cdb || true
 	$(top_srcdir)/bin/make2cdb > $@.tmp && mv $@.tmp $@
 
diff --git a/src/gauth/Makefile.am b/src/gauth/Makefile.am
index cffcbbc..4da08f9 100644
--- a/src/gauth/Makefile.am
+++ b/src/gauth/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
diff --git a/src/gauth/gcram.cpp b/src/gauth/gcram.cpp
index ce498a5..7e369d1 100644
--- a/src/gauth/gcram.cpp
+++ b/src/gauth/gcram.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,6 +24,7 @@
 #include "ghashstate.h"
 #include "gmd5.h"
 #include "gstr.h"
+#include "gstringlist.h"
 #include "gssl.h"
 #include "gbase64.h"
 #include "glocal.h"
@@ -39,18 +40,18 @@ namespace GAuth
 		GSsl::Library & lib()
 		{
 			GSsl::Library * p = GSsl::Library::instance() ;
-			if( p == nullptr ) throw G::Exception( "no tls library" ) ;
+			if( p == nullptr ) throw Cram::NoTls() ;
 			return *p ;
 		}
 		struct DigesterAdaptor /// Used by GAuth::Cram to use GSsl::Digester.
 		{
-			explicit DigesterAdaptor( const std::string & name ) :
-				m_name(name)
+			explicit DigesterAdaptor( G::string_view name ) :
+				m_name(G::sv_to_string(name))
 			{
 				GSsl::Digester d( CramImp::lib().digester(m_name) ) ;
 				m_blocksize = d.blocksize() ;
 			}
-			std::string operator()( const std::string & data_1 , const std::string & data_2 ) const
+			std::string operator()( G::string_view data_1 , G::string_view data_2 ) const
 			{
 				GSsl::Digester d( CramImp::lib().digester(m_name) ) ;
 				d.add( data_1 ) ;
@@ -66,8 +67,8 @@ namespace GAuth
 		} ;
 		struct PostDigesterAdaptor /// Used by GAuth::Cram to use GSsl::Digester.
 		{
-			explicit PostDigesterAdaptor( const std::string & name ) :
-				m_name(name)
+			explicit PostDigesterAdaptor( G::string_view name ) :
+				m_name(G::sv_to_string(name))
 			{
 				GSsl::Digester d( CramImp::lib().digester(m_name,std::string(),true) ) ;
 				if( d.statesize() == 0U )
@@ -93,9 +94,8 @@ namespace GAuth
 	}
 }
 
-std::string GAuth::Cram::response( const std::string & hash_type , bool as_hmac ,
-	const Secret & secret , const std::string & challenge ,
-	const std::string & id_prefix )
+std::string GAuth::Cram::response( G::string_view hash_type , bool as_hmac ,
+	const Secret & secret , G::string_view challenge , G::string_view id_prefix )
 {
 	try
 	{
@@ -106,7 +106,7 @@ std::string GAuth::Cram::response( const std::string & hash_type , bool as_hmac
 			<< "[" << G::Str::printable(id_prefix) << "]"
 			<< "[" << responseImp(hash_type,as_hmac,secret,challenge) << "]" ) ;
 
-		return id_prefix + " " + responseImp(hash_type,as_hmac,secret,challenge) ;
+		return G::sv_to_string(id_prefix).append(1U,' ').append(responseImp(hash_type,as_hmac,secret,challenge)) ;
 	}
 	catch( std::exception & e )
 	{
@@ -115,9 +115,9 @@ std::string GAuth::Cram::response( const std::string & hash_type , bool as_hmac
 	}
 }
 
-bool GAuth::Cram::validate( const std::string & hash_type , bool as_hmac ,
-	const Secret & secret , const std::string & challenge ,
-	const std::string & response_in )
+bool GAuth::Cram::validate( G::string_view hash_type , bool as_hmac ,
+	const Secret & secret , G::string_view challenge ,
+	G::string_view response_in )
 {
 	try
 	{
@@ -139,14 +139,15 @@ bool GAuth::Cram::validate( const std::string & hash_type , bool as_hmac ,
 	}
 }
 
-std::string GAuth::Cram::id( const std::string & response )
+std::string GAuth::Cram::id( G::string_view response )
 {
 	// the response is "<id> <hexchars>" but also allow for ids with spaces
-	return G::Str::head( response , response.rfind(' ') ) ;
+	std::size_t pos = response.rfind( ' ' ) ;
+	return G::Str::head( response , pos ) ;
 }
 
-std::string GAuth::Cram::responseImp( const std::string & mechanism_hash_type , bool as_hmac ,
-	const Secret & secret , const std::string & challenge )
+std::string GAuth::Cram::responseImp( G::string_view mechanism_hash_type , bool as_hmac ,
+	const Secret & secret , G::string_view challenge )
 {
 	G_DEBUG( "GAuth::Cram::responseImp: mechanism-hash=[" << mechanism_hash_type << "] "
 		<< "secret-hash=[" << secret.maskType() << "] "
@@ -157,7 +158,7 @@ std::string GAuth::Cram::responseImp( const std::string & mechanism_hash_type ,
 		if( secret.masked() )
 			throw BadType( secret.maskType() ) ;
 
-		if( mechanism_hash_type == "MD5" )
+		if( mechanism_hash_type == "MD5"_sv )
 		{
 			return G::Hash::printable( G::Md5::digest(challenge,secret.key()) ) ;
 		}
@@ -170,33 +171,33 @@ std::string GAuth::Cram::responseImp( const std::string & mechanism_hash_type ,
 	else if( secret.masked() )
 	{
 		if( ! G::Str::imatch(secret.maskType(),mechanism_hash_type) )
-			throw Mismatch( secret.maskType() , mechanism_hash_type ) ;
+			throw Mismatch( secret.maskType() , G::sv_to_string(mechanism_hash_type) ) ;
 
-		if( mechanism_hash_type == "MD5" )
+		if( mechanism_hash_type == "MD5"_sv )
 		{
-			return G::Hash::printable( G::Hash::hmac(G::Md5::postdigest,secret.key(),challenge,G::Hash::Masked()) ) ;
+			return G::Hash::printable( G::Hash::hmac(G::Md5::postdigest,secret.key(),G::sv_to_string(challenge),G::Hash::Masked()) ) ;
 		}
 		else
 		{
 			CramImp::PostDigesterAdaptor postdigest( mechanism_hash_type ) ;
-			return G::Hash::printable( G::Hash::hmac(postdigest,secret.key(),challenge,G::Hash::Masked()) ) ;
+			return G::Hash::printable( G::Hash::hmac(postdigest,secret.key(),G::sv_to_string(challenge),G::Hash::Masked()) ) ;
 		}
 	}
 	else
 	{
-		if( mechanism_hash_type == "MD5" )
+		if( mechanism_hash_type == "MD5"_sv )
 		{
-			return G::Hash::printable( G::Hash::hmac(G::Md5::digest2,G::Md5::blocksize(),secret.key(),challenge) ) ;
+			return G::Hash::printable( G::Hash::hmac(G::Md5::digest2,G::Md5::blocksize(),secret.key(),G::sv_to_string(challenge)) ) ;
 		}
 		else
 		{
 			CramImp::DigesterAdaptor digest( mechanism_hash_type ) ;
-			return G::Hash::printable( G::Hash::hmac(digest,digest.blocksize(),secret.key(),challenge) ) ;
+			return G::Hash::printable( G::Hash::hmac(digest,digest.blocksize(),secret.key(),G::sv_to_string(challenge)) ) ;
 		}
 	}
 }
 
-G::StringArray GAuth::Cram::hashTypes( const std::string & prefix , bool require_state )
+G::StringArray GAuth::Cram::hashTypes( G::string_view prefix , bool require_state )
 {
 	// we can do CRAM-X for all hash functions (X) provided by the TLS library
 	// but if we only have masked passwords (ie. require_state) then we only
@@ -211,23 +212,22 @@ G::StringArray GAuth::Cram::hashTypes( const std::string & prefix , bool require
 		<< "(" << (require_state?1:0) << ")" ) ;
 
 	// always include MD5 since we use G::Md5 code
-	if( !G::Str::match( result , "MD5" ) )
+	if( !G::StringList::match( result , "MD5" ) )
 		result.push_back( "MD5" ) ;
 
 	if( !prefix.empty() )
 	{
 		for( auto & hashtype : result )
-			hashtype.insert( 0U , prefix ) ;
+			hashtype.insert( 0U , prefix.data() , prefix.size() ) ;
 	}
 	return result ;
 }
 
 std::string GAuth::Cram::challenge( unsigned int random )
 {
-	std::ostringstream ss ;
-	ss << "<" << random << "."
-		<< G::SystemTime::now().s() << "@"
-		<< GNet::Local::canonicalName() << ">" ;
-	return ss.str() ;
+	return std::string(1U,'<')
+		.append(std::to_string(random)).append(1U,'.')
+		.append(std::to_string(G::SystemTime::now().s())).append(1U,'@')
+		.append(GNet::Local::canonicalName()).append(1U,'>') ;
 }
 
diff --git a/src/gauth/gcram.h b/src/gauth/gcram.h
index 84c5325..7fb4226 100644
--- a/src/gauth/gcram.h
+++ b/src/gauth/gcram.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,7 +22,8 @@
 #define G_AUTH_CRAM_H
 
 #include "gdef.h"
-#include "gstrings.h"
+#include "gstringarray.h"
+#include "gstringview.h"
 #include "gsecret.h"
 #include "gexception.h"
 #include <string>
@@ -50,30 +51,31 @@ namespace GAuth
 class GAuth::Cram
 {
 public:
-	G_EXCEPTION( BadType , "invalid secret type" ) ;
-	G_EXCEPTION( Mismatch , "mismatched hash types" ) ;
-	G_EXCEPTION( NoState , "no intermediate-state hash function available" ) ;
-	G_EXCEPTION( InvalidState , "invalid hash function intermediate state" ) ;
+	G_EXCEPTION( BadType , tx("invalid secret type") ) ;
+	G_EXCEPTION( Mismatch , tx("mismatched hash types") ) ;
+	G_EXCEPTION( NoState , tx("no intermediate-state hash function available") ) ;
+	G_EXCEPTION( InvalidState , tx("invalid hash function intermediate state") ) ;
+	G_EXCEPTION( NoTls , tx("no tls library") ) ;
 
-	static std::string response( const std::string & hash_type , bool hmac ,
-		const Secret & secret , const std::string & challenge ,
-		const std::string & response_prefix ) ;
+	static std::string response( G::string_view hash_type , bool hmac ,
+		const Secret & secret , G::string_view challenge ,
+		G::string_view response_prefix ) ;
 			///< Constructs a response to a challenge comprising the
 			///< response-prefix, space, and digest-or-hmac of
 			///< secretkey-plus-challenge. Returns an empty string on
 			///< error; does not throw.
 
-	static std::string id( const std::string & response ) ;
+	static std::string id( G::string_view response ) ;
 		///< Returns the leading id part of the response. Returns
 		///< the empty string on error.
 
-	static bool validate( const std::string & hash_type , bool hmac ,
-		const Secret & secret , const std::string & challenge ,
-		const std::string & response ) ;
+	static bool validate( G::string_view hash_type , bool hmac ,
+		const Secret & secret , G::string_view challenge ,
+		G::string_view response ) ;
 			///< Validates the response with respect to the original
 			///< challenge. Returns false on error; does not throw.
 
-	static G::StringArray hashTypes( const std::string & prefix = std::string() , bool require_state = false ) ;
+	static G::StringArray hashTypes( G::string_view prefix = {} , bool require_state = false ) ;
 		///< Returns a list of supported hash types, such as "MD5"
 		///< and "SHA1", ordered with the strongest first. Optionally
 		///< adds a prefix to each type, and optionally limits the
@@ -88,7 +90,7 @@ public:
 	Cram() = delete ;
 
 private:
-	static std::string responseImp( const std::string & , bool , const Secret & , const std::string & ) ;
+	static std::string responseImp( G::string_view , bool , const Secret & , G::string_view ) ;
 } ;
 
 #endif
diff --git a/src/gauth/gsaslclient.cpp b/src/gauth/gsaslclient.cpp
index 58cd1ea..26bdf90 100644
--- a/src/gauth/gsaslclient.cpp
+++ b/src/gauth/gsaslclient.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -20,6 +20,8 @@
 
 #include "gdef.h"
 #include "gsaslclient.h"
+#include "gstringview.h"
+#include "gstringlist.h"
 #include "gssl.h"
 #include "gmd5.h"
 #include "ghash.h"
@@ -29,7 +31,6 @@
 #include "gassert.h"
 #include "glog.h"
 #include <algorithm>
-#include <sstream>
 
 //| \class GAuth::SaslClientImp
 /// A private pimple-pattern implementation class used by GAuth::SaslClient.
@@ -41,8 +42,8 @@ public:
 	SaslClientImp( const SaslClientSecrets & , const std::string & ) ;
 	bool active() const ;
 	std::string mechanism( const G::StringArray & ) const ;
-	std::string initialResponse( std::size_t limit ) const ;
-	Response response( const std::string & mechanism , const std::string & challenge ) const ;
+	Response initialResponse( std::size_t limit ) const ;
+	Response response( G::string_view mechanism , G::string_view challenge ) const ;
 	bool next() ;
 	std::string mechanism() const ;
 	std::string id() const ;
@@ -57,12 +58,12 @@ private:
 	mutable std::string m_id ;
 	std::string PLAIN ;
 	std::string LOGIN ;
-	static const char * const login_challenge_1 ;
-	static const char * const login_challenge_2 ;
+	static G::string_view login_challenge_1 ;
+	static G::string_view login_challenge_2 ;
 } ;
 
-const char * const GAuth::SaslClientImp::login_challenge_1 = "Username:" ;
-const char * const GAuth::SaslClientImp::login_challenge_2 = "Password:" ;
+G::string_view GAuth::SaslClientImp::login_challenge_1 { "Username:" , 9U } ;
+G::string_view GAuth::SaslClientImp::login_challenge_2 { "Password:" , 9U } ;
 
 // ===
 
@@ -96,7 +97,8 @@ std::string GAuth::SaslClientImp::mechanism( const G::StringArray & server_mecha
 		our_list = Cram::hashTypes( "CRAM-" , true ) ;
 		for( auto p = our_list.begin() ; p != our_list.end() ; )
 		{
-			if( m_secrets.clientSecret((*p).substr(5U)).valid() )
+			std::string type = (*p).substr( 5U ) ;
+			if( m_secrets.clientSecret(type).valid() )
 				++p ;
 			else
 				p = our_list.erase( p ) ;
@@ -115,12 +117,12 @@ std::string GAuth::SaslClientImp::mechanism( const G::StringArray & server_mecha
 	// use the configuration string as a mechanism whitelist and/or blocklist
 	if( !m_config.empty() )
 	{
-		bool simple = G::Str::imatch( our_list , m_config ) ; // eg. allow "plain" as well as "m:plain"
+		bool simple = G::StringList::imatch( our_list , m_config ) ; // eg. allow "plain" as well as "m:plain"
 		G::StringArray list = G::Str::splitIntoTokens( G::Str::upper(m_config) , ";" ) ;
-		G::StringArray whitelist = G::Str::splitIntoTokens( simple?G::Str::upper(m_config): G::Str::headMatchResidue( list , "M:" ) , "," ) ;
-		G::StringArray blocklist = G::Str::splitIntoTokens( G::Str::headMatchResidue( list , "X:" ) , "," ) ;
-		our_list.erase( G::Str::keepMatch( our_list.begin() , our_list.end() , whitelist , true ) , our_list.end() ) ;
-		our_list.erase( G::Str::removeMatch( our_list.begin() , our_list.end() , blocklist , true ) , our_list.end() ) ;
+		G::StringArray whitelist = G::Str::splitIntoTokens( simple ? G::Str::upper(m_config) : G::StringList::headMatchResidue( list , "M:" ) , "," ) ;
+		G::StringArray blocklist = G::Str::splitIntoTokens( G::StringList::headMatchResidue( list , "X:" ) , "," ) ;
+		G::StringList::keepMatch( our_list , whitelist , G::StringList::Ignore::Case ) ;
+		G::StringList::removeMatch( our_list , blocklist , G::StringList::Ignore::Case ) ;
 	}
 
 	// build the list of mechanisms that we can use with the server
@@ -152,25 +154,24 @@ std::string GAuth::SaslClientImp::mechanism() const
 	return m_mechanisms.empty() ? std::string() : m_mechanisms.at(0U) ;
 }
 
-std::string GAuth::SaslClientImp::initialResponse( std::size_t limit ) const
+GAuth::SaslClient::Response GAuth::SaslClientImp::initialResponse( std::size_t limit ) const
 {
 	// (the implementation of response() is stateless because it can derive
 	// state from the challege, so we doesn't need to worry here about
 	// side-effects between initialResponse() and response())
 
-	const std::string m = mechanism() ;
-	if( m.empty() || m.find("CRAM-") == 0U )
-		return std::string() ;
+	if( m_mechanisms.empty() || m_mechanisms[0U].find("CRAM-") == 0U )
+		return {} ;
 
-	Response rsp = response( m , m=="LOGIN"?std::string(login_challenge_1):std::string() ) ;
+	const std::string & m = m_mechanisms[0] ;
+	Response rsp = response( m , m == "LOGIN" ? login_challenge_1 : G::string_view() ) ;
 	if( rsp.error || rsp.data.size() > limit )
-		return std::string() ;
+		return {} ;
 	else
-		return rsp.data ;
+		return rsp ;
 }
 
-GAuth::SaslClient::Response GAuth::SaslClientImp::response( const std::string & mechanism ,
-	const std::string & challenge ) const
+GAuth::SaslClient::Response GAuth::SaslClientImp::response( G::string_view mechanism , G::string_view challenge ) const
 {
 	Response rsp ;
 	rsp.sensitive = true ;
@@ -180,7 +181,7 @@ GAuth::SaslClient::Response GAuth::SaslClientImp::response( const std::string &
 	Secret secret = Secret::none() ;
 	if( mechanism.find("CRAM-") == 0U )
 	{
-		std::string hash_type = mechanism.substr( 5U ) ;
+		G::string_view hash_type = mechanism.substr( 5U ) ;
 		secret = m_secrets.clientSecret( hash_type ) ;
 		if( !secret.valid() )
 			secret = m_secrets.clientSecret( "plain" ) ;
@@ -188,24 +189,23 @@ GAuth::SaslClient::Response GAuth::SaslClientImp::response( const std::string &
 		rsp.error = rsp.data.empty() ;
 		rsp.final = true ;
 	}
-	else if( mechanism == "APOP" )
+	else if( mechanism == "APOP"_sv )
 	{
-		secret = m_secrets.clientSecret( "MD5" ) ;
-		rsp.data = Cram::response( "MD5" , false , secret , challenge , secret.id() ) ;
+		secret = m_secrets.clientSecret( "MD5"_sv ) ;
+		rsp.data = Cram::response( "MD5"_sv , false , secret , challenge , secret.id() ) ;
 		rsp.error = rsp.data.empty() ;
 		rsp.final = true ;
 	}
 	else if( mechanism == PLAIN )
 	{
-		secret = m_secrets.clientSecret( "plain" ) ;
-		const std::string sep( 1U , '\0' ) ;
-		rsp.data = sep + secret.id() + sep + secret.key() ;
+		secret = m_secrets.clientSecret( "plain"_sv ) ;
+		rsp.data = std::string(1U,'\0').append(secret.id()).append(1U,'\0').append(secret.key()) ;
 		rsp.error = !secret.valid() ;
 		rsp.final = true ;
 	}
 	else if( mechanism == LOGIN && challenge == login_challenge_1 )
 	{
-		secret = m_secrets.clientSecret( "plain" ) ;
+		secret = m_secrets.clientSecret( "plain"_sv ) ;
 		rsp.data = secret.id() ;
 		rsp.error = !secret.valid() ;
 		rsp.final = false ;
@@ -213,21 +213,21 @@ GAuth::SaslClient::Response GAuth::SaslClientImp::response( const std::string &
 	}
 	else if( mechanism == LOGIN && challenge == login_challenge_2 )
 	{
-		secret = m_secrets.clientSecret( "plain" ) ;
+		secret = m_secrets.clientSecret( "plain"_sv ) ;
 		rsp.data = secret.key() ;
 		rsp.error = !secret.valid() ;
 		rsp.final = true ;
 	}
-	else if( mechanism == "XOAUTH2" && challenge.empty() )
+	else if( mechanism == "XOAUTH2"_sv && challenge.empty() )
 	{
-		secret = m_secrets.clientSecret( "oauth" ) ;
+		secret = m_secrets.clientSecret( "oauth"_sv ) ;
 		rsp.data = secret.key() ;
 		rsp.error = !secret.valid() ;
 		rsp.final = true ; // not always -- may get an informational challenge
 	}
-	else if( mechanism == "XOAUTH2" )
+	else if( mechanism == "XOAUTH2"_sv )
 	{
-		secret = m_secrets.clientSecret( "oauth" ) ;
+		secret = m_secrets.clientSecret( "oauth"_sv ) ;
 		rsp.data.clear() ; // information-only challenge gets an empty response
 		rsp.error = false ;
 		rsp.final = true ;
@@ -236,9 +236,11 @@ GAuth::SaslClient::Response GAuth::SaslClientImp::response( const std::string &
 
 	if( rsp.final )
 	{
-		std::ostringstream ss ;
-		ss << "using mechanism [" << G::Str::lower(mechanism) << "] and " << secret.info() ;
-		m_info = ss.str() ;
+		m_info
+			.assign("using mechanism [")
+			.append(G::Str::lower(G::sv_to_string(mechanism)))
+			.append("] and ",6U)
+			.append(secret.info()) ;
 		m_id = secret.id() ;
 	}
 
@@ -280,12 +282,12 @@ bool GAuth::SaslClient::active() const
 	return m_imp->active() ;
 }
 
-GAuth::SaslClient::Response GAuth::SaslClient::response( const std::string & mechanism , const std::string & challenge ) const
+GAuth::SaslClient::Response GAuth::SaslClient::response( G::string_view mechanism , G::string_view challenge ) const
 {
 	return m_imp->response( mechanism , challenge ) ;
 }
 
-std::string GAuth::SaslClient::initialResponse( std::size_t limit ) const
+GAuth::SaslClient::Response GAuth::SaslClient::initialResponse( std::size_t limit ) const
 {
 	return m_imp->initialResponse( limit ) ;
 }
diff --git a/src/gauth/gsaslclient.h b/src/gauth/gsaslclient.h
index f98dfba..7d5a5d7 100644
--- a/src/gauth/gsaslclient.h
+++ b/src/gauth/gsaslclient.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,7 +24,8 @@
 #include "gdef.h"
 #include "gsaslclientsecrets.h"
 #include "gexception.h"
-#include "gstrings.h"
+#include "gstringview.h"
+#include "gstringarray.h"
 #include <memory>
 
 namespace GAuth
@@ -57,11 +58,11 @@ public:
 	bool active() const ;
 		///< Returns true if the constructor's secrets object is valid.
 
-	Response response( const std::string & mechanism , const std::string & challenge ) const ;
+	Response response( G::string_view mechanism , G::string_view challenge ) const ;
 		///< Returns a response to the given challenge. The mechanism is
 		///< used to choose the appropriate entry in the secrets file.
 
-	std::string initialResponse( std::size_t limit = 0U ) const ;
+	Response initialResponse( std::size_t limit = 0U ) const ;
 		///< Returns an optional initial response. Always returns the empty
 		///< string if the mechanism is 'server-first'. Returns the empty
 		///< string, with no side-effects, if the initial response is longer
@@ -79,9 +80,8 @@ public:
 
 	std::string next( const std::string & ) ;
 		///< A convenience overload that moves to the next() mechanism
-		///< and returns it. Returns the empty string if the
-		///< given string is empty or if there are no more
-		///< mechanisms.
+		///< and returns it. Returns the empty string if the given string
+		///< is empty or if there are no more mechanisms.
 
 	std::string mechanism() const ;
 		///< Returns the name of the current mechanism once next() has
@@ -98,8 +98,8 @@ public:
 public:
 	SaslClient( const SaslClient & ) = delete ;
 	SaslClient( SaslClient && ) = delete ;
-	void operator=( const SaslClient & ) = delete ;
-	void operator=( SaslClient && ) = delete ;
+	SaslClient & operator=( const SaslClient & ) = delete ;
+	SaslClient & operator=( SaslClient && ) = delete ;
 
 private:
 	std::unique_ptr<SaslClientImp> m_imp ;
diff --git a/src/gauth/gsaslclientsecrets.cpp b/src/gauth/gsaslclientsecrets.cpp
index 7f13530..b819452 100644
--- a/src/gauth/gsaslclientsecrets.cpp
+++ b/src/gauth/gsaslclientsecrets.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gauth/gsaslclientsecrets.h b/src/gauth/gsaslclientsecrets.h
index cf52ec8..f964542 100644
--- a/src/gauth/gsaslclientsecrets.h
+++ b/src/gauth/gsaslclientsecrets.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,6 +24,7 @@
 #include "gdef.h"
 #include "gvalid.h"
 #include "gsecret.h"
+#include "gstringview.h"
 
 namespace GAuth
 {
@@ -38,7 +39,7 @@ namespace GAuth
 class GAuth::SaslClientSecrets : public virtual Valid
 {
 public:
-	virtual Secret clientSecret( const std::string & type ) const = 0 ;
+	virtual Secret clientSecret( G::string_view type ) const = 0 ;
 		///< Returns the client secret for the given type.
 		///< The type is "plain" or the CRAM hash algorithm or "oauth".
 		///< Returns an invalid secret if none.
diff --git a/src/gauth/gsaslserver.cpp b/src/gauth/gsaslserver.cpp
index 7d8b184..8a74d31 100644
--- a/src/gauth/gsaslserver.cpp
+++ b/src/gauth/gsaslserver.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gauth/gsaslserver.h b/src/gauth/gsaslserver.h
index 79893d6..fec55ca 100644
--- a/src/gauth/gsaslserver.h
+++ b/src/gauth/gsaslserver.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -25,10 +25,10 @@
 #include "gvalid.h"
 #include "gexception.h"
 #include "gaddress.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gpath.h"
-#include <map>
 #include <memory>
+#include <utility>
 
 namespace GAuth
 {
@@ -44,58 +44,70 @@ namespace GAuth
 /// Usage:
 /// \code
 /// SaslServer sasl( secrets ) ;
-/// peer.advertise( sasl.mechanisms() ) ;
-/// if( sasl.init(peer.preferred()) )
+/// if( !sasl.mechanisms(peer.secure()).empty() )
 /// {
-///   if( peer.haveInitialResponse() && sasl.mustChallenge() ) throw ProtocolError() ;
-///   bool done = false ;
-///   string challenge = peer.haveInitialResponse() ?
-///     sasl.apply(peer.initialResponse(),done) : sasl.initialChallenge() ;
-///   while( !done )
+///   peer.advertise( sasl.mechanisms(peer.secure()) ) ;
+///   if( sasl.init(peer.secure(),peer.preferred()) )
 ///   {
-///     peer.send( challenge ) ;
-///     string response = peer.receive() ;
-///     challenge = sasl.apply( response , done ) ;
+///     if( peer.haveInitialResponse() && sasl.mustChallenge() )
+///       throw ProtocolError() ;
+///     bool done = false ;
+///     string challenge = peer.haveInitialResponse() ?
+///       sasl.apply(peer.initialResponse(),done) : sasl.initialChallenge() ;
+///     while( !done )
+///     {
+///       peer.send( challenge ) ;
+///       string response = peer.receive() ;
+///       challenge = sasl.apply( response , done ) ;
+///     }
+///     bool ok = sasl.authenticated() ;
 ///   }
-///   bool ok = sasl.authenticated() ;
 /// }
 /// \endcode
 ///
 /// \see GAuth::SaslClient, RFC-2554, RFC-4422
 ///
+/// Available mechanisms depend on the encryption state ('secure'). In practice
+/// there can often be no mechanisms when in the insecure state. If there are no
+/// mechanisms then the protocol might advertise a mechanism that always fails
+/// to authenticate, returning a 'secure connection required' error to the
+/// client -- but that behaviour is out of scope at this interface.
+///
 class GAuth::SaslServer
 {
 public:
 	virtual ~SaslServer() = default ;
 		///< Destructor.
 
-	virtual bool requiresEncryption() const = 0 ;
-		///< Returns true if the implementation requires that
-		///< the challenge/response dialog should only take
-		///< place over an encrypted transport.
-
-	virtual bool active() const = 0 ;
-		///< Returns true if the constructor's "secrets" object
-		///< was valid. See also Secrets::valid().
-
-	virtual std::string mechanisms( char space_separator ) const = 0 ;
-		///< Returns a list of supported, standard mechanisms
-		///< that can be advertised to the client.
+	virtual G::StringArray mechanisms( bool secure ) const = 0 ;
+		///< Returns a list of supported, standard mechanisms that
+		///< can be advertised to the client. The parameter
+		///< indicates whether the transport connection is currently
+		///< encrypted.
 		///<
-		///< Some mechanisms (like "APOP") may be accepted by
-		///< init() even though they are not advertised.
+		///< Returns the empty set if authentication is not possible
+		///< for the given encryption state.
 
-	virtual bool init( const std::string & mechanism ) = 0 ;
-		///< Initialiser. Returns true if the mechanism is in the
-		///< mechanisms() list, or if it is some other supported
-		///< mechanism (like "APOP") that the derived-class object
-		///< allows implicitly. May be used more than once.
-		///< The initialChallenge() is re-initialised on each
-		///< successful init().
+	virtual void reset() = 0 ;
+		///< Clears the internal state as if just constructed.
+		///< Postcondition: mechanism().empty() && id().empty() && !authenticated() && !trusted()
+
+	virtual bool init( bool secure , const std::string & mechanism ) = 0 ;
+		///< Initialiser for the given mechanism. Returns true iff
+		///< the requested mechanism is in the mechanisms() list.
+		///< May be used more than once. The initialChallenge() is
+		///< re-initialised on each successful init().
 
 	virtual std::string mechanism() const = 0 ;
-		///< Returns the mechanism, as passed to the last init()
-		///< call to return true.
+		///< Returns the current mechanism, as selected by the last
+		///< successful init().
+
+	virtual std::string preferredMechanism( bool secure ) const = 0 ;
+		///< Returns a preferred mechanism if authentication with the
+		///< current mechanism has failed. Returns the empty string if
+		///< there is no preference. This allows the negotiation of the
+		///< mechanism to be user-specific, perhaps by having the
+		///< first probe mechanism fail for all users.
 
 	virtual bool mustChallenge() const = 0 ;
 		///< Returns true if authentication using the current mechanism
@@ -133,8 +145,8 @@ public:
 		///< empty string if not authenticated and not trusted.
 
 	virtual bool trusted( const GNet::Address & ) const = 0 ;
-		///< Returns true if a trusted client that
-		///< does not need to authenticate.
+		///< Returns true if a trusted client that does not need
+		///< to authenticate.
 } ;
 
 #endif
diff --git a/src/gauth/gsaslserverbasic.cpp b/src/gauth/gsaslserverbasic.cpp
index f50dba7..087b08b 100644
--- a/src/gauth/gsaslserverbasic.cpp
+++ b/src/gauth/gsaslserverbasic.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -28,11 +28,14 @@
 #include "gtest.h"
 #include "gdatetime.h"
 #include "grandom.h"
+#include "gstringview.h"
+#include "gstringlist.h"
 #include "glog.h"
 #include "gassert.h"
 #include <sstream>
 #include <algorithm>
 #include <functional>
+#include <utility>
 
 //| \class GAuth::SaslServerBasicImp
 /// A private pimple-pattern implementation class used by GAuth::SaslServerBasic.
@@ -40,89 +43,143 @@
 class GAuth::SaslServerBasicImp
 {
 public:
-	SaslServerBasicImp( const SaslServerSecrets & , const std::string & , bool ) ;
-	std::string mechanisms( const std::string & ) const ;
-	bool init( const std::string & mechanism ) ;
+	SaslServerBasicImp( const SaslServerSecrets & , bool , const std::string & , bool ) ;
+	G::StringArray mechanisms( bool ) const ;
+	void reset() ;
+	bool init( bool , const std::string & mechanism ) ;
 	std::string mechanism() const ;
+	std::string preferredMechanism( bool ) const ;
 	std::string initialChallenge() const ;
 	std::string apply( const std::string & response , bool & done ) ;
 	bool trusted( const GNet::Address & ) const ;
 	bool trustedCore( const std::string & , const GNet::Address & ) const ;
-	bool active() const ;
 	std::string id() const ;
 	bool authenticated() const ;
 
 private:
-	bool m_allow_apop ;
 	bool m_first_apply ;
 	const SaslServerSecrets & m_secrets ;
-	G::StringArray m_mechanisms ; // that have secrets
+	G::StringArray m_mechanisms_secure ;
+	G::StringArray m_mechanisms_insecure ;
 	std::string m_mechanism ;
 	std::string m_challenge ;
 	bool m_authenticated ;
 	std::string m_id ;
 	std::string m_trustee ;
-	static const char * login_challenge_1 ;
-	static const char * login_challenge_2 ;
+	static G::string_view login_challenge_1 ;
+	static G::string_view login_challenge_2 ;
 } ;
 
-const char * GAuth::SaslServerBasicImp::login_challenge_1 = "Username:" ;
-const char * GAuth::SaslServerBasicImp::login_challenge_2 = "Password:" ;
+G::string_view GAuth::SaslServerBasicImp::login_challenge_1 {"Username:",9U} ;
+G::string_view GAuth::SaslServerBasicImp::login_challenge_2 {"Password:",9U} ;
 
 // ===
 
-GAuth::SaslServerBasicImp::SaslServerBasicImp( const SaslServerSecrets & secrets , const std::string & sasl_server_config , bool allow_apop ) :
-	m_allow_apop(allow_apop) ,
-	m_first_apply(true) ,
-	m_secrets(secrets) ,
-	m_authenticated(false)
+GAuth::SaslServerBasicImp::SaslServerBasicImp( const SaslServerSecrets & secrets ,
+	bool with_apop , const std::string & config , bool force_no_insecure_mechanisms ) :
+		m_first_apply(true) ,
+		m_secrets(secrets) ,
+		m_authenticated(false)
 {
-	m_mechanisms = Cram::hashTypes( "CRAM-" ) ;
-	m_mechanisms.push_back( "PLAIN" ) ;
-	m_mechanisms.push_back( "LOGIN" ) ;
-	if( G::Test::enabled("sasl-server-oauth") )
-		m_mechanisms.push_back( "XOAUTH2" ) ; // to allow testing of the client-side
-
-	// use the configuration string as a mechanism whitelist and/or blacklist
-	if( !sasl_server_config.empty() )
+	// prepare a list of mechanisms, but remove any that are completely unusable
+	G::StringArray mechanisms ;
 	{
-		G::StringArray list = G::Str::splitIntoTokens( G::Str::upper(sasl_server_config) , ";" ) ;
-		G::StringArray whitelist = G::Str::splitIntoTokens( G::Str::headMatchResidue( list , "M:" ) , "," ) ;
-		G::StringArray blacklist = G::Str::splitIntoTokens( G::Str::headMatchResidue( list , "X:" ) , "," ) ;
-		m_mechanisms.erase( G::Str::keepMatch( m_mechanisms.begin() , m_mechanisms.end() , whitelist , true ) , m_mechanisms.end() ) ;
-		m_mechanisms.erase( G::Str::removeMatch( m_mechanisms.begin() , m_mechanisms.end() , blacklist , true ) , m_mechanisms.end() ) ;
-		if( m_mechanisms.empty() )
-			throw SaslServerBasic::NoMechanisms() ;
+		// if there are any plain secrets then all mechanisms are usable
+		if( secrets.contains( "PLAIN" , {} ) )
+		{
+			mechanisms = Cram::hashTypes( "CRAM-" ) ;
+			mechanisms.push_back( "PLAIN" ) ;
+			mechanisms.push_back( "LOGIN" ) ;
+		}
+		else
+		{
+			// if there are any CRAM-X secrets then enable the CRAM-X mechansism
+			for( const auto & cram : Cram::hashTypes({},true) )
+			{
+				if( secrets.contains( cram , {} ) )
+					mechanisms.push_back( std::string("CRAM-").append(cram) ) ;
+			}
+		}
+		if( with_apop )
+			mechanisms.push_back( "APOP" ) ;
 	}
+
+	m_mechanisms_secure = mechanisms ;
+	m_mechanisms_insecure = mechanisms ;
+
+	// RFC-4954 4 p6 -- PLAIN is always an option when secure
+	if( m_mechanisms_secure.empty() && secrets.valid() )
+	{
+		m_mechanisms_secure.push_back( "PLAIN" ) ;
+	}
+
+	// apply the allow/deny configuration
+	//
+	// backwards compatibility if no A or D:
+	// M: for secure/insecure (M)echanisms to allow
+	// X: for secure/insecure mechanisms to e(X)clude
+	//
+	// new behaviour:
+	// M: for insecure (M)echanisms to allow
+	// X: for insecure mechanisms to e(X)clude
+	// A: for the secure (A)llow list
+	// D: for the secure (D)eny list
+	//
+	// eg: "m:;a:plain,login"
+	//
+	G::StringArray config_list = G::Str::splitIntoTokens( G::Str::upper(config) , ";" ) ;
+	bool have_m = G::StringList::headMatch( config_list , "M:" ) ;
+	bool have_a = G::StringList::headMatch( config_list , "A:" ) ;
+	bool have_d = G::StringList::headMatch( config_list , "D:" ) ;
+	std::string m = G::StringList::headMatchResidue( config_list , "M:" ) ;
+	std::string x = G::StringList::headMatchResidue( config_list , "X:" ) ;
+	std::string a = G::StringList::headMatchResidue( config_list , "A:" ) ;
+	std::string d = G::StringList::headMatchResidue( config_list , "D:" ) ;
+	G::optional<std::string> m_( have_m , m ) ;
+	G::optional<std::string> a_( have_a , a ) ;
+	if( have_a || have_d )
+	{
+		G::StringList::Filter(m_mechanisms_insecure).allow(m_).deny(x) ;
+		G::StringList::Filter(m_mechanisms_secure).allow(a_).deny(d) ;
+	}
+	else
+	{
+		G::StringList::Filter(m_mechanisms_insecure).allow(m_).deny(x) ;
+		G::StringList::Filter(m_mechanisms_secure).allow(m_).deny(x) ;
+	}
+
+	if( force_no_insecure_mechanisms )
+		m_mechanisms_insecure.clear() ;
 }
 
-std::string GAuth::SaslServerBasicImp::mechanisms( const std::string & sep ) const
-{
-	return G::Str::join( sep , m_mechanisms ) ;
-}
-
-bool GAuth::SaslServerBasicImp::init( const std::string & mechanism_in )
+void GAuth::SaslServerBasicImp::reset()
 {
 	m_first_apply = true ;
 	m_authenticated = false ;
-	m_id.erase() ;
-	m_trustee.erase() ;
-	m_challenge.erase() ;
-	m_mechanism.erase() ;
+	m_id.clear() ;
+	m_trustee.clear() ;
+	m_challenge.clear() ;
+	m_mechanism.clear() ;
+}
+
+G::StringArray GAuth::SaslServerBasicImp::mechanisms( bool secure ) const
+{
+	return secure ? m_mechanisms_secure : m_mechanisms_insecure ;
+}
+
+bool GAuth::SaslServerBasicImp::init( bool secure , const std::string & mechanism_in )
+{
+	reset() ;
 
 	std::string mechanism = G::Str::upper( mechanism_in ) ;
-	if( m_allow_apop && mechanism == "APOP" )
-	{
-		m_mechanism = mechanism ;
-		m_challenge = Cram::challenge( G::Random::rand() ) ;
-		return true ;
-	}
-	else if( std::find(m_mechanisms.begin(),m_mechanisms.end(),mechanism) == m_mechanisms.end() )
+	const G::StringArray & mechanisms = secure ? m_mechanisms_secure : m_mechanisms_insecure ;
+
+	if( mechanism.empty() || std::find(mechanisms.begin(),mechanisms.end(),mechanism) == mechanisms.end() )
 	{
 		G_DEBUG( "GAuth::SaslServerBasicImp::init: requested mechanism [" << mechanism << "] is not in our list" ) ;
 		return false ;
 	}
-	else if( mechanism.find("CRAM-") == 0U )
+	else if( mechanism == "APOP" || mechanism.find("CRAM-") == 0U )
 	{
 		m_mechanism = mechanism ;
 		m_challenge = Cram::challenge( G::Random::rand() ) ;
@@ -135,16 +192,33 @@ bool GAuth::SaslServerBasicImp::init( const std::string & mechanism_in )
 	}
 }
 
+std::string GAuth::SaslServerBasicImp::preferredMechanism( bool secure ) const
+{
+	if( !m_id.empty() )
+	{
+		auto mechanism_list = mechanisms( secure ) ;
+		std::reverse( mechanism_list.begin() , mechanism_list.end() ) ;
+		for( const auto & m : mechanism_list )
+		{
+			if( G::Str::headMatch( m , "CRAM-" ) )
+			{
+				std::string type = G::Str::lower( m.substr(5U) ) ; // eg. "sha1"
+				if( m_secrets.contains( type , m_id ) )
+					return m ;
+			}
+		}
+	}
+	return std::string() ;
+}
+
 std::string GAuth::SaslServerBasicImp::initialChallenge() const
 {
 	// see RFC-4422 section 5
 	if( m_mechanism == "PLAIN" ) // "client-first"
 		return std::string() ;
-	else if( m_mechanism == "XOAUTH2" ) // for testing -- "client-first"
-		return std::string() ;
 	else if( m_mechanism == "LOGIN" ) // "variable"
-		return login_challenge_1 ;
-	else // CRAM-X "server-first"
+		return G::sv_to_string(login_challenge_1) ;
+	else // APOP/CRAM-X "server-first"
 		return m_challenge ;
 }
 
@@ -168,14 +242,14 @@ std::string GAuth::SaslServerBasicImp::apply( const std::string & response , boo
 		{
 			if( m_mechanism == "APOP" )
 			{
-				secret = m_secrets.serverSecret( "plain" , id ) ; // (APOP is MD5 but not HMAC)
+				secret = m_secrets.serverSecret( "plain"_sv , id ) ; // (APOP is MD5 but not HMAC)
 			}
 			else
 			{
 				std::string hash_type = m_mechanism.substr(5U) ;
 				secret = m_secrets.serverSecret( hash_type , id ) ;
 				if( !secret.valid() )
-					secret = m_secrets.serverSecret( "plain" , id ) ;
+					secret = m_secrets.serverSecret( "plain"_sv , id ) ;
 			}
 		}
 		if( !secret.valid() )
@@ -195,48 +269,29 @@ std::string GAuth::SaslServerBasicImp::apply( const std::string & response , boo
 	else if( m_mechanism == "PLAIN" )
 	{
 		// PLAIN has a single response containing three nul-separated fields
-		std::string sep( 1U , '\0' ) ;
-		std::string id_pwd_in = G::Str::tail( response , sep ) ;
+		G::string_view sep( "\0" , 1U ) ;
+		G::string_view id_pwd_in = G::Str::tailView( response , sep ) ;
 		id = G::Str::head( id_pwd_in , sep ) ;
-		std::string pwd_in = G::Str::tail( id_pwd_in , sep ) ;
-		secret = m_secrets.serverSecret( "plain" , id ) ;
+		G::string_view pwd_in = G::Str::tailView( id_pwd_in , sep ) ;
+		secret = m_secrets.serverSecret( "plain"_sv , id ) ;
 
 		m_authenticated = secret.valid() && !id.empty() && !pwd_in.empty() && pwd_in == secret.key() ;
 		m_id = id ;
 		done = true ;
 	}
-	else if( m_mechanism == "XOAUTH2" && first_apply ) // for testing
-	{
-		if( G::Test::enabled("sasl-server-oauth-pass") )
-		{
-			m_id = "test" ;
-			m_authenticated = true ;
-			done = true ;
-		}
-		else
-		{
-			next_challenge = "not authenticated, send empty response" ;
-			done = false ;
-		}
-	}
-	else if( m_mechanism == "XOAUTH2" ) // for testing
-	{
-		m_authenticated = false ;
-		done = true ;
-	}
 	else if( first_apply ) // LOGIN username
 	{
 		// LOGIN uses two prompts; the first response is the username and the second is the password
 		G_ASSERT( m_mechanism == "LOGIN" ) ;
 		id = m_id = response ;
 		if( !m_id.empty() )
-			next_challenge = login_challenge_2 ;
+			next_challenge = G::sv_to_string(login_challenge_2) ;
 	}
 	else // LOGIN password
 	{
 		G_ASSERT( m_mechanism == "LOGIN" ) ;
 		id = m_id ;
-		secret = m_secrets.serverSecret( "plain" , m_id ) ;
+		secret = m_secrets.serverSecret( "plain"_sv , m_id ) ;
 		m_authenticated = secret.valid() && !response.empty() && response == secret.key() ;
 		done = true ;
 	}
@@ -282,11 +337,6 @@ bool GAuth::SaslServerBasicImp::trustedCore( const std::string & address_wildcar
 	}
 }
 
-bool GAuth::SaslServerBasicImp::active() const
-{
-	return m_secrets.valid() ;
-}
-
 std::string GAuth::SaslServerBasicImp::mechanism() const
 {
 	return m_mechanism ;
@@ -304,17 +354,18 @@ bool GAuth::SaslServerBasicImp::authenticated() const
 
 // ===
 
-GAuth::SaslServerBasic::SaslServerBasic( const SaslServerSecrets & secrets , const std::string & config , bool allow_apop ) :
-	m_imp(std::make_unique<SaslServerBasicImp>(secrets,config,allow_apop))
+GAuth::SaslServerBasic::SaslServerBasic( const SaslServerSecrets & secrets ,
+	bool with_apop , const std::string & config , bool no_insecure_mechanisms ) :
+		m_imp(std::make_unique<SaslServerBasicImp>(secrets,with_apop,config,no_insecure_mechanisms))
 {
 }
 
 GAuth::SaslServerBasic::~SaslServerBasic()
 = default ;
 
-std::string GAuth::SaslServerBasic::mechanisms( char c ) const
+G::StringArray GAuth::SaslServerBasic::mechanisms( bool secure ) const
 {
-	return m_imp->mechanisms( std::string(1U,c) ) ;
+	return m_imp->mechanisms( secure ) ;
 }
 
 std::string GAuth::SaslServerBasic::mechanism() const
@@ -322,25 +373,31 @@ std::string GAuth::SaslServerBasic::mechanism() const
 	return m_imp->mechanism() ;
 }
 
+std::string GAuth::SaslServerBasic::preferredMechanism( bool secure ) const
+{
+	return m_imp->preferredMechanism( secure ) ;
+}
+
 bool GAuth::SaslServerBasic::trusted( const GNet::Address & address ) const
 {
 	return m_imp->trusted( address ) ;
 }
 
-bool GAuth::SaslServerBasic::active() const
+void GAuth::SaslServerBasic::reset()
 {
-	return m_imp->active() ;
+	return m_imp->reset() ;
 }
 
-bool GAuth::SaslServerBasic::init( const std::string & mechanism )
+bool GAuth::SaslServerBasic::init( bool secure , const std::string & mechanism )
 {
-	return m_imp->init( mechanism ) ;
+	return m_imp->init( secure , mechanism ) ;
 }
 
 bool GAuth::SaslServerBasic::mustChallenge() const
 {
-	std::string m = G::Str::upper( m_imp->mechanism() ) ; // upper() just in case
-	return m != "PLAIN" && m != "LOGIN" && m != "XOAUTH2" ;
+	const bool plain = G::Str::imatch( m_imp->mechanism() , "PLAIN" ) ;
+	const bool login = !plain && G::Str::imatch( m_imp->mechanism() , "LOGIN" ) ;
+	return !plain && !login ;
 }
 
 std::string GAuth::SaslServerBasic::initialChallenge() const
@@ -363,8 +420,3 @@ std::string GAuth::SaslServerBasic::id() const
 	return m_imp->id() ;
 }
 
-bool GAuth::SaslServerBasic::requiresEncryption() const
-{
-	return false ;
-}
-
diff --git a/src/gauth/gsaslserverbasic.h b/src/gauth/gsaslserverbasic.h
index 9ec3964..20485ed 100644
--- a/src/gauth/gsaslserverbasic.h
+++ b/src/gauth/gsaslserverbasic.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -27,10 +27,11 @@
 #include "gsaslserver.h"
 #include "gexception.h"
 #include "gaddress.h"
-#include "gstrings.h"
+#include "gstringarray.h"
+#include "goptional.h"
 #include "gpath.h"
-#include <map>
 #include <memory>
+#include <utility>
 
 namespace GAuth
 {
@@ -45,24 +46,24 @@ namespace GAuth
 class GAuth::SaslServerBasic : public SaslServer
 {
 public:
-	G_EXCEPTION( NoMechanisms , "no server authentication mechanisms available" ) ;
-
-	explicit SaslServerBasic( const SaslServerSecrets & , const std::string & config , bool allow_apop ) ;
-		///< Constructor.
+	explicit SaslServerBasic( const SaslServerSecrets & , bool allow_pop ,
+		const std::string & config , bool force_no_insecure_mechanisms ) ;
+			///< Constructor. The 'config' parameters can be used to reduce the
+			///< set of available authentication mechanisms.
 
 public:
 	~SaslServerBasic() override ;
 	SaslServerBasic( const SaslServerBasic & ) = delete ;
 	SaslServerBasic( SaslServerBasic && ) = delete ;
-	void operator=( const SaslServerBasic & ) = delete ;
-	void operator=( SaslServerBasic && ) = delete ;
+	SaslServerBasic & operator=( const SaslServerBasic & ) = delete ;
+	SaslServerBasic & operator=( SaslServerBasic && ) = delete ;
 
 private: // overrides
-	bool requiresEncryption() const override ; // Override from GAuth::SaslServer.
-	bool active() const override ; // Override from GAuth::SaslServer.
-	std::string mechanisms( char sep ) const override ; // Override from GAuth::SaslServer.
-	bool init( const std::string & mechanism ) override ; // Override from GAuth::SaslServer.
+	void reset() override ; // Override from GAuth::SaslServer.
+	G::StringArray mechanisms( bool ) const override ; // Override from GAuth::SaslServer.
+	bool init( bool , const std::string & mechanism ) override ; // Override from GAuth::SaslServer.
 	std::string mechanism() const override ; // Override from GAuth::SaslServer.
+	std::string preferredMechanism( bool ) const override ; // Override from GAuth::SaslServer.
 	bool mustChallenge() const override ; // Override from GAuth::SaslServer.
 	std::string initialChallenge() const override ; // Override from GAuth::SaslServer.
 	std::string apply( const std::string & response , bool & done ) override ; // Override from GAuth::SaslServer.
diff --git a/src/gauth/gsaslserverfactory.h b/src/gauth/gsaslserverfactory.h
index 3520f4d..c4b25d3 100644
--- a/src/gauth/gsaslserverfactory.h
+++ b/src/gauth/gsaslserverfactory.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,6 +24,8 @@
 #include "gdef.h"
 #include "gsaslserver.h"
 #include "gsecrets.h"
+#include "goptional.h"
+#include <utility>
 #include <memory>
 
 namespace GAuth
@@ -37,8 +39,9 @@ namespace GAuth
 class GAuth::SaslServerFactory
 {
 public:
-	static std::unique_ptr<SaslServer> newSaslServer( const SaslServerSecrets & , const std::string & config , bool allow_apop ) ;
-		///< A factory function for a SaslServer.
+	static std::unique_ptr<SaslServer> newSaslServer( const SaslServerSecrets & ,
+		bool allow_pop , const std::string & config , bool no_insecure_mechanisms ) ;
+			///< A factory function for a SaslServer.
 
 public:
 	SaslServerFactory() = delete ;
diff --git a/src/gauth/gsaslserverfactory_basic.cpp b/src/gauth/gsaslserverfactory_basic.cpp
index 8c69037..16ca9ba 100644
--- a/src/gauth/gsaslserverfactory_basic.cpp
+++ b/src/gauth/gsaslserverfactory_basic.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,8 +23,9 @@
 #include "gsaslserver.h"
 #include "gsaslserverbasic.h"
 
-std::unique_ptr<GAuth::SaslServer> GAuth::SaslServerFactory::newSaslServer( const SaslServerSecrets & secrets , const std::string & config , bool allow_apop )
+std::unique_ptr<GAuth::SaslServer> GAuth::SaslServerFactory::newSaslServer( const SaslServerSecrets & secrets ,
+	bool allow_pop , const std::string & config , bool no_insecure_mechanisms )
 {
-	return std::make_unique<SaslServerBasic>(secrets,config,allow_apop) ; // up-cast
+	return std::make_unique<SaslServerBasic>( secrets , allow_pop , config , no_insecure_mechanisms ) ;
 }
 
diff --git a/src/gauth/gsaslserverfactory_pam.cpp b/src/gauth/gsaslserverfactory_pam.cpp
index d5ea0a8..dd3859e 100644
--- a/src/gauth/gsaslserverfactory_pam.cpp
+++ b/src/gauth/gsaslserverfactory_pam.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,11 +24,12 @@
 #include "gsaslserverbasic.h"
 #include "gsaslserverpam.h"
 
-std::unique_ptr<GAuth::SaslServer> GAuth::SaslServerFactory::newSaslServer( const SaslServerSecrets & secrets , const std::string & config , bool allow_apop )
+std::unique_ptr<GAuth::SaslServer> GAuth::SaslServerFactory::newSaslServer( const SaslServerSecrets & secrets ,
+	bool allow_pop , const std::string & config , bool no_insecure_mechanisms )
 {
 	if( secrets.source() == "/pam" )
-		return std::make_unique<SaslServerPam>(secrets,config,allow_apop) ; // up-cast
+		return std::make_unique<SaslServerPam>( secrets , allow_pop ) ;
 	else
-		return std::make_unique<SaslServerBasic>(secrets,config,allow_apop) ; // up-cast
+		return std::make_unique<SaslServerBasic>( secrets , allow_pop , config , no_insecure_mechanisms ) ;
 }
 
diff --git a/src/gauth/gsaslserverpam.cpp b/src/gauth/gsaslserverpam.cpp
index 9e02317..329a0a8 100644
--- a/src/gauth/gsaslserverpam.cpp
+++ b/src/gauth/gsaslserverpam.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -37,10 +37,12 @@ namespace GAuth
 class GAuth::SaslServerPamImp
 {
 public:
-	SaslServerPamImp( bool valid , const std::string & config , bool allow_apop ) ;
+	SaslServerPamImp( bool valid , bool with_apop ) ;
 	virtual ~SaslServerPamImp() ;
-	bool active() const ;
-	bool init( const std::string & mechanism ) ;
+	G::StringArray mechanisms() const ;
+	std::string mechanism() const ;
+	void reset() ;
+	bool init( bool , const std::string & mechanism ) ;
 	std::string apply( const std::string & pwd , bool & done ) ;
 	std::string id() const ;
 	bool authenticated() const ;
@@ -48,13 +50,13 @@ public:
 public:
 	SaslServerPamImp( const SaslServerPamImp & ) = delete ;
 	SaslServerPamImp( SaslServerPamImp && ) = delete ;
-	void operator=( const SaslServerPamImp & ) = delete ;
-	void operator=( SaslServerPamImp && ) = delete ;
+	SaslServerPamImp & operator=( const SaslServerPamImp & ) = delete ;
+	SaslServerPamImp & operator=( SaslServerPamImp && ) = delete ;
 
 private:
-	bool m_active ;
-	bool m_allow_apop ;
 	std::unique_ptr<PamImp> m_pam ;
+	G::StringArray m_mechanisms ;
+	std::string m_mechanism ;
 } ;
 
 //| \class GAuth::PamImp
@@ -66,7 +68,7 @@ class GAuth::PamImp : public G::Pam
 {
 public:
 	using ItemArray = GAuth::PamImp::ItemArray ;
-	G_EXCEPTION_CLASS( NoPrompt , "no password prompt received from pam module" ) ;
+	G_EXCEPTION_CLASS( NoPrompt , tx("no password prompt received from pam module") ) ;
 
 	PamImp( const std::string & app , const std::string & id ) ;
 	~PamImp() override ;
@@ -81,8 +83,8 @@ protected:
 public:
 	PamImp( const PamImp & ) = delete ;
 	PamImp( PamImp && ) = delete ;
-	void operator=( const PamImp & ) = delete ;
-	void operator=( PamImp && ) = delete ;
+	PamImp & operator=( const PamImp & ) = delete ;
+	PamImp & operator=( PamImp && ) = delete ;
 
 private:
 	std::string m_app ;
@@ -140,25 +142,39 @@ void GAuth::PamImp::delay( unsigned int )
 
 // ==
 
-GAuth::SaslServerPamImp::SaslServerPamImp( bool active , const std::string & /*config*/ , bool allow_apop ) :
-	m_active(active) ,
-	m_allow_apop(allow_apop)
+GAuth::SaslServerPamImp::SaslServerPamImp( bool active , bool with_apop )
 {
+	if( active )
+	{
+		m_mechanisms.push_back( "PLAIN" ) ;
+		if( with_apop )
+			m_mechanisms.push_back( "APOP" ) ;
+	}
 }
 
 GAuth::SaslServerPamImp::~SaslServerPamImp()
 = default;
 
-bool GAuth::SaslServerPamImp::active() const
+G::StringArray GAuth::SaslServerPamImp::mechanisms() const
 {
-	return m_active ;
+	return m_mechanisms ;
 }
 
-bool GAuth::SaslServerPamImp::init( const std::string & mechanism )
+std::string GAuth::SaslServerPamImp::mechanism() const
 {
-	return
-		G::Str::upper(mechanism) == "PLAIN" ||
-		( m_allow_apop && G::Str::upper(mechanism) == "APOP" ) ;
+	return m_mechanism ;
+}
+
+void GAuth::SaslServerPamImp::reset()
+{
+	m_mechanism.clear() ;
+	m_pam.reset() ;
+}
+
+bool GAuth::SaslServerPamImp::init( bool , const std::string & mechanism )
+{
+	m_mechanism = G::Str::upper( mechanism ) ;
+	return std::find( m_mechanisms.begin() , m_mechanisms.end() , m_mechanism ) != m_mechanisms.end() ;
 }
 
 std::string GAuth::SaslServerPamImp::id() const
@@ -197,22 +213,27 @@ std::string GAuth::SaslServerPamImp::apply( const std::string & response , bool
 
 // ==
 
-GAuth::SaslServerPam::SaslServerPam( const SaslServerSecrets & secrets , const std::string & config , bool allow_apop ) :
-	m_imp(std::make_unique<SaslServerPamImp>(secrets.valid(),config,allow_apop))
+GAuth::SaslServerPam::SaslServerPam( const SaslServerSecrets & secrets , bool with_apop ) :
+	m_imp(std::make_unique<SaslServerPamImp>(secrets.valid(),with_apop))
 {
 }
 
 GAuth::SaslServerPam::~SaslServerPam()
 = default ;
 
-std::string GAuth::SaslServerPam::mechanisms( char ) const
+G::StringArray GAuth::SaslServerPam::mechanisms( bool /*secure*/ ) const
 {
-	return "PLAIN" ;
+	return m_imp->mechanisms() ;
 }
 
 std::string GAuth::SaslServerPam::mechanism() const
 {
-	return "PLAIN" ;
+	return m_imp->mechanism() ;
+}
+
+std::string GAuth::SaslServerPam::preferredMechanism( bool ) const
+{
+	return std::string() ;
 }
 
 bool GAuth::SaslServerPam::trusted( const GNet::Address & ) const
@@ -220,19 +241,19 @@ bool GAuth::SaslServerPam::trusted( const GNet::Address & ) const
 	return false ;
 }
 
-bool GAuth::SaslServerPam::active() const
-{
-	return m_imp->active() ;
-}
-
 bool GAuth::SaslServerPam::mustChallenge() const
 {
 	return false ;
 }
 
-bool GAuth::SaslServerPam::init( const std::string & mechanism )
+void GAuth::SaslServerPam::reset()
 {
-	return m_imp->init( mechanism ) ;
+	return m_imp->reset() ;
+}
+
+bool GAuth::SaslServerPam::init( bool secure , const std::string & mechanism )
+{
+	return m_imp->init( secure , mechanism ) ;
 }
 
 std::string GAuth::SaslServerPam::initialChallenge() const
@@ -255,8 +276,3 @@ std::string GAuth::SaslServerPam::id() const
 	return m_imp->id() ;
 }
 
-bool GAuth::SaslServerPam::requiresEncryption() const
-{
-	return true ;
-}
-
diff --git a/src/gauth/gsaslserverpam.h b/src/gauth/gsaslserverpam.h
index a41227d..4aa22e6 100644
--- a/src/gauth/gsaslserverpam.h
+++ b/src/gauth/gsaslserverpam.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -28,7 +28,6 @@
 #include "gexception.h"
 #include "gaddress.h"
 #include "gpath.h"
-#include <map>
 #include <memory>
 
 namespace GAuth
@@ -38,18 +37,18 @@ namespace GAuth
 }
 
 //| \class GAuth::SaslServerPam
-/// An implementation of the SaslServer interface using PAM as
-/// the authentication mechanism.
+/// An implementation of the SaslServer interface using PAM as the
+/// authentication mechanism.
 ///
 /// This class tries to match up the PAM interface with the SASL server
-/// interface. The match is not perfect; only single-challenge PAM mechanisms
-/// are supported, the PAM delay feature is not implemented, and PAM sessions
-/// are not part of the SASL interface.
+/// interface. The match is not perfect; only single-challenge PAM
+/// mechanisms are supported, the PAM delay feature is not implemented,
+/// and PAM sessions are not part of the SASL interface.
 ///
 class GAuth::SaslServerPam : public SaslServer
 {
 public:
-	SaslServerPam( const SaslServerSecrets & , const std::string & config , bool allow_apop ) ;
+	SaslServerPam( const SaslServerSecrets & , bool with_apop ) ;
 		///< Constructor.
 
 public:
@@ -60,11 +59,11 @@ public:
 	SaslServerPam & operator=( SaslServerPam && ) = delete ;
 
 private: // overrides
-	bool requiresEncryption() const override ; // Override from GAuth::SaslServer.
-	bool active() const override ; // Override from GAuth::SaslServer.
-	std::string mechanisms( char sep ) const override ; // Override from GAuth::SaslServer.
-	bool init( const std::string & mechanism ) override ; // Override from GAuth::SaslServer.
+	G::StringArray mechanisms( bool ) const override ; // Override from GAuth::SaslServer.
+	void reset() override ; // Override from GAuth::SaslServer.
+	bool init( bool , const std::string & mechanism ) override ; // Override from GAuth::SaslServer.
 	std::string mechanism() const override ; // Override from GAuth::SaslServer.
+	std::string preferredMechanism( bool ) const override ; // Override from GAuth::SaslServer.
 	bool mustChallenge() const override ; // Override from GAuth::SaslServer.
 	std::string initialChallenge() const override ; // Override from GAuth::SaslServer.
 	std::string apply( const std::string & response , bool & done ) override ; // Override from GAuth::SaslServer.
diff --git a/src/gauth/gsaslserversecrets.cpp b/src/gauth/gsaslserversecrets.cpp
index 8047e20..d8777f1 100644
--- a/src/gauth/gsaslserversecrets.cpp
+++ b/src/gauth/gsaslserversecrets.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gauth/gsaslserversecrets.h b/src/gauth/gsaslserversecrets.h
index 95fd868..3b3c5e4 100644
--- a/src/gauth/gsaslserversecrets.h
+++ b/src/gauth/gsaslserversecrets.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,6 +24,7 @@
 #include "gdef.h"
 #include "gvalid.h"
 #include "gsecret.h"
+#include "gstringview.h"
 #include <string>
 #include <utility>
 
@@ -39,7 +40,7 @@ namespace GAuth
 class GAuth::SaslServerSecrets : public virtual Valid
 {
 public:
-	virtual Secret serverSecret( const std::string & type , const std::string & id ) const = 0 ;
+	virtual Secret serverSecret( G::string_view type , G::string_view id ) const = 0 ;
 		///< Returns the server secret for the given client id.
 		///< The type is "plain" or the CRAM hash algorithm.
 		///< Returns an invalid secret if not found.
@@ -52,9 +53,10 @@ public:
 	virtual std::string source() const = 0 ;
 		///< Returns the source identifier (eg. file name).
 
-	virtual bool contains( const std::string & mechanism ) const = 0 ;
-		///< Returns true if any user has a secret encoded for
-		///< the given mechanism.
+	virtual bool contains( G::string_view type , G::string_view id ) const = 0 ;
+		///< Returns true if there is a secret of the given type
+		///< either for one user in particular or for any user if
+		///< the id is empty.
 } ;
 
 #endif
diff --git a/src/gauth/gsecret.cpp b/src/gauth/gsecret.cpp
index 8aebb3b..68fc992 100644
--- a/src/gauth/gsecret.cpp
+++ b/src/gauth/gsecret.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,6 +21,7 @@
 #include "gdef.h"
 #include "gsecret.h"
 #include "gstr.h"
+#include "gstringfield.h"
 #include "gbase64.h"
 #include "gxtext.h"
 #include "gmd5.h"
@@ -32,42 +33,42 @@ GAuth::Secret::Secret()
 	G_ASSERT( !valid() ) ;
 }
 
-GAuth::Secret::Secret( const std::string & id ) :
-	m_id(id)
+GAuth::Secret::Secret( G::string_view id ) :
+	m_id(G::sv_to_string(id))
 {
 	G_ASSERT( !valid() ) ;
 }
 
-GAuth::Secret::Secret( const std::string & secret , const std::string & secret_encoding ,
-	const std::string & id , bool id_encoding_xtext , const std::string & context ) :
-		m_id(id) ,
-		m_context(context)
+GAuth::Secret::Secret( G::string_view secret , G::string_view secret_encoding ,
+	G::string_view id , bool id_encoding_xtext , G::string_view context ) :
+		m_id(G::sv_to_string(id)) ,
+		m_context(G::sv_to_string(context))
 {
 	G_ASSERT( secret_encoding == G::Str::lower(secret_encoding) ) ;
 	std::string reason = check( secret , secret_encoding , id , id_encoding_xtext ) ;
 	if( !reason.empty() )
-		throw context.empty() ? Error(reason) : Error(context,reason) ;
+		throw context.empty() ? Error(reason) : Error(m_context,reason) ;
 
-	if( secret_encoding == "plain" )
+	if( secret_encoding == "plain"_sv )
 	{
 		G_ASSERT( G::Xtext::valid(secret) ) ;
 		m_key = G::Xtext::decode( secret ) ;
 	}
-	else if( secret_encoding == "md5" && isDotted(secret) )
+	else if( secret_encoding == "md5"_sv && isDotted(secret) )
 	{
 		m_key = undotted( secret ) ;
-		m_mask_type = secret_encoding ;
+		m_mask_type = G::sv_to_string( secret_encoding ) ;
 	}
 	else
 	{
 		G_ASSERT( G::Base64::valid(secret) ) ; // check()ed
 		m_key = G::Base64::decode( secret ) ;
-		m_mask_type = secret_encoding ;
+		m_mask_type = G::sv_to_string( secret_encoding ) ;
 	}
 }
 
-std::string GAuth::Secret::check( const std::string & secret , const std::string & secret_encoding ,
-	const std::string & id , bool id_encoding_xtext )
+std::string GAuth::Secret::check( G::string_view secret , G::string_view secret_encoding ,
+	G::string_view id , bool id_encoding_xtext )
 {
 	if( secret.empty() )
 		return "empty secret" ;
@@ -77,16 +78,16 @@ std::string GAuth::Secret::check( const std::string & secret , const std::string
 		return "empty id" ;
 	if( id_encoding_xtext && !G::Xtext::valid(id) )
 		return "invalid xtext encoding of id" ;
-	if( secret_encoding == "plain" && !G::Xtext::valid(secret) )
+	if( secret_encoding == "plain"_sv && !G::Xtext::valid(secret) )
 		return "invalid xtext encoding of secret" ;
-	if( secret_encoding == "md5" && !( isDotted(secret) || G::Base64::valid(secret) ) )
+	if( secret_encoding == "md5"_sv && !( isDotted(secret) || G::Base64::valid(secret) ) )
 		return "invalid encoding of md5 secret" ;
-	if( secret_encoding != "md5" && secret_encoding != "plain" && !G::Base64::valid(secret) )
+	if( secret_encoding != "md5"_sv && secret_encoding != "plain"_sv && !G::Base64::valid(secret) )
 		return "invalid base64 encoding of secret" ;
 	return std::string() ;
 }
 
-GAuth::Secret GAuth::Secret::none( const std::string & id )
+GAuth::Secret GAuth::Secret::none( G::string_view id )
 {
 	return Secret( id ) ;
 }
@@ -140,23 +141,22 @@ std::string GAuth::Secret::info( const std::string & id_in ) const
 	return ss.str() ;
 }
 
-bool GAuth::Secret::isDotted( const std::string & s )
+bool GAuth::Secret::isDotted( G::string_view s )
 {
 	return
-		s.length() >= 15U &&
-		s.find_first_not_of("0123456789.") == std::string::npos &&
-		G::Str::splitIntoFields(s,".").size() == 8U ;
+		s.size() >= 15U &&
+		s.find_first_not_of("0123456789."_sv) == std::string::npos &&
+		G::StringFieldView(s,'.').count() == 8U ;
 }
 
-std::string GAuth::Secret::undotted( const std::string & s )
+std::string GAuth::Secret::undotted( G::string_view s )
 {
-	G::StringArray decimals = G::Str::splitIntoFields( s , "." ) ;
-	decimals.resize( 8U ) ;
 	std::string result ;
-	for( std::size_t i = 0U ; i < 8U ; i++ )
+	for( G::StringFieldView decimal(s,".",1U) ; decimal ; ++decimal )
 	{
 		G::Md5::big_t n = 0U ;
-		for( const char & c : decimals[i] )
+		G::string_view d = decimal() ;
+		for( const char & c : d )
 		{
 			n *= 10U ;
 			n += (c-'0') ;
diff --git a/src/gauth/gsecret.h b/src/gauth/gsecret.h
index e1f2abe..45906d6 100644
--- a/src/gauth/gsecret.h
+++ b/src/gauth/gsecret.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -36,22 +36,22 @@ namespace GAuth
 /// by a hash function. If masked then it can only be verified by an hmac
 /// operation using the matching hash function. However, the hmac hash function
 /// must be capable of accepting an intermediate hash state, and this is might
-/// only be available for md5.
+/// only be the case for md5.
 ///
 class GAuth::Secret
 {
 public:
-	G_EXCEPTION( Error , "invalid authorisation secret" ) ;
-	G_EXCEPTION( BadId , "invalid authorisation id" ) ;
+	G_EXCEPTION( Error , tx("invalid authorisation secret") ) ;
+	G_EXCEPTION( BadId , tx("invalid authorisation id") ) ;
 
-	Secret( const std::string & secret , const std::string & secret_encoding ,
-		const std::string & id , bool id_encoding_xtext ,
-		const std::string & context = std::string() ) ;
+	Secret( G::string_view secret , G::string_view secret_encoding ,
+		G::string_view id , bool id_encoding_xtext ,
+		G::string_view context = {} ) ;
 			///< Constructor used by the SecretsFile class. Throws on error,
 			///< including if the encodings are invalid.
 
-	static std::string check( const std::string & secret , const std::string & secret_encoding ,
-		const std::string & id , bool id_encoding_xtext ) ;
+	static std::string check( G::string_view secret , G::string_view secret_encoding ,
+		G::string_view id , bool id_encoding_xtext ) ;
 			///< Does a non-throwing check of the constructor parameters,
 			///< returning an error message or the empty string.
 
@@ -71,7 +71,7 @@ public:
 	std::string id() const ;
 		///< Returns the associated identity. Throws if not valid().
 
-	static Secret none( const std::string & id ) ;
+	static Secret none( G::string_view id ) ;
 		///< Factory function that returns a secret that is not valid(),
 		///< as used by the SecretsFile class.
 
@@ -79,15 +79,15 @@ public:
 		///< Factory function that returns a secret that is not valid() and
 		///< has an empty id().
 
-	std::string info( const std::string & id = std::string() ) const ;
+	std::string info( const std::string & id = {} ) const ;
 		///< Returns information for logging, excluding anything
 		///< sensitive. The secret may be in-valid().
 
 private:
 	Secret() ; // Secret::none()
-	explicit Secret( const std::string & ) ;
-	static bool isDotted( const std::string & ) ;
-	static std::string undotted( const std::string & ) ;
+	explicit Secret( G::string_view ) ;
+	static bool isDotted( G::string_view ) ;
+	static std::string undotted( G::string_view ) ;
 
 private:
 	std::string m_server_type ;
diff --git a/src/gauth/gsecrets.cpp b/src/gauth/gsecrets.cpp
index aee08c8..9f55c98 100644
--- a/src/gauth/gsecrets.cpp
+++ b/src/gauth/gsecrets.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -26,10 +26,7 @@
 
 void GAuth::Secrets::check( const std::string & p1 , const std::string & p2 , const std::string & p3 )
 {
-	G::StringArray list ;
-	list.push_back( p1 ) ;
-	list.push_back( p2 ) ;
-	list.push_back( p3 ) ;
+	G::StringArray list { p1 , p2 , p3 } ;
 	list.erase( std::remove(list.begin(),list.end(),std::string()) , list.end() ) ;
 	list.erase( std::remove(list.begin(),list.end(),"/pam") , list.end() ) ;
 	std::sort( list.begin() , list.end() ) ;
@@ -37,12 +34,12 @@ void GAuth::Secrets::check( const std::string & p1 , const std::string & p2 , co
 	std::for_each( list.begin() , list.end() , &SecretsFile::check ) ;
 }
 
-GAuth::Secrets::Secrets( const std::string & path , const std::string & name ) :
+GAuth::Secrets::Secrets( const std::string & path , const std::string & log_name ) :
 	m_source(path)
 {
 	G_DEBUG( "GAuth::Secrets:ctor: [" << path << "]" ) ;
 	if( m_source != "/pam" )
-		m_imp = std::make_unique<SecretsFile>( path , true , name ) ;
+		m_imp = std::make_unique<SecretsFile>( path , true , log_name ) ;
 }
 
 GAuth::Secrets::Secrets()
@@ -64,14 +61,14 @@ bool GAuth::Secrets::valid() const
 	return m_source == "/pam" || m_imp->valid() ;
 }
 
-GAuth::Secret GAuth::Secrets::clientSecret( const std::string & type ) const
+GAuth::Secret GAuth::Secrets::clientSecret( G::string_view type ) const
 {
 	return valid() ? m_imp->clientSecret(type) : Secret::none() ;
 }
 
-GAuth::Secret GAuth::Secrets::serverSecret( const std::string & type , const std::string & id ) const
+GAuth::Secret GAuth::Secrets::serverSecret( G::string_view type , G::string_view id ) const
 {
-	return valid() ? m_imp->serverSecret( type , id ) : Secret::none() ;
+	return valid() ? m_imp->serverSecret(type,id) : Secret::none() ;
 }
 
 std::pair<std::string,std::string> GAuth::Secrets::serverTrust( const std::string & address_range ) const
@@ -79,8 +76,8 @@ std::pair<std::string,std::string> GAuth::Secrets::serverTrust( const std::strin
 	return valid() ? m_imp->serverTrust( address_range ) : std::make_pair(std::string(),std::string()) ;
 }
 
-bool GAuth::Secrets::contains( const std::string & type ) const
+bool GAuth::Secrets::contains( G::string_view type , G::string_view id ) const
 {
-	return valid() ? m_imp->contains( type ) : false ;
+	return valid() ? m_imp->contains( type , id ) : false ;
 }
 
diff --git a/src/gauth/gsecrets.h b/src/gauth/gsecrets.h
index df1ef9d..c03ef28 100644
--- a/src/gauth/gsecrets.h
+++ b/src/gauth/gsecrets.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -26,6 +26,8 @@
 #include "gexception.h"
 #include "gsaslserversecrets.h"
 #include "gsaslclientsecrets.h"
+#include <memory>
+#include <string>
 
 namespace GAuth
 {
@@ -40,19 +42,15 @@ namespace GAuth
 class GAuth::Secrets : public SaslClientSecrets , public SaslServerSecrets
 {
 public:
-	G_EXCEPTION( OpenError , "cannot read secrets file" ) ;
+	G_EXCEPTION( OpenError , tx("cannot read secrets file") ) ;
 
 	static void check( const std::string & , const std::string & , const std::string & ) ;
 		///< Checks the given secret sources. Logs warnings and throws
 		///< an exception if there are any fatal errors.
 
-	Secrets( const std::string & source_storage_path , const std::string & debug_name ) ;
-		///< Constructor. The connection string is a secrets file path
-		///< or "/pam".
-		///<
-		///< The 'debug-name' is used in log and error messages to
-		///< identify the repository.
-		///<
+	Secrets( const std::string & source_storage_path , const std::string & log_name ) ;
+		///< Constructor. The path is a secrets file path or "/pam".
+		///< The 'log-name' is used in log and error messages.
 		///< Throws on error, although an empty path is not
 		///< considered an error: see valid().
 
@@ -62,22 +60,22 @@ public:
 	bool valid() const override ;
 		///< Override from GAuth::Valid virtual base.
 
-	Secret serverSecret( const std::string & type , const std::string & id ) const override ;
+	Secret serverSecret( G::string_view type , G::string_view id ) const override ;
 		///< Override from GAuth::SaslServerSecrets.
 
-	bool contains( const std::string & type ) const override ;
+	bool contains( G::string_view type , G::string_view id ) const override ;
 		///< Override from GAuth::SaslServerSecrets.
 
 public:
 	~Secrets() override ;
 	Secrets( const Secrets & ) = delete ;
 	Secrets( Secrets && ) = delete ;
-	void operator=( const Secrets & ) = delete ;
-	void operator=( Secrets && ) = delete ;
+	Secrets & operator=( const Secrets & ) = delete ;
+	Secrets & operator=( Secrets && ) = delete ;
 
 private: // overrides
 	std::string source() const override ; // Override from GAuth::SaslServerSecrets.
-	Secret clientSecret( const std::string & type ) const override ; // Override from GAuth::SaslClientSecrets.
+	Secret clientSecret( G::string_view ) const override ; // Override from GAuth::SaslClientSecrets.
 	std::pair<std::string,std::string> serverTrust( const std::string & address_range ) const override ; // Override from GAuth::SaslServerSecrets.
 
 private:
diff --git a/src/gauth/gsecretsfile.cpp b/src/gauth/gsecretsfile.cpp
index 6f4f544..9648e25 100644
--- a/src/gauth/gsecretsfile.cpp
+++ b/src/gauth/gsecretsfile.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -25,6 +25,7 @@
 #include "gxtext.h"
 #include "gbase64.h"
 #include "gstr.h"
+#include "gstringtoken.h"
 #include "gdatetime.h"
 #include "gfile.h"
 #include "gassert.h"
@@ -120,25 +121,30 @@ GAuth::SecretsFile::Contents GAuth::SecretsFile::readContents( const G::Path & p
 GAuth::SecretsFile::Contents GAuth::SecretsFile::readContents( std::istream & file )
 {
 	Contents contents ;
+	std::string line ;
 	for( unsigned int line_number = 1U ; file.good() ; ++line_number )
 	{
-		std::string line = G::Str::readLineFrom( file ) ;
+		G::Str::readLineFrom( file , "\n"_sv , line ) ;
 		if( !file )
 			break ;
 
 		G::Str::trim( line , G::Str::ws() ) ;
 		if( !line.empty() && line.at(0U) != '#' )
 		{
-			G::StringArray word_array ;
-			G::Str::splitIntoTokens( line , word_array , " \t" ) ;
-			if( word_array.size() >= 4U )
+			G::string_view line_sv( line ) ;
+			G::StringTokenView t( line_sv , " \t"_sv ) ;
+			G::string_view w1 = t() ;
+			G::string_view w2 = (++t)() ;
+			G::string_view w3 = (++t)() ;
+			G::string_view w4 = (++t)() ;
+			if( t.valid() )
 			{
 				// 0=<client-server> 1=<encoding-type> 2=<userid-or-ipaddress> 3=<secret-or-verifier-hint>
-				processLine( contents , line_number , word_array[0U] , word_array[1U] , word_array[2U] , word_array[3U] ) ;
+				processLine( contents , line_number , w1 , w2 , w3 , w4 ) ;
 			}
 			else
 			{
-				addWarning( contents , line_number , "too few fields" ) ;
+				addWarning( contents , line_number , "too few fields"_sv ) ;
 			}
 		}
 	}
@@ -146,74 +152,70 @@ GAuth::SecretsFile::Contents GAuth::SecretsFile::readContents( std::istream & fi
 }
 
 void GAuth::SecretsFile::processLine( Contents & contents ,
-	unsigned int line_number , const std::string & side , const std::string & type_in ,
-	const std::string & id_or_ip_in , const std::string & secret_in )
+	unsigned int line_number , G::string_view side , G::string_view type ,
+	G::string_view id_or_ip , G::string_view secret )
 {
-	std::string type = G::Str::lower( type_in ) ;
-	std::string id_or_ip = id_or_ip_in ;
-	std::string secret = secret_in ;
-	if( type == "plain:b" )
+	if( G::Str::imatch( type , "plain:b"_sv ) )
 	{
 		// for now just re-encode to xtext -- TODO rework secrets-file encodings
         bool valid_id = G::Base64::valid( id_or_ip ) ;
 		bool valid_secret = G::Base64::valid( secret ) ;
 		if( !valid_id )
-            addWarning( contents , line_number , "invalid base64 encoding in third field" , id_or_ip ) ;
+            addWarning( contents , line_number , "invalid base64 encoding in third field"_sv , id_or_ip ) ;
         if( !valid_secret )
-            addWarning( contents , line_number , "invalid base64 encoding in fourth field" ) ;
+            addWarning( contents , line_number , "invalid base64 encoding in fourth field"_sv ) ;
 		if( !valid_id || !valid_secret )
 			return ;
-		type = "plain" ;
+		type = "plain"_sv ;
         id_or_ip = G::Xtext::encode( G::Base64::decode(id_or_ip) ) ;
         secret = G::Xtext::encode( G::Base64::decode(secret) ) ;
 	}
-	processLineImp( contents , line_number , G::Str::lower(side) , type , id_or_ip , secret ) ;
+	processLineImp( contents , line_number , side , type , id_or_ip , secret ) ;
 }
 
 void GAuth::SecretsFile::processLineImp( Contents & contents ,
-	unsigned int line_number , const std::string & side , const std::string & type ,
-	const std::string & id_or_ip , const std::string & secret )
+	unsigned int line_number , G::string_view side , G::string_view type ,
+	G::string_view id_or_ip , G::string_view secret )
 {
 	G_ASSERT( !side.empty() && !type.empty() && !id_or_ip.empty() && !secret.empty() ) ;
 
-	if( type == "plain" )
+	if( type == "plain"_sv )
 	{
 		if( !G::Xtext::valid(id_or_ip) ) // (ip address ranges are valid xtext)
-			addWarning( contents , line_number , "invalid xtext encoding in third field" , id_or_ip ) ;
+			addWarning( contents , line_number , "invalid xtext encoding in third field"_sv , id_or_ip ) ;
 		if( !G::Xtext::valid(secret) )
-			addWarning( contents , line_number , "invalid xtext encoding in fourth field" ) ; // (new)
+			addWarning( contents , line_number , "invalid xtext encoding in fourth field"_sv ) ;
 	}
 
-	if( side == "server" )
+	if( G::Str::imatch( side , "server"_sv ) )
 	{
 		// server-side
-		std::string key = serverKey( type , id_or_ip ) ;
-		Value value( secret , line_number ) ;
-		bool inserted = contents.m_map.insert(std::make_pair(key,value)).second ;
+		Value server_value( secret , line_number ) ;
+		bool inserted = contents.m_map.insert(std::make_pair(serverKey(type,id_or_ip),server_value)).second ;
 		if( inserted )
 			contents.m_types.insert( canonical(type) ) ;
 		else
-			addWarning( contents , line_number , "duplicate server secret" , key ) ;
+			addWarning( contents , line_number , "duplicate server secret"_sv , serverKey(type,id_or_ip) ) ;
 	}
-	else if( side == "client" )
+	else if( G::Str::imatch( side , "client"_sv ) )
 	{
 		// client-side
-		const std::string & id = id_or_ip ;
-		std::string key = clientKey( type ) ; // not including user id
-		Value value( id + " " + secret , line_number ) ;
-		bool inserted = contents.m_map.insert(std::make_pair(key,value)).second ;
+		Value client_value( clientValue(id_or_ip,secret) , line_number ) ;
+		bool inserted = contents.m_map.insert(std::make_pair(clientKey(type),client_value)).second ;
 		if( !inserted )
-			addWarning( contents , line_number , "too many client secrets" , key ) ;
+			addWarning( contents , line_number , "too many client secrets"_sv , clientKey(type) ) ;
 	}
 	else
 	{
-		addWarning( contents , line_number , "invalid value in first field" , side ) ;
+		addWarning( contents , line_number , "invalid value in first field"_sv , side ) ;
 	}
 }
 
-void GAuth::SecretsFile::addWarning( Contents & contents , unsigned int line_number , const std::string & message_in , const std::string & more )
+void GAuth::SecretsFile::addWarning( Contents & contents , unsigned int line_number , G::string_view message_in , G::string_view more )
 {
-	std::string message = more.empty() ? message_in : ( message_in + ": [" + G::Str::printable(more) + "]" ) ;
+	std::string message( message_in.data() , message_in.size() ) ;
+	if( !more.empty() )
+		message.append(": [",3U).append(G::Str::printable(more)).append(1U,']') ;
 	contents.m_warnings.push_back( Warnings::value_type(line_number,message) ) ;
 }
 
@@ -230,36 +232,40 @@ void GAuth::SecretsFile::showWarnings( const Warnings & warnings , const G::Path
 	}
 }
 
-std::string GAuth::SecretsFile::canonical( const std::string & type_in )
+std::string GAuth::SecretsFile::canonical( G::string_view type )
 {
-	// (cram-md5, apop and login are for backwards compatibility -- new
-	// code exects plain, md5, sha1, sha512 etc)
-	std::string type = G::Str::lower( type_in ) ;
-	if( type == "cram-md5" ) type = "md5" ;
-	if( type == "apop" ) type = "md5" ;
-	if( type == "login" ) type = "plain" ;
-	return type ;
+	// (for backwards compatibility -- new code exects plain, md5, sha1, sha512 etc)
+	if( G::Str::imatch( type , "cram-md5"_sv ) ) return "md5" ;
+	if( G::Str::imatch( type , "apop"_sv ) ) return "md5" ;
+	if( G::Str::imatch( type , "login"_sv ) ) return "plain" ;
+
+	return G::Str::lower( type ) ;
 }
 
-std::string GAuth::SecretsFile::serverKey( const std::string & type , const std::string & id_xtext )
+std::string GAuth::SecretsFile::serverKey( G::string_view type , G::string_view id_xtext )
 {
 	// eg. key -> value...
 	// "server plain bob" -> "e+3Dmc2"
 	// "server md5 bob" -> "xbase64x=="
 	// "server none 192.168.0.0/24" -> "trustee"
 	// "server none ::1/128" -> "trustee"
-	return "server " + canonical(type) + " " + id_xtext ;
+	return std::string("server ",7U).append(canonical(type)).append(1U,' ').append(id_xtext.data(),id_xtext.size()) ;
 }
 
-std::string GAuth::SecretsFile::clientKey( const std::string & type )
+std::string GAuth::SecretsFile::clientKey( G::string_view type )
 {
 	// eg. key -> value...
 	// "client plain" -> "alice secret+21"
 	// "client md5" -> "alice xbase64x=="
-	return "client " + canonical(type) ;
+	return std::string("client ",7U).append(canonical(type)) ;
 }
 
-GAuth::Secret GAuth::SecretsFile::clientSecret( const std::string & type ) const
+std::string GAuth::SecretsFile::clientValue( G::string_view id , G::string_view secret )
+{
+	return G::sv_to_string(id).append(1U,' ').append(secret.data(),secret.size()) ;
+}
+
+GAuth::Secret GAuth::SecretsFile::clientSecret( G::string_view type ) const
 {
 	reread() ;
 
@@ -276,7 +282,7 @@ GAuth::Secret GAuth::SecretsFile::clientSecret( const std::string & type ) const
 	}
 }
 
-GAuth::Secret GAuth::SecretsFile::serverSecret( const std::string & type , const std::string & id ) const
+GAuth::Secret GAuth::SecretsFile::serverSecret( G::string_view type , G::string_view id ) const
 {
 	if( id.empty() )
 		return Secret::none() ;
@@ -296,12 +302,13 @@ GAuth::Secret GAuth::SecretsFile::serverSecret( const std::string & type , const
 
 std::pair<std::string,std::string> GAuth::SecretsFile::serverTrust( const std::string & address_range ) const
 {
-	reread() ; // (new)
+	reread() ;
 
 	std::pair<std::string,std::string> result ;
-	std::string type = "none" ;
+	G::string_view type = "none"_sv ;
 	const std::string & id = address_range ; // the address-range lives in the id field
-	auto p = m_contents.m_map.find( serverKey(type,G::Xtext::encode(id)) ) ;
+	std::string xid = G::Xtext::encode( id ) ;
+	auto p = m_contents.m_map.find( serverKey(type,{xid.data(),xid.size()}) ) ;
 	if( p != m_contents.m_map.end() )
 	{
 		result.first = (*p).second.s ; // the trustee name lives in the shared-secret field
@@ -315,7 +322,7 @@ std::string GAuth::SecretsFile::path() const
 	return m_path.str() ;
 }
 
-bool GAuth::SecretsFile::contains( const std::string & type , const std::string & id ) const
+bool GAuth::SecretsFile::contains( G::string_view type , G::string_view id ) const
 {
 	return id.empty() ?
 		m_contents.m_types.find( canonical(type) ) != m_contents.m_types.end() :
diff --git a/src/gauth/gsecretsfile.h b/src/gauth/gsecretsfile.h
index 9d4700f..53b52f6 100644
--- a/src/gauth/gsecretsfile.h
+++ b/src/gauth/gsecretsfile.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,6 +24,7 @@
 #include "gdef.h"
 #include "gpath.h"
 #include "gdatetime.h"
+#include "gstringview.h"
 #include "gsecret.h"
 #include "gexception.h"
 #include <string>
@@ -45,7 +46,7 @@ namespace GAuth
 class GAuth::SecretsFile
 {
 public:
-	G_EXCEPTION( Error , "invalid secrets file" ) ;
+	G_EXCEPTION( Error , tx("invalid secrets file") ) ;
 
 	static void check( const std::string & path ) ;
 		///< Checks the given file. Logs warnings and throws an exception
@@ -58,11 +59,11 @@ public:
 	bool valid() const ;
 		///< Returns true if the file path was supplied in the ctor.
 
-	Secret clientSecret( const std::string & type ) const ;
+	Secret clientSecret( G::string_view type ) const ;
 		///< Returns the client id and secret for the given type.
 		///< Returns the empty string if none.
 
-	Secret serverSecret( const std::string & type , const std::string & id ) const ;
+	Secret serverSecret( G::string_view type , G::string_view id ) const ;
 		///< Returns the server secret for the given id and type.
 		///< Returns the empty string if none.
 
@@ -73,14 +74,15 @@ public:
 	std::string path() const ;
 		///< Returns the file path, as supplied to the ctor.
 
-	bool contains( const std::string & type , const std::string & id = {} ) const ;
+	bool contains( G::string_view type , G::string_view id = {} ) const ;
 		///< Returns true if a server secret of the given type
 		///< is available for the particular user or any user.
 
 private:
 	struct Value
 	{
-		Value(const std::string &s_,unsigned int n_):s(s_),n(n_) {}
+		Value( const std::string & s_ , unsigned int n_ ) : s(s_), n(n_) {}
+		Value( G::string_view s_ , unsigned int n_ ) : s(G::sv_to_string(s_)), n(n_) {}
 		std::string s ;
 		unsigned int n ;
 	} ;
@@ -102,14 +104,15 @@ private:
 	static Contents readContents( const G::Path & ) ;
 	static Contents readContents( std::istream & ) ;
 	static void processLine( Contents & ,
-		unsigned int , const std::string & side , const std::string & , const std::string & , const std::string & ) ;
+		unsigned int , G::string_view side , G::string_view , G::string_view , G::string_view ) ;
 	static void processLineImp( Contents & ,
-		unsigned int , const std::string & side , const std::string & , const std::string & , const std::string & ) ;
+		unsigned int , G::string_view side , G::string_view , G::string_view , G::string_view ) ;
 	static void showWarnings( const Warnings & warnings , const G::Path & path , const std::string & debug_name = {} ) ;
-	static void addWarning( Contents & , unsigned int , const std::string & , const std::string & = {} ) ;
-	static std::string canonical( const std::string & encoding_type ) ;
-	static std::string serverKey( const std::string & , const std::string & ) ;
-	static std::string clientKey( const std::string & ) ;
+	static void addWarning( Contents & , unsigned int , G::string_view , G::string_view = {} ) ;
+	static std::string canonical( G::string_view encoding_type ) ;
+	static std::string serverKey( G::string_view , G::string_view ) ;
+	static std::string clientKey( G::string_view ) ;
+	static std::string clientValue( G::string_view id , G::string_view secret ) ;
 	static G::SystemTime readFileTime( const G::Path & ) ;
 	static std::string line( unsigned int ) ;
 
diff --git a/src/gauth/gvalid.cpp b/src/gauth/gvalid.cpp
index 57a9190..ca67324 100644
--- a/src/gauth/gvalid.cpp
+++ b/src/gauth/gvalid.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gauth/gvalid.h b/src/gauth/gvalid.h
index 64f34df..f104dbd 100644
--- a/src/gauth/gvalid.h
+++ b/src/gauth/gvalid.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gconfig_defs.h.in b/src/gconfig_defs.h.in
index dae83e4..355a686 100644
--- a/src/gconfig_defs.h.in
+++ b/src/gconfig_defs.h.in
@@ -69,6 +69,9 @@
 /* Define true if grp.h is available */
 #undef GCONFIG_HAVE_GRP_H
 
+/* Define true if struct ifreq has ifr_ifindex */
+#undef GCONFIG_HAVE_IFINDEX
+
 /* Define true if if_nametoindex() is available */
 #undef GCONFIG_HAVE_IFNAMETOINDEX
 
@@ -225,6 +228,9 @@
 /* Define true to use unix domain sockets */
 #undef GCONFIG_HAVE_UDS
 
+/* Define true if sockaddr_un has a sun_len field */
+#undef GCONFIG_HAVE_UDS_LEN
+
 /* Define true if uid_t is a type */
 #undef GCONFIG_HAVE_UID_T
 
diff --git a/src/glib/Makefile.am b/src/glib/Makefile.am
index 819e25c..6839246 100644
--- a/src/glib/Makefile.am
+++ b/src/glib/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -15,14 +15,13 @@
 ## along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
-AM_CPPFLAGS =
+AM_CPPFLAGS = -DG_LIB_SMALL
 
 noinst_LIBRARIES = libglib.a
 
-if GCONFIG_WINDOWS
-
-EXTRA_DIST=\
+UNIX_SOURCES = \
 	gcleanup_unix.cpp \
+	gconvert_unix.cpp \
 	gdaemon_unix.cpp \
 	gdirectory_unix.cpp \
 	genvironment_unix.cpp \
@@ -33,10 +32,24 @@ EXTRA_DIST=\
 	glogoutput_unix.cpp \
 	gmsg_unix.cpp \
 	gnewprocess_unix.cpp \
-	gpam_linux.cpp \
 	gprocess_unix.cpp
 
-libglib_a_SOURCES = \
+WINDOWS_SOURCES = \
+	gcleanup_win32.cpp \
+	gconvert_win32.cpp \
+	gdaemon_win32.cpp \
+	gdirectory_win32.cpp \
+	genvironment_win32.cpp \
+	gexecutablecommand_win32.cpp \
+	gfile_win32.cpp \
+	ghostname_win32.cpp \
+	gidentity_win32.cpp \
+	glogoutput_win32.cpp \
+	gmsg_win32.cpp \
+	gnewprocess_win32.cpp \
+	gprocess_win32.cpp
+
+COMMON_SOURCES = \
 	galign.h \
 	garg.h \
 	garg.cpp \
@@ -48,12 +61,9 @@ libglib_a_SOURCES = \
 	gbuffer.h \
 	gcall.h \
 	gcleanup.h \
-	gcleanup_win32.cpp \
 	gconvert.h \
 	gconvert.cpp \
-	gconvert_win32.cpp \
 	gdaemon.h \
-	gdaemon_win32.cpp \
 	gdate.h \
 	gdate.cpp \
 	gdatetime.h \
@@ -61,64 +71,58 @@ libglib_a_SOURCES = \
 	gdef.h \
 	gdirectory.h \
 	gdirectory.cpp \
-	gdirectory_win32.cpp \
 	geightbit.h \
 	genvironment.h \
 	genvironment.cpp \
-	genvironment_win32.cpp \
 	gexception.h \
 	gexception.cpp \
 	gexecutablecommand.h \
 	gexecutablecommand.cpp \
-	gexecutablecommand_win32.cpp \
+	gfbuf.h \
 	gfile.h \
 	gfile.cpp \
-	gfile_win32.cpp \
 	gformat.h \
 	gformat.cpp \
 	ggetopt.h \
 	ggetopt.cpp \
-	ggettext.h \
 	ghash.h \
 	ghash.cpp \
 	ghashstate.h \
 	ghostname.h \
-	ghostname_win32.cpp \
 	gidentity.h \
-	gidentity_win32.cpp \
 	gimembuf.h \
 	glimits.h \
 	glog.h \
 	glog.cpp \
+	glogstream.h \
+	glogstream.cpp \
 	glogoutput.h \
 	glogoutput.cpp \
-	glogoutput_win32.cpp \
 	gstrmacros.h \
 	gmapfile.h \
 	gmapfile.cpp \
 	gmd5.h \
 	gmd5.cpp \
 	gmsg.h \
-	gmsg_win32.cpp \
 	gnewprocess.h \
-	gnewprocess_win32.cpp \
 	gomembuf.h \
 	goptional.h \
+	goption.h \
+	goption.cpp \
 	goptionmap.h \
 	goptionmap.cpp \
 	goptionparser.h \
 	goptionparser.cpp \
 	goptions.h \
 	goptions.cpp \
+	goptionsusage.h \
+	goptionsusage.cpp \
 	goptionvalue.h \
-	gpam.h \
-	gpam_none.cpp \
 	gpath.h \
 	gpath.cpp \
 	gpidfile.h \
 	gpidfile.cpp \
 	gprocess.h \
-	gprocess_win32.cpp \
 	grandom.h \
 	grandom.cpp \
 	greadwrite.h \
@@ -133,10 +137,17 @@ libglib_a_SOURCES = \
 	gstatemachine.h \
 	gstr.h \
 	gstr.cpp \
+	gstringarray.h \
+	gstringfield.h \
+	gstringtoken.h \
+	gstringlist.h \
+	gstringlist.cpp \
+	gstringmap.h \
 	gstrings.h \
 	gstringwrap.cpp \
 	gstringwrap.h \
 	gstringview.h \
+	gstringview.cpp \
 	gtest.h \
 	gtest.cpp \
 	gthread.cpp \
@@ -145,134 +156,82 @@ libglib_a_SOURCES = \
 	gxtext.h \
 	gxtext.cpp
 
-else
+# -- PAM
 
 if GCONFIG_PAM
-PAM_EXTRA_DIST = gpam_none.cpp
-PAM_SOURCES = gpam_linux.cpp
+if GCONFIG_WINDOWS
+PAM_SOURCES = \
+	gpam.h \
+	gpam_none.cpp
+PAM_EXTRA_DIST = \
+	gpam_linux.cpp
 else
-PAM_EXTRA_DIST = gpam_linux.cpp
-PAM_SOURCES = gpam_none.cpp
+PAM_SOURCES = \
+	gpam.h \
+	gpam_linux.cpp
+PAM_EXTRA_DIST = \
+	gpam_none.cpp
+endif
+else
+PAM_SOURCES = \
+	gpam.h \
+	gpam_none.cpp
+PAM_EXTRA_DIST = \
+	gpam_linux.cpp
 endif
 
-EXTRA_DIST=\
-	$(PAM_EXTRA_DIST) \
-	gcleanup_win32.cpp \
-	gconvert.cpp \
-	gconvert_win32.cpp \
-	gdaemon_win32.cpp \
-	gdirectory_win32.cpp \
-	genvironment_win32.cpp \
-	gexecutablecommand_win32.cpp \
-	gfile_win32.cpp \
-	ghostname_win32.cpp \
-	gidentity_win32.cpp \
-	glogoutput_win32.cpp \
-	gprocess_win32.cpp \
-	gnewprocess_win32.cpp \
-	gmsg_win32.cpp
+# -- GETTEXT
+
+if GCONFIG_GETTEXT
+if GCONFIG_WINDOWS
+GETTEXT_SOURCES = \
+	ggettext.h \
+	ggettext_win32.cpp
+GETTEXT_EXTRA_DIST = \
+	ggettext_none.cpp \
+	ggettext_unix.cpp
+else
+GETTEXT_SOURCES = \
+	ggettext.h \
+	ggettext_unix.cpp
+GETTEXT_EXTRA_DIST = \
+	ggettext_none.cpp \
+	ggettext_win32.cpp
+endif
+else
+GETTEXT_SOURCES = \
+	ggettext_none.cpp \
+	ggettext.h
+GETTEXT_EXTRA_DIST = \
+	ggettext_win32.cpp \
+	ggettext_unix.cpp
+endif
+
+# -- OS
+
+if GCONFIG_WINDOWS
+OS_SOURCES = \
+	$(COMMON_SOURCES) \
+	$(WINDOWS_SOURCES)
+OS_EXTRA_DIST = \
+	$(UNIX_SOURCES)
+else
+OS_SOURCES = \
+	$(COMMON_SOURCES) \
+	$(UNIX_SOURCES)
+OS_EXTRA_DIST = \
+	$(WINDOWS_SOURCES)
+endif
+
+# ===
 
 libglib_a_SOURCES = \
-	$(PAM_SOURCES) \
-	garg.h \
-	garg.cpp \
-	gassert.h \
-	gbase64.h \
-	gbase64.cpp \
-	gbatchfile.h \
-	gbatchfile.cpp \
-	gbuffer.h \
-	gcall.h \
-	gcleanup.h \
-	gcleanup_unix.cpp \
-	gconvert.h \
-	gdaemon.h \
-	gdaemon_unix.cpp \
-	gdate.h \
-	gdate.cpp \
-	gdatetime.h \
-	gdatetime.cpp \
-	gdef.h \
-	gdirectory.h \
-	gdirectory.cpp \
-	gdirectory_unix.cpp \
-	genvironment.h \
-	genvironment.cpp \
-	genvironment_unix.cpp \
-	gexception.h \
-	gexception.cpp \
-	gexecutablecommand.h \
-	gexecutablecommand.cpp \
-	gexecutablecommand_unix.cpp \
-	gfile.h \
-	gfile.cpp \
-	gfile_unix.cpp \
-	gformat.h \
-	gformat.cpp \
-	ggetopt.h \
-	ggetopt.cpp \
-	ggettext.h \
-	ghash.h \
-	ghash.cpp \
-	ghostname.h \
-	ghostname_unix.cpp \
-	gidentity.h \
-	gidentity_unix.cpp \
-	gimembuf.h \
-	glimits.h \
-	glog.h \
-	glog.cpp \
-	glogoutput.h \
-	glogoutput.cpp \
-	glogoutput_unix.cpp \
-	gmapfile.h \
-	gmapfile.cpp \
-	gmd5.h \
-	gmd5.cpp \
-	gmsg_unix.cpp \
-	gmsg.h \
-	gnewprocess.h \
-	gnewprocess_unix.cpp \
-	gomembuf.h \
-	goptional.h \
-	goptionmap.h \
-	goptionmap.cpp \
-	goptionparser.h \
-	goptionparser.cpp \
-	goptions.h \
-	goptions.cpp \
-	goptionvalue.h \
-	gpam.h \
-	gpath.h \
-	gpath.cpp \
-	gpidfile.h \
-	gpidfile.cpp \
-	gprocess.h \
-	gprocess_unix.cpp \
-	grandom.h \
-	grandom.cpp \
-	greadwrite.h \
-	greadwrite.cpp \
-	groot.h \
-	groot.cpp \
-	gscope.h \
-	gsignalsafe.h \
-	gsleep.h \
-	gslot.h \
-	gslot.cpp \
-	gstatemachine.h \
-	gstr.h \
-	gstr.cpp \
-	gstrings.h \
-	gstringwrap.cpp \
-	gstringwrap.h \
-	gstringview.h \
-	gtest.h \
-	gtest.cpp \
-	gthread.cpp \
-	gtime.h \
-	gtime.cpp \
-	gxtext.h \
-	gxtext.cpp
+	$(GETTEXT_SOURCES) \
+	$(OS_SOURCES) \
+	$(PAM_SOURCES)
+
+EXTRA_DIST = \
+	$(GETTEXT_EXTRA_DIST) \
+	$(OS_EXTRA_DIST) \
+	$(PAM_EXTRA_DIST)
 
-endif
diff --git a/src/glib/Makefile.in b/src/glib/Makefile.in
index 01926b1..7f55ce5 100644
--- a/src/glib/Makefile.in
+++ b/src/glib/Makefile.in
@@ -110,105 +110,82 @@ am__v_AR_0 = @echo "  AR      " $@;
 am__v_AR_1 = 
 libglib_a_AR = $(AR) $(ARFLAGS)
 libglib_a_LIBADD =
-am__libglib_a_SOURCES_DIST = gpam_none.cpp gpam_linux.cpp garg.h \
-	garg.cpp gassert.h gbase64.h gbase64.cpp gbatchfile.h \
-	gbatchfile.cpp gbuffer.h gcall.h gcleanup.h gcleanup_unix.cpp \
-	gconvert.h gdaemon.h gdaemon_unix.cpp gdate.h gdate.cpp \
-	gdatetime.h gdatetime.cpp gdef.h gdirectory.h gdirectory.cpp \
-	gdirectory_unix.cpp genvironment.h genvironment.cpp \
-	genvironment_unix.cpp gexception.h gexception.cpp \
-	gexecutablecommand.h gexecutablecommand.cpp \
-	gexecutablecommand_unix.cpp gfile.h gfile.cpp gfile_unix.cpp \
-	gformat.h gformat.cpp ggetopt.h ggetopt.cpp ggettext.h ghash.h \
-	ghash.cpp ghostname.h ghostname_unix.cpp gidentity.h \
-	gidentity_unix.cpp gimembuf.h glimits.h glog.h glog.cpp \
-	glogoutput.h glogoutput.cpp glogoutput_unix.cpp gmapfile.h \
-	gmapfile.cpp gmd5.h gmd5.cpp gmsg_unix.cpp gmsg.h \
-	gnewprocess.h gnewprocess_unix.cpp gomembuf.h goptional.h \
-	goptionmap.h goptionmap.cpp goptionparser.h goptionparser.cpp \
-	goptions.h goptions.cpp goptionvalue.h gpam.h gpath.h \
-	gpath.cpp gpidfile.h gpidfile.cpp gprocess.h gprocess_unix.cpp \
-	grandom.h grandom.cpp greadwrite.h greadwrite.cpp groot.h \
-	groot.cpp gscope.h gsignalsafe.h gsleep.h gslot.h gslot.cpp \
-	gstatemachine.h gstr.h gstr.cpp gstrings.h gstringwrap.cpp \
-	gstringwrap.h gstringview.h gtest.h gtest.cpp gthread.cpp \
-	gtime.h gtime.cpp gxtext.h gxtext.cpp galign.h \
-	gcleanup_win32.cpp gconvert.cpp gconvert_win32.cpp \
-	gdaemon_win32.cpp gdirectory_win32.cpp geightbit.h \
-	genvironment_win32.cpp gexecutablecommand_win32.cpp \
-	gfile_win32.cpp ghashstate.h ghostname_win32.cpp \
-	gidentity_win32.cpp glogoutput_win32.cpp gstrmacros.h \
-	gmsg_win32.cpp gnewprocess_win32.cpp gprocess_win32.cpp
-@GCONFIG_PAM_FALSE@@GCONFIG_WINDOWS_FALSE@am__objects_1 =  \
-@GCONFIG_PAM_FALSE@@GCONFIG_WINDOWS_FALSE@	gpam_none.$(OBJEXT)
-@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_FALSE@am__objects_1 =  \
+am__libglib_a_SOURCES_DIST = ggettext_none.cpp ggettext.h \
+	ggettext_unix.cpp ggettext_win32.cpp galign.h garg.h garg.cpp \
+	gassert.h gbase64.h gbase64.cpp gbatchfile.h gbatchfile.cpp \
+	gbuffer.h gcall.h gcleanup.h gconvert.h gconvert.cpp gdaemon.h \
+	gdate.h gdate.cpp gdatetime.h gdatetime.cpp gdef.h \
+	gdirectory.h gdirectory.cpp geightbit.h genvironment.h \
+	genvironment.cpp gexception.h gexception.cpp \
+	gexecutablecommand.h gexecutablecommand.cpp gfbuf.h gfile.h \
+	gfile.cpp gformat.h gformat.cpp ggetopt.h ggetopt.cpp ghash.h \
+	ghash.cpp ghashstate.h ghostname.h gidentity.h gimembuf.h \
+	glimits.h glog.h glog.cpp glogstream.h glogstream.cpp \
+	glogoutput.h glogoutput.cpp gstrmacros.h gmapfile.h \
+	gmapfile.cpp gmd5.h gmd5.cpp gmsg.h gnewprocess.h gomembuf.h \
+	goptional.h goption.h goption.cpp goptionmap.h goptionmap.cpp \
+	goptionparser.h goptionparser.cpp goptions.h goptions.cpp \
+	goptionsusage.h goptionsusage.cpp goptionvalue.h gpath.h \
+	gpath.cpp gpidfile.h gpidfile.cpp gprocess.h grandom.h \
+	grandom.cpp greadwrite.h greadwrite.cpp groot.h groot.cpp \
+	gscope.h gsignalsafe.h gsleep.h gslot.h gslot.cpp \
+	gstatemachine.h gstr.h gstr.cpp gstringarray.h gstringfield.h \
+	gstringtoken.h gstringlist.h gstringlist.cpp gstringmap.h \
+	gstrings.h gstringwrap.cpp gstringwrap.h gstringview.h \
+	gstringview.cpp gtest.h gtest.cpp gthread.cpp gtime.h \
+	gtime.cpp gxtext.h gxtext.cpp gcleanup_unix.cpp \
+	gconvert_unix.cpp gdaemon_unix.cpp gdirectory_unix.cpp \
+	genvironment_unix.cpp gexecutablecommand_unix.cpp \
+	gfile_unix.cpp ghostname_unix.cpp gidentity_unix.cpp \
+	glogoutput_unix.cpp gmsg_unix.cpp gnewprocess_unix.cpp \
+	gprocess_unix.cpp gcleanup_win32.cpp gconvert_win32.cpp \
+	gdaemon_win32.cpp gdirectory_win32.cpp genvironment_win32.cpp \
+	gexecutablecommand_win32.cpp gfile_win32.cpp \
+	ghostname_win32.cpp gidentity_win32.cpp glogoutput_win32.cpp \
+	gmsg_win32.cpp gnewprocess_win32.cpp gprocess_win32.cpp gpam.h \
+	gpam_none.cpp gpam_linux.cpp
+@GCONFIG_GETTEXT_FALSE@am__objects_1 = ggettext_none.$(OBJEXT)
+@GCONFIG_GETTEXT_TRUE@@GCONFIG_WINDOWS_FALSE@am__objects_1 = ggettext_unix.$(OBJEXT)
+@GCONFIG_GETTEXT_TRUE@@GCONFIG_WINDOWS_TRUE@am__objects_1 = ggettext_win32.$(OBJEXT)
+am__objects_2 = garg.$(OBJEXT) gbase64.$(OBJEXT) gbatchfile.$(OBJEXT) \
+	gconvert.$(OBJEXT) gdate.$(OBJEXT) gdatetime.$(OBJEXT) \
+	gdirectory.$(OBJEXT) genvironment.$(OBJEXT) \
+	gexception.$(OBJEXT) gexecutablecommand.$(OBJEXT) \
+	gfile.$(OBJEXT) gformat.$(OBJEXT) ggetopt.$(OBJEXT) \
+	ghash.$(OBJEXT) glog.$(OBJEXT) glogstream.$(OBJEXT) \
+	glogoutput.$(OBJEXT) gmapfile.$(OBJEXT) gmd5.$(OBJEXT) \
+	goption.$(OBJEXT) goptionmap.$(OBJEXT) goptionparser.$(OBJEXT) \
+	goptions.$(OBJEXT) goptionsusage.$(OBJEXT) gpath.$(OBJEXT) \
+	gpidfile.$(OBJEXT) grandom.$(OBJEXT) greadwrite.$(OBJEXT) \
+	groot.$(OBJEXT) gslot.$(OBJEXT) gstr.$(OBJEXT) \
+	gstringlist.$(OBJEXT) gstringwrap.$(OBJEXT) \
+	gstringview.$(OBJEXT) gtest.$(OBJEXT) gthread.$(OBJEXT) \
+	gtime.$(OBJEXT) gxtext.$(OBJEXT)
+am__objects_3 = gcleanup_unix.$(OBJEXT) gconvert_unix.$(OBJEXT) \
+	gdaemon_unix.$(OBJEXT) gdirectory_unix.$(OBJEXT) \
+	genvironment_unix.$(OBJEXT) gexecutablecommand_unix.$(OBJEXT) \
+	gfile_unix.$(OBJEXT) ghostname_unix.$(OBJEXT) \
+	gidentity_unix.$(OBJEXT) glogoutput_unix.$(OBJEXT) \
+	gmsg_unix.$(OBJEXT) gnewprocess_unix.$(OBJEXT) \
+	gprocess_unix.$(OBJEXT)
+am__objects_4 = gcleanup_win32.$(OBJEXT) gconvert_win32.$(OBJEXT) \
+	gdaemon_win32.$(OBJEXT) gdirectory_win32.$(OBJEXT) \
+	genvironment_win32.$(OBJEXT) \
+	gexecutablecommand_win32.$(OBJEXT) gfile_win32.$(OBJEXT) \
+	ghostname_win32.$(OBJEXT) gidentity_win32.$(OBJEXT) \
+	glogoutput_win32.$(OBJEXT) gmsg_win32.$(OBJEXT) \
+	gnewprocess_win32.$(OBJEXT) gprocess_win32.$(OBJEXT)
+@GCONFIG_WINDOWS_FALSE@am__objects_5 = $(am__objects_2) \
+@GCONFIG_WINDOWS_FALSE@	$(am__objects_3)
+@GCONFIG_WINDOWS_TRUE@am__objects_5 = $(am__objects_2) \
+@GCONFIG_WINDOWS_TRUE@	$(am__objects_4)
+@GCONFIG_PAM_FALSE@am__objects_6 = gpam_none.$(OBJEXT)
+@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_FALSE@am__objects_6 =  \
 @GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_FALSE@	gpam_linux.$(OBJEXT)
-@GCONFIG_WINDOWS_FALSE@am_libglib_a_OBJECTS = $(am__objects_1) \
-@GCONFIG_WINDOWS_FALSE@	garg.$(OBJEXT) gbase64.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gbatchfile.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gcleanup_unix.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gdaemon_unix.$(OBJEXT) gdate.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gdatetime.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gdirectory.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gdirectory_unix.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	genvironment.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	genvironment_unix.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gexception.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gexecutablecommand.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gexecutablecommand_unix.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gfile.$(OBJEXT) gfile_unix.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gformat.$(OBJEXT) ggetopt.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	ghash.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	ghostname_unix.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gidentity_unix.$(OBJEXT) glog.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	glogoutput.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	glogoutput_unix.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gmapfile.$(OBJEXT) gmd5.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gmsg_unix.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gnewprocess_unix.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	goptionmap.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	goptionparser.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	goptions.$(OBJEXT) gpath.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gpidfile.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gprocess_unix.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	grandom.$(OBJEXT) greadwrite.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	groot.$(OBJEXT) gslot.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gstr.$(OBJEXT) gstringwrap.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gtest.$(OBJEXT) gthread.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gtime.$(OBJEXT) gxtext.$(OBJEXT)
-@GCONFIG_WINDOWS_TRUE@am_libglib_a_OBJECTS = garg.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gbase64.$(OBJEXT) gbatchfile.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gcleanup_win32.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gconvert.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gconvert_win32.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gdaemon_win32.$(OBJEXT) gdate.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gdatetime.$(OBJEXT) gdirectory.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gdirectory_win32.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	genvironment.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	genvironment_win32.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gexception.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gexecutablecommand.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gexecutablecommand_win32.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gfile.$(OBJEXT) gfile_win32.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gformat.$(OBJEXT) ggetopt.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	ghash.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	ghostname_win32.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gidentity_win32.$(OBJEXT) glog.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	glogoutput.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	glogoutput_win32.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gmapfile.$(OBJEXT) gmd5.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gmsg_win32.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gnewprocess_win32.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	goptionmap.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	goptionparser.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	goptions.$(OBJEXT) gpam_none.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gpath.$(OBJEXT) gpidfile.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gprocess_win32.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	grandom.$(OBJEXT) greadwrite.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	groot.$(OBJEXT) gslot.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gstr.$(OBJEXT) gstringwrap.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gtest.$(OBJEXT) gthread.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gtime.$(OBJEXT) gxtext.$(OBJEXT)
+@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_TRUE@am__objects_6 =  \
+@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_TRUE@	gpam_none.$(OBJEXT)
+am_libglib_a_OBJECTS = $(am__objects_1) $(am__objects_5) \
+	$(am__objects_6)
 libglib_a_OBJECTS = $(am_libglib_a_OBJECTS)
 AM_V_P = $(am__v_P_@AM_V@)
 am__v_P_ = $(am__v_P_@AM_DEFAULT_V@)
@@ -228,31 +205,36 @@ am__maybe_remake_depfiles = depfiles
 am__depfiles_remade = ./$(DEPDIR)/garg.Po ./$(DEPDIR)/gbase64.Po \
 	./$(DEPDIR)/gbatchfile.Po ./$(DEPDIR)/gcleanup_unix.Po \
 	./$(DEPDIR)/gcleanup_win32.Po ./$(DEPDIR)/gconvert.Po \
-	./$(DEPDIR)/gconvert_win32.Po ./$(DEPDIR)/gdaemon_unix.Po \
-	./$(DEPDIR)/gdaemon_win32.Po ./$(DEPDIR)/gdate.Po \
-	./$(DEPDIR)/gdatetime.Po ./$(DEPDIR)/gdirectory.Po \
-	./$(DEPDIR)/gdirectory_unix.Po ./$(DEPDIR)/gdirectory_win32.Po \
-	./$(DEPDIR)/genvironment.Po ./$(DEPDIR)/genvironment_unix.Po \
+	./$(DEPDIR)/gconvert_unix.Po ./$(DEPDIR)/gconvert_win32.Po \
+	./$(DEPDIR)/gdaemon_unix.Po ./$(DEPDIR)/gdaemon_win32.Po \
+	./$(DEPDIR)/gdate.Po ./$(DEPDIR)/gdatetime.Po \
+	./$(DEPDIR)/gdirectory.Po ./$(DEPDIR)/gdirectory_unix.Po \
+	./$(DEPDIR)/gdirectory_win32.Po ./$(DEPDIR)/genvironment.Po \
+	./$(DEPDIR)/genvironment_unix.Po \
 	./$(DEPDIR)/genvironment_win32.Po ./$(DEPDIR)/gexception.Po \
 	./$(DEPDIR)/gexecutablecommand.Po \
 	./$(DEPDIR)/gexecutablecommand_unix.Po \
 	./$(DEPDIR)/gexecutablecommand_win32.Po ./$(DEPDIR)/gfile.Po \
 	./$(DEPDIR)/gfile_unix.Po ./$(DEPDIR)/gfile_win32.Po \
 	./$(DEPDIR)/gformat.Po ./$(DEPDIR)/ggetopt.Po \
-	./$(DEPDIR)/ghash.Po ./$(DEPDIR)/ghostname_unix.Po \
-	./$(DEPDIR)/ghostname_win32.Po ./$(DEPDIR)/gidentity_unix.Po \
-	./$(DEPDIR)/gidentity_win32.Po ./$(DEPDIR)/glog.Po \
-	./$(DEPDIR)/glogoutput.Po ./$(DEPDIR)/glogoutput_unix.Po \
-	./$(DEPDIR)/glogoutput_win32.Po ./$(DEPDIR)/gmapfile.Po \
+	./$(DEPDIR)/ggettext_none.Po ./$(DEPDIR)/ggettext_unix.Po \
+	./$(DEPDIR)/ggettext_win32.Po ./$(DEPDIR)/ghash.Po \
+	./$(DEPDIR)/ghostname_unix.Po ./$(DEPDIR)/ghostname_win32.Po \
+	./$(DEPDIR)/gidentity_unix.Po ./$(DEPDIR)/gidentity_win32.Po \
+	./$(DEPDIR)/glog.Po ./$(DEPDIR)/glogoutput.Po \
+	./$(DEPDIR)/glogoutput_unix.Po ./$(DEPDIR)/glogoutput_win32.Po \
+	./$(DEPDIR)/glogstream.Po ./$(DEPDIR)/gmapfile.Po \
 	./$(DEPDIR)/gmd5.Po ./$(DEPDIR)/gmsg_unix.Po \
 	./$(DEPDIR)/gmsg_win32.Po ./$(DEPDIR)/gnewprocess_unix.Po \
-	./$(DEPDIR)/gnewprocess_win32.Po ./$(DEPDIR)/goptionmap.Po \
-	./$(DEPDIR)/goptionparser.Po ./$(DEPDIR)/goptions.Po \
+	./$(DEPDIR)/gnewprocess_win32.Po ./$(DEPDIR)/goption.Po \
+	./$(DEPDIR)/goptionmap.Po ./$(DEPDIR)/goptionparser.Po \
+	./$(DEPDIR)/goptions.Po ./$(DEPDIR)/goptionsusage.Po \
 	./$(DEPDIR)/gpam_linux.Po ./$(DEPDIR)/gpam_none.Po \
 	./$(DEPDIR)/gpath.Po ./$(DEPDIR)/gpidfile.Po \
 	./$(DEPDIR)/gprocess_unix.Po ./$(DEPDIR)/gprocess_win32.Po \
 	./$(DEPDIR)/grandom.Po ./$(DEPDIR)/greadwrite.Po \
 	./$(DEPDIR)/groot.Po ./$(DEPDIR)/gslot.Po ./$(DEPDIR)/gstr.Po \
+	./$(DEPDIR)/gstringlist.Po ./$(DEPDIR)/gstringview.Po \
 	./$(DEPDIR)/gstringwrap.Po ./$(DEPDIR)/gtest.Po \
 	./$(DEPDIR)/gthread.Po ./$(DEPDIR)/gtime.Po \
 	./$(DEPDIR)/gxtext.Po
@@ -436,256 +418,222 @@ target_alias = @target_alias@
 top_build_prefix = @top_build_prefix@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
-AM_CPPFLAGS = 
+AM_CPPFLAGS = -DG_LIB_SMALL
 noinst_LIBRARIES = libglib.a
-@GCONFIG_WINDOWS_FALSE@EXTRA_DIST = \
-@GCONFIG_WINDOWS_FALSE@	$(PAM_EXTRA_DIST) \
-@GCONFIG_WINDOWS_FALSE@	gcleanup_win32.cpp \
-@GCONFIG_WINDOWS_FALSE@	gconvert.cpp \
-@GCONFIG_WINDOWS_FALSE@	gconvert_win32.cpp \
-@GCONFIG_WINDOWS_FALSE@	gdaemon_win32.cpp \
-@GCONFIG_WINDOWS_FALSE@	gdirectory_win32.cpp \
-@GCONFIG_WINDOWS_FALSE@	genvironment_win32.cpp \
-@GCONFIG_WINDOWS_FALSE@	gexecutablecommand_win32.cpp \
-@GCONFIG_WINDOWS_FALSE@	gfile_win32.cpp \
-@GCONFIG_WINDOWS_FALSE@	ghostname_win32.cpp \
-@GCONFIG_WINDOWS_FALSE@	gidentity_win32.cpp \
-@GCONFIG_WINDOWS_FALSE@	glogoutput_win32.cpp \
-@GCONFIG_WINDOWS_FALSE@	gprocess_win32.cpp \
-@GCONFIG_WINDOWS_FALSE@	gnewprocess_win32.cpp \
-@GCONFIG_WINDOWS_FALSE@	gmsg_win32.cpp
+UNIX_SOURCES = \
+	gcleanup_unix.cpp \
+	gconvert_unix.cpp \
+	gdaemon_unix.cpp \
+	gdirectory_unix.cpp \
+	genvironment_unix.cpp \
+	gexecutablecommand_unix.cpp \
+	gfile_unix.cpp \
+	ghostname_unix.cpp \
+	gidentity_unix.cpp \
+	glogoutput_unix.cpp \
+	gmsg_unix.cpp \
+	gnewprocess_unix.cpp \
+	gprocess_unix.cpp
 
-@GCONFIG_WINDOWS_TRUE@EXTRA_DIST = \
-@GCONFIG_WINDOWS_TRUE@	gcleanup_unix.cpp \
-@GCONFIG_WINDOWS_TRUE@	gdaemon_unix.cpp \
-@GCONFIG_WINDOWS_TRUE@	gdirectory_unix.cpp \
-@GCONFIG_WINDOWS_TRUE@	genvironment_unix.cpp \
-@GCONFIG_WINDOWS_TRUE@	gexecutablecommand_unix.cpp \
-@GCONFIG_WINDOWS_TRUE@	gfile_unix.cpp \
-@GCONFIG_WINDOWS_TRUE@	ghostname_unix.cpp \
-@GCONFIG_WINDOWS_TRUE@	gidentity_unix.cpp \
-@GCONFIG_WINDOWS_TRUE@	glogoutput_unix.cpp \
-@GCONFIG_WINDOWS_TRUE@	gmsg_unix.cpp \
-@GCONFIG_WINDOWS_TRUE@	gnewprocess_unix.cpp \
-@GCONFIG_WINDOWS_TRUE@	gpam_linux.cpp \
-@GCONFIG_WINDOWS_TRUE@	gprocess_unix.cpp
+WINDOWS_SOURCES = \
+	gcleanup_win32.cpp \
+	gconvert_win32.cpp \
+	gdaemon_win32.cpp \
+	gdirectory_win32.cpp \
+	genvironment_win32.cpp \
+	gexecutablecommand_win32.cpp \
+	gfile_win32.cpp \
+	ghostname_win32.cpp \
+	gidentity_win32.cpp \
+	glogoutput_win32.cpp \
+	gmsg_win32.cpp \
+	gnewprocess_win32.cpp \
+	gprocess_win32.cpp
 
-@GCONFIG_WINDOWS_FALSE@libglib_a_SOURCES = \
-@GCONFIG_WINDOWS_FALSE@	$(PAM_SOURCES) \
-@GCONFIG_WINDOWS_FALSE@	garg.h \
-@GCONFIG_WINDOWS_FALSE@	garg.cpp \
-@GCONFIG_WINDOWS_FALSE@	gassert.h \
-@GCONFIG_WINDOWS_FALSE@	gbase64.h \
-@GCONFIG_WINDOWS_FALSE@	gbase64.cpp \
-@GCONFIG_WINDOWS_FALSE@	gbatchfile.h \
-@GCONFIG_WINDOWS_FALSE@	gbatchfile.cpp \
-@GCONFIG_WINDOWS_FALSE@	gbuffer.h \
-@GCONFIG_WINDOWS_FALSE@	gcall.h \
-@GCONFIG_WINDOWS_FALSE@	gcleanup.h \
-@GCONFIG_WINDOWS_FALSE@	gcleanup_unix.cpp \
-@GCONFIG_WINDOWS_FALSE@	gconvert.h \
-@GCONFIG_WINDOWS_FALSE@	gdaemon.h \
-@GCONFIG_WINDOWS_FALSE@	gdaemon_unix.cpp \
-@GCONFIG_WINDOWS_FALSE@	gdate.h \
-@GCONFIG_WINDOWS_FALSE@	gdate.cpp \
-@GCONFIG_WINDOWS_FALSE@	gdatetime.h \
-@GCONFIG_WINDOWS_FALSE@	gdatetime.cpp \
-@GCONFIG_WINDOWS_FALSE@	gdef.h \
-@GCONFIG_WINDOWS_FALSE@	gdirectory.h \
-@GCONFIG_WINDOWS_FALSE@	gdirectory.cpp \
-@GCONFIG_WINDOWS_FALSE@	gdirectory_unix.cpp \
-@GCONFIG_WINDOWS_FALSE@	genvironment.h \
-@GCONFIG_WINDOWS_FALSE@	genvironment.cpp \
-@GCONFIG_WINDOWS_FALSE@	genvironment_unix.cpp \
-@GCONFIG_WINDOWS_FALSE@	gexception.h \
-@GCONFIG_WINDOWS_FALSE@	gexception.cpp \
-@GCONFIG_WINDOWS_FALSE@	gexecutablecommand.h \
-@GCONFIG_WINDOWS_FALSE@	gexecutablecommand.cpp \
-@GCONFIG_WINDOWS_FALSE@	gexecutablecommand_unix.cpp \
-@GCONFIG_WINDOWS_FALSE@	gfile.h \
-@GCONFIG_WINDOWS_FALSE@	gfile.cpp \
-@GCONFIG_WINDOWS_FALSE@	gfile_unix.cpp \
-@GCONFIG_WINDOWS_FALSE@	gformat.h \
-@GCONFIG_WINDOWS_FALSE@	gformat.cpp \
-@GCONFIG_WINDOWS_FALSE@	ggetopt.h \
-@GCONFIG_WINDOWS_FALSE@	ggetopt.cpp \
-@GCONFIG_WINDOWS_FALSE@	ggettext.h \
-@GCONFIG_WINDOWS_FALSE@	ghash.h \
-@GCONFIG_WINDOWS_FALSE@	ghash.cpp \
-@GCONFIG_WINDOWS_FALSE@	ghostname.h \
-@GCONFIG_WINDOWS_FALSE@	ghostname_unix.cpp \
-@GCONFIG_WINDOWS_FALSE@	gidentity.h \
-@GCONFIG_WINDOWS_FALSE@	gidentity_unix.cpp \
-@GCONFIG_WINDOWS_FALSE@	gimembuf.h \
-@GCONFIG_WINDOWS_FALSE@	glimits.h \
-@GCONFIG_WINDOWS_FALSE@	glog.h \
-@GCONFIG_WINDOWS_FALSE@	glog.cpp \
-@GCONFIG_WINDOWS_FALSE@	glogoutput.h \
-@GCONFIG_WINDOWS_FALSE@	glogoutput.cpp \
-@GCONFIG_WINDOWS_FALSE@	glogoutput_unix.cpp \
-@GCONFIG_WINDOWS_FALSE@	gmapfile.h \
-@GCONFIG_WINDOWS_FALSE@	gmapfile.cpp \
-@GCONFIG_WINDOWS_FALSE@	gmd5.h \
-@GCONFIG_WINDOWS_FALSE@	gmd5.cpp \
-@GCONFIG_WINDOWS_FALSE@	gmsg_unix.cpp \
-@GCONFIG_WINDOWS_FALSE@	gmsg.h \
-@GCONFIG_WINDOWS_FALSE@	gnewprocess.h \
-@GCONFIG_WINDOWS_FALSE@	gnewprocess_unix.cpp \
-@GCONFIG_WINDOWS_FALSE@	gomembuf.h \
-@GCONFIG_WINDOWS_FALSE@	goptional.h \
-@GCONFIG_WINDOWS_FALSE@	goptionmap.h \
-@GCONFIG_WINDOWS_FALSE@	goptionmap.cpp \
-@GCONFIG_WINDOWS_FALSE@	goptionparser.h \
-@GCONFIG_WINDOWS_FALSE@	goptionparser.cpp \
-@GCONFIG_WINDOWS_FALSE@	goptions.h \
-@GCONFIG_WINDOWS_FALSE@	goptions.cpp \
-@GCONFIG_WINDOWS_FALSE@	goptionvalue.h \
-@GCONFIG_WINDOWS_FALSE@	gpam.h \
-@GCONFIG_WINDOWS_FALSE@	gpath.h \
-@GCONFIG_WINDOWS_FALSE@	gpath.cpp \
-@GCONFIG_WINDOWS_FALSE@	gpidfile.h \
-@GCONFIG_WINDOWS_FALSE@	gpidfile.cpp \
-@GCONFIG_WINDOWS_FALSE@	gprocess.h \
-@GCONFIG_WINDOWS_FALSE@	gprocess_unix.cpp \
-@GCONFIG_WINDOWS_FALSE@	grandom.h \
-@GCONFIG_WINDOWS_FALSE@	grandom.cpp \
-@GCONFIG_WINDOWS_FALSE@	greadwrite.h \
-@GCONFIG_WINDOWS_FALSE@	greadwrite.cpp \
-@GCONFIG_WINDOWS_FALSE@	groot.h \
-@GCONFIG_WINDOWS_FALSE@	groot.cpp \
-@GCONFIG_WINDOWS_FALSE@	gscope.h \
-@GCONFIG_WINDOWS_FALSE@	gsignalsafe.h \
-@GCONFIG_WINDOWS_FALSE@	gsleep.h \
-@GCONFIG_WINDOWS_FALSE@	gslot.h \
-@GCONFIG_WINDOWS_FALSE@	gslot.cpp \
-@GCONFIG_WINDOWS_FALSE@	gstatemachine.h \
-@GCONFIG_WINDOWS_FALSE@	gstr.h \
-@GCONFIG_WINDOWS_FALSE@	gstr.cpp \
-@GCONFIG_WINDOWS_FALSE@	gstrings.h \
-@GCONFIG_WINDOWS_FALSE@	gstringwrap.cpp \
-@GCONFIG_WINDOWS_FALSE@	gstringwrap.h \
-@GCONFIG_WINDOWS_FALSE@	gstringview.h \
-@GCONFIG_WINDOWS_FALSE@	gtest.h \
-@GCONFIG_WINDOWS_FALSE@	gtest.cpp \
-@GCONFIG_WINDOWS_FALSE@	gthread.cpp \
-@GCONFIG_WINDOWS_FALSE@	gtime.h \
-@GCONFIG_WINDOWS_FALSE@	gtime.cpp \
-@GCONFIG_WINDOWS_FALSE@	gxtext.h \
-@GCONFIG_WINDOWS_FALSE@	gxtext.cpp
+COMMON_SOURCES = \
+	galign.h \
+	garg.h \
+	garg.cpp \
+	gassert.h \
+	gbase64.h \
+	gbase64.cpp \
+	gbatchfile.h \
+	gbatchfile.cpp \
+	gbuffer.h \
+	gcall.h \
+	gcleanup.h \
+	gconvert.h \
+	gconvert.cpp \
+	gdaemon.h \
+	gdate.h \
+	gdate.cpp \
+	gdatetime.h \
+	gdatetime.cpp \
+	gdef.h \
+	gdirectory.h \
+	gdirectory.cpp \
+	geightbit.h \
+	genvironment.h \
+	genvironment.cpp \
+	gexception.h \
+	gexception.cpp \
+	gexecutablecommand.h \
+	gexecutablecommand.cpp \
+	gfbuf.h \
+	gfile.h \
+	gfile.cpp \
+	gformat.h \
+	gformat.cpp \
+	ggetopt.h \
+	ggetopt.cpp \
+	ghash.h \
+	ghash.cpp \
+	ghashstate.h \
+	ghostname.h \
+	gidentity.h \
+	gimembuf.h \
+	glimits.h \
+	glog.h \
+	glog.cpp \
+	glogstream.h \
+	glogstream.cpp \
+	glogoutput.h \
+	glogoutput.cpp \
+	gstrmacros.h \
+	gmapfile.h \
+	gmapfile.cpp \
+	gmd5.h \
+	gmd5.cpp \
+	gmsg.h \
+	gnewprocess.h \
+	gomembuf.h \
+	goptional.h \
+	goption.h \
+	goption.cpp \
+	goptionmap.h \
+	goptionmap.cpp \
+	goptionparser.h \
+	goptionparser.cpp \
+	goptions.h \
+	goptions.cpp \
+	goptionsusage.h \
+	goptionsusage.cpp \
+	goptionvalue.h \
+	gpath.h \
+	gpath.cpp \
+	gpidfile.h \
+	gpidfile.cpp \
+	gprocess.h \
+	grandom.h \
+	grandom.cpp \
+	greadwrite.h \
+	greadwrite.cpp \
+	groot.h \
+	groot.cpp \
+	gscope.h \
+	gsignalsafe.h \
+	gsleep.h \
+	gslot.h \
+	gslot.cpp \
+	gstatemachine.h \
+	gstr.h \
+	gstr.cpp \
+	gstringarray.h \
+	gstringfield.h \
+	gstringtoken.h \
+	gstringlist.h \
+	gstringlist.cpp \
+	gstringmap.h \
+	gstrings.h \
+	gstringwrap.cpp \
+	gstringwrap.h \
+	gstringview.h \
+	gstringview.cpp \
+	gtest.h \
+	gtest.cpp \
+	gthread.cpp \
+	gtime.h \
+	gtime.cpp \
+	gxtext.h \
+	gxtext.cpp
 
-@GCONFIG_WINDOWS_TRUE@libglib_a_SOURCES = \
-@GCONFIG_WINDOWS_TRUE@	galign.h \
-@GCONFIG_WINDOWS_TRUE@	garg.h \
-@GCONFIG_WINDOWS_TRUE@	garg.cpp \
-@GCONFIG_WINDOWS_TRUE@	gassert.h \
-@GCONFIG_WINDOWS_TRUE@	gbase64.h \
-@GCONFIG_WINDOWS_TRUE@	gbase64.cpp \
-@GCONFIG_WINDOWS_TRUE@	gbatchfile.h \
-@GCONFIG_WINDOWS_TRUE@	gbatchfile.cpp \
-@GCONFIG_WINDOWS_TRUE@	gbuffer.h \
-@GCONFIG_WINDOWS_TRUE@	gcall.h \
-@GCONFIG_WINDOWS_TRUE@	gcleanup.h \
-@GCONFIG_WINDOWS_TRUE@	gcleanup_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	gconvert.h \
-@GCONFIG_WINDOWS_TRUE@	gconvert.cpp \
-@GCONFIG_WINDOWS_TRUE@	gconvert_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	gdaemon.h \
-@GCONFIG_WINDOWS_TRUE@	gdaemon_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	gdate.h \
-@GCONFIG_WINDOWS_TRUE@	gdate.cpp \
-@GCONFIG_WINDOWS_TRUE@	gdatetime.h \
-@GCONFIG_WINDOWS_TRUE@	gdatetime.cpp \
-@GCONFIG_WINDOWS_TRUE@	gdef.h \
-@GCONFIG_WINDOWS_TRUE@	gdirectory.h \
-@GCONFIG_WINDOWS_TRUE@	gdirectory.cpp \
-@GCONFIG_WINDOWS_TRUE@	gdirectory_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	geightbit.h \
-@GCONFIG_WINDOWS_TRUE@	genvironment.h \
-@GCONFIG_WINDOWS_TRUE@	genvironment.cpp \
-@GCONFIG_WINDOWS_TRUE@	genvironment_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	gexception.h \
-@GCONFIG_WINDOWS_TRUE@	gexception.cpp \
-@GCONFIG_WINDOWS_TRUE@	gexecutablecommand.h \
-@GCONFIG_WINDOWS_TRUE@	gexecutablecommand.cpp \
-@GCONFIG_WINDOWS_TRUE@	gexecutablecommand_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	gfile.h \
-@GCONFIG_WINDOWS_TRUE@	gfile.cpp \
-@GCONFIG_WINDOWS_TRUE@	gfile_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	gformat.h \
-@GCONFIG_WINDOWS_TRUE@	gformat.cpp \
-@GCONFIG_WINDOWS_TRUE@	ggetopt.h \
-@GCONFIG_WINDOWS_TRUE@	ggetopt.cpp \
-@GCONFIG_WINDOWS_TRUE@	ggettext.h \
-@GCONFIG_WINDOWS_TRUE@	ghash.h \
-@GCONFIG_WINDOWS_TRUE@	ghash.cpp \
-@GCONFIG_WINDOWS_TRUE@	ghashstate.h \
-@GCONFIG_WINDOWS_TRUE@	ghostname.h \
-@GCONFIG_WINDOWS_TRUE@	ghostname_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	gidentity.h \
-@GCONFIG_WINDOWS_TRUE@	gidentity_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	gimembuf.h \
-@GCONFIG_WINDOWS_TRUE@	glimits.h \
-@GCONFIG_WINDOWS_TRUE@	glog.h \
-@GCONFIG_WINDOWS_TRUE@	glog.cpp \
-@GCONFIG_WINDOWS_TRUE@	glogoutput.h \
-@GCONFIG_WINDOWS_TRUE@	glogoutput.cpp \
-@GCONFIG_WINDOWS_TRUE@	glogoutput_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	gstrmacros.h \
-@GCONFIG_WINDOWS_TRUE@	gmapfile.h \
-@GCONFIG_WINDOWS_TRUE@	gmapfile.cpp \
-@GCONFIG_WINDOWS_TRUE@	gmd5.h \
-@GCONFIG_WINDOWS_TRUE@	gmd5.cpp \
-@GCONFIG_WINDOWS_TRUE@	gmsg.h \
-@GCONFIG_WINDOWS_TRUE@	gmsg_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	gnewprocess.h \
-@GCONFIG_WINDOWS_TRUE@	gnewprocess_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	gomembuf.h \
-@GCONFIG_WINDOWS_TRUE@	goptional.h \
-@GCONFIG_WINDOWS_TRUE@	goptionmap.h \
-@GCONFIG_WINDOWS_TRUE@	goptionmap.cpp \
-@GCONFIG_WINDOWS_TRUE@	goptionparser.h \
-@GCONFIG_WINDOWS_TRUE@	goptionparser.cpp \
-@GCONFIG_WINDOWS_TRUE@	goptions.h \
-@GCONFIG_WINDOWS_TRUE@	goptions.cpp \
-@GCONFIG_WINDOWS_TRUE@	goptionvalue.h \
-@GCONFIG_WINDOWS_TRUE@	gpam.h \
-@GCONFIG_WINDOWS_TRUE@	gpam_none.cpp \
-@GCONFIG_WINDOWS_TRUE@	gpath.h \
-@GCONFIG_WINDOWS_TRUE@	gpath.cpp \
-@GCONFIG_WINDOWS_TRUE@	gpidfile.h \
-@GCONFIG_WINDOWS_TRUE@	gpidfile.cpp \
-@GCONFIG_WINDOWS_TRUE@	gprocess.h \
-@GCONFIG_WINDOWS_TRUE@	gprocess_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	grandom.h \
-@GCONFIG_WINDOWS_TRUE@	grandom.cpp \
-@GCONFIG_WINDOWS_TRUE@	greadwrite.h \
-@GCONFIG_WINDOWS_TRUE@	greadwrite.cpp \
-@GCONFIG_WINDOWS_TRUE@	groot.h \
-@GCONFIG_WINDOWS_TRUE@	groot.cpp \
-@GCONFIG_WINDOWS_TRUE@	gscope.h \
-@GCONFIG_WINDOWS_TRUE@	gsignalsafe.h \
-@GCONFIG_WINDOWS_TRUE@	gsleep.h \
-@GCONFIG_WINDOWS_TRUE@	gslot.h \
-@GCONFIG_WINDOWS_TRUE@	gslot.cpp \
-@GCONFIG_WINDOWS_TRUE@	gstatemachine.h \
-@GCONFIG_WINDOWS_TRUE@	gstr.h \
-@GCONFIG_WINDOWS_TRUE@	gstr.cpp \
-@GCONFIG_WINDOWS_TRUE@	gstrings.h \
-@GCONFIG_WINDOWS_TRUE@	gstringwrap.cpp \
-@GCONFIG_WINDOWS_TRUE@	gstringwrap.h \
-@GCONFIG_WINDOWS_TRUE@	gstringview.h \
-@GCONFIG_WINDOWS_TRUE@	gtest.h \
-@GCONFIG_WINDOWS_TRUE@	gtest.cpp \
-@GCONFIG_WINDOWS_TRUE@	gthread.cpp \
-@GCONFIG_WINDOWS_TRUE@	gtime.h \
-@GCONFIG_WINDOWS_TRUE@	gtime.cpp \
-@GCONFIG_WINDOWS_TRUE@	gxtext.h \
-@GCONFIG_WINDOWS_TRUE@	gxtext.cpp
+@GCONFIG_PAM_FALSE@PAM_SOURCES = \
+@GCONFIG_PAM_FALSE@	gpam.h \
+@GCONFIG_PAM_FALSE@	gpam_none.cpp
+
+@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_FALSE@PAM_SOURCES = \
+@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_FALSE@	gpam.h \
+@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_FALSE@	gpam_linux.cpp
+
+
+# -- PAM
+@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_TRUE@PAM_SOURCES = \
+@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_TRUE@	gpam.h \
+@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_TRUE@	gpam_none.cpp
+
+@GCONFIG_PAM_FALSE@PAM_EXTRA_DIST = \
+@GCONFIG_PAM_FALSE@	gpam_linux.cpp
+
+@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_FALSE@PAM_EXTRA_DIST = \
+@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_FALSE@	gpam_none.cpp
+
+@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_TRUE@PAM_EXTRA_DIST = \
+@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_TRUE@	gpam_linux.cpp
+
+@GCONFIG_GETTEXT_FALSE@GETTEXT_SOURCES = \
+@GCONFIG_GETTEXT_FALSE@	ggettext_none.cpp \
+@GCONFIG_GETTEXT_FALSE@	ggettext.h
+
+@GCONFIG_GETTEXT_TRUE@@GCONFIG_WINDOWS_FALSE@GETTEXT_SOURCES = \
+@GCONFIG_GETTEXT_TRUE@@GCONFIG_WINDOWS_FALSE@	ggettext.h \
+@GCONFIG_GETTEXT_TRUE@@GCONFIG_WINDOWS_FALSE@	ggettext_unix.cpp
+
+
+# -- GETTEXT
+@GCONFIG_GETTEXT_TRUE@@GCONFIG_WINDOWS_TRUE@GETTEXT_SOURCES = \
+@GCONFIG_GETTEXT_TRUE@@GCONFIG_WINDOWS_TRUE@	ggettext.h \
+@GCONFIG_GETTEXT_TRUE@@GCONFIG_WINDOWS_TRUE@	ggettext_win32.cpp
+
+@GCONFIG_GETTEXT_FALSE@GETTEXT_EXTRA_DIST = \
+@GCONFIG_GETTEXT_FALSE@	ggettext_win32.cpp \
+@GCONFIG_GETTEXT_FALSE@	ggettext_unix.cpp
+
+@GCONFIG_GETTEXT_TRUE@@GCONFIG_WINDOWS_FALSE@GETTEXT_EXTRA_DIST = \
+@GCONFIG_GETTEXT_TRUE@@GCONFIG_WINDOWS_FALSE@	ggettext_none.cpp \
+@GCONFIG_GETTEXT_TRUE@@GCONFIG_WINDOWS_FALSE@	ggettext_win32.cpp
+
+@GCONFIG_GETTEXT_TRUE@@GCONFIG_WINDOWS_TRUE@GETTEXT_EXTRA_DIST = \
+@GCONFIG_GETTEXT_TRUE@@GCONFIG_WINDOWS_TRUE@	ggettext_none.cpp \
+@GCONFIG_GETTEXT_TRUE@@GCONFIG_WINDOWS_TRUE@	ggettext_unix.cpp
+
+@GCONFIG_WINDOWS_FALSE@OS_SOURCES = \
+@GCONFIG_WINDOWS_FALSE@	$(COMMON_SOURCES) \
+@GCONFIG_WINDOWS_FALSE@	$(UNIX_SOURCES)
+
+
+# -- OS
+@GCONFIG_WINDOWS_TRUE@OS_SOURCES = \
+@GCONFIG_WINDOWS_TRUE@	$(COMMON_SOURCES) \
+@GCONFIG_WINDOWS_TRUE@	$(WINDOWS_SOURCES)
+
+@GCONFIG_WINDOWS_FALSE@OS_EXTRA_DIST = \
+@GCONFIG_WINDOWS_FALSE@	$(WINDOWS_SOURCES)
+
+@GCONFIG_WINDOWS_TRUE@OS_EXTRA_DIST = \
+@GCONFIG_WINDOWS_TRUE@	$(UNIX_SOURCES)
+
+
+# ===
+libglib_a_SOURCES = \
+	$(GETTEXT_SOURCES) \
+	$(OS_SOURCES) \
+	$(PAM_SOURCES)
+
+EXTRA_DIST = \
+	$(GETTEXT_EXTRA_DIST) \
+	$(OS_EXTRA_DIST) \
+	$(PAM_EXTRA_DIST)
 
-@GCONFIG_PAM_FALSE@@GCONFIG_WINDOWS_FALSE@PAM_EXTRA_DIST = gpam_linux.cpp
-@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_FALSE@PAM_EXTRA_DIST = gpam_none.cpp
-@GCONFIG_PAM_FALSE@@GCONFIG_WINDOWS_FALSE@PAM_SOURCES = gpam_none.cpp
-@GCONFIG_PAM_TRUE@@GCONFIG_WINDOWS_FALSE@PAM_SOURCES = gpam_linux.cpp
 all: all-am
 
 .SUFFIXES:
@@ -740,6 +688,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gcleanup_unix.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gcleanup_win32.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gconvert.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gconvert_unix.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gconvert_win32.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gdaemon_unix.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gdaemon_win32.Po@am__quote@ # am--include-marker
@@ -760,6 +709,9 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gfile_win32.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gformat.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ggetopt.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ggettext_none.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ggettext_unix.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ggettext_win32.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ghash.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ghostname_unix.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ghostname_win32.Po@am__quote@ # am--include-marker
@@ -769,15 +721,18 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/glogoutput.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/glogoutput_unix.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/glogoutput_win32.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/glogstream.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gmapfile.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gmd5.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gmsg_unix.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gmsg_win32.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gnewprocess_unix.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gnewprocess_win32.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/goption.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/goptionmap.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/goptionparser.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/goptions.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/goptionsusage.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gpam_linux.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gpam_none.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gpath.Po@am__quote@ # am--include-marker
@@ -789,6 +744,8 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/groot.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gslot.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gstr.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gstringlist.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gstringview.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gstringwrap.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gtest.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gthread.Po@am__quote@ # am--include-marker
@@ -945,6 +902,7 @@ distclean: distclean-am
 	-rm -f ./$(DEPDIR)/gcleanup_unix.Po
 	-rm -f ./$(DEPDIR)/gcleanup_win32.Po
 	-rm -f ./$(DEPDIR)/gconvert.Po
+	-rm -f ./$(DEPDIR)/gconvert_unix.Po
 	-rm -f ./$(DEPDIR)/gconvert_win32.Po
 	-rm -f ./$(DEPDIR)/gdaemon_unix.Po
 	-rm -f ./$(DEPDIR)/gdaemon_win32.Po
@@ -965,6 +923,9 @@ distclean: distclean-am
 	-rm -f ./$(DEPDIR)/gfile_win32.Po
 	-rm -f ./$(DEPDIR)/gformat.Po
 	-rm -f ./$(DEPDIR)/ggetopt.Po
+	-rm -f ./$(DEPDIR)/ggettext_none.Po
+	-rm -f ./$(DEPDIR)/ggettext_unix.Po
+	-rm -f ./$(DEPDIR)/ggettext_win32.Po
 	-rm -f ./$(DEPDIR)/ghash.Po
 	-rm -f ./$(DEPDIR)/ghostname_unix.Po
 	-rm -f ./$(DEPDIR)/ghostname_win32.Po
@@ -974,15 +935,18 @@ distclean: distclean-am
 	-rm -f ./$(DEPDIR)/glogoutput.Po
 	-rm -f ./$(DEPDIR)/glogoutput_unix.Po
 	-rm -f ./$(DEPDIR)/glogoutput_win32.Po
+	-rm -f ./$(DEPDIR)/glogstream.Po
 	-rm -f ./$(DEPDIR)/gmapfile.Po
 	-rm -f ./$(DEPDIR)/gmd5.Po
 	-rm -f ./$(DEPDIR)/gmsg_unix.Po
 	-rm -f ./$(DEPDIR)/gmsg_win32.Po
 	-rm -f ./$(DEPDIR)/gnewprocess_unix.Po
 	-rm -f ./$(DEPDIR)/gnewprocess_win32.Po
+	-rm -f ./$(DEPDIR)/goption.Po
 	-rm -f ./$(DEPDIR)/goptionmap.Po
 	-rm -f ./$(DEPDIR)/goptionparser.Po
 	-rm -f ./$(DEPDIR)/goptions.Po
+	-rm -f ./$(DEPDIR)/goptionsusage.Po
 	-rm -f ./$(DEPDIR)/gpam_linux.Po
 	-rm -f ./$(DEPDIR)/gpam_none.Po
 	-rm -f ./$(DEPDIR)/gpath.Po
@@ -994,6 +958,8 @@ distclean: distclean-am
 	-rm -f ./$(DEPDIR)/groot.Po
 	-rm -f ./$(DEPDIR)/gslot.Po
 	-rm -f ./$(DEPDIR)/gstr.Po
+	-rm -f ./$(DEPDIR)/gstringlist.Po
+	-rm -f ./$(DEPDIR)/gstringview.Po
 	-rm -f ./$(DEPDIR)/gstringwrap.Po
 	-rm -f ./$(DEPDIR)/gtest.Po
 	-rm -f ./$(DEPDIR)/gthread.Po
@@ -1050,6 +1016,7 @@ maintainer-clean: maintainer-clean-am
 	-rm -f ./$(DEPDIR)/gcleanup_unix.Po
 	-rm -f ./$(DEPDIR)/gcleanup_win32.Po
 	-rm -f ./$(DEPDIR)/gconvert.Po
+	-rm -f ./$(DEPDIR)/gconvert_unix.Po
 	-rm -f ./$(DEPDIR)/gconvert_win32.Po
 	-rm -f ./$(DEPDIR)/gdaemon_unix.Po
 	-rm -f ./$(DEPDIR)/gdaemon_win32.Po
@@ -1070,6 +1037,9 @@ maintainer-clean: maintainer-clean-am
 	-rm -f ./$(DEPDIR)/gfile_win32.Po
 	-rm -f ./$(DEPDIR)/gformat.Po
 	-rm -f ./$(DEPDIR)/ggetopt.Po
+	-rm -f ./$(DEPDIR)/ggettext_none.Po
+	-rm -f ./$(DEPDIR)/ggettext_unix.Po
+	-rm -f ./$(DEPDIR)/ggettext_win32.Po
 	-rm -f ./$(DEPDIR)/ghash.Po
 	-rm -f ./$(DEPDIR)/ghostname_unix.Po
 	-rm -f ./$(DEPDIR)/ghostname_win32.Po
@@ -1079,15 +1049,18 @@ maintainer-clean: maintainer-clean-am
 	-rm -f ./$(DEPDIR)/glogoutput.Po
 	-rm -f ./$(DEPDIR)/glogoutput_unix.Po
 	-rm -f ./$(DEPDIR)/glogoutput_win32.Po
+	-rm -f ./$(DEPDIR)/glogstream.Po
 	-rm -f ./$(DEPDIR)/gmapfile.Po
 	-rm -f ./$(DEPDIR)/gmd5.Po
 	-rm -f ./$(DEPDIR)/gmsg_unix.Po
 	-rm -f ./$(DEPDIR)/gmsg_win32.Po
 	-rm -f ./$(DEPDIR)/gnewprocess_unix.Po
 	-rm -f ./$(DEPDIR)/gnewprocess_win32.Po
+	-rm -f ./$(DEPDIR)/goption.Po
 	-rm -f ./$(DEPDIR)/goptionmap.Po
 	-rm -f ./$(DEPDIR)/goptionparser.Po
 	-rm -f ./$(DEPDIR)/goptions.Po
+	-rm -f ./$(DEPDIR)/goptionsusage.Po
 	-rm -f ./$(DEPDIR)/gpam_linux.Po
 	-rm -f ./$(DEPDIR)/gpam_none.Po
 	-rm -f ./$(DEPDIR)/gpath.Po
@@ -1099,6 +1072,8 @@ maintainer-clean: maintainer-clean-am
 	-rm -f ./$(DEPDIR)/groot.Po
 	-rm -f ./$(DEPDIR)/gslot.Po
 	-rm -f ./$(DEPDIR)/gstr.Po
+	-rm -f ./$(DEPDIR)/gstringlist.Po
+	-rm -f ./$(DEPDIR)/gstringview.Po
 	-rm -f ./$(DEPDIR)/gstringwrap.Po
 	-rm -f ./$(DEPDIR)/gtest.Po
 	-rm -f ./$(DEPDIR)/gthread.Po
diff --git a/src/glib/galign.h b/src/glib/galign.h
index 52cbe49..9de579d 100644
--- a/src/glib/galign.h
+++ b/src/glib/galign.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -63,27 +63,33 @@ namespace G
 		}
 	}
 
+	/// \code
 	/// Returns a pointer inside the given buffer that is aligned for
 	/// values of type T.
 	///
+	/// \endcode
 	template <typename T>
 	inline void * align( const char * buffer , std::size_t buffer_size )
 	{
 		return AlignImp::align_imp<T>( buffer , buffer_size ) ;
 	}
 
+	/// \code
 	/// Returns a pointer inside the given unsigned-char buffer that
 	/// is aligned for values of type T.
 	///
+	/// \endcode
 	template <typename T>
 	inline void * align( const unsigned char * buffer , std::size_t buffer_size )
 	{
 		return AlignImp::align_imp<T>( buffer , buffer_size ) ;
 	}
 
+	/// \code
 	/// Divides the number of bytes in a range to give the number
 	/// of whole Ts.
 	///
+	/// \endcode
 	template <typename T>
 	inline
 	constexpr std::size_t align_shift( std::size_t n )
@@ -91,9 +97,11 @@ namespace G
 		return AlignImp::shift<T>( n ) ;
 	}
 
+	/// \code
 	/// Rounds down the number of bytes in a range to give a number of
 	/// bytes that will hold an exact number of Ts.
 	///
+	/// \endcode
 	template <typename T>
 	inline
 	constexpr std::size_t align_mask( std::size_t n )
diff --git a/src/glib/garg.cpp b/src/glib/garg.cpp
index 00ac2e5..d247d30 100644
--- a/src/glib/garg.cpp
+++ b/src/glib/garg.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/garg.h b/src/glib/garg.h
index ad30dab..8a6aae6 100644
--- a/src/glib/garg.h
+++ b/src/glib/garg.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gassert.h b/src/glib/gassert.h
index 6079e63..c246ad7 100644
--- a/src/glib/gassert.h
+++ b/src/glib/gassert.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gbase64.cpp b/src/glib/gbase64.cpp
index f6280c1..e53d5f9 100644
--- a/src/glib/gbase64.cpp
+++ b/src/glib/gbase64.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -35,24 +35,22 @@ namespace G
 		using uint32_type = g_uint32_t ;
 		#endif
 
-		static constexpr string_view character_map_with_pad( "=ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-			"abcdefghijklmnopqrstuvwxyz" "0123456789+/" , nullptr ) ;
+		static constexpr string_view character_map_with_pad = "=ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"_sv ;
 		static constexpr string_view character_map( character_map_with_pad.data()+1 , character_map_with_pad.size()-1 ) ;
 		static constexpr char pad = '=' ;
 
 		static_assert( character_map_with_pad.size() == 1+26+26+10+2 , "" ) ;
 		static_assert( character_map.size() == 26+26+10+2 , "" ) ;
 
-		using string_in = string_view ;
 		using iterator_in = string_view::const_iterator ;
 		using iterator_out = std::back_insert_iterator<std::string> ;
 
-		std::string encode( string_in , string_in eol ) ;
-		std::string decode( string_in , bool do_throw , bool strict ) ;
-		bool valid( string_in , bool strict ) ;
+		std::string encode( string_view , string_view eol ) ;
+		std::string decode( string_view , bool do_throw , bool strict ) ;
+		bool valid( string_view , bool strict ) ;
 
-		void encode_imp( iterator_out , string_in , string_in , std::size_t ) ;
-		void decode_imp( iterator_out , string_in s , bool & error ) ;
+		void encode_imp( iterator_out , string_view , string_view , std::size_t ) ;
+		void decode_imp( iterator_out , string_view s , bool & error ) ;
 		void generate_6( uint32_type & n , int & i , iterator_out & ) ;
 		void accumulate_8( uint32_type & n , iterator_in & , iterator_in , int & ) ;
 		void accumulate_6( g_uint32_t & n , iterator_in & , iterator_in , std::size_t & , bool & error ) ;
@@ -81,24 +79,24 @@ namespace G
 
 // ==
 
-std::string G::Base64::encode( const std::string & s , const std::string & eol )
+std::string G::Base64::encode( string_view s , string_view eol )
 {
-	return Base64Imp::encode( {s.data(),s.size()} , {eol.data(),eol.size()} ) ;
+	return Base64Imp::encode( s , eol ) ;
 }
 
-std::string G::Base64::decode( const std::string & s , bool do_throw , bool strict )
+std::string G::Base64::decode( string_view s , bool do_throw , bool strict )
 {
-	return Base64Imp::decode( {s.data(),s.size()} , do_throw , strict ) ;
+	return Base64Imp::decode( s , do_throw , strict ) ;
 }
 
-bool G::Base64::valid( const std::string & s , bool strict )
+bool G::Base64::valid( string_view s , bool strict )
 {
-	return Base64Imp::valid( {s.data(),s.size()} , strict ) ;
+	return Base64Imp::valid( s , strict ) ;
 }
 
 // ==
 
-std::string G::Base64Imp::encode( string_in input , string_in eol )
+std::string G::Base64Imp::encode( string_view input , string_view eol )
 {
 	std::string result ;
 	result.reserve( input.size() + input.size()/2U ) ;
@@ -106,7 +104,7 @@ std::string G::Base64Imp::encode( string_in input , string_in eol )
 	return result ;
 }
 
-void G::Base64Imp::encode_imp( iterator_out result_p , string_in input , string_in eol , std::size_t blocks_per_line )
+void G::Base64Imp::encode_imp( iterator_out result_p , string_view input , string_view eol , std::size_t blocks_per_line )
 {
 	std::size_t blocks = 0U ;
 	auto const end = input.end() ;
@@ -127,7 +125,7 @@ void G::Base64Imp::encode_imp( iterator_out result_p , string_in input , string_
 	}
 }
 
-std::string G::Base64Imp::decode( string_in input , bool do_throw , bool strict )
+std::string G::Base64Imp::decode( string_view input , bool do_throw , bool strict )
 {
 	bool error = false ;
 	if( strict && !strictlyValid(input) )
@@ -145,7 +143,7 @@ std::string G::Base64Imp::decode( string_in input , bool do_throw , bool strict
 	return result ;
 }
 
-void G::Base64Imp::decode_imp( iterator_out result_p , string_in s , bool & error )
+void G::Base64Imp::decode_imp( iterator_out result_p , string_view s , bool & error )
 {
 	auto const end = s.end() ;
 	for( auto p = s.begin() ; p != end ; )
@@ -170,7 +168,7 @@ void G::Base64Imp::decode_imp( iterator_out result_p , string_in s , bool & erro
 	}
 }
 
-bool G::Base64Imp::valid( string_in input , bool strict )
+bool G::Base64Imp::valid( string_view input , bool strict )
 {
 	if( strict && !strictlyValid(input) )
 		return false ;
diff --git a/src/glib/gbase64.h b/src/glib/gbase64.h
index 4728f51..feca457 100644
--- a/src/glib/gbase64.h
+++ b/src/glib/gbase64.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,6 +23,7 @@
 
 #include "gdef.h"
 #include "gexception.h"
+#include "gstringview.h"
 #include <string>
 
 namespace G
@@ -37,17 +38,17 @@ namespace G
 class G::Base64
 {
 public:
-	G_EXCEPTION( Error , "base64 encoding error" ) ;
+	G_EXCEPTION( Error , tx("base64 encoding error") ) ;
 
-	static std::string encode( const std::string & s , const std::string & line_break = std::string() ) ;
+	static std::string encode( string_view , string_view line_break = {} ) ;
 		///< Encodes the given string, optionally inserting line-breaks
 		///< to limit the line length.
 
-	static std::string decode( const std::string & , bool throw_on_invalid = false , bool strict = true ) ;
+	static std::string decode( string_view , bool throw_on_invalid = false , bool strict = true ) ;
 		///< Decodes the given string. Either throws an exception if
 		///< not a valid() encoding, or returns the empty string.
 
-	static bool valid( const std::string & , bool strict = true ) ;
+	static bool valid( string_view , bool strict = true ) ;
 		///< Returns true if the string is a valid base64 encoding,
 		///< possibly allowing for embedded newlines, carriage returns,
 		///< and space characters. Strict checking permits one or
diff --git a/src/glib/gbatchfile.cpp b/src/glib/gbatchfile.cpp
index 5487a6c..e95dffb 100644
--- a/src/glib/gbatchfile.cpp
+++ b/src/glib/gbatchfile.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gbatchfile.h b/src/glib/gbatchfile.h
index 4220482..3a89100 100644
--- a/src/glib/gbatchfile.h
+++ b/src/glib/gbatchfile.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,7 +23,7 @@
 
 #include "gdef.h"
 #include "gpath.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gexception.h"
 #include <iostream>
 #include <string>
@@ -39,10 +39,17 @@ namespace G
 /// A class for reading and writing windows-style startup batch files
 /// containing a single command-line, optionally using "start".
 ///
+/// Eg:
+/// \code
+///  @echo off
+///  rem a windows batch file
+///  start "my app" "c:\my app\run.exe" arg-one "arg two"
+/// \endcode
+///
 class G::BatchFile
 {
 public:
-	G_EXCEPTION( Error , "batch file error" ) ;
+	G_EXCEPTION( Error , tx("batch file error") ) ;
 
 	explicit BatchFile( const Path & ) ;
 		///< Constructor that reads from a file.
@@ -51,7 +58,7 @@ public:
 		///< Constructor that reads from a file that might be missing
 		///< or empty.
 
-	explicit BatchFile( std::istream & , const std::string & stream_name = std::string() ) ;
+	explicit BatchFile( std::istream & , const std::string & stream_name = {} ) ;
 		///< Constructor that reads from a stream.
 
 	std::string line() const ;
@@ -69,7 +76,7 @@ public:
 		///< Returns the position in line() where the arguments start.
 
 	static void write( const Path & , const StringArray & args ,
-		const std::string & start_window_name = std::string() ) ;
+		const std::string & start_window_name = {} ) ;
 			///< Writes a startup batch file, including a "start" prefix.
 			///< If the "start" window name is not supplied then it is
 			///< derived from the command-line.
diff --git a/src/glib/gbuffer.h b/src/glib/gbuffer.h
index 2d44a21..d003f67 100644
--- a/src/glib/gbuffer.h
+++ b/src/glib/gbuffer.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gcall.h b/src/glib/gcall.h
index cf85d13..049166e 100644
--- a/src/glib/gcall.h
+++ b/src/glib/gcall.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -47,6 +47,7 @@ namespace G
 ///   void do_stuff()
 ///   {
 ///      CallFrame this_( m_stack ) ;
+///      do_some_stuff() ;
 ///      emit( "doing stuff" ) ; // call client code - can do anything
 ///      if( this_.deleted() ) return ; // just in case
 ///      do_more_stuff() ;
@@ -72,8 +73,8 @@ public:
 public:
 	CallStack( const CallStack & ) = delete ;
 	CallStack( CallStack && ) = delete ;
-	void operator=( const CallStack & ) = delete ;
-	void operator=( CallStack && ) = delete ;
+	CallStack & operator=( const CallStack & ) = delete ;
+	CallStack & operator=( CallStack && ) = delete ;
 
 private:
 	CallFrame * m_inner{nullptr} ;
@@ -110,8 +111,8 @@ public:
 public:
 	CallFrame( const CallFrame & ) = delete ;
 	CallFrame( CallFrame && ) = delete ;
-	void operator=( const CallFrame & ) = delete ;
-	void operator=( CallFrame && ) = delete ;
+	CallFrame & operator=( const CallFrame & ) = delete ;
+	CallFrame & operator=( CallFrame && ) = delete ;
 
 private:
 	CallStack & m_stack ;
diff --git a/src/glib/gcleanup.h b/src/glib/gcleanup.h
index 9818cdb..ff36e88 100644
--- a/src/glib/gcleanup.h
+++ b/src/glib/gcleanup.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -39,7 +39,7 @@ namespace G
 class G::Cleanup
 {
 public:
-	G_EXCEPTION( Error , "cleanup error" ) ;
+	G_EXCEPTION( Error , tx("cleanup error") ) ;
 	struct Block /// A RAII class to temporarily block signal delivery.
 	{
 		explicit Block( bool active = true ) noexcept ;
@@ -47,8 +47,8 @@ public:
 		bool m_active ;
 		Block( const Block & ) = delete ;
 		Block( Block && ) = delete ;
-		void operator=( const Block & ) = delete ;
-		void operator=( Block && ) = delete ;
+		Block & operator=( const Block & ) = delete ;
+		Block & operator=( Block && ) = delete ;
 	} ;
 
 	static void init() ;
diff --git a/src/glib/gcleanup_unix.cpp b/src/glib/gcleanup_unix.cpp
index de652f7..ec9bc85 100644
--- a/src/glib/gcleanup_unix.cpp
+++ b/src/glib/gcleanup_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gcleanup_win32.cpp b/src/glib/gcleanup_win32.cpp
index ec36eef..41cd39e 100644
--- a/src/glib/gcleanup_win32.cpp
+++ b/src/glib/gcleanup_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gconvert.cpp b/src/glib/gconvert.cpp
index ff8a174..d009f04 100644
--- a/src/glib/gconvert.cpp
+++ b/src/glib/gconvert.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gconvert.h b/src/glib/gconvert.h
index ecfc99f..d79779c 100644
--- a/src/glib/gconvert.h
+++ b/src/glib/gconvert.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -61,7 +61,7 @@ namespace G
 class G::Convert
 {
 public:
-	G_EXCEPTION_CLASS( Error , "string character-set conversion error" ) ;
+	G_EXCEPTION_CLASS( Error , tx("string character-set conversion error") ) ;
 	using tstring = std::basic_string<TCHAR> ;
 
 	struct utf8 /// A string wrapper that indicates UTF-8 encoding.
diff --git a/src/glib/gconvert_unix.cpp b/src/glib/gconvert_unix.cpp
new file mode 100644
index 0000000..e60120f
--- /dev/null
+++ b/src/glib/gconvert_unix.cpp
@@ -0,0 +1,42 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file gconvert_none.cpp
+///
+
+#include "gdef.h"
+#include "gconvert.h"
+#include "glog.h"
+
+std::wstring G::Convert::widen( const std::string & s , bool utf8 , const std::string & /*context*/ )
+{
+	if( utf8 ) G_WARNING_ONCE( "G::Convert::widen: utf8 character-set conversions not supported" ) ;
+	std::wstring result ;
+	for( char c : s )
+		result.append( 1U , static_cast<wchar_t>(c) ) ;
+	return result ;
+}
+
+std::string G::Convert::narrow( const std::wstring & s , bool utf8 , const std::string & /*context*/ )
+{
+	if( utf8 ) G_WARNING_ONCE( "G::Convert::narrow: utf8 character-set conversions not supported" ) ;
+	std::string result ;
+	for( wchar_t wc : s )
+		result.append( 1U , static_cast<char>(wc) ) ;
+	return result ;
+}
+
diff --git a/src/glib/gconvert_win32.cpp b/src/glib/gconvert_win32.cpp
index 7a79ae6..61ee1a0 100644
--- a/src/glib/gconvert_win32.cpp
+++ b/src/glib/gconvert_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gdaemon.h b/src/glib/gdaemon.h
index c385ae2..a1b2f89 100644
--- a/src/glib/gdaemon.h
+++ b/src/glib/gdaemon.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -45,19 +45,11 @@ public:
 	static void detach() ;
 		///< Detaches from the parent environment. This typically
 		///< involves fork()ing, std::_Exit()ing the parent, and calling
-		///< setsid() in the child.
+		///< setsid() in the child. See also G::PidFile.
 
-	static void detach( PidFile & pid_file ) ;
-		///< An overload which allows for a delayed write of the
-		///< new process-id to a file.
-		///<
-		///< A delayed write is useful for network daemons that open
-		///< a listening port. A second instance of the process will
-		///< fail on startup, and should not overwrite the pid file
-		///< of the running server. In this situation PidFile::commit()
-		///< should be called just before entering the event loop.
-		///<
-		///< Throws PidFile::Error on error.
+	static void detach( const G::Path & pid_file ) ;
+		///< Does a detach() but the calling process waits a while
+		///< for the pid file to be created before it exits.
 
 public:
 	Daemon() = delete ;
diff --git a/src/glib/gdaemon_unix.cpp b/src/glib/gdaemon_unix.cpp
index 14730e8..309f894 100644
--- a/src/glib/gdaemon_unix.cpp
+++ b/src/glib/gdaemon_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,20 +21,44 @@
 #include "gdef.h"
 #include "gdaemon.h"
 #include "gprocess.h"
+#include "gfile.h"
 #include "gnewprocess.h"
+#include <chrono>
+#include <thread>
 
-void G::Daemon::detach( PidFile & pid_file )
+namespace G
 {
-	pid_file.check() ; // absolute path
-	detach() ;
+	namespace DaemonImp
+	{
+		void waitfor( const G::Path & pid_file )
+		{
+			if( !pid_file.empty() )
+			{
+				for( int i = 0 ; i < 100 ; i++ )
+				{
+					if( G::File::exists( pid_file , std::nothrow ) )
+						break ;
+					std::this_thread::sleep_for( std::chrono::milliseconds(10) ) ;
+				}
+			}
+		}
+	}
 }
 
 void G::Daemon::detach()
+{
+	detach( G::Path() ) ;
+}
+
+void G::Daemon::detach( const G::Path & pid_file )
 {
 	// see Stevens, ISBN 0-201-563137-7, ch 13.
 
 	if( !NewProcess::fork().first )
+	{
+		DaemonImp::waitfor( pid_file ) ; // because systemd
 		std::_Exit( 0 ) ; // exit from parent
+	}
 
 	setsid() ;
 	Process::cd( "/" , std::nothrow ) ;
diff --git a/src/glib/gdaemon_win32.cpp b/src/glib/gdaemon_win32.cpp
index 19bbfd7..58b0da5 100644
--- a/src/glib/gdaemon_win32.cpp
+++ b/src/glib/gdaemon_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,13 +22,13 @@
 #include "gdaemon.h"
 #include "gprocess.h"
 
-void G::Daemon::detach( PidFile & )
-{
-	detach() ;
-}
-
 void G::Daemon::detach()
 {
 	// no-op
 }
 
+void G::Daemon::detach( const G::Path & )
+{
+	detach() ;
+}
+
diff --git a/src/glib/gdate.cpp b/src/glib/gdate.cpp
index 62157d7..d931b46 100644
--- a/src/glib/gdate.cpp
+++ b/src/glib/gdate.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -20,18 +20,18 @@
 
 #include "gdef.h"
 #include "gdate.h"
+#include "gstr.h"
 #include "glog.h"
 #include "gassert.h"
 #include <ctime>
-#include <iomanip>
-#include <sstream>
 
-int G::Date::yearUpperLimit()
+int G::Date::yearUpperLimit() noexcept
 {
-	return 2035 ; // see mktime()
+	//return 2035 ; // see mktime()
+	return 9999 ;
 }
 
-int G::Date::yearLowerLimit()
+int G::Date::yearLowerLimit() noexcept
 {
 	return 1970 ; // see mktime()
 }
@@ -39,26 +39,41 @@ int G::Date::yearLowerLimit()
 G::Date::Date()
 {
 	init( SystemTime::now().utc() ) ;
+	//check() ;
 }
 
 G::Date::Date( SystemTime t )
 {
 	init( t.utc() ) ;
+	//check() ;
 }
 
 G::Date::Date( SystemTime t , const LocalTime & )
 {
 	init( t.local() ) ;
+	//check() ;
 }
 
 G::Date::Date( const BrokenDownTime & tm )
 {
 	init( tm ) ;
+	//check() ;
 }
 
 G::Date::Date( const LocalTime & )
 {
 	init( SystemTime::now().local() ) ;
+	//check() ;
+}
+
+G::Date::Date( int year , Date::Month month , int day_of_month , std::nothrow_t ) noexcept :
+	m_day(day_of_month) ,
+	m_month(static_cast<int>(month)) ,
+	m_year(year)
+{
+	m_day = std::max( 1 , std::min(m_day,31) ) ;
+	m_month = std::max( 1 , std::min(m_month,12) ) ;
+	m_year = std::max( yearLowerLimit() , std::min(m_year,yearUpperLimit()) ) ;
 }
 
 G::Date::Date( int year , Date::Month month , int day_of_month ) :
@@ -66,12 +81,7 @@ G::Date::Date( int year , Date::Month month , int day_of_month ) :
 	m_month(static_cast<int>(month)) ,
 	m_year(year)
 {
-	G_ASSERT( year >= yearLowerLimit() ) ;
-	G_ASSERT( year <= yearUpperLimit() ) ;
-	G_ASSERT( day_of_month > 0 ) ;
-	G_ASSERT( day_of_month < 32 ) ;
-	G_ASSERT( static_cast<int>(month) >= 1 ) ;
-	G_ASSERT( static_cast<int>(month) <= 12 ) ;
+	check() ;
 }
 
 void G::Date::init( const BrokenDownTime & tm )
@@ -81,6 +91,19 @@ void G::Date::init( const BrokenDownTime & tm )
 	m_day = tm.day() ;
 }
 
+void G::Date::check()
+{
+	bool ok =
+		m_year >= yearLowerLimit() &&
+		m_year <= yearUpperLimit() &&
+		m_month >= 1 &&
+		m_month <= 12 &&
+		m_day >= 1 &&
+		m_day <= 31 ;
+	if( !ok )
+		throw DateError( "out of range" ) ;
+}
+
 std::string G::Date::str( Format format ) const
 {
 	std::ostringstream ss ;
@@ -110,16 +133,17 @@ int G::Date::monthday() const
 
 std::string G::Date::dd() const
 {
-	std::ostringstream ss ;
-	ss << std::setw(2) << std::setfill('0') << m_day ;
-	return ss.str() ;
+	return Str::fromInt(std::min(99,std::max(0,m_day))+100).substr(1U) ;
 }
 
 std::string G::Date::mm() const
 {
-	std::ostringstream ss ;
-	ss << std::setw(2) << std::setfill('0') << m_month ;
-	return ss.str() ;
+	return Str::fromInt(std::min(99,std::max(0,m_month))+100).substr(1U) ;
+}
+
+std::string G::Date::yyyy() const
+{
+	return Str::fromInt(std::min(9999,std::max(0,m_year))+10000).substr(1U) ;
 }
 
 G::Date::Weekday G::Date::weekday() const
@@ -135,14 +159,16 @@ G::Date::Weekday G::Date::weekday() const
 
 std::string G::Date::weekdayName( bool brief ) const
 {
-	if( weekday() == Weekday::sunday ) return brief ? "Sun" : "Sunday" ;
-	if( weekday() == Weekday::monday ) return brief ? "Mon" : "Monday" ;
-	if( weekday() == Weekday::tuesday ) return brief ? "Tue" : "Tuesday" ;
-	if( weekday() == Weekday::wednesday ) return brief ? "Wed" : "Wednesday" ;
-	if( weekday() == Weekday::thursday ) return brief ? "Thu" : "Thursday" ;
-	if( weekday() == Weekday::friday ) return brief ? "Fri" : "Friday" ;
-	if( weekday() == Weekday::saturday ) return brief ? "Sat" : "Saturday" ;
-	return "" ;
+	Weekday d = weekday() ;
+	const char * p = "" ;
+	if( d == Weekday::sunday ) p = brief ? "Sun" : "Sunday" ;
+	else if( d == Weekday::monday ) p = brief ? "Mon" : "Monday" ;
+	else if( d == Weekday::tuesday ) p = brief ? "Tue" : "Tuesday" ;
+	else if( d == Weekday::wednesday ) p = brief ? "Wed" : "Wednesday" ;
+	else if( d == Weekday::thursday ) p= brief ? "Thu" : "Thursday" ;
+	else if( d == Weekday::friday ) p = brief ? "Fri" : "Friday" ;
+	else if( d == Weekday::saturday ) p = brief ? "Sat" : "Saturday" ;
+	return std::string(p) ;
 }
 
 G::Date::Month G::Date::month() const
@@ -152,19 +178,21 @@ G::Date::Month G::Date::month() const
 
 std::string G::Date::monthName( bool brief ) const
 {
-	if( month() == Month::january ) return brief ? "Jan" : "January" ;
-	if( month() == Month::february ) return brief ? "Feb" : "February" ;
-	if( month() == Month::march ) return brief ? "Mar" : "March" ;
-	if( month() == Month::april ) return brief ? "Apr" : "April" ;
-	if( month() == Month::may ) return "May" ;
-	if( month() == Month::june ) return brief ? "Jun" : "June" ;
-	if( month() == Month::july ) return brief ? "Jul" : "July" ;
-	if( month() == Month::august ) return brief ? "Aug" : "August" ;
-	if( month() == Month::september ) return brief ? "Sep" : "September" ;
-	if( month() == Month::october ) return brief ? "Oct" : "October" ;
-	if( month() == Month::november ) return brief ? "Nov" : "November" ;
-	if( month() == Month::december ) return brief ? "Dec" : "December" ;
-	return "" ;
+	Month m = month() ;
+	const char * p = "" ;
+	if( m == Month::january ) p = brief ? "Jan" : "January" ;
+	else if( m == Month::february ) p = brief ? "Feb" : "February" ;
+	else if( m == Month::march ) p = brief ? "Mar" : "March" ;
+	else if( m == Month::april ) p = brief ? "Apr" : "April" ;
+	else if( m == Month::may ) p = "May" ;
+	else if( m == Month::june ) p = brief ? "Jun" : "June" ;
+	else if( m == Month::july ) p = brief ? "Jul" : "July" ;
+	else if( m == Month::august ) p = brief ? "Aug" : "August" ;
+	else if( m == Month::september ) p = brief ? "Sep" : "September" ;
+	else if( m == Month::october ) p = brief ? "Oct" : "October" ;
+	else if( m == Month::november ) p = brief ? "Nov" : "November" ;
+	else if( m == Month::december ) p = brief ? "Dec" : "December" ;
+	return std::string(p) ;
 }
 
 int G::Date::year() const
@@ -172,11 +200,11 @@ int G::Date::year() const
 	return m_year ;
 }
 
-std::string G::Date::yyyy() const
+G::Date G::Date::next() const
 {
-	std::ostringstream ss ;
-	ss << std::setw(4) << std::setfill('0') << m_year ;
-	return ss.str() ;
+	Date d( *this ) ;
+	++d ;
+	return d ;
 }
 
 G::Date & G::Date::operator++()
@@ -202,6 +230,13 @@ G::Date & G::Date::operator++()
 	return *this ;
 }
 
+G::Date G::Date::previous() const
+{
+	Date d( *this ) ;
+	--d ;
+	return d ;
+}
+
 G::Date & G::Date::operator--()
 {
 	if( m_day == 1 )
diff --git a/src/glib/gdate.h b/src/glib/gdate.h
index 5f49106..cc11c1f 100644
--- a/src/glib/gdate.h
+++ b/src/glib/gdate.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,9 +23,11 @@
 
 #include "gdef.h"
 #include "gdatetime.h"
+#include "gexception.h"
 #include "glog.h"
 #include <ctime>
 #include <string>
+#include <new>
 
 namespace G
 {
@@ -39,6 +41,7 @@ namespace G
 class G::Date
 {
 public:
+	G_EXCEPTION( DateError , tx("invalid date") ) ;
 	class LocalTime /// An overload discriminator class for Date constructors.
 		{} ;
 
@@ -48,10 +51,10 @@ public:
 
 	enum class Format { yyyy_mm_dd_slash , yyyy_mm_dd , mm_dd } ;
 
-	static int yearUpperLimit() ;
+	static int yearUpperLimit() noexcept ;
 		///< Returns the largest supported year value.
 
-	static int yearLowerLimit() ;
+	static int yearLowerLimit() noexcept ;
 		///< Returns the smallest supported year value.
 
 	Date() ;
@@ -75,6 +78,10 @@ public:
 
 	Date( int year , Month month , int day_of_month ) ;
 		///< Constructor for the specified date.
+		///< Throws if out of range.
+
+	Date( int year , Month month , int day_of_month , std::nothrow_t ) noexcept ;
+		///< Constructor for the specified date.
 
 	std::string str( Format format = Format::yyyy_mm_dd_slash ) const ;
 		///< Returns a string representation of the date.
@@ -107,6 +114,12 @@ public:
 	std::string yyyy() const ;
 		///< Returns the year as a four-digit decimal string.
 
+	Date next() const ;
+		///< Returns the next date.
+
+	Date previous() const ;
+		///< Returns the previous date.
+
 	Date & operator++() ;
 		///< Increments the date by one day.
 
@@ -121,6 +134,7 @@ public:
 
 private:
 	void init( const BrokenDownTime & ) ;
+	void check() ;
 	static int lastDay( int month , int year ) ;
 	static bool isLeapYear( int y ) ;
 
diff --git a/src/glib/gdatetime.cpp b/src/glib/gdatetime.cpp
index d017f88..3d7531e 100644
--- a/src/glib/gdatetime.cpp
+++ b/src/glib/gdatetime.cpp
@@ -78,7 +78,7 @@ namespace G
 				a.tm_hour == b.tm_hour &&
 				a.tm_min == b.tm_min ;
 		}
-		bool same( const std::tm & a , const std::tm & b ) noexcept
+		bool sameSecond( const std::tm & a , const std::tm & b ) noexcept
 		{
 			return sameMinute( a , b ) && a.tm_sec == b.tm_sec ;
 		}
@@ -159,7 +159,7 @@ std::time_t G::BrokenDownTime::epochTimeFromUtc() const
 	{
 		std::tm tm {} ;
 		DateTimeImp::gmtime( tm , t0+memo.value() ) ;
-		if( DateTimeImp::same(tm,m_tm) )
+		if( DateTimeImp::sameSecond(tm,m_tm) )
 			return t0 + memo.value() ;
 	}
 
@@ -193,7 +193,7 @@ G::BrokenDownTime G::BrokenDownTime::utc( SystemTime t )
 	return bdt ;
 }
 
-G::BrokenDownTime::BrokenDownTime( int y , int mon , int d , int h , int min , int sec ) :
+G::BrokenDownTime::BrokenDownTime( int y , int mon , int d , int h , int min , int s ) :
 	m_tm{}
 {
 	m_tm.tm_year = y - 1900 ;
@@ -201,7 +201,7 @@ G::BrokenDownTime::BrokenDownTime( int y , int mon , int d , int h , int min , i
 	m_tm.tm_mday = d ;
 	m_tm.tm_hour = h ;
 	m_tm.tm_min = min ;
-	m_tm.tm_sec = sec ;
+	m_tm.tm_sec = s ;
 	m_tm.tm_isdst = -1 ;
 	m_tm.tm_wday = 0 ;
 	m_tm.tm_yday = 0 ;
@@ -222,7 +222,7 @@ bool G::BrokenDownTime::format( char * out , std::size_t out_size , const char *
 	for( const char * p = std::strchr(fmt,'%') ; p && p[1] ; p = std::strchr(p+1,'%') )
 	{
 		if( std::strchr(DateTimeImp::good_format,p[1]) == nullptr )
-			throw DateTime::Error("bad format string") ;
+			throw DateTime::Error( "bad format string" ) ;
 	}
 
 	std::tm tm_copy = m_tm ;
@@ -370,6 +370,11 @@ G::SystemTime G::SystemTime::zero()
 	return SystemTime( time_point_type(zero) ) ;
 }
 
+bool G::SystemTime::isZero() const
+{
+	return m_tp == time_point_type( duration_type(0) ) ;
+}
+
 bool G::SystemTime::operator<( const SystemTime & other ) const
 {
 	return m_tp < other.m_tp ;
@@ -433,38 +438,44 @@ std::ostream & G::operator<<( std::ostream & stream , const SystemTime & t )
 
 // ==
 
-G::TimerTime G::TimerTime::now()
-{
-	return { std::chrono::steady_clock::now() , false } ;
-}
-
-G::TimerTime G::TimerTime::zero()
-{
-	duration_type zero_duration{0} ;
-	return { time_point_type(zero_duration) , true } ;
-}
-
-G::TimerTime::TimerTime( time_point_type tp , bool is_zero ) :
-	m_is_zero(is_zero) ,
+G::TimerTime::TimerTime( time_point_type tp ) :
 	m_tp(tp)
 {
 }
 
+G::TimerTime G::TimerTime::now()
+{
+	time_point_type tp = std::chrono::steady_clock::now() ;
+	if( tp == time_point_type() ) tp += duration_type(1) ;
+	return TimerTime( tp ) ;
+}
+
+G::TimerTime G::TimerTime::zero()
+{
+	return TimerTime( time_point_type( duration_type(0) ) ) ;
+}
+
+bool G::TimerTime::isZero() const noexcept
+{
+	return m_tp == time_point_type( duration_type(0) ) ;
+}
+
 G::TimerTime G::TimerTime::test( int s , int us )
 {
-	return { time_point_type(std::chrono::seconds(s)+std::chrono::microseconds(us)) , s==0 && us==0 } ;
+	using namespace std::chrono ;
+	return TimerTime( time_point_type( seconds(s) + microseconds(us) ) ) ;
 }
 
 unsigned long G::TimerTime::s() const
 {
 	using namespace std::chrono ;
-	return static_cast<unsigned long>(duration_cast<seconds>(m_tp.time_since_epoch()).count()) ;
+	return static_cast<unsigned long>( duration_cast<seconds>(m_tp.time_since_epoch()).count() ) ;
 }
 
 unsigned long G::TimerTime::us() const
 {
 	using namespace std::chrono ;
-	return static_cast<unsigned long>((duration_cast<microseconds>(m_tp.time_since_epoch()) % seconds(1)).count()) ;
+	return static_cast<unsigned long>( (duration_cast<microseconds>(m_tp.time_since_epoch()) % seconds(1)).count() ) ;
 }
 
 std::string G::TimerTime::str() const
@@ -478,7 +489,6 @@ G::TimerTime G::TimerTime::operator+( const TimeInterval & interval ) const
 {
 	TimerTime t( *this ) ;
 	t += interval ;
-	t.m_is_zero = m_is_zero && interval.s() == 0U && interval.us() == 0U ;
 	return t ;
 }
 
@@ -487,7 +497,6 @@ void G::TimerTime::operator+=( TimeInterval i )
 	using namespace std::chrono ;
 	m_tp += seconds(i.s()) ;
 	m_tp += microseconds(i.us()) ;
-	m_is_zero = m_is_zero && i.s() == 0U && i.us() == 0U ;
 }
 
 G::TimeInterval G::TimerTime::operator-( const TimerTime & start ) const
@@ -508,11 +517,6 @@ bool G::TimerTime::sameSecond( const TimerTime & t ) const
 		duration_cast<seconds>(t.m_tp.time_since_epoch()) ;
 }
 
-bool G::TimerTime::operator<( const TimerTime & other ) const
-{
-	return m_tp < other.m_tp ;
-}
-
 bool G::TimerTime::operator<=( const TimerTime & other ) const
 {
 	return m_tp <= other.m_tp ;
diff --git a/src/glib/gdatetime.h b/src/glib/gdatetime.h
index 450e3aa..23f23f2 100644
--- a/src/glib/gdatetime.h
+++ b/src/glib/gdatetime.h
@@ -61,12 +61,12 @@ public:
 		///< Factory function for midnight starting the given date.
 
 	static BrokenDownTime local( SystemTime ) ;
-		///< Factory function for the locale-dependent local time of the
-		///< given epoch time. See also SystemTime::local().
+		///< Factory function for the locale-dependent local broken-down
+		///< time of the given epoch time. See also SystemTime::local().
 
 	static BrokenDownTime utc( SystemTime ) ;
-		///< Factory function for the utc time of the given epoch time.
-		///< See also SystemTime::utc().
+		///< Factory function for the utc broken-down time of the given
+		///< epoch time. See also SystemTime::utc().
 
 	bool format( char * out , std::size_t out_size , const char * fmt ) const ;
 		///< Puts the formatted date, including a terminating null character,
@@ -108,8 +108,7 @@ public:
 		///< Returns week day where sunday=0 and saturday=6.
 
 	std::time_t epochTimeFromUtc() const ;
-		///< Searches std::mktime() over the range of all timezones
-		///< to convert this utc broken-down time into epoch time.
+		///< Converts this utc broken-down time into epoch time.
 
 	std::time_t epochTimeFromLocal() const ;
 		///< Uses std::mktime() to convert this locale-dependent
@@ -145,6 +144,9 @@ public:
 		///< large positive number. The second parameter can be
 		///< more than 10^6.
 
+	bool isZero() const ;
+		///< Returns true if zero().
+
 	bool sameSecond( const SystemTime & other ) const noexcept ;
 		///< Returns true if this time and the other time are the same,
 		///< at second resolution.
@@ -206,8 +208,8 @@ public:
 
 private:
 	friend class G::DateTimeTest ;
-	using duration_type = std::chrono::system_clock::duration ;
 	using time_point_type = std::chrono::time_point<std::chrono::system_clock> ;
+	using duration_type = time_point_type::duration ;
 	explicit SystemTime( time_point_type ) ;
 	SystemTime & add( unsigned long us ) ;
 
@@ -222,11 +224,14 @@ private:
 class G::TimerTime
 {
 public:
+	using time_point_type = std::chrono::time_point<std::chrono::steady_clock> ;
+
 	static TimerTime now() ;
 		///< Factory function for the current steady-clock time.
 
 	static TimerTime zero() ;
-		///< Factory function for the start of the epoch.
+		///< Factory function for the start of the epoch, guaranteed
+		///< to be less than any now().
 
 	bool isZero() const noexcept ;
 		///< Returns true if zero().
@@ -235,7 +240,9 @@ public:
 		///< Returns true if this time and the other time are the same,
 		///< at second resolution.
 
-	bool operator<( const TimerTime & ) const ;
+	static constexpr bool less_noexcept = noexcept(time_point_type() < time_point_type()) ; // NOLINT bogus cert-err58-cpp
+
+	static bool less( const TimerTime & , const TimerTime & ) noexcept(less_noexcept) ;
 		///< Comparison operator.
 
 	bool operator<=( const TimerTime & ) const ;
@@ -273,25 +280,17 @@ public:
 
 private:
 	friend class G::DateTimeTest ;
-	using duration_type = std::chrono::steady_clock::duration ;
-	using time_point_type = std::chrono::time_point<std::chrono::steady_clock> ;
-	TimerTime( time_point_type , bool ) ;
+	using duration_type = time_point_type::duration ;
+	explicit TimerTime( time_point_type ) ;
 	static TimerTime test( int , int ) ;
 	unsigned long s() const ; // DateTimeTest
 	unsigned long us() const ; // DateTimeTest
 	std::string str() const ; // DateTimeTest
 
 private:
-	bool m_is_zero ;
 	time_point_type m_tp ;
 } ;
 
-inline
-bool G::TimerTime::isZero() const noexcept
-{
-	return m_is_zero ;
-}
-
 //| \class G::TimeInterval
 /// An interval between two G::SystemTime values or two G::TimerTime
 /// values.
@@ -368,19 +367,13 @@ private:
 	unsigned int m_us ;
 } ;
 
-namespace G
-{
-	std::ostream & operator<<( std::ostream & , const SystemTime & ) ;
-	std::ostream & operator<<( std::ostream & , const TimeInterval & ) ;
-}
-
 //| \class G::DateTime
 /// A static class that knows about timezone offsets.
 ///
 class G::DateTime
 {
 public:
-	G_EXCEPTION_CLASS( Error , "date/time error" ) ;
+	G_EXCEPTION_CLASS( Error , tx("date/time error") ) ;
 	using Offset = std::pair<bool,unsigned int> ;
 
 	static Offset offset( SystemTime ) ;
@@ -400,4 +393,19 @@ public:
 	DateTime() = delete ;
 } ;
 
+namespace G
+{
+	std::ostream & operator<<( std::ostream & , const SystemTime & ) ;
+	std::ostream & operator<<( std::ostream & , const TimeInterval & ) ;
+	inline bool operator<( const TimerTime & a , const TimerTime & b ) noexcept(TimerTime::less_noexcept)
+	{
+		return TimerTime::less( a , b ) ;
+	}
+}
+
+inline bool G::TimerTime::less( const TimerTime & a , const TimerTime & b ) noexcept(less_noexcept)
+{
+	return a.m_tp < b.m_tp ;
+}
+
 #endif
diff --git a/src/glib/gdef.h b/src/glib/gdef.h
index bc16fd1..0f9592d 100644
--- a/src/glib/gdef.h
+++ b/src/glib/gdef.h
@@ -1,5 +1,5 @@
 /*
-   Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+   Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -22,8 +22,7 @@
 /* This header is always the first header included in source
  * files. It takes care of a lot of portability concerns
  * and it works best when autoconf is used to set GCONFIG
- * preprocessor switches. Either G_UNIX or G_WINDOWS are expected
- * to be defined on the compiler command-line.
+ * preprocessor switches.
  */
 
 #ifndef G_DEF_H
@@ -79,60 +78,11 @@
 		#define G_UNIX_LINUX 1
 	#endif
 
-	/* Define the compiler c++ dialect
-	 */
-	#define G_COMPILER_CXX_11 1
-
 	/* Apply GCONFIG defaults in case of no autoconf
 	 */
-	#if !defined(GCONFIG_HAVE_CXX_NULLPTR)
-		#define GCONFIG_HAVE_CXX_NULLPTR 1
-	#endif
-	#if !defined(GCONFIG_HAVE_CXX_CONSTEXPR)
-		#define GCONFIG_HAVE_CXX_CONSTEXPR 1
-	#endif
-	#if !defined(GCONFIG_HAVE_CXX_ENUM_CLASS)
-		#define GCONFIG_HAVE_CXX_ENUM_CLASS 1
-	#endif
-	#if !defined(GCONFIG_HAVE_CXX_NOEXCEPT)
-		#define GCONFIG_HAVE_CXX_NOEXCEPT 1
-	#endif
-	#if !defined(GCONFIG_HAVE_CXX_OVERRIDE)
-		#define GCONFIG_HAVE_CXX_OVERRIDE 1
-	#endif
-	#if !defined(GCONFIG_HAVE_CXX_FINAL)
-		#define GCONFIG_HAVE_CXX_FINAL 1
-	#endif
 	#if !defined(GCONFIG_HAVE_CXX_ALIGNMENT)
 		#define GCONFIG_HAVE_CXX_ALIGNMENT 1
 	#endif
-	#if !defined(GCONFIG_HAVE_CXX_SHARED_PTR)
-		#define GCONFIG_HAVE_CXX_SHARED_PTR 1
-	#endif
-	#if !defined(GCONFIG_HAVE_CXX_STD_THREAD)
-		#define GCONFIG_HAVE_CXX_STD_THREAD 1
-	#endif
-	#if !defined(GCONFIG_HAVE_CXX_TYPE_TRAITS_MAKE_UNSIGNED)
-		#define GCONFIG_HAVE_CXX_TYPE_TRAITS_MAKE_UNSIGNED 1
-	#endif
-	#if !defined(GCONFIG_HAVE_CXX_EMPLACE)
-		#define GCONFIG_HAVE_CXX_EMPLACE 1
-	#endif
-	#if !defined(GCONFIG_HAVE_CXX_MOVE)
-		#define GCONFIG_HAVE_CXX_MOVE 1
-	#endif
-	#if !defined(GCONFIG_HAVE_CXX_DELETED)
-		#define GCONFIG_HAVE_CXX_DELETED 1
-	#endif
-	#if !defined(GCONFIG_HAVE_CXX_DEFAULTED)
-		#define GCONFIG_HAVE_CXX_DEFAULTED
-	#endif
-	#if !defined(GCONFIG_HAVE_CXX_INITIALIZER_LIST)
-		#define GCONFIG_HAVE_CXX_INITIALIZER_LIST 1
-	#endif
-	#if !defined(GCONFIG_HAVE_CXX_STD_WSTRING)
-		#define GCONFIG_HAVE_CXX_STD_WSTRING 1
-	#endif
 	#if !defined(GCONFIG_HAVE_CXX_STD_MAKE_UNIQUE)
 		#if defined(_MSC_VER)
 			#define GCONFIG_HAVE_CXX_STD_MAKE_UNIQUE 1
@@ -418,13 +368,24 @@
 		#define GCONFIG_HAVE_INET_NTOP 1
 	#endif
 	#if !defined(GCONFIG_HAVE_IFNAMETOINDEX)
-		#define GCONFIG_HAVE_IFNAMETOINDEX 1
+		#ifdef G_UNIX
+			#define GCONFIG_HAVE_IFNAMETOINDEX 1
+		#else
+			#define GCONFIG_HAVE_IFNAMETOINDEX 0
+		#endif
 	#endif
 	#if !defined(GCONFIG_HAVE_IFNAMETOLUID)
-		#ifdef G_UNIX
-			#define GCONFIG_HAVE_IFNAMETOLUID 0
-		#else
+		#if defined(G_WINDOWS) && !defined(G_MINGW)
 			#define GCONFIG_HAVE_IFNAMETOLUID 1
+		#else
+			#define GCONFIG_HAVE_IFNAMETOLUID 0
+		#endif
+	#endif
+	#if !defined(GCONFIG_HAVE_IFINDEX)
+		#ifdef G_UNIX_LINUX
+			#define GCONFIG_HAVE_IFINDEX 1
+		#else
+			#define GCONFIG_HAVE_IFINDEX 0
 		#endif
 	#endif
 	#if !defined(GCONFIG_HAVE_INET_PTON)
@@ -538,7 +499,12 @@
 		#define GCONFIG_HAVE_LIBV4L 0
 	#endif
 	#if !defined(GCONFIG_HAVE_GETTEXT)
-		#define GCONFIG_HAVE_GETTEXT 0
+		/* see AM_GNU_GETTEXT */
+		#if defined(ENABLE_NLS) && ENABLE_NLS == 1
+			#define GCONFIG_HAVE_GETTEXT 1
+		#else
+			#define GCONFIG_HAVE_GETTEXT 0
+		#endif
 	#endif
 	#if !defined(GCONFIG_ENABLE_IPV6)
 		#define GCONFIG_ENABLE_IPV6 GCONFIG_HAVE_IPV6
@@ -700,6 +666,20 @@
 			#define GCONFIG_HAVE_PTHREAD_SIGMASK 0
 		#endif
 	#endif
+	#if !defined(GCONFIG_HAVE_DIRENT_D_TYPE)
+		#if defined(_DIRENT_HAVE_D_TYPE)
+			#define GCONFIG_HAVE_DIRENT_D_TYPE 1
+		#else
+			#define GCONFIG_HAVE_DIRENT_D_TYPE 0
+		#endif
+	#endif
+	#if !defined(GCONFIG_HAVE_IOVEC_SIMPLE)
+		#ifdef G_UNIX
+			#define GCONFIG_HAVE_IOVEC_SIMPLE 1
+		#else
+			#define GCONFIG_HAVE_IOVEC_SIMPLE 0
+		#endif
+	#endif
 	#if !defined(GCONFIG_HAVE_UDS)
 		#ifdef G_UNIX
 			#define GCONFIG_HAVE_UDS 1
@@ -707,6 +687,13 @@
 			#define GCONFIG_HAVE_UDS 0
 		#endif
 	#endif
+	#if !defined(GCONFIG_HAVE_UDS_LEN)
+		#ifdef G_UNIX_BSD
+			#define GCONFIG_HAVE_UDS_LEN 1
+		#else
+			#define GCONFIG_HAVE_UDS_LEN 0
+		#endif
+	#endif
 
 	/* Include early o/s headers
 	 */
@@ -897,21 +884,19 @@
 		#else
 			using g_uintptr_t = std::size_t ; // assumes a non-segmented architecture - see also windows LONG_PTR
 		#endif
-		#if __cplusplus
-			#if GCONFIG_HAVE_INT64
-				static_assert( sizeof(g_int64_t) == 8U , "uint64 wrong size" ) ;
-				static_assert( sizeof(g_uint64_t) == 8U , "int64 wrong size" ) ;
-			#endif
-			#if GCONFIG_HAVE_INT32
-				static_assert( sizeof(g_uint32_t) == 4U , "uint32 wrong size" ) ;
-				static_assert( sizeof(g_int32_t) == 4U , "int32 wrong size" ) ;
-			#endif
-			#if GCONFIG_HAVE_INT16
-				static_assert( sizeof(g_uint16_t) == 2U , "uint16 wrong size" ) ;
-				static_assert( sizeof(g_int16_t) == 2U , "int16 wrong size" ) ;
-			#endif
-			static_assert( sizeof(g_uintptr_t) >= sizeof(void*) , "uintptr_t wrong size; try using g_uintptr_t = unsigned long" ) ;
+		#if GCONFIG_HAVE_INT64
+			static_assert( sizeof(g_int64_t) == 8U , "uint64 wrong size" ) ;
+			static_assert( sizeof(g_uint64_t) == 8U , "int64 wrong size" ) ;
 		#endif
+		#if GCONFIG_HAVE_INT32
+			static_assert( sizeof(g_uint32_t) == 4U , "uint32 wrong size" ) ;
+			static_assert( sizeof(g_int32_t) == 4U , "int32 wrong size" ) ;
+		#endif
+		#if GCONFIG_HAVE_INT16
+			static_assert( sizeof(g_uint16_t) == 2U , "uint16 wrong size" ) ;
+			static_assert( sizeof(g_int16_t) == 2U , "int16 wrong size" ) ;
+		#endif
+		static_assert( sizeof(g_uintptr_t) >= sizeof(void*) , "" ) ; // try 'using g_uintptr_t = unsigned long'
 
 		/* Define missing standard types
 	 	*/
@@ -942,34 +927,42 @@
 		/* Attributes
 	 	*/
 		#if __cplusplus >= 201700L
+			#define GDEF_NORETURN_LHS [[noreturn]]
 			#define GDEF_UNUSED [[maybe_unused]]
-			#define GDEF_NORETURN [[noreturn]]
-			#define GDEF_FALLTHROUGH [[fallthrough]]
+			#define GDEF_FALLTHROUGH [[fallthrough]];
 		#else
 			#if defined(__GNUC__) || defined(__clang__)
-				#define GDEF_UNUSED __attribute__((__unused__))
-				#define GDEF_NORETURN __attribute__((__noreturn__))
+				#define GDEF_NORETURN_RHS __attribute__((noreturn))
+				#define GDEF_UNUSED __attribute__((unused))
+				#if defined(__GNUC__) && __GNUC__ >= 7
+					#define GDEF_FALLTHROUGH __attribute__((fallthrough));
+				#endif
+				#if defined(__clang__) && __clang_major__ >= 10
+					#define GDEF_FALLTHROUGH __attribute__((fallthrough));
+				#endif
 			#endif
-			#ifdef _MSC_VER
-				// __declspec(noreturn) goes on the lhs
+			#if defined(_MSC_VER)
+				#define GDEF_NORETURN_LHS __declspec(noreturn)
 			#endif
 		#endif
+		#ifndef GDEF_NORETURN_LHS
+			#define GDEF_NORETURN_LHS
+		#endif
+		#ifndef GDEF_NORETURN_RHS
+			#define GDEF_NORETURN_RHS
+		#endif
 		#ifndef GDEF_UNUSED
 			#define GDEF_UNUSED
 		#endif
-		#ifndef GDEF_NORETURN
-			#define GDEF_NORETURN
-		#endif
 		#ifndef GDEF_FALLTHROUGH
 			#define GDEF_FALLTHROUGH
 		#endif
-		#ifdef __cplusplus
-			#include <tuple>
-			namespace G { template <typename... T> inline void ignore( T&& ... ) {} }
-			#define GDEF_IGNORE_PARAMS(...) G::ignore(__VA_ARGS__)
-			#define GDEF_IGNORE_RETURN std::ignore =
-			#define GDEF_IGNORE_PARAM(name) std::ignore = name
-		#endif
+		#include <tuple>
+		namespace G { template <typename... T> inline void gdef_ignore( T&& ... ) {} }
+		#define GDEF_IGNORE_PARAMS(...) G::gdef_ignore(__VA_ARGS__)
+		#define GDEF_IGNORE_RETURN std::ignore =
+		#define GDEF_IGNORE_PARAM(name) std::ignore = name
+		#define GDEF_IGNORE_VARIABLE(name) std::ignore = name
 
 		/* C++ language backwards compatibility
 	 	*/
@@ -1043,6 +1036,11 @@
 			#else
 				inline constexpr bool is_windows() { return false ; }
 			#endif
+			#ifdef G_MINGW
+				inline constexpr bool is_wine() { return true ; }
+			#else
+				inline constexpr bool is_wine() { return false ; }
+			#endif
 			#ifdef G_UNIX_LINUX
 				inline constexpr bool is_linux() { return true ; }
 			#else
@@ -1318,7 +1316,7 @@
 		#endif
 
 		#if ! GCONFIG_HAVE_GET_WINDOW_LONG_PTR && defined(G_WINDOWS)
-			static_assert( sizeof(void*) == 4U , "unexpected pointer size" ) ; // if this fails then we are on win64 so no need for this block at all
+			static_assert( sizeof(void*) == 4U , "" ) ; // if this fails then we are on win64 so no need for this block at all
 			const int GWLP_HINSTANCE = GWL_HINSTANCE ;
 			const int GWLP_WNDPROC = GWL_WNDPROC ;
 			const int DWLP_USER = DWL_USER ;
diff --git a/src/glib/gdirectory.cpp b/src/glib/gdirectory.cpp
index de2dd3c..c7afd2b 100644
--- a/src/glib/gdirectory.cpp
+++ b/src/glib/gdirectory.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,8 +24,7 @@
 #include "gpath.h"
 #include "gprocess.h"
 #include "gstr.h"
-#include "glog.h"
-#include <algorithm> // std::sort
+#include <algorithm>
 #include <functional>
 #include <iterator> // std::distance
 
@@ -34,7 +33,7 @@ G::Directory::Directory() :
 {
 }
 
-G::Directory::Directory( const char * path ) :
+G::Directory::Directory( const Path & path ) :
 	m_path(path)
 {
 }
@@ -44,11 +43,6 @@ G::Directory::Directory( const std::string & path ) :
 {
 }
 
-G::Directory::Directory( const Path & path ) :
-	m_path(path)
-{
-}
-
 G::Path G::Directory::path() const
 {
 	return m_path ;
@@ -72,36 +66,35 @@ bool G::Directory::valid( bool for_creation ) const
 G::DirectoryList::DirectoryList()
 = default;
 
-void G::DirectoryList::readAll( const G::Path & dir , std::vector<G::DirectoryList::Item> & out , bool sorted )
+void G::DirectoryList::readAll( const G::Path & dir , std::vector<G::DirectoryList::Item> & out )
 {
 	DirectoryList list ;
 	list.readAll( dir ) ;
-	if( sorted ) list.sort() ;
 	list.m_list.swap( out ) ;
 }
 
 void G::DirectoryList::readAll( const G::Path & dir )
 {
-	readType( dir , std::string() ) ;
+	readType( dir , {} ) ;
 }
 
-void G::DirectoryList::readType( const G::Path & dir , const std::string & suffix , unsigned int limit )
+void G::DirectoryList::readType( const G::Path & dir , G::string_view suffix , unsigned int limit )
 {
-	// we do our own filename matching here so as to
-	// reduce our dependency on glob()
 	Directory directory( dir ) ;
 	DirectoryIterator iter( directory ) ;
 	for( unsigned int i = 0U ; iter.more() && !iter.error() ; ++i )
 	{
+		// (we do our own filename matching here to avoid glob())
 		if( suffix.empty() || Str::tailMatch(iter.fileName(),suffix) )
 		{
 			if( limit == 0U || m_list.size() < limit )
 			{
 				Item item ;
 				item.m_is_dir = iter.isDir() ;
+				item.m_is_link = iter.isLink() ;
 				item.m_path = iter.filePath() ;
 				item.m_name = iter.fileName() ;
-				m_list.push_back( item ) ;
+				m_list.insert( std::lower_bound(m_list.begin(),m_list.end(),item) , item ) ;
 			}
 			if( m_list.size() == limit )
 				break ;
@@ -125,6 +118,11 @@ bool G::DirectoryList::more()
 	return more ;
 }
 
+bool G::DirectoryList::isLink() const
+{
+	return m_list.at(m_index).m_is_link ;
+}
+
 bool G::DirectoryList::isDir() const
 {
 	return m_list.at(m_index).m_is_dir ;
@@ -140,13 +138,3 @@ std::string G::DirectoryList::fileName() const
 	return m_list.at(m_index).m_name ;
 }
 
-bool G::DirectoryList::compare( const Item & a , const Item & b )
-{
-	return a.m_name.compare( b.m_name ) < 0 ;
-}
-
-void G::DirectoryList::sort()
-{
-	std::sort( m_list.begin() , m_list.end() , compare ) ;
-}
-
diff --git a/src/glib/gdirectory.h b/src/glib/gdirectory.h
index 11d1752..0b0165d 100644
--- a/src/glib/gdirectory.h
+++ b/src/glib/gdirectory.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -26,6 +26,7 @@
 #include "gexception.h"
 #include <string>
 #include <vector>
+#include <memory>
 #include <list>
 #include <sys/types.h>
 
@@ -48,9 +49,6 @@ public:
 	Directory() ;
 		///< Default constructor for the current directory.
 
-	explicit Directory( const char * path ) ;
-		///< Constructor.
-
 	explicit Directory( const Path & path ) ;
 		///< Constructor.
 
@@ -90,10 +88,10 @@ private:
 } ;
 
 //| \class G::DirectoryIterator
-/// A iterator that returns filenames in a directory.
+/// A iterator that returns unsorted filenames in a directory.
 /// The iteration model is:
 /// \code
-/// while(iter.more()) { (void)iter.filePath() ; }
+/// while(iter.more()) { auto path = iter.filePath() ; }
 /// \endcode
 ///
 class G::DirectoryIterator
@@ -115,6 +113,9 @@ public:
 	bool isDir() const ;
 		///< Returns true if the current item is a directory.
 
+	bool isLink() const ;
+		///< Returns true if the current item is a symlink.
+
 	std::string sizeString() const ;
 		///< Returns the file size as a decimal string. The value
 		///< may be bigger than any integer type can hold.
@@ -130,7 +131,7 @@ public:
 public:
 	DirectoryIterator( const DirectoryIterator & ) = delete ;
 	DirectoryIterator( DirectoryIterator && ) noexcept = default ;
-	void operator=( const DirectoryIterator & ) = delete ;
+	DirectoryIterator & operator=( const DirectoryIterator & ) = delete ;
 	DirectoryIterator & operator=( DirectoryIterator && ) noexcept = default ;
 
 private:
@@ -139,8 +140,9 @@ private:
 
 //| \class G::DirectoryList
 /// A iterator similar to G::DirectoryIterator but doing all file
-/// i/o in one go. This is useful when temporarily adopting
-/// additional process privileges to read a directory.
+/// i/o in one go and providing a sorted result. This can be useful
+/// when temporarily adopting additional process privileges to
+/// read a directory.
 ///
 class G::DirectoryList
 {
@@ -148,8 +150,10 @@ public:
 	struct Item /// A directory-entry item for G::DirectoryList.
 	{
 		bool m_is_dir{false} ;
+		bool m_is_link{false} ;
 		Path m_path ;
 		std::string m_name ;
+		bool operator<( const Item & ) const noexcept ;
 	} ;
 
 	DirectoryList() ;
@@ -157,13 +161,13 @@ public:
 		///< of the two read methods to do all the file i/o in one go.
 
 	void readAll( const Path & dir ) ;
-		///< An initialiser that is to be used after default
-		///< construction. Reads all files in the directory.
+		///< An initialiser that is to be used after default construction.
+		///< Reads all files in the directory.
 
-	void readType( const Path & dir , const std::string & suffix , unsigned int limit = 0U ) ;
+	void readType( const Path & dir , string_view suffix , unsigned int limit = 0U ) ;
 		///< An initialiser that is to be used after default
 		///< construction. Reads all files that have the given
-		///< suffix.
+		///< suffix (unsorted).
 
 	bool more() ;
 		///< Returns true if more and advances by one.
@@ -171,23 +175,20 @@ public:
 	bool isDir() const ;
 		///< Returns true if the current item is a directory.
 
+	bool isLink() const ;
+		///< Returns true if the current item is a symlink.
+
 	Path filePath() const ;
 		///< Returns the current path.
 
 	std::string fileName() const ;
-		///< Returns the current filename. On Windows
-		///< any characters that cannot be represented in the
-		///< active code page are replaced by '?'.
+		///< Returns the current filename. On Windows any characters
+		///< that cannot be represented in the active code page are
+		///< replaced by '?'.
 
-	void sort() ;
-		///< Sorts the files lexicographically.
-
-	static void readAll( const Path & dir , std::vector<Item> & out , bool sorted ) ;
+	static void readAll( const Path & dir , std::vector<Item> & out ) ;
 		///< A static overload returning by reference a collection
-		///< of Items.
-
-private:
-	static bool compare( const Item & , const Item & ) ;
+		///< of Items, sorted by name.
 
 private:
 	bool m_first{true} ;
@@ -195,4 +196,9 @@ private:
 	std::vector<Item> m_list ;
 } ;
 
+inline bool G::DirectoryList::Item::operator<( const Item & other ) const noexcept
+{
+	return m_name < other.m_name ;
+}
+
 #endif
diff --git a/src/glib/gdirectory_unix.cpp b/src/glib/gdirectory_unix.cpp
index ab09b29..0fdf33e 100644
--- a/src/glib/gdirectory_unix.cpp
+++ b/src/glib/gdirectory_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -46,6 +46,7 @@ public:
 	explicit DirectoryIteratorImp( const Directory & dir ) ;
 	~DirectoryIteratorImp() ;
 	bool isDir() const ;
+	bool isLink() const ;
 	bool more() ;
 	bool error() const ;
 	std::string sizeString() const ;
@@ -55,8 +56,8 @@ public:
 public:
 	DirectoryIteratorImp( const DirectoryIteratorImp & ) = delete ;
 	DirectoryIteratorImp( DirectoryIteratorImp && ) = delete ;
-	void operator=( const DirectoryIteratorImp & ) = delete ;
-	void operator=( DirectoryIteratorImp && ) = delete ;
+	DirectoryIteratorImp & operator=( const DirectoryIteratorImp & ) = delete ;
+	DirectoryIteratorImp & operator=( DirectoryIteratorImp && ) = delete ;
 
 private:
 	DIR * m_d ;
@@ -64,6 +65,7 @@ private:
 	Directory m_dir ;
 	bool m_error ;
 	bool m_is_dir ;
+	bool m_is_link ;
 } ;
 
 //
@@ -79,11 +81,11 @@ int G::Directory::usable( bool for_creation ) const
 	std::string path_dot = m_path.str() + (m_path.str()=="/"?"":"/") + "." ;
 
 	DIR * p = ::opendir( path_dot.c_str() ) ;
-	int error = p ? 0 : Process::errno_() ;
-	if( p )
+	int error = p == nullptr ? Process::errno_() : 0 ;
+	if( p != nullptr )
 		::closedir( p ) ;
 
-	if( !error && for_creation )
+	if( error == 0 && for_creation )
 	{
 		// (not definitive -- see also GNU/Linux ::euidaccess())
 		int rc = ::access( m_path.cstr() , W_OK ) ;
@@ -128,6 +130,11 @@ std::string G::DirectoryIterator::fileName() const
 	return m_imp->fileName() ;
 }
 
+bool G::DirectoryIterator::isLink() const
+{
+	return m_imp->isLink() ;
+}
+
 bool G::DirectoryIterator::isDir() const
 {
 	return m_imp->isDir() ;
@@ -145,7 +152,8 @@ G::DirectoryIteratorImp::DirectoryIteratorImp( const Directory & dir ) :
 	m_dp(nullptr) ,
 	m_dir(dir) ,
 	m_error(true) ,
-	m_is_dir(false)
+	m_is_dir(false) ,
+	m_is_link(false)
 {
 	m_d = ::opendir( dir.path().cstr() ) ;
 	m_error = m_d == nullptr ;
@@ -162,8 +170,33 @@ bool G::DirectoryIteratorImp::more()
 	{
 		m_dp = ::readdir( m_d ) ;
 		m_error = m_dp == nullptr ;
-		bool special = !m_error && ( fileName() == "." || fileName() == ".." ) ;
-		m_is_dir = !m_error && ( special || File::isDirectory(filePath(),std::nothrow) ) ;
+		if( m_error )
+			break ;
+
+		static_assert( sizeof(dirent::d_name) > 2U , "" ) ;
+		bool special = m_dp->d_name[0] == '.' && (
+			( m_dp->d_name[1] == '\0' ) ||
+			( m_dp->d_name[1] == '.' && m_dp->d_name[2] == '\0' ) ) ;
+
+		if( special )
+		{
+			m_is_dir = true ;
+			m_is_link = false ;
+		}
+		#if GCONFIG_HAVE_DIRENT_D_TYPE
+		else if( m_dp->d_type != DT_UNKNOWN )
+		{
+			m_is_dir = m_dp->d_type == DT_DIR ;
+			m_is_link = m_dp->d_type == DT_LNK ;
+			if( m_is_link )
+				m_is_dir = File::isDirectory(filePath(),std::nothrow) ;
+		}
+		#endif
+		else
+		{
+			m_is_dir = File::isDirectory(filePath(),std::nothrow) ;
+			m_is_link = File::isLink(filePath(),std::nothrow) ;
+		}
 		if( !special )
 			break ;
 	}
@@ -185,6 +218,11 @@ bool G::DirectoryIteratorImp::isDir() const
 	return m_is_dir ;
 }
 
+bool G::DirectoryIteratorImp::isLink() const
+{
+	return m_is_link ;
+}
+
 G::DirectoryIteratorImp::~DirectoryIteratorImp()
 {
 	if( m_d != nullptr )
@@ -194,6 +232,6 @@ G::DirectoryIteratorImp::~DirectoryIteratorImp()
 std::string G::DirectoryIteratorImp::sizeString() const
 {
 	std::string s = File::sizeString( filePath() ) ;
-	return s.empty() ? std::string("0") : s ;
+	return s.empty() ? std::string(1U,'0') : s ;
 }
 
diff --git a/src/glib/gdirectory_win32.cpp b/src/glib/gdirectory_win32.cpp
index 7c968a2..f7d80d2 100644
--- a/src/glib/gdirectory_win32.cpp
+++ b/src/glib/gdirectory_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -38,7 +38,7 @@ namespace G
 	class DirectoryIteratorImp ;
 }
 
-int G::Directory::usable( bool for_creation ) const
+int G::Directory::usable( bool /*for_creation*/ ) const
 {
 	DWORD attributes = ::GetFileAttributesA( m_path.cstr() ) ;
 	if( attributes == INVALID_FILE_ATTRIBUTES )
@@ -77,8 +77,8 @@ public:
 public:
 	DirectoryIteratorImp( const DirectoryIteratorImp & ) = delete ;
 	DirectoryIteratorImp( DirectoryIteratorImp && ) = delete ;
-	void operator=( const DirectoryIteratorImp & ) = delete ;
-	void operator=( DirectoryIteratorImp && ) = delete ;
+	DirectoryIteratorImp & operator=( const DirectoryIteratorImp & ) = delete ;
+	DirectoryIteratorImp & operator=( DirectoryIteratorImp && ) = delete ;
 
 private:
 	WIN32_FIND_DATAA m_context ;
@@ -120,6 +120,11 @@ bool G::DirectoryIterator::isDir() const
 	return m_imp->isDir() ;
 }
 
+bool G::DirectoryIterator::isLink() const
+{
+	return false ;
+}
+
 std::string G::DirectoryIterator::sizeString() const
 {
 	return m_imp->sizeString() ;
diff --git a/src/glib/geightbit.h b/src/glib/geightbit.h
index c7eb751..66f21ba 100644
--- a/src/glib/geightbit.h
+++ b/src/glib/geightbit.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -102,36 +102,44 @@ namespace G
 		}
 	}
 
+	/// \code
 	/// Returns true if the given data buffer contains a byte greater than 127.
 	/// An overload for an unsigned char buffer.
 	///
+	/// \endcode
 	inline bool eightbit( const unsigned char * p , std::size_t n )
 	{
 		namespace imp = EightBitImp ;
 		return imp::is8bit_faster( p , n ) ;
 	}
 
+	/// \code
 	/// Returns true if the given data buffer contains a character greater than 127.
 	/// An overload for a char buffer.
 	///
+	/// \endcode
 	inline bool eightbit( const char * p , std::size_t n )
 	{
 		namespace imp = EightBitImp ;
 		return imp::is8bit_faster( reinterpret_cast<const unsigned char *>(p) , n ) ;
 	}
 
+	/// \code
 	/// Returns true if the given data buffer contains a byte greater than 127.
 	/// An overload for an unsigned char buffer, with no optimisation.
 	///
+	/// \endcode
 	inline bool eightbit( const unsigned char * p , std::size_t n , int )
 	{
 		namespace imp = EightBitImp ;
 		return imp::is8bit_slow( p , n ) ;
 	}
 
+	/// \code
 	/// Returns true if the given data buffer contains a character greater than 127.
 	/// An overload for a char buffer, with no optimisation.
 	///
+	/// \endcode
 	inline bool eightbit( const char * p , std::size_t n , int )
 	{
 		namespace imp = EightBitImp ;
diff --git a/src/glib/genvironment.cpp b/src/glib/genvironment.cpp
index d1f09d0..2289b6b 100644
--- a/src/glib/genvironment.cpp
+++ b/src/glib/genvironment.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -121,7 +121,8 @@ void G::Environment::setBlock()
 
 void G::Environment::add( const std::string & name , const std::string & value )
 {
-	if( name.find('=') != std::string::npos ) throw std::runtime_error( "invalid environment variable [" + name + "]" ) ;
+	if( name.find('=') != std::string::npos )
+		throw Error( name ) ;
 	m_map.insert( std::make_pair(name,value) ) ;
 	setup() ;
 }
diff --git a/src/glib/genvironment.h b/src/glib/genvironment.h
index 2693b59..4f65717 100644
--- a/src/glib/genvironment.h
+++ b/src/glib/genvironment.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,6 +22,7 @@
 #define G_ENVIRONMENT_H
 
 #include "gdef.h"
+#include "gexception.h"
 #include <string>
 #include <vector>
 #include <map>
@@ -38,6 +39,8 @@ namespace G
 class G::Environment
 {
 public:
+	G_EXCEPTION( Error , tx("invalid environment variable") ) ;
+
 	static std::string get( const std::string & name , const std::string & default_ ) ;
 		///< Returns the environment variable value or the given default.
 
@@ -64,7 +67,7 @@ public:
 	bool contains( const std::string & name ) const ;
 		///< Returns true if the given variable is in this set.
 
-	std::string value( const std::string & name , const std::string & default_ = std::string() ) const ;
+	std::string value( const std::string & name , const std::string & default_ = {} ) const ;
 		///< Returns the value of the given variable in this set.
 
 	void set( const std::string & name , const std::string & value ) ;
diff --git a/src/glib/genvironment_unix.cpp b/src/glib/genvironment_unix.cpp
index 564fc1f..55b3c25 100644
--- a/src/glib/genvironment_unix.cpp
+++ b/src/glib/genvironment_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/genvironment_win32.cpp b/src/glib/genvironment_win32.cpp
index baad58a..b3ca472 100644
--- a/src/glib/genvironment_win32.cpp
+++ b/src/glib/genvironment_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gexception.cpp b/src/glib/gexception.cpp
index 9a02e3e..33ff5c3 100644
--- a/src/glib/gexception.cpp
+++ b/src/glib/gexception.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,82 +21,44 @@
 #include "gdef.h"
 #include "gexception.h"
 #include "gstr.h"
-#include "ggettext.h"
 
-namespace G
-{
-	namespace ExceptionImp
-	{
-		std::string join( std::string s1 , const std::string & s2 )
-		{
-			if( !s2.empty() ) s1.append(": ").append(s2) ;
-			return s1 ;
-		}
-		std::string join( std::string s1 , const std::string & s2 , const std::string & s3 )
-		{
-			if( !s2.empty() ) s1.append(": ").append(s2) ;
-			if( !s3.empty() ) s1.append(": ").append(s3) ;
-			return s1 ;
-		}
-		std::string join( std::string s1 , const std::string & s2 , const std::string & s3 ,
-			const std::string & s4 )
-		{
-			if( !s2.empty() ) s1.append(": ").append(s2) ;
-			if( !s3.empty() ) s1.append(": ").append(s3) ;
-			if( !s4.empty() ) s1.append(": ").append(s4) ;
-			return s1 ;
-		}
-		std::string join( std::string s1 , const std::string & s2 , const std::string & s3 ,
-			const std::string & s4 , const std::string & s5 )
-		{
-			if( !s2.empty() ) s1.append(": ").append(s2) ;
-			if( !s3.empty() ) s1.append(": ").append(s3) ;
-			if( !s4.empty() ) s1.append(": ").append(s4) ;
-			if( !s5.empty() ) s1.append(": ").append(s5) ;
-			return s1 ;
-		}
-	}
-}
-
-G::Exception::Exception( const char * what ) :
-	std::runtime_error(what?what:"")
+G::Exception::Exception( std::initializer_list<string_view> args ) :
+	std::runtime_error(join(args))
 {
 }
 
-G::Exception::Exception( const std::string & what ) :
-	std::runtime_error(what)
+G::Exception::Exception( string_view what ) :
+	Exception{what}
 {
 }
 
-G::Exception::Exception( const char * what , const std::string & more ) :
-	std::runtime_error(ExceptionImp::join(what,more))
+G::Exception::Exception( string_view what , string_view more ) :
+	Exception{what,more}
 {
 }
 
-G::Exception::Exception( const std::string & what , const std::string & more ) :
-	std::runtime_error(ExceptionImp::join(what,more))
+G::Exception::Exception( string_view what , string_view more1 , string_view more2 ) :
+	Exception{what,more1,more2}
 {
 }
 
-G::Exception::Exception( const char * what , const std::string & more1 , const std::string & more2 ) :
-	std::runtime_error(ExceptionImp::join(what,more1,more2))
+G::Exception::Exception( string_view what , string_view more1 , string_view more2 ,
+	string_view more3 ) :
+		Exception{what,more1,more2,more3}
 {
 }
 
-G::Exception::Exception( const std::string & what , const std::string & more1 , const std::string & more2 ) :
-	std::runtime_error(ExceptionImp::join(what,more1,more2))
+G::Exception::Exception( string_view what , string_view more1 , string_view more2 ,
+	string_view more3 , string_view more4 ) :
+		Exception{what,more1,more2,more3,more4}
 {
 }
 
-G::Exception::Exception( const char * what , const std::string & more1 , const std::string & more2 ,
-	const std::string & more3 ) :
-	std::runtime_error(ExceptionImp::join(what,more1,more2,more3))
-{
-}
-
-G::Exception::Exception( const std::string & what , const std::string & more1 , const std::string & more2 ,
-	const std::string & more3 ) :
-		std::runtime_error(ExceptionImp::join(what,more1,more2,more3))
+std::string G::Exception::join( std::initializer_list<string_view> args )
 {
+	std::string result ;
+	for( auto arg : args )
+		result.append(": ",result.empty()||arg.empty()?0U:2U).append(arg.data(),arg.size()) ;
+	return result ;
 }
 
diff --git a/src/glib/gexception.h b/src/glib/gexception.h
index 23b21ca..50a0af1 100644
--- a/src/glib/gexception.h
+++ b/src/glib/gexception.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,6 +22,9 @@
 #define G_EXCEPTION_H
 
 #include "gdef.h"
+#include "gstringview.h"
+#include "ggettext.h"
+#include <initializer_list>
 #include <string>
 #include <iostream>
 #include <stdexcept>
@@ -41,49 +44,63 @@ namespace G
 ///	throw G::Exception( "initialisation error" , "no such file" , path ) ;
 /// \endcode
 ///
+/// The G_EXCEPTION macro is normally used in class declarations, as follows:
+/// \code
+/// class Foo
+/// {
+/// public:
+///    G_EXCEPTION( Error , tx("foo error") ) ;
+/// ...
+/// };
+/// \endcode
+///
+/// The tx() identifies the string at build-time as requiring translation.
+/// The G_EXCEPTION macro adds a "G::" scope so that at compile-time the
+/// do-nothing function G::tx() from "ggettext.h" is used. The xgettext
+/// utility should be run as "xgettext --c++ --keyword=tx". Note that
+/// xgettext keywords cannot use scoped names.
+///
 class G::Exception : public std::runtime_error
 {
 public:
-	explicit Exception( const char * what ) ;
+	Exception( std::initializer_list<string_view> ) ;
 		///< Constructor.
 
-	explicit Exception( const std::string & what ) ;
+	explicit Exception( string_view what ) ;
 		///< Constructor.
 
-	Exception( const char * what , const std::string & more ) ;
+	Exception( string_view what , string_view more ) ;
 		///< Constructor.
 
-	Exception( const std::string & what , const std::string & more ) ;
+	Exception( string_view what , string_view more1 , string_view more2 ) ;
 		///< Constructor.
 
-	Exception( const char * what , const std::string & more1 , const std::string & more2 ) ;
+	Exception( string_view what , string_view more1 , string_view more2 , string_view more3 ) ;
 		///< Constructor.
 
-	Exception( const std::string & what , const std::string & more1 , const std::string & more2 ) ;
+	Exception( string_view what , string_view more1 , string_view more2 , string_view more3 , string_view more4 ) ;
 		///< Constructor.
 
-	Exception( const char * what , const std::string & more1 , const std::string & more2 , const std::string & more3 ) ;
-		///< Constructor.
-
-	Exception( const std::string & what , const std::string & more1 , const std::string & more2 , const std::string & more3 ) ;
-		///< Constructor.
+private:
+	static std::string join( std::initializer_list<string_view> ) ;
 } ;
 
-#define G_EXCEPTION_CLASS( class_name , description ) class class_name : public G::Exception { public: class_name() : G::Exception((description)) {} explicit class_name(const char *more) : G::Exception((description),more) {} explicit class_name(const std::string &more) : G::Exception((description),more) {} class_name(const std::string &more1,const std::string &more2) : G::Exception((description),more1,more2) {} class_name(const std::string &more1,const std::string &more2,const std::string &more3) : G::Exception((description),more1,more2,more3) {} }
+#define G_EXCEPTION_CLASS_( class_name , description ) \
+	class class_name : public G::Exception { public: /* NOLINT bugprone-macro-parentheses */ \
+	class_name() : G::Exception(description) {} \
+	explicit class_name( G::string_view more ) : G::Exception(description,more) {} \
+	class_name( G::string_view more1 , G::string_view more2 ) : G::Exception(description,more1,more2) {} \
+	class_name( G::string_view more1 , G::string_view more2 , G::string_view more3 ) : G::Exception(description,more1,more2,more3) {} }
 
-#define G_EXCEPTION_FUNCTION( name , description ) \
+#define G_EXCEPTION_FUNCTION_( name , description ) \
 	inline static G::Exception name() { return G::Exception((description)) ; } \
-	inline static G::Exception name( const std::string & s ) { return G::Exception((description),s) ; } \
-	inline static G::Exception name( const std::string & s1 , const std::string & s2 ) { return G::Exception((description),s1,s2) ; } \
-	inline static G::Exception name( const std::string & s1 , const std::string & s2 , const std::string & s3 ) { return G::Exception((description),s1,s2,s3) ; }
+	inline static G::Exception name( G::string_view s ) { return G::Exception(description,s) ; } \
+	inline static G::Exception name( G::string_view s1 , G::string_view s2 ) { return G::Exception(description,s1,s2) ; } \
+	inline static G::Exception name( G::string_view s1 , G::string_view s2 , G::string_view s3 ) { return G::Exception(description,s1,s2,s3) ; } \
+	inline static G::Exception name( G::string_view s1 , G::string_view s2 , G::string_view s3 , G::string_view s4 ) { return G::Exception(description,s1,s2,s3,s4) ; }
 
-// as a code-size optimisation G_EXCEPTION can be implemented as inline
-// functions using G_EXCEPTION_FUNCION rather than separate classes
-// with G_EXCEPTION_CLASS -- G_EXCEPTION_CLASS is required when catching
-// specific errors
-//
-#ifndef G_EXCEPTION
-#define G_EXCEPTION( class_name , description ) G_EXCEPTION_FUNCTION( class_name , description )
-#endif
+#define G_EXCEPTION_CLASS( class_name , tx_description ) G_EXCEPTION_CLASS_( class_name , G::tx_description )
+#define G_EXCEPTION_FUNCTION( name , tx_description ) G_EXCEPTION_FUNCTION_( name , G::tx_description )
+#define G_EXCEPTION( class_name , tx_description ) G_EXCEPTION_FUNCTION_( class_name , G::tx_description )
 
 #endif
diff --git a/src/glib/gexecutablecommand.cpp b/src/glib/gexecutablecommand.cpp
index e8016cc..986cb50 100644
--- a/src/glib/gexecutablecommand.cpp
+++ b/src/glib/gexecutablecommand.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gexecutablecommand.h b/src/glib/gexecutablecommand.h
index cce6ba2..bc88e5e 100644
--- a/src/glib/gexecutablecommand.h
+++ b/src/glib/gexecutablecommand.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,7 +23,8 @@
 
 #include "gdef.h"
 #include "gpath.h"
-#include "gstrings.h"
+#include "gstringarray.h"
+#include "gexception.h"
 #include <string>
 
 namespace G
@@ -43,7 +44,9 @@ namespace G
 class G::ExecutableCommand
 {
 public:
-	explicit ExecutableCommand( const std::string & command_line = std::string() ) ;
+	G_EXCEPTION( WindowsError , tx("cannot determine the windows directory") ) ;
+
+	explicit ExecutableCommand( const std::string & command_line = {} ) ;
 		///< Constructor taking a complete command-line. The command-line
 		///< is split up on unescaped-and-unquoted space characters.
 
diff --git a/src/glib/gexecutablecommand_unix.cpp b/src/glib/gexecutablecommand_unix.cpp
index fa1e897..fa8ac8d 100644
--- a/src/glib/gexecutablecommand_unix.cpp
+++ b/src/glib/gexecutablecommand_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gexecutablecommand_win32.cpp b/src/glib/gexecutablecommand_win32.cpp
index e380c95..7db7f26 100644
--- a/src/glib/gexecutablecommand_win32.cpp
+++ b/src/glib/gexecutablecommand_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -44,7 +44,7 @@ void G::ExecutableCommand::osAddWrapper()
 		buffer.at(0) = '\0' ;
 		unsigned int n = ::GetWindowsDirectoryA( &buffer[0] , MAX_PATH ) ;
 		if( n == 0 || n > MAX_PATH )
-			throw std::runtime_error( "cannot determine the windows directory" ) ;
+			throw WindowsError() ;
 		windows = std::string( &buffer[0] , n ) ;
 	}
 
diff --git a/src/glib/gfbuf.h b/src/glib/gfbuf.h
new file mode 100644
index 0000000..e328226
--- /dev/null
+++ b/src/glib/gfbuf.h
@@ -0,0 +1,232 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file gfbuf.h
+///
+
+#ifndef G_FBUF_H
+#define G_FBUF_H
+
+#include "gdef.h"
+#include <streambuf>
+#include <functional>
+#include <array>
+
+namespace G
+{
+	template <typename T, int N=1024> class fbuf ;
+}
+
+//| \class G::fbuf
+/// A simple file streambuf using a file descriptor and three
+/// function pointers for read, write and close operations.
+/// The file descriptor type is templated to allow for non-integer
+/// file descriptors, such as std::FILE. Does not support seeking.
+///
+/// Eg:
+/// \code
+/// G::fbuf<int,1024> fbuf( ::open("temp.out",O_WRONLY) , ::read , ::write , ::close ) ;
+/// std::ostream stream( &fbuf ) ;
+/// if( fbuf.file() < 0 )
+///     stream.clear( std::ios_base::failbit ) ;
+/// stream << "hello, world!\n" ;
+/// \endcode
+///
+/// The implementation specialises std::streambuf, overriding
+/// overflow(), underflow() and sync() to operate the internal
+/// character buffer and file descriptor.
+///
+template <typename T, int N>
+class G::fbuf : public std::streambuf
+{
+public:
+	using read_fn_t = std::function<ssize_t(T,char*,std::size_t)> ;
+	using write_fn_t = std::function<ssize_t(T,const char*,std::size_t)> ;
+	using close_fn_t = std::function<void(T)> ;
+
+	explicit fbuf( read_fn_t , write_fn_t , close_fn_t ) ;
+		///< Constructor.
+
+	explicit fbuf( T file , read_fn_t , write_fn_t , close_fn_t ) ;
+		///< Constructor.
+
+	~fbuf() override ;
+		///< Destructor. Closes the file.
+
+	void open( T file ) ;
+		///< Installs the given file descriptor.
+
+	T file() const ;
+		///< Returns the current file descriptor.
+
+protected:
+	int overflow( int c ) override ;
+		///< Called to put a character into the output buffer.
+
+	int underflow() override ;
+		///< Called to pull a character out of the input buffer,
+		///< and pre-fill the input buffer if necessary.
+
+	int sync() override ;
+		///< Called to sync the stream.
+
+public:
+	fbuf( const fbuf<T,N> & ) = delete ;
+	fbuf( fbuf<T,N> && ) = delete ;
+	fbuf<T,N> & operator=( const fbuf<T,N> & ) = delete ;
+	fbuf<T,N> & operator=( fbuf<T,N> && ) = delete ;
+
+private:
+	using traits_type = std::streambuf::traits_type ;
+	void close() ;
+
+private:
+	static constexpr int sync_ok = 0 ;
+	static constexpr int sync_fail = -1 ;
+	read_fn_t m_read_fn ;
+	write_fn_t m_write_fn ;
+	close_fn_t m_close_fn ;
+	std::array<char,N> m_input ;
+	std::array<char,N> m_output ;
+	bool m_file_open ;
+	T m_file ;
+} ;
+
+template <typename T,int N>
+G::fbuf<T,N>::fbuf( G::fbuf<T,N>::read_fn_t read , G::fbuf<T,N>::write_fn_t write , G::fbuf<T,N>::close_fn_t close ) :
+	m_read_fn(read) ,
+	m_write_fn(write) ,
+	m_close_fn(close) ,
+	m_input() ,
+	m_output() ,
+	m_file_open(false) ,
+	m_file()
+{
+}
+
+template <typename T,int N>
+G::fbuf<T,N>::fbuf( T file , G::fbuf<T,N>::read_fn_t read , G::fbuf<T,N>::write_fn_t write , G::fbuf<T,N>::close_fn_t close ) :
+	m_read_fn(read) ,
+	m_write_fn(write) ,
+	m_close_fn(close) ,
+	m_input() ,
+	m_output() ,
+	m_file_open(false) ,
+	m_file()
+{
+	open( file ) ;
+}
+
+namespace G
+{
+	template <typename T,int N>
+	fbuf<T,N>::~fbuf()
+	{
+		close() ;
+	}
+}
+
+template <typename T,int N>
+void G::fbuf<T,N>::open( T file )
+{
+	close() ;
+
+	m_file = file ;
+	m_file_open = true ;
+
+	char * input_begin = &m_input[0] ;
+	setg( input_begin , input_begin , input_begin ) ;
+
+	char * output_begin = &m_output[0] ;
+	char * output_end = output_begin + m_output.size() ;
+	setp( output_begin , output_end-1 ) ;
+}
+
+template <typename T,int N>
+void G::fbuf<T,N>::close()
+{
+	if( m_file_open )
+	{
+		sync() ;
+		m_close_fn( m_file ) ;
+		m_file_open = false ;
+	}
+}
+
+template <typename T,int N>
+int G::fbuf<T,N>::overflow( int c )
+{
+	if( !traits_type::eq_int_type( c , traits_type::eof() ) )
+	{
+		*pptr() = traits_type::to_char_type( c ) ;
+		pbump( 1 ) ;
+	}
+	return sync() == sync_fail ? traits_type::eof() : traits_type::not_eof(c) ;
+}
+
+template <typename T,int N>
+int G::fbuf<T,N>::sync()
+{
+	if( pbase() == pptr() )
+	{
+		return sync_ok ;
+	}
+	else
+	{
+		std::size_t size = pptr() - pbase() ;
+		ssize_t nwrite = m_write_fn( m_file , pbase() , size ) ;
+		if( nwrite <= 0 )
+		{
+			return sync_fail ;
+		}
+		else if( static_cast<std::size_t>(nwrite) < size )
+		{
+			std::copy( pbase()+nwrite , pptr() , pbase() ) ;
+			setp( pbase() , epptr() ) ; // reset pptr()
+			pbump( static_cast<int>(size-nwrite) ) ;
+			return sync_fail ;
+		}
+		else
+		{
+			setp( pbase() , epptr() ) ;
+			return sync_ok ;
+		}
+	}
+}
+
+template <typename T,int N>
+int G::fbuf<T,N>::underflow()
+{
+	if( gptr() == egptr() )
+	{
+		char * input_begin = &m_input[0] ;
+		ssize_t nread = m_read_fn( m_file , input_begin , m_input.size() ) ;
+		if( nread <= 0 )
+			return traits_type::eof() ;
+		std::size_t nreadu = nread >= 0 ? static_cast<std::size_t>(nread) : std::size_t(0U) ;
+		setg( input_begin , input_begin , input_begin+nreadu ) ;
+	}
+	return traits_type::to_int_type( *gptr() ) ;
+}
+
+template <typename T,int N>
+T G::fbuf<T,N>::file() const
+{
+	return m_file ;
+}
+
+#endif
diff --git a/src/glib/gfile.cpp b/src/glib/gfile.cpp
index 63d2d03..1886f00 100644
--- a/src/glib/gfile.cpp
+++ b/src/glib/gfile.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -45,13 +45,7 @@ void G::File::remove( const Path & path )
 
 bool G::File::rename( const Path & from , const Path & to , std::nothrow_t ) noexcept
 {
-	bool ok = 0 == std::rename( from.cstr() , to.cstr() ) ;
-	if( !ok )
-	{
-		std::remove( to.cstr() ) ;
-		ok = 0 == std::rename( from.cstr() , to.cstr() ) ;
-	}
-	return ok ;
+	return 0 == std::rename( from.cstr() , to.cstr() ) ;
 }
 
 void G::File::rename( const Path & from , const Path & to , bool ignore_missing )
@@ -85,6 +79,7 @@ bool G::File::copy( const Path & from , const Path & to , std::nothrow_t )
 	return copy(from,to,0).empty() ;
 }
 
+#ifndef G_LIB_SMALL
 bool G::File::copyInto( const Path & from , const Path & to_dir , std::nothrow_t )
 {
 	G::Path to = to_dir + from.basename() ;
@@ -93,6 +88,7 @@ bool G::File::copyInto( const Path & from , const Path & to_dir , std::nothrow_t
 		ok = chmodx( to , std::nothrow ) ;
 	return ok ;
 }
+#endif
 
 std::string G::File::copy( const Path & from , const Path & to , int )
 {
@@ -118,9 +114,10 @@ std::string G::File::copy( const Path & from , const Path & to , int )
 	if( out.fail() && !empty )
 		return "write error" ;
 
-	return std::string() ;
+	return {} ;
 }
 
+#ifndef G_LIB_SMALL
 void G::File::copy( std::istream & in , std::ostream & out , std::streamsize limit , std::string::size_type block )
 {
 	std::ios_base::iostate in_state = in.rdstate() ;
@@ -147,6 +144,7 @@ void G::File::copy( std::istream & in , std::ostream & out , std::streamsize lim
 	// restore the input failbit because it might have been set by us reading an incomplete block at eof
 	in.clear( (in.rdstate() & ~std::ios_base::failbit) | (in_state & std::ios_base::failbit) ) ;
 }
+#endif
 
 bool G::File::exists( const Path & path )
 {
@@ -180,7 +178,7 @@ bool G::File::exists( const Path & path , bool error_return_value , bool do_thro
 
 bool G::File::isLink( const Path & path , std::nothrow_t )
 {
-	Stat s = statImp( path.cstr() ) ;
+	Stat s = statImp( path.cstr() , true ) ;
 	return 0 == s.error && s.is_link ;
 }
 
@@ -196,11 +194,13 @@ bool G::File::isExecutable( const Path & path , std::nothrow_t )
 	return 0 == s.error && s.is_executable ;
 }
 
+#ifndef G_LIB_SMALL
 bool G::File::isEmpty( const Path & path , std::nothrow_t )
 {
 	Stat s = statImp( path.cstr() ) ;
 	return 0 == s.error && s.is_empty ;
 }
+#endif
 
 std::string G::File::sizeString( const Path & path )
 {
@@ -216,6 +216,7 @@ G::SystemTime G::File::time( const Path & path )
 	return SystemTime( s.mtime_s , s.mtime_us ) ;
 }
 
+#ifndef G_LIB_SMALL
 G::SystemTime G::File::time( const Path & path , std::nothrow_t )
 {
 	Stat s = statImp( path.cstr() ) ;
@@ -223,68 +224,74 @@ G::SystemTime G::File::time( const Path & path , std::nothrow_t )
 		return SystemTime( 0 ) ;
 	return SystemTime( s.mtime_s , s.mtime_us ) ;
 }
+#endif
 
 bool G::File::chmodx( const Path & path , std::nothrow_t )
 {
 	return chmodx( path , false ) ;
 }
 
+#ifndef G_LIB_SMALL
 void G::File::chmodx( const Path & path )
 {
 	chmodx( path , true ) ;
 }
+#endif
 
 bool G::File::mkdir( const Path & dir , std::nothrow_t )
 {
 	return 0 == mkdirImp( dir ) ;
 }
 
+#ifndef G_LIB_SMALL
 void G::File::mkdir( const Path & dir )
 {
 	int e = mkdirImp( dir ) ;
 	if( e )
 		throw CannotMkdir( dir.str() , Process::strerror(e) ) ;
 }
+#endif
 
-bool G::File::mkdirsr( int * ep , const Path & path , int limit )
+bool G::File::mkdirsr( const Path & path , int & e , int & limit )
 {
 	// (recursive)
 
-	if( limit == 0 )
-		return false ;
-
 	if( exists(path) )
 		return true ;
 
 	if( path.str().empty() )
 		return true ;
 
-	if( !mkdirsr( ep , path.dirname() , limit-1 ) ) // (recursion)
+	bool ok = mkdirsr( path.dirname() , e , limit ) ; // (recursion)
+	if( !ok )
 		return false ;
 
-	int e = mkdirImp( path ) ;
-	if( e )
-		*ep = e ;
-	else
-		chmodx( path , std::nothrow ) ;
+	e = mkdirImp( path ) ;
+	if( e == 0 && --limit < 0 )
+	{
+		e = ENOENT ; // sort of
+		return false ;
+	}
 
-	return e == 0 ;
+	return true ;
 }
 
 bool G::File::mkdirs( const Path & path , std::nothrow_t , int limit )
 {
 	int e = 0 ;
-	bool ok = mkdirsr( &e , path , limit ) ;
-	return ok || e == EEXIST ;
+	return mkdirsr( path , e , limit ) ;
 }
 
+#ifndef G_LIB_SMALL
 void G::File::mkdirs( const Path & path , int limit )
 {
 	int e = 0 ;
-	if( !mkdirsr(&e,path,limit) && e != EEXIST )
+	if( !mkdirsr(path,e,limit) && e != EEXIST )
 		throw CannotMkdir( path.str() , e ? G::Process::strerror(e) : std::string() ) ;
 }
+#endif
 
+#ifndef G_LIB_SMALL
 int G::File::compare( const Path & path_1 , const Path & path_2 , bool ignore_whitespace )
 {
 	std::ifstream file_1 ; open( file_1 , path_1 ) ;
@@ -311,4 +318,5 @@ int G::File::compare( const Path & path_1 , const Path & path_2 , bool ignore_wh
 	}
 	return result ;
 }
+#endif
 
diff --git a/src/glib/gfile.h b/src/glib/gfile.h
index b5908c6..3d5d564 100644
--- a/src/glib/gfile.h
+++ b/src/glib/gfile.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -42,18 +42,18 @@ namespace G
 class G::File
 {
 public:
-	G_EXCEPTION( StatError , "cannot access file" ) ;
-	G_EXCEPTION( CannotRemove , "cannot delete file" ) ;
-	G_EXCEPTION( CannotRename , "cannot rename file" ) ;
-	G_EXCEPTION( CannotCopy , "cannot copy file" ) ;
-	G_EXCEPTION( CannotMkdir , "cannot create directory" ) ;
-	G_EXCEPTION( CannotChmod , "cannot chmod file" ) ;
-	G_EXCEPTION( CannotChgrp , "cannot chgrp file" ) ;
-	G_EXCEPTION( CannotLink , "cannot create symlink" ) ;
-	G_EXCEPTION( CannotCreate , "cannot create file" ) ;
-	G_EXCEPTION( CannotReadLink , "cannot read symlink" ) ;
-	G_EXCEPTION( SizeOverflow , "file size overflow" ) ;
-	G_EXCEPTION( TimeError , "cannot get file modification time" ) ;
+	G_EXCEPTION( StatError , tx("cannot access file") ) ;
+	G_EXCEPTION( CannotRemove , tx("cannot delete file") ) ;
+	G_EXCEPTION( CannotRename , tx("cannot rename file") ) ;
+	G_EXCEPTION( CannotCopy , tx("cannot copy file") ) ;
+	G_EXCEPTION( CannotMkdir , tx("cannot create directory") ) ;
+	G_EXCEPTION( CannotChmod , tx("cannot chmod file") ) ;
+	G_EXCEPTION( CannotChgrp , tx("cannot chgrp file") ) ;
+	G_EXCEPTION( CannotLink , tx("cannot create symlink") ) ;
+	G_EXCEPTION( CannotCreate , tx("cannot create file") ) ;
+	G_EXCEPTION( CannotReadLink , tx("cannot read symlink") ) ;
+	G_EXCEPTION( SizeOverflow , tx("file size overflow") ) ;
+	G_EXCEPTION( TimeError , tx("cannot get file modification time") ) ;
 	enum class InOut { In , Out } ;
 	enum class InOutAppend { In , Out , Append } ;
 	class Append /// An overload discriminator for G::File::open().
@@ -107,7 +107,6 @@ public:
 
 	static bool mkdirs( const Path & dir , std::nothrow_t , int = 100 ) ;
 		///< Creates a directory and all necessary parents.
-		///< Does chmodx() on all created directories.
 		///< Returns false on error, but EEXIST is not
 		///< an error and chmod errors are also ignored.
 		///<
@@ -118,7 +117,6 @@ public:
 
 	static void mkdirs( const Path & dir , int = 100 ) ;
 		///< Creates a directory and all necessary parents.
-		///< Does chmodx() on all created directories.	
 		///< Throws on error, but EEXIST is not an error
 		///< and chmod errors are also ignored.
 
@@ -252,6 +250,9 @@ public:
 	static void close( int fd ) noexcept ;
 		///< Calls ::close() or equivalent.
 
+	static void setNonBlocking( int fd ) noexcept ;
+		///< Sets the file descriptor to non-blocking mode.
+
 public:
 	File() = delete ;
 
@@ -272,7 +273,7 @@ private:
 	static int linkImp( const char * , const char * ) ;
 	static bool linked( const Path & , const Path & ) ;
 	static int mkdirImp( const Path & dir ) noexcept ;
-	static bool mkdirsr( int * , const Path & dir , int ) ;
+	static bool mkdirsr( const Path & dir , int & , int & ) ;
 	static bool chmod( const Path & , const std::string & , std::nothrow_t ) ;
 } ;
 
diff --git a/src/glib/gfile_unix.cpp b/src/glib/gfile_unix.cpp
index 2390f48..faca911 100644
--- a/src/glib/gfile_unix.cpp
+++ b/src/glib/gfile_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -105,6 +105,7 @@ bool G::File::probe( const char * path ) noexcept
 	return true ;
 }
 
+#ifndef G_LIB_SMALL
 void G::File::create( const Path & path )
 {
 	int fd = ::open( path.cstr() , O_RDONLY|O_CREAT , 0666 ) ; // NOLINT
@@ -112,6 +113,7 @@ void G::File::create( const Path & path )
 		throw CannotCreate( path.str() ) ;
 	::close( fd ) ;
 }
+#endif
 
 ssize_t G::File::read( int fd , char * p , std::size_t n ) noexcept
 {
@@ -202,12 +204,15 @@ bool G::File::chmodx( const Path & path , bool do_throw )
 	return ok ;
 }
 
+#ifndef G_LIB_SMALL
 void G::File::chmod( const Path & path , const std::string & spec )
 {
 	if( !chmod( path , spec , std::nothrow ) )
 		throw CannotChmod( path.str() ) ;
 }
+#endif
 
+#ifndef G_LIB_SMALL
 bool G::File::chmod( const Path & path , const std::string & spec , std::nothrow_t )
 {
 	if( spec.empty() )
@@ -228,11 +233,13 @@ bool G::File::chmod( const Path & path , const std::string & spec , std::nothrow
 		return pair.first && 0 == ::chmod( path.cstr() , pair.second ) ;
 	}
 }
+#endif
 
+#ifndef G_LIB_SMALL
 std::pair<bool,mode_t> G::FileImp::newmode( mode_t mode , const std::string & spec_in )
 {
 	mode &= mode_t(07777) ;
-	G::StringArray spec_list = G::Str::splitIntoFields( spec_in , "," ) ;
+	G::StringArray spec_list = G::Str::splitIntoFields( spec_in , ',' ) ;
 	bool ok = !spec_list.empty() ;
 	for( auto spec : spec_list )
 	{
@@ -297,19 +304,25 @@ std::pair<bool,mode_t> G::FileImp::newmode( mode_t mode , const std::string & sp
 	}
 	return { ok , mode } ;
 }
+#endif
 
+#ifndef G_LIB_SMALL
 void G::File::chgrp( const Path & path , const std::string & group )
 {
 	bool ok = 0 == ::chown( path.cstr() , -1 , Identity::lookupGroup(group) ) ;
 	if( !ok )
 		throw CannotChgrp( path.str() ) ;
 }
+#endif
 
+#ifndef G_LIB_SMALL
 bool G::File::chgrp( const Path & path , const std::string & group , std::nothrow_t )
 {
 	return 0 == ::chown( path.cstr() , -1 , Identity::lookupGroup(group) ) ;
 }
+#endif
 
+#ifndef G_LIB_SMALL
 void G::File::link( const Path & target , const Path & new_link )
 {
 	if( linked(target,new_link) ) // optimisation
@@ -327,7 +340,9 @@ void G::File::link( const Path & target , const Path & new_link )
 		throw CannotLink( ss.str() ) ;
 	}
 }
+#endif
 
+#ifndef G_LIB_SMALL
 bool G::File::link( const Path & target , const Path & new_link , std::nothrow_t )
 {
 	if( linked(target,new_link) ) // optimisation
@@ -338,14 +353,18 @@ bool G::File::link( const Path & target , const Path & new_link , std::nothrow_t
 
 	return 0 == linkImp( target.cstr() , new_link.cstr() ) ;
 }
+#endif
 
+#ifndef G_LIB_SMALL
 int G::File::linkImp( const char * target , const char * new_link )
 {
 	int rc = ::symlink( target , new_link ) ;
 	int error = Process::errno_() ;
 	return rc == 0 ? 0 : (error?error:EINVAL) ;
 }
+#endif
 
+#ifndef G_LIB_SMALL
 G::Path G::File::readlink( const Path & link )
 {
 	Path result = readlink( link , std::nothrow ) ;
@@ -353,6 +372,7 @@ G::Path G::File::readlink( const Path & link )
 		throw CannotReadLink( link.str() ) ;
 	return result ;
 }
+#endif
 
 G::Path G::File::readlink( const Path & link , std::nothrow_t )
 {
@@ -375,9 +395,20 @@ G::Path G::File::readlink( const Path & link , std::nothrow_t )
 	return result ;
 }
 
+#ifndef G_LIB_SMALL
 bool G::File::linked( const Path & target , const Path & new_link )
 {
 	// see if already linked correctly - errors and overflows are not fatal
 	return readlink(new_link,std::nothrow) == target ;
 }
+#endif
+
+#ifndef G_LIB_SMALL
+void G::File::setNonBlocking( int fd ) noexcept
+{
+	int flags = ::fcntl( fd , F_GETFL ) ; // NOLINT
+	flags |= O_NONBLOCK ; // NOLINT
+	GDEF_IGNORE_RETURN ::fcntl( fd , F_SETFL , flags ) ; // NOLINT
+}
+#endif
 
diff --git a/src/glib/gfile_win32.cpp b/src/glib/gfile_win32.cpp
index 3c00f5d..b9fc94d 100644
--- a/src/glib/gfile_win32.cpp
+++ b/src/glib/gfile_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -50,13 +50,13 @@ namespace G
 			#if GCONFIG_HAVE_SOPEN_S
 				_set_errno( 0 ) ; // mingw bug
 				int fd = -1 ;
-				errno_t rc = _sopen_s( &fd , path , flags , _SH_DENYNO , pmode ) ;
+				errno_t rc = _sopen_s( &fd , path , flags | _O_NOINHERIT , _SH_DENYNO , pmode ) ;
 				return rc == 0 ? fd : -1 ;
 			#else
 				#if GCONFIG_HAVE_SOPEN
-					return _sopen( path , flags , _SH_DENYNO , pmode ) ;
+					return _sopen( path , flags | _O_NOINHERIT , _SH_DENYNO , pmode ) ;
 				#else
-					return _open( path , flags , pmode ) ;
+					return _open( path , flags | _O_NOINHERIT , pmode ) ;
 				#endif
 			#endif
 		}
diff --git a/src/glib/gformat.cpp b/src/glib/gformat.cpp
index 14a84c9..371e70b 100644
--- a/src/glib/gformat.cpp
+++ b/src/glib/gformat.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gformat.h b/src/glib/gformat.h
index 98fbba6..4f3f65d 100644
--- a/src/glib/gformat.h
+++ b/src/glib/gformat.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/ggetopt.cpp b/src/glib/ggetopt.cpp
index fc3590f..2b09151 100644
--- a/src/glib/ggetopt.cpp
+++ b/src/glib/ggetopt.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -25,6 +25,7 @@
 #include "goptionvalue.h"
 #include "goptionparser.h"
 #include "gstr.h"
+#include "gstringmap.h"
 #include "gassert.h"
 #include "glog.h"
 #include <fstream>
@@ -73,6 +74,19 @@ void G::GetOpt::parseArgs( std::size_t ignore_non_options )
 	m_args = Arg( new_args ) ;
 }
 
+bool G::GetOpt::addOptionsFromFile( std::size_t n , const StringArray & block )
+{
+	if( n < m_args.c() )
+	{
+		G::Path path = m_args.v( n ) ;
+		if( std::find( block.begin() , block.end() , path.extension() ) != block.end() )
+			return false ;
+		m_args.removeAt( n ) ;
+		addOptionsFromFile( path ) ;
+	}
+	return true ;
+}
+
 void G::GetOpt::addOptionsFromFile( std::size_t n , const std::string & varkey , const std::string & varvalue )
 {
 	if( n < m_args.c() )
@@ -110,9 +124,9 @@ void G::GetOpt::addOptionsFromFile( const G::Path & filename )
 	OptionParser::parse( optionsFromFile(m_spec,filename) , m_spec , m_map , &m_errors , 0U ) ;
 }
 
-const G::Options & G::GetOpt::options() const
+const std::vector<G::Option> & G::GetOpt::options() const
 {
-	return m_spec ;
+	return m_spec.list() ;
 }
 
 const G::OptionMap & G::GetOpt::map() const
@@ -130,23 +144,23 @@ bool G::GetOpt::contains( char c ) const
 	return m_map.contains( m_spec.lookup(c) ) ;
 }
 
-bool G::GetOpt::contains( const std::string & name ) const
+bool G::GetOpt::contains( string_view name ) const
 {
 	return m_map.contains( name ) ;
 }
 
-std::size_t G::GetOpt::count( const std::string & name ) const
+std::size_t G::GetOpt::count( string_view name ) const
 {
 	return m_map.count( name ) ;
 }
 
-std::string G::GetOpt::value( char c , const std::string & default_ ) const
+std::string G::GetOpt::value( char c , string_view default_ ) const
 {
 	G_ASSERT( contains(c) ) ;
 	return value( m_spec.lookup(c) , default_ ) ;
 }
 
-std::string G::GetOpt::value( const std::string & name , const std::string & default_ ) const
+std::string G::GetOpt::value( string_view name , string_view default_ ) const
 {
 	return m_map.value( name , default_ ) ;
 }
diff --git a/src/glib/ggetopt.h b/src/glib/ggetopt.h
index 70f12e7..8d7c6b8 100644
--- a/src/glib/ggetopt.h
+++ b/src/glib/ggetopt.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,16 +22,17 @@
 #define G_GETOPT_H
 
 #include "gdef.h"
+#include "goption.h"
 #include "goptions.h"
 #include "goptionvalue.h"
 #include "goptionparser.h"
 #include "garg.h"
 #include "gpath.h"
-#include "gstrings.h"
+#include "gstringview.h"
+#include "gstringarray.h"
 #include "gexception.h"
 #include <string>
 #include <list>
-#include <map>
 
 namespace G
 {
@@ -43,14 +44,19 @@ namespace G
 ///
 /// Usage:
 /// \code
+///  using Layout = G::OptionsOutputLayout ;
+///  using Output = G::OptionsOutput ;
 ///  G::Arg arg( argc , argv ) ;
 ///  G::GetOpt opt( arg , "e!extra!does something! extra!1!something!1" "|" "h!help!shows help!!0!!1" ) ;
 ///  if( opt.hasErrors() ) { opt.showErrors( std::cerr ) ; exit( 2 ) ; }
-///  if( opt.contains("help") ) { opt.options().showUsage( std::cout , arg.prefix() , " [<more>]" ) ; exit( 0 ) ; }
-///  run( opt.args() , opt.contains("extra") ? opt.value("extra") : std::string() ) ;
+///  if( opt.contains("help"sv) ) { Output(opt.options()).showUsage( Layout().set_whatever() ,
+///    std::cout , arg.prefix() , " [<more>]" ) ; exit( 0 ) ; }
+///  run( opt.args() , opt.contains("extra"sv) ? opt.value("extra"sv) : std::string() ) ;
 /// \endcode
 ///
-/// \see G::Arg, G::Options, G::OptionMap, G::OptionParser
+/// This class is a thin layer over G::Options, G::OptionMap, G::OptionParser etc,
+/// but also adding file loading. The G::OptionsOutput class is kept separate in
+/// order to minimise dependencies.
 ///
 class G::GetOpt
 {
@@ -77,25 +83,30 @@ public:
 		///< The program name in the first position is expected but ignored.
 
 	void addOptionsFromFile( size_type n = 1U ,
-		const std::string & varkey = std::string() , const std::string & varvalue = std::string() ) ;
+		const std::string & varkey = {} , const std::string & varvalue = {} ) ;
 			///< Adds options from the config file named by the n'th non-option
 			///< command-line argument (zero-based and allowing for the program
 			///< name in argv0). The n'th argument is then removed. Does nothing
-			///< if the n'th argument does not exists or if it is empty. Throws
+			///< if the n'th argument does not exist or if it is empty. Throws
 			///< if the file is specified but cannot be opened. Parsing errors
 			///< are added to errorList(). The optional trailing string parameters
 			///< are used to perform leading sub-string substitution on the
 			///< filename.
 
+	bool addOptionsFromFile( size_t n , const G::StringArray & extension_block_list ) ;
+		///< Adds options from the config file named by the n'th non-option
+		///< argument, but not if the file extension matches any in the block
+		///< list. Returns false if blocked.
+
 	void addOptionsFromFile( const Path & file ) ;
 		///< Adds options from the given config file. Throws if the file
 		///< cannot be opened. Parsing errors are added to errorList().
 
-	const Options & options() const ;
-		///< Returns a reference to the option specification sub-object.
+	const std::vector<Option> & options() const ;
+		///< Returns the list of option specification objects.
 
 	const OptionMap & map() const ;
-		///< Returns a reference to the OptionMap sub-object.
+		///< Returns the map of option-values.
 
 	Arg args() const ;
 		///< Returns the G::Arg command-line, excluding options.
@@ -119,21 +130,21 @@ public:
 		///< Returns true if the command-line contains the option identified by its
 		///< short-form letter.
 
-	bool contains( const std::string & option_name ) const ;
+	bool contains( string_view option_name ) const ;
 		///< Returns true if the command-line contains the option identified by its
 		///< long-form name.
 
-	std::size_t count( const std::string & option_name ) const ;
+	std::size_t count( string_view option_name ) const ;
 		///< Returns the option's repeat count.
 
-	std::string value( const std::string & option_name , const std::string & default_ = std::string() ) const ;
+	std::string value( string_view option_name , string_view default_ = {} ) const ;
 		///< Returns the value for the option identified by its long-form name.
 		///< If the option is multi-valued then the returned value is a
 		///< comma-separated list. If the option-value is 'on' then
 		///< Str::positive() is returned; if the option-value is 'off'
 		///< then the given default is returned.
 
-	std::string value( char option_letter , const std::string & default_ = std::string() ) const ;
+	std::string value( char option_letter , string_view default_ = {} ) const ;
 		///< An overload that returns the value of the option identified
 		///< by its short-form letter.
 		///< Precondition: contains(option_letter)
@@ -142,8 +153,8 @@ public:
 	~GetOpt() = default ;
 	GetOpt( const GetOpt & ) = delete ;
 	GetOpt( GetOpt && ) = delete ;
-	void operator=( const GetOpt & ) = delete ;
-	void operator=( GetOpt && ) = delete ;
+	GetOpt & operator=( const GetOpt & ) = delete ;
+	GetOpt & operator=( GetOpt && ) = delete ;
 
 private:
 	void parseArgs( std::size_t ) ;
diff --git a/src/glib/ggettext.h b/src/glib/ggettext.h
index 7dc62cd..231c617 100644
--- a/src/glib/ggettext.h
+++ b/src/glib/ggettext.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,12 +22,21 @@
 #define G_GETTEXT_H
 
 #include "gdef.h"
+#include "gstringview.h"
 #include <string>
-#include <clocale>
 
-#if GCONFIG_HAVE_GETTEXT
-#include <libintl.h>
-#endif
+// Strings should be marked for translation using gettext() or gettext_noop(),
+// but not using the namespace scoping so that 'xgettext(1)' will still work.
+// For brevity G::txt() or G::tx() can be used instead. See also G::format.
+//
+// Eg:
+/// \code
+/// #include "ggettext.h"
+/// using G::tx ;
+/// using G::txt ;
+/// Message msg( tx("world") ) ;
+/// std::cout << txt("hello") << msg.translated() << "\n" ;
+/// \endcode
 
 namespace G
 {
@@ -36,45 +45,43 @@ namespace G
 		///< to set the CTYPE and MESSAGES facets of the global C locale as a
 		///< side-effect.
 
-	constexpr const char * gettext_noop( const char * p ) ;
-		///< Marks a string for translation at build-time, but no translation is
-		///< applied at run-time.
-
-	const char * gettext( const char * ) ;
+	const char * gettext( const char * ) noexcept ;
 		///< Returns the message translation in the current locale's codeset,
-		///< eg. ISO8859-1 or UTF-8, transcoding from the catalogue as
+		///< eg. ISO-8859-1 or UTF-8, transcoding from the catalogue as
 		///< necessary.
+
+	constexpr const char * gettext_noop( const char * p ) ;
+		///< Returns the parameter. Used as a marker for xgettext
+		///< for potential translation at build-time.
+
+	const char * txt( const char * p ) ;
+		///< A briefer alternative to G::gettext().
+
+	constexpr const char * tx( const char * p ) ;
+		///< A briefer alternative to G::gettext_noop().
+
+	constexpr string_view tx( string_view sv ) ;
+		///< String view overload.
 }
 
-#if GCONFIG_HAVE_GETTEXT
-inline void G::gettext_init( const std::string & localedir , const std::string & appname )
+inline const char * G::txt( const char * p )
 {
-	if( !appname.empty() )
-	{
-		std::setlocale( LC_MESSAGES , "" ) ;
-		std::setlocale( LC_CTYPE , "" ) ;
-		if( !localedir.empty() )
-            bindtextdomain( appname.c_str() , localedir.c_str() ) ;
-		textdomain( appname.c_str() ) ;
-	}
+	return G::gettext( p ) ;
 }
-inline const char * G::gettext( const char * p )
-{
-		return ::gettext( p ) ;
-}
-#else
-inline void G::gettext_init( const std::string & , const std::string & )
-{
-}
-inline const char * G::gettext( const char * p )
-{
-		return p ;
-}
-#endif
 
 constexpr const char * G::gettext_noop( const char * p )
 {
 	return p ;
 }
 
+constexpr const char * G::tx( const char * p )
+{
+	return p ;
+}
+
+constexpr G::string_view G::tx( string_view sv )
+{
+	return sv ;
+}
+
 #endif
diff --git a/src/glib/ggettext_none.cpp b/src/glib/ggettext_none.cpp
new file mode 100644
index 0000000..6b1c249
--- /dev/null
+++ b/src/glib/ggettext_none.cpp
@@ -0,0 +1,32 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file ggettext_none.cpp
+///
+
+#include "gdef.h"
+#include "ggettext.h"
+
+void G::gettext_init( const std::string & , const std::string & )
+{
+}
+
+const char * G::gettext( const char * p ) noexcept
+{
+	return p ;
+}
+
diff --git a/src/glib/ggettext_unix.cpp b/src/glib/ggettext_unix.cpp
new file mode 100644
index 0000000..e77294a
--- /dev/null
+++ b/src/glib/ggettext_unix.cpp
@@ -0,0 +1,42 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file ggettext_unix.cpp
+///
+
+#include "gdef.h"
+#include "ggettext.h"
+#include <clocale>
+#include <libintl.h>
+
+void G::gettext_init( const std::string & localedir , const std::string & appname )
+{
+	if( !appname.empty() )
+	{
+		std::setlocale( LC_MESSAGES , "" ) ;
+		std::setlocale( LC_CTYPE , "" ) ;
+		if( !localedir.empty() )
+            bindtextdomain( appname.c_str() , localedir.c_str() ) ;
+		textdomain( appname.c_str() ) ;
+	}
+}
+
+const char * G::gettext( const char * p ) noexcept
+{
+	return ::gettext( p ) ;
+}
+
diff --git a/src/glib/ggettext_win32.cpp b/src/glib/ggettext_win32.cpp
new file mode 100644
index 0000000..9b9cc48
--- /dev/null
+++ b/src/glib/ggettext_win32.cpp
@@ -0,0 +1,32 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file ggettext_win32.cpp
+///
+
+#include "gdef.h"
+#include "ggettext.h"
+
+void G::gettext_init( const std::string & , const std::string & )
+{
+}
+
+const char * G::gettext( const char * p ) noexcept
+{
+	return p ;
+}
+
diff --git a/src/glib/ghash.cpp b/src/glib/ghash.cpp
index 54e4ec2..bec4ee4 100644
--- a/src/glib/ghash.cpp
+++ b/src/glib/ghash.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/ghash.h b/src/glib/ghash.h
index cb37e3e..cb7396b 100644
--- a/src/glib/ghash.h
+++ b/src/glib/ghash.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/ghashstate.h b/src/glib/ghashstate.h
index 8c5cf4d..7fb3b43 100644
--- a/src/glib/ghashstate.h
+++ b/src/glib/ghashstate.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/ghostname.h b/src/glib/ghostname.h
index fe6f3b9..9c07510 100644
--- a/src/glib/ghostname.h
+++ b/src/glib/ghostname.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/ghostname_unix.cpp b/src/glib/ghostname_unix.cpp
index 4999bc5..c0dcb8e 100644
--- a/src/glib/ghostname_unix.cpp
+++ b/src/glib/ghostname_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -29,7 +29,7 @@ std::string G::hostname()
 	struct utsname info {} ;
 	int rc = ::uname( &info ) ;
 	if( rc == -1 )
-		return std::string() ;
+		return {} ;
 
 	std::string name = std::string( info.nodename ) ;
 	std::string::size_type pos = name.find( '.' ) ;
diff --git a/src/glib/ghostname_win32.cpp b/src/glib/ghostname_win32.cpp
index e0c2384..0b33b48 100644
--- a/src/glib/ghostname_win32.cpp
+++ b/src/glib/ghostname_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gidentity.h b/src/glib/gidentity.h
index f12baf0..b5feea3 100644
--- a/src/glib/gidentity.h
+++ b/src/glib/gidentity.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -42,9 +42,9 @@ namespace G
 class G::Identity
 {
 public:
-	G_EXCEPTION( NoSuchUser , "no such user" ) ;
-	G_EXCEPTION( NoSuchGroup , "no such group" ) ;
-	G_EXCEPTION( Error , "cannot read user database" ) ;
+	G_EXCEPTION( NoSuchUser , tx("no such user") ) ;
+	G_EXCEPTION( NoSuchGroup , tx("no such group") ) ;
+	G_EXCEPTION( Error , tx("cannot read user database") ) ;
 
 	explicit Identity( const std::string & username ,
 		const std::string & group_name_override = std::string() ) ;
diff --git a/src/glib/gidentity_unix.cpp b/src/glib/gidentity_unix.cpp
index 0491fce..7367212 100644
--- a/src/glib/gidentity_unix.cpp
+++ b/src/glib/gidentity_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gidentity_win32.cpp b/src/glib/gidentity_win32.cpp
index 9bea086..828bdf6 100644
--- a/src/glib/gidentity_win32.cpp
+++ b/src/glib/gidentity_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gimembuf.h b/src/glib/gimembuf.h
index d4bb05a..5284c6f 100644
--- a/src/glib/gimembuf.h
+++ b/src/glib/gimembuf.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,7 +22,6 @@
 #define G_IMEMBUF_H
 
 #include "gdef.h"
-#include "gstringview.h"
 #include <streambuf>
 #include <algorithm>
 
@@ -55,9 +54,6 @@ public:
 	basic_imembuf( const Tchar * p , std::size_t n ) ;
 		///< Constructor.
 
-	explicit basic_imembuf( basic_string_view<Tchar> ) ;
-		///< Constructor.
-
 protected:
 	std::streamsize xsgetn( Tchar * s , std::streamsize n ) override ;
 	std::streampos seekpos( std::streampos pos , std::ios_base::openmode which ) override ;
@@ -67,8 +63,8 @@ public:
 	~basic_imembuf() override = default ;
 	basic_imembuf( const basic_imembuf<Tchar> & ) = delete ;
 	basic_imembuf( basic_imembuf<Tchar> && ) = delete ;
-	void operator=( const basic_imembuf<Tchar> & ) = delete ;
-	void operator=( basic_imembuf<Tchar> && ) = delete ;
+	basic_imembuf<Tchar> & operator=( const basic_imembuf<Tchar> & ) = delete ;
+	basic_imembuf<Tchar> & operator=( basic_imembuf<Tchar> && ) = delete ;
 
 private:
 	template <typename Tint> static std::streamsize min( Tint a , std::streamsize b ) ;
@@ -84,16 +80,6 @@ template <typename Tint> std::streamsize G::basic_imembuf<Tchar>::min( Tint a ,
 	return std::min( static_cast<std::streamsize>(a) , b ) ;
 }
 
-template <typename Tchar>
-G::basic_imembuf<Tchar>::basic_imembuf( basic_string_view<Tchar> s ) :
-	m_p(s.data()) ,
-	m_n(s.size())
-{
-	using base_t = std::basic_streambuf<Tchar> ;
-	Tchar * mp = const_cast<Tchar*>(m_p) ;
-	base_t::setg( mp , mp , mp+m_n ) ;
-}
-
 template <typename Tchar>
 G::basic_imembuf<Tchar>::basic_imembuf( const Tchar * p_in , std::size_t n ) :
 	m_p(p_in) ,
diff --git a/src/glib/glimits.h b/src/glib/glimits.h
index ef2591c..6d8b0b4 100644
--- a/src/glib/glimits.h
+++ b/src/glib/glimits.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/glog.cpp b/src/glib/glog.cpp
index 3d0df6c..f6cb3e7 100644
--- a/src/glib/glog.cpp
+++ b/src/glib/glog.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,39 +22,40 @@
 #include "glog.h"
 #include "glogoutput.h"
 
-G::Log::Log( Severity severity , const char * file , int line ) :
+G::Log::Log( Severity severity , const char * file , int line ) noexcept :
 	m_severity(severity) ,
 	m_file(file) ,
 	m_line(line) ,
-	m_ostream(LogOutput::start(m_severity,m_file,m_line))
+	m_logstream(LogOutput::start(m_severity,m_file,m_line))
 {
+	static_assert( noexcept(LogStream(nullptr)) , "" ) ;
 }
 
 G::Log::~Log()
 {
-	try
-	{
-		LogOutput::output( m_ostream ) ;
-	}
-	catch(...)
-	{
-	}
+	static_assert( noexcept(LogOutput::output(m_logstream)) , "" ) ;
+	LogOutput::output( m_logstream ) ;
 }
 
-bool G::Log::at( Severity s )
+bool G::Log::at( Severity s ) noexcept
 {
+	static_assert( noexcept(LogOutput::instance()) , "" ) ;
 	const LogOutput * log_output = LogOutput::instance() ;
+
+	static_assert( noexcept(log_output->at(s)) , "" ) ;
 	return log_output && log_output->at( s ) ;
 }
 
-std::ostream & G::Log::operator<<( const char * s )
+G::LogStream & G::Log::operator<<( const char * s ) noexcept
 {
+	static_assert( noexcept(m_logstream <<s) , "" ) ;
 	s = s ? s : "" ;
-	return m_ostream << s ;
+	return m_logstream << s ;
 }
 
-std::ostream & G::Log::operator<<( const std::string & s )
+G::LogStream & G::Log::operator<<( const std::string & s ) noexcept
 {
-	return m_ostream << s ;
+	static_assert( noexcept(m_logstream <<s) , "" ) ;
+	return m_logstream << s ;
 }
 
diff --git a/src/glib/glog.h b/src/glib/glog.h
index cb389bb..5fd4cde 100644
--- a/src/glib/glog.h
+++ b/src/glib/glog.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,6 +22,7 @@
 #define G_LOG_H
 
 #include "gdef.h"
+#include "glogstream.h"
 #include <sstream>
 #include <string>
 
@@ -36,7 +37,7 @@ namespace G
 ///
 /// Usage:
 /// \code
-///	G::Log(G::Log::Severity::s_InfoSummary,__FILE__,__LINE__) << a << b ;
+///	G::Log(G::Log::Severity::InfoSummary,__FILE__,__LINE__) << a << b ;
 /// \endcode
 /// or
 /// \code
@@ -48,33 +49,38 @@ namespace G
 class G::Log
 {
 public:
-	enum class Severity { s_InfoVerbose , s_InfoSummary , s_Debug , s_Warning , s_Error , s_Assertion } ;
+	enum class Severity
+	{
+		InfoVerbose ,
+		InfoSummary ,
+		Debug ,
+		Warning ,
+		Error ,
+		Assertion
+	} ;
 
-	Log( Severity , const char * file , int line ) ;
+	Log( Severity , const char * file , int line ) noexcept ;
 		///< Constructor.
 
 	~Log() ;
 		///< Destructor. Writes the accumulated string to the log output.
 
-	std::ostream & operator<<( const char * s ) ;
+	LogStream & operator<<( const char * s ) noexcept ;
 		///< Streams 's' and then returns a stream for streaming more stuff into.
 
-	std::ostream & operator<<( const std::string & s ) ;
+	LogStream & operator<<( const std::string & s ) noexcept ;
 		///< Streams 's' and then returns a stream for streaming more stuff into.
 
-	static bool at( Severity ) ;
+	static bool at( Severity ) noexcept ;
 		///< Returns true if G::LogOutput::output() would log at the given level.
 		///< This can be used as an optimisation to short-ciruit the stream-out
 		///< expression evaluation.
 
-	static bool at( Severity , const char * group ) ;
-		///< An overload that adds a logging group name to the test.
-
 public:
 	Log( const Log & ) = delete ;
 	Log( Log && ) = delete ;
-	void operator=( const Log & ) = delete ;
-	void operator=( Log && ) = delete ;
+	Log & operator=( const Log & ) = delete ;
+	Log & operator=( Log && ) = delete ;
 
 private:
 	void flush() ;
@@ -83,25 +89,25 @@ private:
 	Severity m_severity ;
 	const char * m_file ;
 	int m_line ;
-	std::ostream & m_ostream ;
+	LogStream & m_logstream ;
 } ;
 
-/// The DEBUG macro is for debugging during development, the LOG macro
-/// generates informational logging in verbose mode only, the 'summary'
-/// LOG_S macro generates informational logging even when not verbose,
-/// and the WARNING and ERROR macros are used for error warning/error
-/// messages although in programs where logging can be disabled completely (see
-/// G::LogOutput) error conditions should be made visible by some other means
-/// (such as stderr).
-///
-#define G_LOG_IMP( expr , severity ) do { try { if(G::Log::at(severity)) G::Log((severity),__FILE__,__LINE__) << expr ; } catch(...) {} } while(0)
-#define G_LOG_IMP_IF( cond , expr , severity ) do { try { if(G::Log::at(severity)&&(cond)) G::Log((severity),__FILE__,__LINE__) << expr ; } catch(...) {} } while(0)
-#define G_LOG_IMP_ONCE( expr , severity ) do { static bool done__ = false ; try { if(!done__) G::Log((severity),__FILE__,__LINE__) << expr ; } catch(...) {} done__ = true ; } while(0)
+// The DEBUG macro is for debugging during development, the LOG macro
+// generates informational logging in verbose mode only, the 'summary'
+// LOG_S macro generates informational logging even when not verbose,
+// and the WARNING and ERROR macros are used for error warning/error
+// messages although in programs where logging can be disabled completely (see
+// G::LogOutput) error conditions should be made visible by some other means
+// (such as stderr).
+//
+#define G_LOG_IMP( expr , severity ) do { if(G::Log::at(severity)) G::Log((severity),__FILE__,__LINE__) << expr ; } while(0) /* NOLINT bugprone-macro-parentheses */
+#define G_LOG_IMP_IF( cond , expr , severity ) do { if(G::Log::at(severity)&&(cond)) G::Log((severity),__FILE__,__LINE__) << expr ; } while(0) /* NOLINT bugprone-macro-parentheses */
+#define G_LOG_IMP_ONCE( expr , severity ) do { static bool done__ = false ; if(!done__&&G::Log::at(severity)) { G::Log((severity),__FILE__,__LINE__) << expr ;  done__ = true ; } } while(0) /* NOLINT bugprone-macro-parentheses */
 
 #if defined(G_WITH_DEBUG) || ( defined(_DEBUG) && ! defined(G_NO_DEBUG) )
-#define G_DEBUG( expr ) G_LOG_IMP( expr , G::Log::Severity::s_Debug )
-#define G_DEBUG_IF( cond , expr ) G_LOG_IMP_IF( cond , expr , G::Log::Severity::s_Debug )
-#define G_DEBUG_ONCE( expr ) G_LOG_IMP_ONCE( expr , G::Log::Severity::s_Debug )
+#define G_DEBUG( expr ) G_LOG_IMP( expr , G::Log::Severity::Debug )
+#define G_DEBUG_IF( cond , expr ) G_LOG_IMP_IF( cond , expr , G::Log::Severity::Debug )
+#define G_DEBUG_ONCE( expr ) G_LOG_IMP_ONCE( expr , G::Log::Severity::Debug )
 #else
 #define G_DEBUG( expr )
 #define G_DEBUG_IF( cond , expr )
@@ -109,9 +115,9 @@ private:
 #endif
 
 #if ! defined(G_NO_LOG)
-#define G_LOG( expr ) G_LOG_IMP( expr , G::Log::Severity::s_InfoVerbose )
-#define G_LOG_IF( cond , expr ) G_LOG_IMP_IF( cond , expr , G::Log::Severity::s_InfoVerbose )
-#define G_LOG_ONCE( expr ) G_LOG_IMP_ONCE( expr , G::Log::Severity::s_InfoVerbose )
+#define G_LOG( expr ) G_LOG_IMP( expr , G::Log::Severity::InfoVerbose )
+#define G_LOG_IF( cond , expr ) G_LOG_IMP_IF( cond , expr , G::Log::Severity::InfoVerbose )
+#define G_LOG_ONCE( expr ) G_LOG_IMP_ONCE( expr , G::Log::Severity::InfoVerbose )
 #else
 #define G_LOG( expr )
 #define G_LOG_IF( cond , expr )
@@ -119,9 +125,9 @@ private:
 #endif
 
 #if ! defined(G_NO_LOG_S)
-#define G_LOG_S( expr ) G_LOG_IMP( expr , G::Log::Severity::s_InfoSummary )
-#define G_LOG_S_IF( cond , expr ) G_LOG_IMP_IF( cond , expr , G::Log::Severity::s_InfoSummary )
-#define G_LOG_S_ONCE( expr ) G_LOG_IMP_ONCE( expr , G::Log::Severity::s_InfoSummary )
+#define G_LOG_S( expr ) G_LOG_IMP( expr , G::Log::Severity::InfoSummary )
+#define G_LOG_S_IF( cond , expr ) G_LOG_IMP_IF( cond , expr , G::Log::Severity::InfoSummary )
+#define G_LOG_S_ONCE( expr ) G_LOG_IMP_ONCE( expr , G::Log::Severity::InfoSummary )
 #else
 #define G_LOG_S( expr )
 #define G_LOG_S_IF( cond , expr )
@@ -129,15 +135,17 @@ private:
 #endif
 
 #if ! defined(G_NO_WARNING)
-#define G_WARNING( expr ) G_LOG_IMP( expr , G::Log::Severity::s_Warning )
-#define G_WARNING_ONCE( expr ) G_LOG_IMP_ONCE( expr , G::Log::Severity::s_Warning )
+#define G_WARNING( expr ) G_LOG_IMP( expr , G::Log::Severity::Warning )
+#define G_WARNING_IF( cond , expr ) G_LOG_IMP_IF( cond , expr , G::Log::Severity::Warning )
+#define G_WARNING_ONCE( expr ) G_LOG_IMP_ONCE( expr , G::Log::Severity::Warning )
 #else
 #define G_WARNING( expr )
+#define G_WARNING_IF( cond , expr )
 #define G_WARNING_ONCE( expr )
 #endif
 
 #if ! defined(G_NO_ERROR)
-#define G_ERROR( expr ) G_LOG_IMP( expr , G::Log::Severity::s_Error )
+#define G_ERROR( expr ) G_LOG_IMP( expr , G::Log::Severity::Error )
 #else
 #define G_ERROR( expr )
 #endif
diff --git a/src/glib/glogoutput.cpp b/src/glib/glogoutput.cpp
index 4bf895f..3e045b2 100644
--- a/src/glib/glogoutput.cpp
+++ b/src/glib/glogoutput.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,9 +23,12 @@
 #include "gdatetime.h"
 #include "gscope.h"
 #include "gfile.h"
-#include "groot.h"
+#include "ggettext.h"
 #include "gomembuf.h"
+#include "gstringview.h"
 #include "glimits.h"
+#include "groot.h"
+#include "gtest.h"
 #include <algorithm>
 #include <sstream>
 #include <stdexcept>
@@ -37,40 +40,55 @@ namespace G
 {
 	namespace LogOutputImp /// An implementation namespace for G::LogOutput.
 	{
-		static std::string s_info ;
-		static std::string s_warning ;
-		static std::string s_error ;
-		static std::string s_fatal ;
 		constexpr int stderr_fileno = 2 ; // STDERR_FILENO
 		LogOutput * this_ = nullptr ;
 		constexpr std::size_t margin = 7U ;
 		constexpr std::size_t buffer_base_size = limits::log + 40U ;
-		std::array<char,buffer_base_size+margin> buffer_1 ;
-		std::array<char,8> buffer_2 ;
-		struct ostream : std::ostream /// An ostream using a G::omembuf streambuf.
+		std::array<char,buffer_base_size+margin> buffer {} ;
+		struct ostream : std::ostream /// An ostream using G::omembuf.
 		{
 			explicit ostream( G::omembuf * p ) : std::ostream(p) {}
 			void reset() { clear() ; seekp(0) ; }
 		} ;
-		std::ostream & ostream1()
+		LogStream & ostream1()
 		{
-			static G::omembuf buf( &buffer_1[0] , buffer_1.size() ) ; // bogus clang-tidy cert-err58-cpp
+			static G::omembuf buf( &buffer[0] , buffer.size() ) ; // bogus clang-tidy cert-err58-cpp
 			static ostream s( &buf ) ;
+			static LogStream logstream( &s ) ;
 			s.reset() ;
-			return s ;
+			return logstream ;
 		}
-		std::ostream & ostream2()
+		LogStream & ostream2() noexcept
 		{
 			// an ostream for junk that gets discarded
-			static G::omembuf buf( &buffer_2[0] , buffer_2.size() ) ;
-			static ostream s( &buf ) ;
-			s.reset() ;
-			return s ;
+			static LogStream logstream( nullptr ) ; // is noexcept
+			return logstream ;
 		}
-		std::size_t tellp( std::ostream & s )
+		std::size_t tellp( LogStream & logstream )
 		{
-			s.clear() ;
-			return static_cast<std::size_t>( std::max( std::streampos(0) , s.tellp() ) ) ;
+			if( !logstream.m_ostream ) return 0U ;
+			logstream.m_ostream->clear() ;
+			return static_cast<std::size_t>( std::max( std::streampos(0) , logstream.m_ostream->tellp() ) ) ;
+		}
+		G::string_view info()
+		{
+			static std::string s( txt("info: ") ) ;
+			return {s.data(),s.size()} ;
+		}
+		G::string_view warning()
+		{
+			static std::string s( txt("warning: ") ) ;
+			return {s.data(),s.size()} ;
+		}
+		G::string_view error()
+		{
+			static std::string s( txt("error: ") ) ;
+			return {s.data(),s.size()} ;
+		}
+		G::string_view fatal()
+		{
+			static std::string s( txt("fatal: ") ) ;
+			return {s.data(),s.size()} ;
 		}
 	}
 }
@@ -82,10 +100,9 @@ G::LogOutput::LogOutput( const std::string & exename , const Config & config ,
 		m_path(path)
 {
 	updateTime() ;
-	updatePath() ;
+	updatePath( m_path , m_real_path ) ;
 	open( m_real_path , true ) ;
 	osinit() ;
-	m_depth = 0U ;
 	if( LogOutputImp::this_ == nullptr )
 		LogOutputImp::this_ = this ;
 }
@@ -101,10 +118,9 @@ G::LogOutput::LogOutput( bool output_enabled_and_summary_info ,
 		.set_debug(verbose_info_and_debug) ;
 
 	updateTime() ;
-	updatePath() ;
+	updatePath( m_path , m_real_path ) ;
 	open( m_real_path , true ) ;
 	osinit() ;
-	m_depth = 0U ;
 	if( LogOutputImp::this_ == nullptr )
 		LogOutputImp::this_ = this ;
 }
@@ -152,44 +168,70 @@ void * G::LogOutput::contextarg() noexcept
 bool G::LogOutput::at( Log::Severity severity ) const noexcept
 {
 	bool do_output = m_config.m_output_enabled ;
-	if( severity == Log::Severity::s_Debug )
+	if( severity == Log::Severity::Debug )
 		do_output = m_config.m_output_enabled && m_config.m_debug ;
-	else if( severity == Log::Severity::s_InfoSummary )
+	else if( severity == Log::Severity::InfoSummary )
 		do_output = m_config.m_output_enabled && m_config.m_summary_info ;
-	else if( severity == Log::Severity::s_InfoVerbose )
+	else if( severity == Log::Severity::InfoVerbose )
 		do_output = m_config.m_output_enabled && m_config.m_verbose_info ;
 	return do_output ;
 }
 
-std::ostream & G::LogOutput::start( Log::Severity severity , const char * , int )
+G::LogStream & G::LogOutput::start( Log::Severity severity , const char * , int ) noexcept
 {
-	if( instance() )
-		return instance()->start( severity ) ;
-	else
-		return LogOutputImp::ostream2() ;
+	try
+	{
+		if( instance() )
+			return instance()->start( severity ) ; // not noexcept
+		else
+			return LogOutputImp::ostream2() ;
+	}
+	catch(...)
+	{
+		return LogOutputImp::ostream2() ; // is noexcept
+	}
 }
 
-void G::LogOutput::output( std::ostream & ss )
+void G::LogOutput::output( LogStream & s ) noexcept
 {
-	if( instance() )
-		instance()->output( ss , 0 ) ;
+	try
+	{
+		if( instance() )
+			instance()->output( s , 0 ) ; // not noexcept
+	}
+	catch(...)
+	{
+	}
 }
 
-bool G::LogOutput::updatePath()
+bool G::LogOutput::updatePath( const std::string & path_in , std::string & path_out ) const
 {
-	std::string real_path = m_path ;
+	bool changed = false ;
+	if( !path_in.empty() )
+	{
+		std::string new_path_out = makePath( path_in ) ;
+		changed = new_path_out != path_out ;
+		path_out.swap( new_path_out ) ;
+	}
+	return changed ;
+}
+
+std::string G::LogOutput::makePath( const std::string & path_in ) const
+{
+	// this is called at most hourly, so not optimised
+	std::string path_out = path_in ;
 	std::size_t pos = 0U ;
-	if( (pos=real_path.find("%h")) != std::string::npos )
+	if( (pos=path_out.find("%d")) != std::string::npos )
 	{
-		real_path[pos] = m_time_buffer[9] ;
-		real_path[pos+1] = m_time_buffer[10] ;
+		std::string yyyymmdd( &m_time_buffer[0] , 8U ) ;
+		path_out.replace( pos , 2U , yyyymmdd ) ;
 	}
-	if( (pos=real_path.find("%d")) != std::string::npos )
+	if( (pos=path_out.find("%h")) != std::string::npos )
 	{
-		real_path.replace( pos , 2U , std::string(&m_time_buffer[0],8U) ) ;
+		path_out[pos] = m_time_buffer[9] ;
+		path_out[pos+1U] = m_time_buffer[10] ;
 	}
-	real_path.swap( m_real_path ) ;
-	return real_path != m_real_path ;
+	return path_out ;
 }
 
 void G::LogOutput::open( const std::string & path , bool do_throw )
@@ -202,15 +244,13 @@ void G::LogOutput::open( const std::string & path , bool do_throw )
 	{
 		int fd = -1 ;
 		{
+			Process::Umask set_umask( m_config.m_umask ) ;
 			Root claim_root ;
 			fd = File::open( path.c_str() , File::InOutAppend::Append ) ;
+			if( fd < 0 && do_throw )
+				throw LogFileError( path ) ;
 		}
-		if( fd < 0 )
-		{
-			if( do_throw )
-				throw std::runtime_error( "cannot open log file: " + path ) ;
-		}
-		else
+		if( fd >= 0 )
 		{
 			if( m_fd >= 0 && m_fd != LogOutputImp::stderr_fileno )
 				G::File::close( m_fd ) ;
@@ -219,39 +259,39 @@ void G::LogOutput::open( const std::string & path , bool do_throw )
 	}
 }
 
-std::ostream & G::LogOutput::start( Log::Severity severity )
+G::LogStream & G::LogOutput::start( Log::Severity severity )
 {
 	m_depth++ ;
 	if( m_depth > 1 )
 		return LogOutputImp::ostream2() ;
 
-	if( updateTime() && updatePath() )
+	if( updateTime() && updatePath(m_path,m_real_path) )
 		open( m_real_path , false ) ;
 
-	std::ostream & ss = LogOutputImp::ostream1() ;
-	ss << std::dec ;
+	LogStream & logstream = LogOutputImp::ostream1() ;
+	logstream << std::dec ;
 	if( m_exename.length() )
-		ss << m_exename << ": " ;
+		logstream << m_exename << ": " ;
 	if( m_config.m_with_timestamp )
-		appendTimeTo( ss ) ;
+		appendTimeTo( logstream ) ;
 	if( m_config.m_with_level )
-		ss << levelString( severity ) ;
+		logstream << levelString( severity ) ;
 	if( m_config.m_with_context && m_context_fn )
-		ss << (*m_context_fn)( m_context_fn_arg ) ;
+		logstream << (*m_context_fn)( m_context_fn_arg ) ;
 
-	m_start_pos = LogOutputImp::tellp( ss ) ;
+	m_start_pos = LogOutputImp::tellp( logstream ) ;
 	m_severity = severity ;
-	return ss ;
+	return logstream ;
 }
 
-void G::LogOutput::output( std::ostream & ss , int )
+void G::LogOutput::output( LogStream & logstream , int )
 {
 	// reject nested logging
 	if( m_depth ) m_depth-- ;
 	if( m_depth ) return ;
 
-	char * buffer = &LogOutputImp::buffer_1[0] ;
-	std::size_t n = LogOutputImp::tellp( ss ) ;
+	char * buffer = &LogOutputImp::buffer[0] ;
+	std::size_t n = LogOutputImp::tellp( logstream ) ;
 
 	// elipsis on overflow
 	if( n >= LogOutputImp::buffer_base_size )
@@ -294,15 +334,15 @@ void G::LogOutput::assertionFailure( const char * file , int line , const char *
 	// ('noexcept' on this fn so we std::terminate() if any of this throws)
 	if( instance() )
 	{
-		std::ostream & ss = LogOutputImp::ostream1() ;
-		ss << "assertion error: " << basename(file) << "(" << line << "): " << test_expression ;
-		char * p = &LogOutputImp::buffer_1[0] ;
-		std::size_t n = LogOutputImp::tellp( ss ) ;
-		instance()->osoutput( instance()->m_fd , Log::Severity::s_Assertion , p , n ) ;
+		LogStream & logstream = LogOutputImp::ostream1() ;
+		logstream << txt("assertion error: ") << basename(file) << "(" << line << "): " << test_expression ;
+		char * p = &LogOutputImp::buffer[0] ;
+		std::size_t n = LogOutputImp::tellp( logstream ) ;
+		instance()->osoutput( instance()->m_fd , Log::Severity::Assertion , p , n ) ;
 	}
 	else
 	{
-		std::cerr << "assertion error: " << basename(file) << "(" << line << "): " << test_expression << std::endl ;
+		std::cerr << txt("assertion error: ") << basename(file) << "(" << line << "): " << test_expression << std::endl ;
 	}
 }
 
@@ -316,21 +356,24 @@ bool G::LogOutput::updateTime()
 	SystemTime now = SystemTime::now() ;
 	m_time_us = now.us() ;
 	bool new_hour = false ;
-	if( m_time_s == 0 || m_time_s != now.s() || m_time_buffer.empty() )
+	if( m_time_s == 0 || m_time_s != now.s() || m_time_buffer[0] == '\0' )
 	{
 		m_time_s = now.s() ;
-		m_time_buffer.resize( 17U ) ;
-		now.local().format( m_time_buffer , "%Y%m%d.%H%M%S." ) ;
+		m_time_buffer[0] = '\0' ;
+		now.local().format( &m_time_buffer[0] , m_time_buffer.size() , "%Y%m%d.%H%M%S." ) ;
 		m_time_buffer[16U] = '\0' ;
+
 		new_hour = 0 != std::memcmp( &m_time_change_buffer[0] , &m_time_buffer[0] , 11U ) ;
-		std::memcpy( &m_time_change_buffer[0] , &m_time_buffer[0] , m_time_change_buffer.size() ) ;
+
+		static_assert( sizeof(m_time_change_buffer) == sizeof(m_time_buffer) , "" ) ;
+		std::memcpy( &m_time_change_buffer[0] , &m_time_buffer[0] , m_time_buffer.size() ) ;
 	}
 	return new_hour ;
 }
 
-void G::LogOutput::appendTimeTo( std::ostream & ss )
+void G::LogOutput::appendTimeTo( LogStream & logstream )
 {
-	ss
+	logstream
 		<< &m_time_buffer[0]
 		<< static_cast<char>( '0' + ( ( m_time_us / 100000U ) % 10U ) )
 		<< static_cast<char>( '0' + ( ( m_time_us / 10000U ) % 10U ) )
@@ -346,28 +389,18 @@ const char * G::LogOutput::basename( const char * file ) noexcept
 	return p1 > p2 ? (p1+1) : (p2?(p2+1):file) ;
 }
 
-const char * G::LogOutput::levelString( Log::Severity s ) noexcept
+G::string_view G::LogOutput::levelString( Log::Severity s ) noexcept
 {
 	namespace imp = LogOutputImp ;
-	if( s == Log::Severity::s_Debug ) return "debug: " ;
-	else if( s == Log::Severity::s_InfoSummary ) return imp::s_info.empty() ? "info: " : imp::s_info.c_str() ;
-	else if( s == Log::Severity::s_InfoVerbose ) return imp::s_info.empty() ? "info: " : imp::s_info.c_str() ;
-	else if( s == Log::Severity::s_Warning ) return imp::s_warning.empty() ? "warning: " : imp::s_warning.c_str() ;
-	else if( s == Log::Severity::s_Error ) return imp::s_error.empty() ? "error: " : imp::s_error.c_str() ;
-	else if( s == Log::Severity::s_Assertion ) return imp::s_fatal.empty() ? "fatal: " : imp::s_fatal.c_str() ;
+	if( s == Log::Severity::Debug ) return "debug: "_sv ;
+	else if( s == Log::Severity::InfoSummary ) return imp::info() ;
+	else if( s == Log::Severity::InfoVerbose ) return imp::info() ;
+	else if( s == Log::Severity::Warning ) return imp::warning() ;
+	else if( s == Log::Severity::Error ) return imp::error() ;
+	else if( s == Log::Severity::Assertion ) return imp::fatal() ;
 	return "" ;
 }
 
-void G::LogOutput::translate( const std::string & info , const std::string & warning ,
-	const std::string & error , const std::string & fatal )
-{
-	namespace imp = LogOutputImp ;
-	imp::s_info = info ;
-	imp::s_warning = warning ;
-	imp::s_error = error ;
-	imp::s_fatal = fatal ;
-}
-
 // ==
 
 G::LogOutput::Config::Config()
@@ -445,3 +478,9 @@ G::LogOutput::Config & G::LogOutput::Config::set_facility( SyslogFacility facili
 	return *this ;
 }
 
+G::LogOutput::Config & G::LogOutput::Config::set_umask( Process::Umask::Mode umask )
+{
+	m_umask = umask ;
+	return *this ;
+}
+
diff --git a/src/glib/glogoutput.h b/src/glib/glogoutput.h
index 3aecda0..baa704a 100644
--- a/src/glib/glogoutput.h
+++ b/src/glib/glogoutput.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,11 +23,16 @@
 
 #include "gdef.h"
 #include "glog.h"
+#include "glogstream.h"
+#include "gprocess.h"
+#include "gexception.h"
+#include "gstringview.h"
 #include <string>
 #include <vector>
 #include <fstream>
 #include <ctime>
 #include <array>
+#include <utility>
 
 namespace G
 {
@@ -49,7 +54,11 @@ namespace G
 class G::LogOutput
 {
 public:
- 	enum class SyslogFacility {
+	G_EXCEPTION( LogFileError , tx("cannot open log file") ) ;
+	G_EXCEPTION( EventLogError , tx("cannot access the system event log") ) ;
+
+	enum class SyslogFacility
+	{
 		User ,
 		Daemon ,
 		Mail ,
@@ -61,7 +70,8 @@ public:
 		Local4 ,
 		Local5 ,
 		Local6 ,
-		Local7 } ;
+		Local7
+	} ;
 
 	struct Config /// A configuration structure for G::LogOutput.
 	{
@@ -77,6 +87,7 @@ public:
 		bool m_use_syslog{false} ;
 		bool m_allow_bad_syslog{false} ;
 		SyslogFacility m_facility{SyslogFacility::User} ;
+		Process::Umask::Mode m_umask{Process::Umask::Mode::NoChange} ;
 		Config() ;
 		Config & set_output_enabled( bool value = true ) ;
 		Config & set_summary_info( bool value = true ) ;
@@ -90,15 +101,16 @@ public:
 		Config & set_use_syslog( bool value = true ) ;
 		Config & set_allow_bad_syslog( bool value = true ) ;
 		Config & set_facility( SyslogFacility ) ;
+		Config & set_umask( Process::Umask::Mode ) ;
 	} ;
 
 	LogOutput( const std::string & exename , const Config & config ,
-		const std::string & filename = std::string() ) ;
+		const std::string & filename = {} ) ;
 			///< Constructor. If there is no LogOutput object, or if
 			///< 'config.output_enabled' is false, then there is no
-			///< output of any sort (except for assertions to stderr).
-			///< Otherwise at least warning and error messages are
-			///< generated.
+			///< output at all except for assertions to stderr in a
+			///< debug build. Otherwise at least warning and error
+			///< messages are generated.
 			///<
 			///< If 'config.summary_info' is true then log-summary
 			///< messages are output. If 'config.verbose_info' is true
@@ -106,10 +118,10 @@ public:
 			///< is true then debug messages will also be generated (but
 			///< only if compiled in).
 			///<
-			///< If an output filename is given it has a "%d" substitution
-			///< applied and it is then opened or created before this
-			///< constructor returns. If no filename is given then
-			///< logging is sent to the standard error stream; the user
+			///< If an output filename is given it has "%d" and "%h"
+			///< substitutions applied and it is then opened or created
+			///< before this constructor returns. If no filename is given
+			///< then logging is sent to the standard error stream; the user
 			///< is free to close stderr and reopen it onto /dev/null if
 			///< only syslog logging is required.
 			///<
@@ -118,7 +130,7 @@ public:
 
 	explicit LogOutput( bool output_enabled_and_summary_info ,
 		bool verbose_info_and_debug = true ,
-		const std::string & filename = std::string() ) ;
+		const std::string & filename = {} ) ;
 			///< Constructor for test programs. Only generates output if the
 			///< first parameter is true. Never uses syslog.
 
@@ -137,7 +149,6 @@ public:
 
 	bool at( Log::Severity ) const noexcept ;
 		///< Returns true if logging should occur for the given severity level.
-		///< Returns false if there is no LogOutput instance.
 
 	static void context( std::string (*fn)(void*) = nullptr , void * fn_arg = nullptr ) noexcept ;
 		///< Sets a functor that is used to provide a context string for
@@ -148,14 +159,14 @@ public:
 	static void * contextarg() noexcept ;
 		///< Returns the functor argument as set by the last call to context().
 
-	static std::ostream & start( Log::Severity , const char * file , int line ) ;
+	static LogStream & start( Log::Severity , const char * file , int line ) noexcept ;
 		///< Prepares the internal ostream for a new log line and returns a
 		///< reference to it. The caller should stream out the rest of the log
 		///< line into the ostream and then call output(). Calls to start() and
 		///< output() must be strictly in pairs. Returns a pointer to a dummy
 		///< ostream if there is no LogOutput instance.
 
-	static void output( std::ostream & ) ;
+	static void output( LogStream & ) noexcept ;
 		///< Emits the current log line (see start()). Does nothing if there
 		///< is no LogOutput instance.
 
@@ -169,7 +180,7 @@ public:
 	static void assertionFailure( const char * file , int line , const char * test_expression ) noexcept ;
 		///< Reports an assertion failure.
 
-	static void assertionAbort() GDEF_NORETURN ;
+	GDEF_NORETURN_LHS static void assertionAbort() GDEF_NORETURN_RHS ;
 		///< Aborts the program when an assertion has failed.
 
 	static void register_( const std::string & exe ) ;
@@ -186,20 +197,21 @@ public:
 public:
 	LogOutput( const LogOutput & ) = delete ;
 	LogOutput( LogOutput && ) = delete ;
-	void operator=( const LogOutput & ) = delete ;
-	void operator=( LogOutput && ) = delete ;
+	LogOutput & operator=( const LogOutput & ) = delete ;
+	LogOutput & operator=( LogOutput && ) = delete ;
 
 private:
 	void osinit() ;
 	void open( const std::string & , bool ) ;
-	std::ostream & start( Log::Severity ) ;
-	void output( std::ostream & , int ) ;
+	LogStream & start( Log::Severity ) ;
+	void output( LogStream & , int ) ;
 	void osoutput( int , Log::Severity , char * , std::size_t ) ;
 	void oscleanup() const noexcept ;
 	bool updateTime() ;
-	bool updatePath() ;
-	void appendTimeTo( std::ostream & ) ;
-	static const char * levelString( Log::Severity ) noexcept ;
+	bool updatePath( const std::string & , std::string & ) const ;
+	std::string makePath( const std::string & ) const ;
+	void appendTimeTo( LogStream & ) ;
+	static G::string_view levelString( Log::Severity ) noexcept ;
 	static const char * basename( const char * ) noexcept ;
 
 private:
@@ -207,14 +219,14 @@ private:
 	Config m_config ;
 	std::time_t m_time_s{0} ;
 	unsigned int m_time_us{0U} ;
-	std::vector<char> m_time_buffer ;
+	std::array<char,17U> m_time_buffer {} ;
 	std::array<char,17U> m_time_change_buffer {} ;
 	HANDLE m_handle{0} ; // windows
-	std::string m_path ;
+	std::string m_path ; // with %d etc
 	std::string m_real_path ;
 	int m_fd{-1} ;
-	unsigned int m_depth{1U} ;
-	Log::Severity m_severity{Log::Severity::s_Debug} ;
+	unsigned int m_depth{0U} ;
+	Log::Severity m_severity{Log::Severity::Debug} ;
 	std::size_t m_start_pos{0U} ;
 	std::string (*m_context_fn)(void *){nullptr} ;
 	void * m_context_fn_arg{nullptr} ;
diff --git a/src/glib/glogoutput_unix.cpp b/src/glib/glogoutput_unix.cpp
index f47062b..2468484 100644
--- a/src/glib/glogoutput_unix.cpp
+++ b/src/glib/glogoutput_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -30,53 +30,53 @@ namespace G
 	{
 		int decode( G::LogOutput::SyslogFacility facility )
 		{
-			if( facility == G::LogOutput::SyslogFacility::User ) return LOG_USER ;
-			if( facility == G::LogOutput::SyslogFacility::Daemon ) return LOG_DAEMON ;
-			if( facility == G::LogOutput::SyslogFacility::Mail ) return LOG_MAIL ;
-			if( facility == G::LogOutput::SyslogFacility::Cron ) return LOG_CRON ;
-			if( facility == G::LogOutput::SyslogFacility::Local0 ) return LOG_LOCAL0 ;
-			if( facility == G::LogOutput::SyslogFacility::Local1 ) return LOG_LOCAL1 ;
-			if( facility == G::LogOutput::SyslogFacility::Local2 ) return LOG_LOCAL2 ;
-			if( facility == G::LogOutput::SyslogFacility::Local3 ) return LOG_LOCAL3 ;
-			if( facility == G::LogOutput::SyslogFacility::Local4 ) return LOG_LOCAL4 ;
-			if( facility == G::LogOutput::SyslogFacility::Local5 ) return LOG_LOCAL5 ;
-			if( facility == G::LogOutput::SyslogFacility::Local6 ) return LOG_LOCAL6 ;
-			if( facility == G::LogOutput::SyslogFacility::Local7 ) return LOG_LOCAL7 ;
-			return LOG_USER ;
+			if( facility == G::LogOutput::SyslogFacility::User ) return LOG_USER ; // NOLINT
+			if( facility == G::LogOutput::SyslogFacility::Daemon ) return LOG_DAEMON ; // NOLINT
+			if( facility == G::LogOutput::SyslogFacility::Mail ) return LOG_MAIL ; // NOLINT
+			if( facility == G::LogOutput::SyslogFacility::Cron ) return LOG_CRON ; // NOLINT
+			if( facility == G::LogOutput::SyslogFacility::Local0 ) return LOG_LOCAL0 ; // NOLINT
+			if( facility == G::LogOutput::SyslogFacility::Local1 ) return LOG_LOCAL1 ; // NOLINT
+			if( facility == G::LogOutput::SyslogFacility::Local2 ) return LOG_LOCAL2 ; // NOLINT
+			if( facility == G::LogOutput::SyslogFacility::Local3 ) return LOG_LOCAL3 ; // NOLINT
+			if( facility == G::LogOutput::SyslogFacility::Local4 ) return LOG_LOCAL4 ; // NOLINT
+			if( facility == G::LogOutput::SyslogFacility::Local5 ) return LOG_LOCAL5 ; // NOLINT
+			if( facility == G::LogOutput::SyslogFacility::Local6 ) return LOG_LOCAL6 ; // NOLINT
+			if( facility == G::LogOutput::SyslogFacility::Local7 ) return LOG_LOCAL7 ; // NOLINT
+			return LOG_USER ; // NOLINT
 		}
 		int decode( G::Log::Severity severity )
 		{
-			if( severity == G::Log::Severity::s_Warning ) return LOG_WARNING ;
-			if( severity == G::Log::Severity::s_Error ) return LOG_ERR ;
-			if( severity == G::Log::Severity::s_InfoSummary ) return LOG_INFO ;
-			if( severity == G::Log::Severity::s_InfoVerbose ) return LOG_INFO ;
+			if( severity == G::Log::Severity::Warning ) return LOG_WARNING ;
+			if( severity == G::Log::Severity::Error ) return LOG_ERR ;
+			if( severity == G::Log::Severity::InfoSummary ) return LOG_INFO ;
+			if( severity == G::Log::Severity::InfoVerbose ) return LOG_INFO ;
 			return LOG_CRIT ;
 		}
 		int mode( G::LogOutput::SyslogFacility facility , G::Log::Severity severity )
 		{
-			return decode(facility) | decode(severity) ;
+			return decode(facility) | decode(severity) ; // NOLINT
 		}
 	}
 }
 
 void G::LogOutput::osoutput( int fd , G::Log::Severity severity , char * message , std::size_t n )
 {
-	if( m_config.m_use_syslog && severity != Log::Severity::s_Debug )
+	if( m_config.m_use_syslog && severity != Log::Severity::Debug )
 	{
-		message[n] = '\0' ;
-		::syslog( LogOutputImp::mode(m_config.m_facility,severity) , "%s" , message ) ;
+		message[n] = '\0' ; // sic
+		::syslog( LogOutputImp::mode(m_config.m_facility,severity) , "%s" , message ) ; // NOLINT
 	}
 
 	if( m_config.m_quiet_stderr && (
-		severity == Log::Severity::s_Debug ||
-		severity == Log::Severity::s_InfoVerbose ||
-		severity == Log::Severity::s_InfoSummary ) )
+		severity == Log::Severity::Debug ||
+		severity == Log::Severity::InfoVerbose ||
+		severity == Log::Severity::InfoSummary ) )
 	{
 		;
 	}
 	else
 	{
-		message[n] = '\n' ;
+		message[n] = '\n' ; // sic
 		GDEF_IGNORE_RETURN ::write( fd , message , n+1U ) ;
 	}
 }
diff --git a/src/glib/glogoutput_win32.cpp b/src/glib/glogoutput_win32.cpp
index 90b03d6..d44b3eb 100644
--- a/src/glib/glogoutput_win32.cpp
+++ b/src/glib/glogoutput_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -75,18 +75,18 @@ void G::LogOutput::osoutput( int fd , G::Log::Severity severity , char * message
 	// event log
 	//
 	if( m_config.m_use_syslog &&
-		severity != Log::Severity::s_Debug &&
-		severity != Log::Severity::s_InfoVerbose && // (new)
+		severity != Log::Severity::Debug &&
+		severity != Log::Severity::InfoVerbose &&
 		m_handle != HNULL )
 	{
 		DWORD id = 0x400003E9L ; // 1001
 		WORD type = EVENTLOG_INFORMATION_TYPE ;
-		if( severity == Log::Severity::s_Warning )
+		if( severity == Log::Severity::Warning )
 		{
 			id = 0x800003EAL ; // 1002
 			type = EVENTLOG_WARNING_TYPE ;
 		}
-		else if( severity == Log::Severity::s_Error || severity == Log::Severity::s_Assertion )
+		else if( severity == Log::Severity::Error || severity == Log::Severity::Assertion )
 		{
 			id = 0xC00003EBL ; // 1003
 			type = EVENTLOG_ERROR_TYPE ;
@@ -99,7 +99,8 @@ void G::LogOutput::osoutput( int fd , G::Log::Severity severity , char * message
 
 		message[n] = '\0' ;
 		const char * p[] = { message , nullptr } ;
-		GDEF_UNUSED BOOL rc = ReportEventA( m_handle , type , 0 , id , nullptr , 1 , 0 , p , nullptr ) ;
+		BOOL rc = ReportEventA( m_handle , type , 0 , id , nullptr , 1 , 0 , p , nullptr ) ;
+		GDEF_IGNORE_VARIABLE( rc ) ;
 	}
 
 	// standard error or log file -- note that stderr is not accessible if a gui
@@ -121,7 +122,7 @@ void G::LogOutput::osinit()
 			G::LogOutput::register_( this_exe ) ;
 			m_handle = RegisterEventSourceA( nullptr , this_name.c_str() ) ;
 			if( m_handle == HNULL && !m_config.m_allow_bad_syslog )
-				throw std::runtime_error( "cannot access the system event log" ) ;
+				throw EventLogError() ;
 		}
 	}
 }
diff --git a/src/glib/glogstream.cpp b/src/glib/glogstream.cpp
new file mode 100644
index 0000000..1325733
--- /dev/null
+++ b/src/glib/glogstream.cpp
@@ -0,0 +1,120 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file glogstream.cpp
+///
+
+#include "gdef.h"
+#include "glogstream.h"
+#include <ostream>
+
+G::LogStream & G::operator<<( LogStream & s , const std::string & value ) noexcept
+{
+	try
+	{
+		if( s.m_ostream ) *(s.m_ostream) << value ;
+	}
+	catch(...)
+	{
+	}
+	return s ;
+}
+
+G::LogStream & G::operator<<( LogStream & s , const char * value ) noexcept
+{
+	try
+	{
+		if( s.m_ostream ) *(s.m_ostream) << value ;
+	}
+	catch(...)
+	{
+	}
+	return s ;
+}
+
+G::LogStream & G::operator<<( LogStream & s , char value ) noexcept
+{
+	try
+	{
+		if( s.m_ostream ) *(s.m_ostream) << value ;
+	}
+	catch(...)
+	{
+	}
+	return s ;
+}
+
+G::LogStream & G::operator<<( LogStream & s , unsigned char value ) noexcept
+{
+	try
+	{
+		if( s.m_ostream ) *(s.m_ostream) << value ;
+	}
+	catch(...)
+	{
+	}
+	return s ;
+}
+
+G::LogStream & G::operator<<( LogStream & s , int value ) noexcept
+{
+	try
+	{
+		if( s.m_ostream ) *(s.m_ostream) << value ;
+	}
+	catch(...)
+	{
+	}
+	return s ;
+}
+
+G::LogStream & G::operator<<( LogStream & s , unsigned int value ) noexcept
+{
+	try
+	{
+		if( s.m_ostream ) *(s.m_ostream) << value ;
+	}
+	catch(...)
+	{
+	}
+	return s ;
+}
+
+G::LogStream & G::operator<<( LogStream & s , long value ) noexcept
+{
+	try
+	{
+		if( s.m_ostream ) *(s.m_ostream) << value ;
+	}
+	catch(...)
+	{
+	}
+	return s ;
+}
+
+G::LogStream & G::operator<<( LogStream & s , unsigned long value ) noexcept
+{
+	try
+	{
+		if( s.m_ostream ) *(s.m_ostream) << value ;
+	}
+	catch(...)
+	{
+	}
+	return s ;
+}
+
diff --git a/src/glib/glogstream.h b/src/glib/glogstream.h
new file mode 100644
index 0000000..150c489
--- /dev/null
+++ b/src/glib/glogstream.h
@@ -0,0 +1,73 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file glogstream.h
+///
+
+#ifndef G_LOG_STREAM_H
+#define G_LOG_STREAM_H
+
+#include "gdef.h"
+#include <ios>
+
+namespace G
+{
+	//| \class G::LogStream
+	/// A non-throwing wrapper for std::ostream, used by G::Log.
+	/// This allows streaming to a G::Log instance to be inherently
+	/// non-throwing without needing a try/catch block at every
+	/// call site. The most common streaming operators are
+	/// implemented out-of-line as a modest code size optimisation.
+	///
+	struct LogStream
+	{
+		explicit LogStream( std::ostream * s ) noexcept :
+			m_ostream(s)
+		{
+		}
+		std::ostream * m_ostream ;
+	} ;
+}
+
+namespace G
+{
+	LogStream & operator<<( LogStream & s , const std::string & ) noexcept ;
+	LogStream & operator<<( LogStream & s , const char * ) noexcept ;
+	LogStream & operator<<( LogStream & s , char ) noexcept ;
+	LogStream & operator<<( LogStream & s , unsigned char ) noexcept ;
+	LogStream & operator<<( LogStream & s , int ) noexcept ;
+	LogStream & operator<<( LogStream & s , unsigned int ) noexcept ;
+	LogStream & operator<<( LogStream & s , long ) noexcept ;
+	LogStream & operator<<( LogStream & s , unsigned long ) noexcept ;
+
+	template <typename T> LogStream & operator<<( LogStream & s , const T & t ) noexcept
+	{
+		if( s.m_ostream )
+		{
+			try
+			{
+					*(s.m_ostream) << t ;
+			}
+			catch(...)
+			{
+			}
+		}
+		return s ;
+	}
+}
+
+#endif
diff --git a/src/glib/gmapfile.cpp b/src/glib/gmapfile.cpp
index 54ca996..d177c22 100644
--- a/src/glib/gmapfile.cpp
+++ b/src/glib/gmapfile.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,6 +21,7 @@
 #include "gdef.h"
 #include "gmapfile.h"
 #include "gstr.h"
+#include "gstringtoken.h"
 #include "gpath.h"
 #include "gprocess.h"
 #include "gdatetime.h"
@@ -37,8 +38,8 @@
 G::MapFile::MapFile()
 = default;
 
-G::MapFile::MapFile( const G::Path & path , const std::string & kind ) :
-	m_kind(kind)
+G::MapFile::MapFile( const Path & path , string_view kind ) :
+	m_kind(sv_to_string(kind))
 {
 	if( !path.empty() )
 	{
@@ -52,7 +53,7 @@ G::MapFile::MapFile( std::istream & stream )
 	readFrom( stream ) ;
 }
 
-G::MapFile::MapFile( const G::StringMap & map ) :
+G::MapFile::MapFile( const StringMap & map ) :
 	m_map(map)
 {
 	m_keys.reserve( m_map.size() ) ;
@@ -60,14 +61,14 @@ G::MapFile::MapFile( const G::StringMap & map ) :
 		m_keys.push_back( p.first ) ;
 }
 
-G::MapFile::MapFile( const OptionMap & map , const std::string & yes )
+G::MapFile::MapFile( const OptionMap & map , string_view yes )
 {
 	for( auto p = map.begin() ; p != map.end() ; )
 	{
-		std::string key = (*p).first ;
+		const std::string & key = (*p).first ;
 		if( !(*p).second.isOff() )
 		{
-			std::string value = (*p).second.isOn() ? yes : map.value(key) ;
+			std::string value = (*p).second.isOn() ? sv_to_string(yes) : map.value(key) ;
 			add( key , value ) ;
 		}
 		while( p != map.end() && (*p).first == key ) // since we used OptionMap::value() to get them all
@@ -75,16 +76,16 @@ G::MapFile::MapFile( const OptionMap & map , const std::string & yes )
 	}
 }
 
-void G::MapFile::readFrom( const G::Path & path , const std::string & kind )
+void G::MapFile::readFrom( const Path & path , string_view kind )
 {
 	std::ifstream stream ;
 	File::open( stream , path , File::Text() ) ;
 	if( !stream.good() )
-		throw readError( path , kind ) ;
+		throw readError( path , sv_to_string(kind) ) ;
 	G_LOG( "MapFile::read: reading [" << path.str() << "]" ) ;
 	readFrom( stream ) ;
 	if( stream.bad() ) // eg. EISDIR
-		throw readError( path , kind ) ;
+		throw readError( path , sv_to_string(kind) ) ;
 }
 
 void G::MapFile::readFrom( std::istream & stream )
@@ -92,8 +93,8 @@ void G::MapFile::readFrom( std::istream & stream )
 	std::string line ;
 	while( stream.good() )
 	{
-		Str::readLineFrom( stream , "\n" , line ) ;
-		Str::trimRight( line , {"\r",1U} ) ;
+		Str::readLineFrom( stream , "\n"_sv , line ) ;
+		Str::trimRight( line , "\r"_sv ) ;
 		if( line.empty() )
 			continue ;
 		if( !stream )
@@ -102,22 +103,20 @@ void G::MapFile::readFrom( std::istream & stream )
 			continue ;
 
 		// no escaping here -- just strip quotes if the value starts and ends with them
-		std::string key ;
-		std::string value ;
-		{
-			StringArray parts ;
-			Str::splitIntoTokens( line , parts , " =\t" ) ;
-			if( parts.empty() )
-				continue ;
-			key = parts[0] ;
 
-			value = Str::tail( line , line.find(key)+key.size() , std::string() ) ;
-			Str::trimLeft( value , {" =\t",3U} ) ;
-			Str::trimRight( value , Str::ws() ) ;
+		G::string_view line_sv( line ) ;
+		StringTokenView t( line_sv , " =\t"_sv ) ;
+		if( !t.valid() )
+			continue ;
+
+		string_view key = t() ;
+		auto pos = line.find( key.data() , 0U , key.size() ) + key.size() ;
+		string_view value = Str::tailView( line , pos ) ;
+		value = Str::trimLeftView( value , " =\t"_sv ) ;
+		value = Str::trimRightView( value , Str::ws() ) ;
+		if( value.size() >= 2U && value.at(0U) == '"' && value.at(value.size()-1U) == '"' )
+			value = value.substr(1U,value.length()-2U) ;
 
-			if( value.length() >= 2U && value.at(0U) == '"' && value.at(value.length()-1U) == '"' )
-				value = value.substr(1U,value.length()-2U) ;
-		}
 		add( key , value ) ;
 	}
 }
@@ -129,13 +128,10 @@ bool G::MapFile::ignore( const std::string & line ) const
 		return true ;
 
 	std::string::size_type pos_hash = line.find('#') ;
-	if( pos_hash != std::string::npos && pos_hash < pos_interesting )
-		return true ;
-
-	return false ;
+	return pos_hash != std::string::npos && pos_hash < pos_interesting ;
 }
 
-void G::MapFile::check( const G::Path & path , const std::string & kind )
+void G::MapFile::check( const Path & path , string_view kind )
 {
 	MapFile tmp ;
 	tmp.readFrom( path , kind ) ;
@@ -146,7 +142,7 @@ void G::MapFile::log( const std::string & prefix_in ) const
 	std::string prefix = prefix_in.empty() ? std::string() : ( prefix_in + ": " ) ;
 	for( const auto & key : m_keys )
 	{
-		auto p = m_map.find( key ) ;
+		auto p = find( key ) ;
 		if( p == m_map.end() ) continue ;
 		std::string value = (*p).second ;
 		G_LOG( "MapFile::item: " << prefix << key << "=[" <<
@@ -157,13 +153,16 @@ void G::MapFile::log( const std::string & prefix_in ) const
 	}
 }
 
-void G::MapFile::writeItem( std::ostream & stream , const std::string & key ) const
+void G::MapFile::writeItem( std::ostream & stream , string_view key ) const
 {
-	std::string value = m_map.find(key) == m_map.end() ? std::string() : (*m_map.find(key)).second ;
-	writeItem( stream , key , value ) ;
+	auto p = find( key ) ;
+	if( p == m_map.end() )
+		writeItem( stream , key , {} ) ;
+	else
+		writeItem( stream , key , (*p).second ) ;
 }
 
-void G::MapFile::writeItem( std::ostream & stream , const std::string & key , const std::string & value )
+void G::MapFile::writeItem( std::ostream & stream , string_view key , string_view value )
 {
 	const char * qq = value.find(' ') == std::string::npos ? "" : "\"" ;
 	stream << key << "=" << qq << value << qq << "\n" ;
@@ -174,7 +173,7 @@ std::string G::MapFile::quote( const std::string & s )
 	return s.find_first_of(" \t") == std::string::npos ? s : ("\""+s+"\"") ;
 }
 
-void G::MapFile::editInto( const G::Path & path , bool make_backup ,
+void G::MapFile::editInto( const Path & path , bool make_backup ,
 	bool allow_read_error , bool allow_write_error ) const
 {
 	List lines = read( path , m_kind , allow_read_error ) ;
@@ -184,7 +183,7 @@ void G::MapFile::editInto( const G::Path & path , bool make_backup ,
 	save( path , lines , allow_write_error ) ;
 }
 
-G::MapFile::List G::MapFile::read( const G::Path & path , const std::string & kind , bool allow_read_error ) const
+G::MapFile::List G::MapFile::read( const Path & path , string_view kind , bool allow_read_error ) const
 {
 	List line_list ;
 	std::ifstream file_in ;
@@ -194,7 +193,7 @@ G::MapFile::List G::MapFile::read( const G::Path & path , const std::string & ki
 	while( file_in.good() )
 	{
 		std::string line = Str::readLineFrom( file_in , "\n" ) ;
-		Str::trimRight( line , {"\r",1U} ) ;
+		Str::trimRight( line , "\r"_sv ) ;
 		if( !file_in ) break ;
 		line_list.push_back( line ) ;
 	}
@@ -219,13 +218,13 @@ void G::MapFile::replace( List & line_list ) const
 		for( auto & line : line_list )
 		{
 			if( line.empty() ) continue ;
-			StringArray parts ;
-			Str::splitIntoTokens( line , parts , " \r\n\t=#" ) ;
-			if( parts.empty() ) continue ;
-			if( parts.at(0U) == map_item.first )
+			G::string_view line_sv( line ) ;
+			StringTokenView t( line_sv , " \r\n\t=#"_sv ) ;
+			if( !t ) continue ;
+			if( G::Str::match( map_item.first , t() ) )
 			{
-				std::string value = map_item.second ;
-				line = Str::trimmed( map_item.first + " " + quote(value) , Str::ws() ) ;
+				const std::string & value = map_item.second ;
+				line = Str::trimmed( std::string(map_item.first).append(1U,' ').append(quote(value)) , Str::ws() ) ;
 				found = true ;
 				break ;
 			}
@@ -233,13 +232,13 @@ void G::MapFile::replace( List & line_list ) const
 
 		if( !found )
 		{
-			std::string value = map_item.second ;
-			line_list.push_back( Str::trimmed( map_item.first + " " + quote(value) , Str::ws() ) ) ;
+			const std::string & value = map_item.second ;
+			line_list.push_back( Str::trimmed( std::string(map_item.first).append(1U,' ').append(quote(value)) , Str::ws() ) ) ;
 		}
 	}
 }
 
-void G::MapFile::backup( const G::Path & path )
+void G::MapFile::backup( const Path & path )
 {
 	// ignore errors
 	BrokenDownTime now = SystemTime::now().local() ;
@@ -249,7 +248,7 @@ void G::MapFile::backup( const G::Path & path )
 	File::copy( path , backup , std::nothrow ) ;
 }
 
-void G::MapFile::save( const G::Path & path , List & line_list , bool allow_write_error )
+void G::MapFile::save( const Path & path , List & line_list , bool allow_write_error )
 {
 	std::ofstream file_out ;
 	File::open( file_out , path , File::Text() ) ;
@@ -259,9 +258,9 @@ void G::MapFile::save( const G::Path & path , List & line_list , bool allow_writ
 		throw writeError( path ) ;
 }
 
-bool G::MapFile::booleanValue( const std::string & key , bool default_ ) const
+bool G::MapFile::booleanValue( string_view key , bool default_ ) const
 {
-	auto p = m_map.find( key ) ;
+	auto p = find( key ) ;
 	if( p == m_map.end() )
 	{
 		return default_ ;
@@ -272,58 +271,51 @@ bool G::MapFile::booleanValue( const std::string & key , bool default_ ) const
 	}
 	else
 	{
-		return G::Str::isPositive( (*p).second ) ;
+		return Str::isPositive( (*p).second ) ;
 	}
 }
 
-std::string G::MapFile::value( const std::string & key , const std::string & default_ ) const
+std::string G::MapFile::value( string_view key , string_view default_ ) const
 {
-	auto p = m_map.find( key ) ;
-	std::string result = ( p == m_map.end() || (*p).second.empty() ) ? default_ : (*p).second ;
-	return result ;
+	auto p = find( key ) ;
+	return ( p == m_map.end() || (*p).second.empty() ) ? sv_to_string(default_) : (*p).second ;
 }
 
-std::string G::MapFile::value( const std::string & key , const char * default_ ) const
+std::string G::MapFile::mandatoryValue( string_view key ) const
 {
-	return value( key , std::string(default_) ) ;
-}
-
-std::string G::MapFile::mandatoryValue( const std::string & key ) const
-{
-	if( m_map.find(key) == m_map.end() )
-		throw missingValueError( m_path , m_kind , key ) ;
+	if( find(key) == m_map.end() )
+		throw missingValueError( m_path , m_kind , sv_to_string(key) ) ;
 	return value( key ) ;
 }
 
-G::Path G::MapFile::pathValue( const std::string & key ) const
+G::Path G::MapFile::expandedPathValue( string_view key , const Path & default_ ) const
 {
-	return Path( mandatoryValue(key) ) ;
+	return { expand(value(key,default_.str())) } ;
 }
 
-G::Path G::MapFile::expandedPathValue( const std::string & key ) const
+G::Path G::MapFile::expandedPathValue( string_view key ) const
 {
-	return Path( expand(mandatoryValue(key)) ) ;
+	return { expand(mandatoryValue(key)) } ;
 }
 
-G::Path G::MapFile::pathValue( const std::string & key , const G::Path & default_ ) const
+G::Path G::MapFile::pathValue( string_view key , const Path & default_ ) const
 {
-	return Path( value(key,default_.str()) ) ;
+	return { value(key,default_.str()) } ;
 }
 
-G::Path G::MapFile::expandedPathValue( const std::string & key , const G::Path & default_ ) const
+G::Path G::MapFile::pathValue( string_view key ) const
 {
-	return Path( expand(value(key,default_.str())) ) ;
+	return { mandatoryValue(key) } ;
 }
 
-unsigned int G::MapFile::numericValue( const std::string & key , unsigned int default_ ) const
+unsigned int G::MapFile::numericValue( string_view key , unsigned int default_ ) const
 {
-	std::string s = value( key , std::string() ) ;
-	return !s.empty() && Str::isUInt(s) ? Str::toUInt( s ) : default_ ;
+	return Str::toUInt( value(key,{}) , default_ ) ;
 }
 
-void G::MapFile::remove( const std::string & key )
+void G::MapFile::remove( string_view key )
 {
-	auto p = m_map.find( key ) ;
+	auto p = find( key ) ;
 	if( p != m_map.end() )
 	{
 		m_map.erase( p ) ;
@@ -332,9 +324,9 @@ void G::MapFile::remove( const std::string & key )
 	}
 }
 
-std::string G::MapFile::expand( const std::string & value_in ) const
+std::string G::MapFile::expand( string_view value_in ) const
 {
-	std::string value( value_in ) ;
+	std::string value = sv_to_string(value_in) ;
 	expand_( value ) ;
 	return value ;
 }
@@ -388,7 +380,7 @@ bool G::MapFile::expand_( std::string & value ) const
 		if( end == npos ) break ;
 		end++ ;
 		std::string key = value.substr( start+1U , end-start-2U ) ;
-		auto p = m_map.find( key ) ;
+		auto p = find( key ) ;
 		if( p != m_map.end() )
 		{
 			std::size_t old = end - start ;
@@ -402,27 +394,38 @@ bool G::MapFile::expand_( std::string & value ) const
 	return changed ;
 }
 
-void G::MapFile::add( const std::string & key , const std::string & value , bool clear )
+void G::MapFile::add( string_view key_in , string_view value , bool clear )
 {
-	if( m_map.find(key) == m_map.end() )
+	std::string key = sv_to_string( key_in ) ;
+	if( find(key) == m_map.end() )
 	{
 		m_keys.push_back( key ) ;
-		m_map[key] = value ;
+		m_map[key] = sv_to_string(value) ;
 	}
 	else if( clear )
 	{
-		m_map[key] = value ;
+		m_map[key] = sv_to_string(value) ;
 	}
 	else
 	{
 		m_map[key].append( 1U , ',' ) ;
-		m_map[key].append( value ) ;
+		m_map[key].append( value.data() , value.size() ) ;
 	}
 }
 
-bool G::MapFile::contains( const std::string & key ) const
+G::StringMap::iterator G::MapFile::find( string_view key )
 {
-	return m_map.find( key ) != m_map.end() ;
+	return m_map.find( sv_to_string(key) ) ; // or c++14 'generic associative lookup' of string_view
+}
+
+G::StringMap::const_iterator G::MapFile::find( string_view key ) const
+{
+	return m_map.find( sv_to_string(key) ) ; // or c++14 'generic associative lookup' of string_view
+}
+
+bool G::MapFile::contains( string_view key ) const
+{
+	return find( key ) != m_map.end() ;
 }
 
 const G::StringMap & G::MapFile::map() const
@@ -435,32 +438,30 @@ const G::StringArray & G::MapFile::keys() const
 	return m_keys ;
 }
 
-std::string G::MapFile::ekind( const std::string & kind_in )
+std::string G::MapFile::ekind( string_view kind )
 {
-	return kind_in.empty() ? std::string("map") : kind_in ;
+	return kind.empty() ? std::string("map") : sv_to_string(kind) ;
 }
 
-std::string G::MapFile::epath( const G::Path & path_in )
+std::string G::MapFile::epath( const Path & path_in )
 {
 	return path_in.empty() ? std::string() : (" ["+path_in.str()+"]") ;
 }
 
-G::MapFile::Error G::MapFile::readError( const Path & path , const std::string & kind_in )
+G::MapFile::Error G::MapFile::readError( const Path & path , string_view kind )
 {
-	std::string description = "cannot read " + ekind(kind_in) + " file" + epath(path) ;
+	std::string description = "cannot read " + ekind(kind) + " file" + epath(path) ;
 	return Error( description ) ;
 }
 
-G::MapFile::Error G::MapFile::writeError( const Path & path , const std::string & kind_in )
+G::MapFile::Error G::MapFile::writeError( const Path & path , string_view kind )
 {
-	std::string description = "cannot create " + ekind(kind_in) + " file" + epath(path) ;
-	return Error( description ) ;
+	return Error( std::string("cannot create ").append(ekind(kind)).append(" file ").append(epath(path)) ) ;
 }
 
 G::MapFile::Error G::MapFile::missingValueError( const Path & path , const std::string & kind ,
 	const std::string & key )
 {
-	std::string description = "no item [" + key + "] in " + ekind(kind) + " file" + epath(path) ;
-	return Error( description ) ;
+	return Error( std::string("no item [").append(key).append("] in ").append(ekind(kind)).append(" file ").append(epath(path)) ) ;
 }
 
diff --git a/src/glib/gmapfile.h b/src/glib/gmapfile.h
index 26a6544..174caa0 100644
--- a/src/glib/gmapfile.h
+++ b/src/glib/gmapfile.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,12 +23,12 @@
 
 #include "gdef.h"
 #include "gpath.h"
-#include "gstrings.h"
+#include "gstringarray.h"
+#include "gstringmap.h"
 #include "gexception.h"
 #include "goptions.h"
 #include "goptionvalue.h"
 #include "goptionmap.h"
-#include <map>
 #include <string>
 #include <iostream>
 
@@ -64,10 +64,10 @@ public:
 	MapFile() ;
 		///< Constructor for an empty map.
 
-	explicit MapFile( const G::StringMap & map ) ;
+	explicit MapFile( const StringMap & map ) ;
 		///< Constructor that initialises from a string map.
 
-	explicit MapFile( const OptionMap & map , const std::string & yes = std::string() ) ;
+	explicit MapFile( const OptionMap & map , string_view yes = {} ) ;
 		///< Constructor that initialises from an option value map,
 		///< typically parsed out from a command-line. Unvalued 'on'
 		///< options in the option value map are loaded into this
@@ -76,74 +76,73 @@ public:
 		///< Multi-valued options are loaded as a comma-separated
 		///< list.
 
-	explicit MapFile( const G::Path & , const std::string & kind = std::string() ) ;
+	explicit MapFile( const Path & , string_view kind = {} ) ;
 		///< Constructor that reads from a file. Lines can have a key
 		///< and no value (see booleanValue()). Comments must be at
 		///< the start of the line. Values are left and right-trimmed,
-		///< but can otherwise contain whitespace.
+		///< but can otherwise contain whitespace. The trailing parameter
+		///< is used in error messages to describe the kind of file,
+		///< defaulting to "map".
 
 	explicit MapFile( std::istream & ) ;
 		///< Constructor that reads from a stream.
 
-	const G::StringArray & keys() const ;
+	const StringArray & keys() const ;
 		///< Returns a reference to the internal ordered list of keys.
 
-	static void check( const G::Path & , const std::string & kind = std::string() ) ;
+	static void check( const Path & , string_view kind = {} ) ;
 		///< Throws if the file is invalid. This is equivalent to
 		///< constructing a temporary MapFile object, but it
 		///< specifically does not do any logging.
 
-	void add( const std::string & key , const std::string & value , bool clear = false ) ;
+	void add( string_view key , string_view value , bool clear = false ) ;
 		///< Adds or updates a single item in the map.
 		///< If updating then by default the new value
 		///< is appended with a comma separator.
 
-	void writeItem( std::ostream & , const std::string & key ) const ;
+	void writeItem( std::ostream & , string_view key ) const ;
 		///< Writes a single item from this map to the stream.
 
-	static void writeItem( std::ostream & , const std::string & key , const std::string & value ) ;
+	static void writeItem( std::ostream & , string_view key , string_view value ) ;
 		///< Writes an arbitrary item to the stream.
 
-	void editInto( const G::Path & path , bool make_backup ,
+	void editInto( const Path & path , bool make_backup ,
 		bool allow_read_error , bool allow_write_error ) const ;
 			///< Edits an existing file so that its contents
 			///< reflect this map.
 
-	bool contains( const std::string & key ) const ;
+	bool contains( string_view key ) const ;
 		///< Returns true if the map contains the given key.
 
-	G::Path pathValue( const std::string & key ) const ;
+	Path pathValue( string_view key ) const ;
 		///< Returns a mandatory path value from the map.
 		///< Throws if it does not exist.
 
-	G::Path pathValue( const std::string & key , const G::Path & default_ ) const ;
+	Path pathValue( string_view key , const Path & default_ ) const ;
 		///< Returns a path value from the map.
 
-	unsigned int numericValue( const std::string & key , unsigned int default_ ) const ;
+	unsigned int numericValue( string_view key , unsigned int default_ ) const ;
 		///< Returns a numeric value from the map.
 
-	std::string value( const std::string & key , const std::string & default_ = std::string() ) const ;
+	std::string value( string_view key , string_view default_ = {} ) const ;
 		///< Returns a string value from the map. Returns the default
 		///< if there is no such key or if the value is empty.
 
-	std::string value( const std::string & key , const char * default_ ) const ;
-		///< Returns a string value from the map.
-
-	bool booleanValue( const std::string & key , bool default_ ) const ;
+	bool booleanValue( string_view key , bool default_ ) const ;
 		///< Returns a boolean value from the map. Returns true if
 		///< the key exists with an empty value. Returns the default
 		///< if no such key.
 
-	void remove( const std::string & key ) ;
+	void remove( string_view key ) ;
 		///< Removes a value (if it exists).
 
-	const G::StringMap & map() const ;
+	const StringMap & map() const ;
 		///< Returns a reference to the internal map.
 
-	void log( const std::string & prefix = std::string() ) const ;
+	void log( const std::string & prefix = {} ) const ;
 		///< Logs the contents.
 
-	std::string expand( const std::string & value ) const ;
+	std::string expand( string_view value ) const ;
 		///< Does one-pass variable substitution for the given string.
 		///< Sub-strings like "%xyz%" are replaced by 'value("xyz")'
 		///< and "%%" is replaced by "%". If there is no appropriate
@@ -151,38 +150,40 @@ public:
 		///< (so "%xyz%" remains as "%xyz%" if there is no "xyz"
 		///< map item).
 
-	G::Path expandedPathValue( const std::string & key ) const ;
+	Path expandedPathValue( string_view key ) const ;
 		///< Returns a mandatory path value from the map
 		///< with expand(). Throws if it does not exist.
 
-	G::Path expandedPathValue( const std::string & key , const G::Path & default_ ) const ;
+	Path expandedPathValue( string_view key , const Path & default_ ) const ;
 		///< Returns a path value from the map with expand().
 
 private:
 	using List = std::list<std::string> ;
-	void readFrom( const G::Path & , const std::string & ) ;
+	void readFrom( const Path & , string_view ) ;
 	void readFrom( std::istream & ss ) ;
 	static std::string quote( const std::string & ) ;
-	List read( const G::Path & , const std::string & , bool ) const ;
+	List read( const Path & , string_view , bool ) const ;
 	void commentOut( List & ) const ;
 	void replace( List & ) const ;
 	bool expand_( std::string & ) const ;
-	std::string expandAll( const std::string & ) const ;
-	static void backup( const G::Path & ) ;
-	static void save( const G::Path & , List & , bool ) ;
-	std::string mandatoryValue( const std::string & ) const ;
+	std::string expandAll( string_view ) const ;
+	static void backup( const Path & ) ;
+	static void save( const Path & , List & , bool ) ;
+	std::string mandatoryValue( string_view ) const ;
 	bool ignore( const std::string & ) const ;
-	static std::string ekind( const std::string & ) ;
-	static std::string epath( const G::Path & ) ;
-	static Error readError( const G::Path & , const std::string & ) ;
-	static Error writeError( const G::Path & , const std::string & = std::string() ) ;
-	static Error missingValueError( const G::Path & , const std::string & , const std::string & ) ;
+	static std::string ekind( string_view ) ;
+	static std::string epath( const Path & ) ;
+	static Error readError( const Path & , string_view ) ;
+	static Error writeError( const Path & , string_view = {} ) ;
+	static Error missingValueError( const Path & , const std::string & , const std::string & ) ;
+	StringMap::const_iterator find( string_view ) const ;
+	StringMap::iterator find( string_view ) ;
 
 private:
-	G::Path m_path ; // if any
+	Path m_path ; // if any
 	std::string m_kind ;
-	G::StringMap m_map ;
-	G::StringArray m_keys ; // kept in input order
+	StringMap m_map ;
+	StringArray m_keys ; // kept in input order
 } ;
 
 #endif
diff --git a/src/glib/gmd5.cpp b/src/glib/gmd5.cpp
index 4773eb9..d29fbbd 100644
--- a/src/glib/gmd5.cpp
+++ b/src/glib/gmd5.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -60,6 +60,11 @@ public:
 		// message string. Do not use add() with this
 		// constructor.
 
+	explicit digest( G::string_view ) ;
+		// Constuctor. Calculates a digest for the given
+		// message data. Do not use add() with this
+		// constructor.
+
 	explicit digest( digest_state ) ;
 		// Constructor taking the result of an earlier call
 		// to state(). This allows calculation of a digest
@@ -127,14 +132,13 @@ public:
 class G::Md5Imp::block
 {
 public:
-	block( const std::string & s , small_t block_offset , big_t end_value ) ;
-		// Constructor. Unusually, the string reference is
-		// kept, so beware of binding temporaries.
+	block( const char * data_p , std::size_t data_n , small_t block_offset , big_t end_value ) ;
+		// Constructor. The data pointer is kept.
 		//
 		// The 'block-offset' indicates, in units of 64-character
-		// blocks, how far down 's' the current block's data is.
+		// blocks, how far into 'p' the current block's data is.
 		//
-		// The string must hold at least 64 bytes beyond the
+		// The data pointer must have at least 64 bytes beyond the
 		// 'block-offset' point, except for the last block in
 		// a message sequence. Note that this is the number
 		// of blocks, not the number of bytes.
@@ -162,15 +166,16 @@ public:
 	~block() = default ;
 	block( const block & ) = delete ;
 	block( block && ) = delete ;
-	void operator=( const block & ) = delete ;
-	void operator=( block && ) = delete ;
+	block & operator=( const block & ) = delete ;
+	block & operator=( block && ) = delete ;
 
 private:
 	small_t x( small_t ) const ;
 	static small_t rounded( small_t n ) ;
 
 private:
-	const std::string & m_s ;
+	const char * m_p ;
+	std::size_t m_n ;
 	small_t m_block ;
 	big_t m_end_value ;
 } ;
@@ -187,10 +192,22 @@ G::Md5Imp::digest::digest( const std::string & s ) :
 	digest_state{}
 {
 	init() ;
-	small_t n = block::blocks( s.length() ) ;
-	for( small_t i = 0U ; i < n ; ++i )
+	small_t nblocks = block::blocks( s.size() ) ;
+	for( small_t i = 0U ; i < nblocks ; ++i )
 	{
-		block blk( s , i , block::end(s.length()) ) ;
+		block blk( s.data() , s.size() , i , block::end(s.size()) ) ;
+		add( blk ) ;
+	}
+}
+
+G::Md5Imp::digest::digest( string_view sv ) :
+	digest_state{}
+{
+	init() ;
+	small_t nblocks = block::blocks( sv.size() ) ;
+	for( small_t i = 0U ; i < nblocks ; ++i )
+	{
+		block blk( sv.data() , sv.size() , i , block::end(sv.size()) ) ;
 		add( blk ) ;
 	}
 }
@@ -327,7 +344,7 @@ G::Md5Imp::big_t G::Md5Imp::digest::T( small_t i )
 {
 	// T = static_cast<big_t>( 4294967296.0 * std::fabs(std::sin(static_cast<double>(i))) ) for 1 <= i <= 64
 	//
-	static std::array<big_t,64U> t_map {{
+	static constexpr std::array<big_t,64U> t_map {{
 		0xd76aa478UL ,
 		0xe8c7b756UL ,
 		0x242070dbUL ,
@@ -393,7 +410,7 @@ G::Md5Imp::big_t G::Md5Imp::digest::T( small_t i )
 		0x2ad7d2bbUL ,
 		0xeb86d391UL }} ;
 	G_ASSERT( i > 0 && i <= t_map.size() ) ;
-	return t_map[i-1U] ;
+	return t_map.at(i-1U) ;
 }
 
 // ===
@@ -424,8 +441,9 @@ G::Md5Imp::digest_state G::Md5Imp::format::decode( const std::string & str , sma
 
 // ===
 
-G::Md5Imp::block::block( const std::string & s , small_t block_in , big_t end_value ) :
-	m_s(s) ,
+G::Md5Imp::block::block( const char * data_p , std::size_t data_n , small_t block_in , big_t end_value ) :
+	m_p(data_p) ,
+	m_n(data_n) ,
 	m_block(block_in) ,
 	m_end_value(end_value)
 {
@@ -462,10 +480,10 @@ G::Md5Imp::big_t G::Md5Imp::block::X( small_t dword_index ) const
 
 G::Md5Imp::small_t G::Md5Imp::block::x( small_t i ) const
 {
-	small_t length = m_s.length() ;
+	small_t length = m_n ;
 	if( i < length )
 	{
-		return static_cast<unsigned char>(m_s[i]) ;
+		return static_cast<unsigned char>(m_p[i]) ;
 	}
 	else if( i < rounded(length) )
 	{
@@ -507,15 +525,27 @@ std::string G::Md5::state() const
 	return Md5Imp::format::encode( m_d , m_n ) ;
 }
 
+void G::Md5::add( const char * data_p , std::size_t data_n )
+{
+	m_s.append( data_p , data_n ) ;
+	m_n += data_n ;
+	consume() ;
+}
+
 void G::Md5::add( const std::string & data )
 {
-	// add complete blocks and keep the residue in m_s
+	m_s.append( data ) ;
+	m_n += data.size() ;
+	consume() ;
+}
+
+void G::Md5::consume()
+{
+	// consume complete blocks and keep the residue in m_s
 	Md5Imp::digest dd( m_d ) ;
-	m_s.append( data ) ; // could do better
-	m_n += data.length() ;
 	while( m_s.length() >= 64U )
 	{
-		Md5Imp::block blk( m_s , 0U , 0UL ) ;
+		Md5Imp::block blk( m_s.data() , m_s.size() , 0U , 0UL ) ;
 		dd.add( blk ) ;
 		m_s.erase( 0U , 64U ) ;
 	}
@@ -525,7 +555,7 @@ void G::Md5::add( const std::string & data )
 std::string G::Md5::value()
 {
 	Md5Imp::digest dd( m_d ) ;
-	Md5Imp::block blk( m_s , 0U , Md5Imp::block::end(m_n) ) ;
+	Md5Imp::block blk( m_s.data() , m_s.size() , 0U , Md5Imp::block::end(m_n) ) ;
 	dd.add( blk ) ;
 	m_s.erase() ;
 	m_d = dd.state() ;
@@ -538,6 +568,12 @@ std::string G::Md5::digest( const std::string & input )
 	return Md5Imp::format::encode( dd.state() ) ;
 }
 
+std::string G::Md5::digest( string_view input )
+{
+	Md5Imp::digest dd( input ) ;
+	return Md5Imp::format::encode( dd.state() ) ;
+}
+
 std::string G::Md5::digest( const std::string & input_1 , const std::string & input_2 )
 {
 	G::Md5 x ;
@@ -546,6 +582,14 @@ std::string G::Md5::digest( const std::string & input_1 , const std::string & in
 	return x.value() ;
 }
 
+std::string G::Md5::digest( G::string_view input_1 , G::string_view input_2 )
+{
+	G::Md5 x ;
+	x.add( input_1.data() , input_1.size() ) ;
+	x.add( input_2.data() , input_2.size() ) ;
+	return x.value() ;
+}
+
 std::string G::Md5::digest2( const std::string & input_1 , const std::string & input_2 )
 {
 	return digest( input_1 , input_2 ) ;
diff --git a/src/glib/gmd5.h b/src/glib/gmd5.h
index 58c00e2..3f9edf4 100644
--- a/src/glib/gmd5.h
+++ b/src/glib/gmd5.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,6 +23,7 @@
 
 #include "gdef.h"
 #include "gexception.h"
+#include "gstringview.h"
 #include <string>
 
 namespace G
@@ -48,8 +49,8 @@ namespace G
 class G::Md5
 {
 public:
-	G_EXCEPTION( Error , "internal md5 error" ) ;
-	G_EXCEPTION_CLASS( InvalidState , "invalid md5 hash state" ) ;
+	G_EXCEPTION( Error , tx("internal md5 error") ) ;
+	G_EXCEPTION_CLASS( InvalidState , tx("invalid md5 hash state") ) ;
 	using big_t = std::size_t ; // To hold at least 32 bits.
 	using small_t = std::size_t ; // To hold at least a std::size_t and no bigger than a big_t.
 	struct digest_state /// Holds the four parts of the md5 state.
@@ -77,6 +78,9 @@ public:
 	void add( const std::string & data ) ;
 		///< Adds more data.
 
+	void add( const char * data , std::size_t size ) ;
+		///< Adds more data.
+
 	std::string value() ;
 		///< Returns the hash value as a 16-character string. No
 		///< more add()s are allowed. The resulting string is not
@@ -96,10 +100,18 @@ public:
 		///< A convenience function that returns a digest from
 		///< one input.
 
+	static std::string digest( G::string_view input ) ;
+		///< A convenience function that returns a digest from
+		///< one input.
+
 	static std::string digest( const std::string & input_1 , const std::string & input_2 ) ;
 		///< A convenience function that returns a digest from
 		///< two inputs.
 
+	static std::string digest( G::string_view input_1 , G::string_view input_2 ) ;
+		///< A convenience function that returns a digest from
+		///< two inputs.
+
 	static std::string digest2( const std::string & input_1 , const std::string & input_2 ) ;
 		///< A non-overloaded name for the digest() overload
 		///< taking two parameters.
@@ -124,8 +136,11 @@ public:
 	~Md5() = default ;
 	Md5( const Md5 & ) = delete ;
 	Md5( Md5 && ) = delete ;
-	void operator=( const Md5 & ) = delete ;
-	void operator=( Md5 && ) = delete ;
+	Md5 & operator=( const Md5 & ) = delete ;
+	Md5 & operator=( Md5 && ) = delete ;
+
+private:
+	void consume() ;
 
 private:
 	std::size_t m_n{0U} ;
diff --git a/src/glib/gmsg.h b/src/glib/gmsg.h
index 9158d06..239a709 100644
--- a/src/glib/gmsg.h
+++ b/src/glib/gmsg.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,6 +22,8 @@
 #define G_MSG_H
 
 #include "gdef.h"
+#include "gstringview.h"
+#include <vector>
 
 namespace G
 {
@@ -38,18 +40,28 @@ class G::Msg
 {
 public:
 	static ssize_t send( SOCKET , const void * , std::size_t , int flags ) noexcept ;
-			///< A send() replacement using sendmsg().
+		///< A send() wrapper.
 
-	static ssize_t sendto( SOCKET , const void * , std::size_t , int flags ,
-		const sockaddr * , socklen_t ) noexcept ;
-			///< A sendto() replacement using sendmsg().
+	static ssize_t sendto( SOCKET , const void * , std::size_t , int flags , const sockaddr * , socklen_t ) noexcept ;
+		///< A sendto() wrapper.
 
-	static ssize_t recv( SOCKET , void * , std::size_t , int flags ) ;
+	static ssize_t sendto( SOCKET , const void * , std::size_t , int flags , const sockaddr * , socklen_t ,
+		int fd_to_send ) ;
+			///< A sendmsg() wrapper. Not always implemented.
+
+	static ssize_t sendto( SOCKET , const std::vector<string_view> & , int flags , const sockaddr * , socklen_t ) ;
+		///< A sendto() wrapper with scatter-gather data chunks. Not always implemented.
+
+	static ssize_t recv( SOCKET , void * , std::size_t , int flags ) noexcept ;
 		///< A recv() wrapper.
 
-	static ssize_t recvfrom( SOCKET , void * , std::size_t , int flags ,
-		sockaddr * , socklen_t * ) ;
-			///< A recvfrom() replacement using recvmsg().
+	static ssize_t recvfrom( SOCKET , void * , std::size_t , int , sockaddr * , socklen_t * ) noexcept ;
+		///< A recvfrom() wrapper.
+
+	static ssize_t recvfrom( SOCKET , void * , std::size_t , int , sockaddr * , socklen_t * ,
+		int * fd_received_p ) ;
+			///< A recvmsg() wrapper. The address and file descriptor pointers
+			///< can be null independently. Not always implemented.
 
 	static bool fatal( int error ) noexcept ;
 		///< Returns true if the error value indicates a permanent
diff --git a/src/glib/gmsg_unix.cpp b/src/glib/gmsg_unix.cpp
index 3d2b008..5bbde58 100644
--- a/src/glib/gmsg_unix.cpp
+++ b/src/glib/gmsg_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,7 +15,7 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file gmsg_unix.cpp
+/// \file gmsg_linux.cpp
 ///
 
 #include "gdef.h"
@@ -27,28 +27,30 @@
 #include <cerrno> // EINTR etc
 #include <stdexcept>
 #include <array>
+#include <type_traits>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/uio.h>
 
 ssize_t G::Msg::send( int fd , const void * buffer , std::size_t size , int flags ) noexcept
 {
-	return ::sendto( fd , buffer , size , flags | MSG_NOSIGNAL , nullptr , 0U ) ;
+	return sendto( fd , buffer , size , flags , nullptr , 0U ) ;
 }
 
 ssize_t G::Msg::sendto( int fd , const void * buffer , std::size_t size , int flags ,
 	const sockaddr * address_p , socklen_t address_n ) noexcept
 {
-	return ::sendto( fd , buffer , size , flags | MSG_NOSIGNAL , const_cast<sockaddr*>(address_p) , address_n ) ;
+	return ::sendto( fd , buffer , size , flags|MSG_NOSIGNAL , // NOLINT
+		const_cast<sockaddr*>(address_p) , address_n ) ;
 }
 
-ssize_t G::Msg::recv( int fd , void * buffer , std::size_t size , int flags )
+ssize_t G::Msg::recv( int fd , void * buffer , std::size_t size , int flags ) noexcept
 {
 	return ::recv( fd , buffer , size , flags ) ;
 }
 
 ssize_t G::Msg::recvfrom( int fd , void * buffer , std::size_t size , int flags ,
-	sockaddr * address_p , socklen_t * address_np )
+	sockaddr * address_p , socklen_t * address_np ) noexcept
 {
 	return ::recvfrom( fd , buffer , size , flags , address_p , address_np ) ;
 }
@@ -61,7 +63,6 @@ bool G::Msg::fatal( int error ) noexcept
 		error == EINTR ||
 		error == EMSGSIZE || // moot
 		error == ENOBUFS ||
-		error == ENOMEM ||
-		false ) ;
+		error == ENOMEM ) ;
 }
 
diff --git a/src/glib/gmsg_win32.cpp b/src/glib/gmsg_win32.cpp
index fbf7964..108b9e4 100644
--- a/src/glib/gmsg_win32.cpp
+++ b/src/glib/gmsg_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -35,13 +35,13 @@ ssize_t G::Msg::sendto( SOCKET fd , const void * buffer , std::size_t size , int
 		flags , address_p , address_n ) ;
 }
 
-ssize_t G::Msg::recv( SOCKET fd , void * buffer , std::size_t size , int flags )
+ssize_t G::Msg::recv( SOCKET fd , void * buffer , std::size_t size , int flags ) noexcept
 {
 	return ::recv( fd , reinterpret_cast<char*>(buffer) , static_cast<int>(size) , flags ) ;
 }
 
 ssize_t G::Msg::recvfrom( SOCKET fd , void * buffer , std::size_t size , int flags ,
-	sockaddr * address_p , socklen_t * address_np )
+	sockaddr * address_p , socklen_t * address_np ) noexcept
 {
 	return ::recvfrom( fd , reinterpret_cast<char*>(buffer) , static_cast<int>(size) ,
 		flags , address_p , address_np ) ;
diff --git a/src/glib/gnewprocess.h b/src/glib/gnewprocess.h
index 9058ce1..1bd0268 100644
--- a/src/glib/gnewprocess.h
+++ b/src/glib/gnewprocess.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -28,7 +28,7 @@
 #include "gidentity.h"
 #include "gprocess.h"
 #include "gpath.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include <memory>
 #include <new>
 #include <string>
@@ -63,15 +63,15 @@ namespace G
 class G::NewProcess
 {
 public:
-	G_EXCEPTION( Error , "cannot spawn new process" ) ;
-	G_EXCEPTION( CannotFork , "cannot fork" ) ;
-	G_EXCEPTION( WaitError , "failed waiting for child process" ) ;
-	G_EXCEPTION( ChildError , "child process terminated abnormally" ) ;
-	G_EXCEPTION( Insecure , "refusing to exec while the user-id is zero" ) ;
-	G_EXCEPTION( PipeError , "pipe error" ) ;
-	G_EXCEPTION( InvalidPath , "invalid executable path -- must be absolute" ) ;
-	G_EXCEPTION( InvalidParameter , "invalid parameter" ) ;
-	G_EXCEPTION( CreateProcessError , "CreateProcess error" ) ; // windows
+	G_EXCEPTION( Error , tx("cannot spawn new process") ) ;
+	G_EXCEPTION( CannotFork , tx("cannot fork") ) ;
+	G_EXCEPTION( WaitError , tx("failed waiting for child process") ) ;
+	G_EXCEPTION( ChildError , tx("child process terminated abnormally") ) ;
+	G_EXCEPTION( Insecure , tx("refusing to exec while the user-id is zero") ) ;
+	G_EXCEPTION( PipeError , tx("pipe error") ) ;
+	G_EXCEPTION( InvalidPath , tx("invalid executable path -- must be absolute") ) ;
+	G_EXCEPTION( InvalidParameter , tx("invalid parameter") ) ;
+	G_EXCEPTION( CreateProcessError , tx("CreateProcess error") ) ; // windows
 
 	struct Fd /// Wraps up a file descriptor for passing to G::NewProcess.
 	{
@@ -91,7 +91,7 @@ public:
 		const G::Path & cd = G::Path() , bool strict_path = true ,
 		Identity run_as_id = Identity::invalid() , bool strict_id = true ,
 		int exec_error_exit = 127 ,
-		const std::string & exec_error_format = std::string() ,
+		const std::string & exec_error_format = {} ,
 		std::string (*exec_error_format_fn)(std::string,int) = nullptr ) ;
 			///< Constructor. Spawns the given program to run independently in a
 			///< child process.
@@ -155,8 +155,8 @@ public:
 public:
 	NewProcess( const NewProcess & ) = delete ;
 	NewProcess( NewProcess && ) = delete ;
-	void operator=( const NewProcess & ) = delete ;
-	void operator=( NewProcess && ) = delete ;
+	NewProcess & operator=( const NewProcess & ) = delete ;
+	NewProcess & operator=( NewProcess && ) = delete ;
 
 private:
 	static std::string execErrorFormat( const std::string & , int ) ;
@@ -233,8 +233,8 @@ public:
 	~NewProcessWaitable() = default ;
 	NewProcessWaitable( const NewProcessWaitable & ) = delete ;
 	NewProcessWaitable( NewProcessWaitable && ) = delete ;
-	void operator=( const NewProcessWaitable & ) = delete ;
-	void operator=( NewProcessWaitable && ) = delete ;
+	NewProcessWaitable & operator=( const NewProcessWaitable & ) = delete ;
+	NewProcessWaitable & operator=( NewProcessWaitable && ) = delete ;
 
 private:
 	std::vector<char> m_buffer ;
@@ -251,7 +251,8 @@ private:
 } ;
 
 //| \class G::NewProcessConfig
-/// Provides syntactic sugar for the G::NewProcess constructor.
+/// Packages up the parameters of the multi-parameter G::NewProcess
+/// constructor for its one-parameter overload.
 ///
 struct G::NewProcessConfig
 {
diff --git a/src/glib/gnewprocess_unix.cpp b/src/glib/gnewprocess_unix.cpp
index 8077183..566275e 100644
--- a/src/glib/gnewprocess_unix.cpp
+++ b/src/glib/gnewprocess_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -63,8 +63,8 @@ public:
 public:
 	Pipe( const Pipe & ) = delete ;
 	Pipe( Pipe && ) = delete ;
-	void operator=( const Pipe & ) = delete ;
-	void operator=( Pipe && ) = delete ;
+	Pipe & operator=( const Pipe & ) = delete ;
+	Pipe & operator=( Pipe && ) = delete ;
 
 private:
 	std::array<int,2U> m_fds{{-1,-1}} ;
@@ -96,8 +96,8 @@ public:
 	~NewProcessImp() = default ;
 	NewProcessImp( const NewProcessImp & ) = delete ;
 	NewProcessImp( NewProcessImp && ) = delete ;
-	void operator=( const NewProcessImp & ) = delete ;
-	void operator=( NewProcessImp && ) = delete ;
+	NewProcessImp & operator=( const NewProcessImp & ) = delete ;
+	NewProcessImp & operator=( NewProcessImp && ) = delete ;
 
 private:
 	Pipe m_pipe ;
@@ -177,7 +177,7 @@ G::NewProcessImp::NewProcessImp( const Path & exe , const StringArray & args , c
 		{
 			// change directory
 			if( !cd.empty() )
-				Process::cd( cd ) ;
+				Process::cd( cd ) ; // throws on error
 
 			// set real id
 			if( run_as_id != Identity::invalid() )
@@ -236,7 +236,7 @@ std::pair<bool,pid_t> G::NewProcessImp::fork()
 	if( !ok ) throw NewProcess::CannotFork() ;
 	bool in_child = rc == 0 ;
 	auto child_pid = static_cast<pid_t>(rc) ;
-	return std::make_pair( in_child , child_pid ) ;
+	return { in_child , child_pid } ;
 }
 
 void G::NewProcessImp::printError( int stdxxx , const std::string & s )
@@ -522,10 +522,10 @@ int G::NewProcessWaitable::get( std::nothrow_t , int ec ) const
 	{
 		if( m_error || m_read_error )
 			result = ec ;
-		else if( !WIFEXITED(m_status) )
-			result = 128 + WTERMSIG(m_status) ;
+		else if( !WIFEXITED(m_status) ) // NOLINT
+			result = 128 + WTERMSIG(m_status) ; // NOLINT
 		else
-			result = WEXITSTATUS( m_status ) ;
+			result = WEXITSTATUS( m_status ) ; // NOLINT
 	}
 	return result ;
 }
@@ -533,8 +533,8 @@ int G::NewProcessWaitable::get( std::nothrow_t , int ec ) const
 std::string G::NewProcessWaitable::output() const
 {
 	if( m_fd < 0 || m_read_error != 0 )
-		return std::string() ;
+		return {} ;
 	else
-		return std::string( &m_buffer[0] , m_buffer.size() ) ;
+		return { &m_buffer[0] , m_buffer.size() } ;
 }
 
diff --git a/src/glib/gnewprocess_win32.cpp b/src/glib/gnewprocess_win32.cpp
index 8dedbd3..297f36c 100644
--- a/src/glib/gnewprocess_win32.cpp
+++ b/src/glib/gnewprocess_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -51,8 +51,8 @@ public:
 public:
 	Pipe( const Pipe & ) = delete ;
 	Pipe( Pipe && ) = delete ;
-	void operator=( const Pipe & ) = delete ;
-	void operator=( Pipe && ) = delete ;
+	Pipe & operator=( const Pipe & ) = delete ;
+	Pipe & operator=( Pipe && ) = delete ;
 
 private:
 	static void create( HANDLE & read , HANDLE & write ) ;
@@ -94,8 +94,8 @@ public:
 public:
 	NewProcessImp( const NewProcessImp & ) = delete ;
 	NewProcessImp( NewProcessImp && ) = delete ;
-	void operator=( const NewProcessImp & ) = delete ;
-	void operator=( NewProcessImp && ) = delete ;
+	NewProcessImp & operator=( const NewProcessImp & ) = delete ;
+	NewProcessImp & operator=( NewProcessImp && ) = delete ;
 
 private:
 	static std::string commandLine( const std::string & exe , const StringArray & args ) ;
@@ -114,9 +114,9 @@ private:
 
 G::NewProcess::NewProcess( const Path & exe , const StringArray & args , const Environment & env ,
 	Fd fd_stdin , Fd fd_stdout , Fd fd_stderr , const G::Path & cd ,
-	bool strict_path , Identity run_as_id , bool strict_id ,
-	int exec_error_exit , const std::string & exec_error_format ,
-	std::string (*exec_error_format_fn)(std::string,int) ) :
+	bool /*strict_path*/ , Identity /*run_as_id*/ , bool /*strict_id*/ ,
+	int /*exec_error_exit*/ , const std::string & /*exec_error_format*/ ,
+	std::string (*)(std::string,int) ) :
 		m_imp(std::make_unique<NewProcessImp>(exe,args,env,fd_stdin,fd_stdout,fd_stderr,cd))
 {
 }
@@ -243,7 +243,7 @@ std::pair<HANDLE,DWORD> G::NewProcessImp::createProcess( const std::string & exe
 	G_DEBUG( "G::NewProcessImp::createProcess: thread-id=" << info.dwThreadId ) ;
 
 	CloseHandle( info.hThread ) ;
-	return std::make_pair( info.hProcess , info.dwProcessId ) ;
+	return { info.hProcess , info.dwProcessId } ;
 }
 
 std::string G::NewProcessImp::commandLine( const std::string & exe , const StringArray & args )
@@ -399,7 +399,7 @@ G::NewProcessWaitable & G::NewProcessWaitable::wait()
 	// (worker thread - keep it simple)
 	m_data_size = 0U ;
 	m_error = 0 ;
-	std::array<char,64U> discard_buffer ;
+	std::array<char,64U> discard_buffer {} ;
 	char * discard = &discard_buffer[0] ;
 	std::size_t discard_size = discard_buffer.size() ;
 	char * read_p = &m_buffer[0] ;
diff --git a/src/glib/gomembuf.h b/src/glib/gomembuf.h
index 3ce7f86..b26aa11 100644
--- a/src/glib/gomembuf.h
+++ b/src/glib/gomembuf.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -73,8 +73,8 @@ public:
 	~omembuf() override = default ;
 	omembuf( const omembuf & ) = delete ;
 	omembuf( omembuf && ) = delete ;
-	void operator=( const omembuf & ) = delete ;
-	void operator=( omembuf && ) = delete ;
+	omembuf & operator=( const omembuf & ) = delete ;
+	omembuf & operator=( omembuf && ) = delete ;
 } ;
 
 inline
diff --git a/src/glib/goption.cpp b/src/glib/goption.cpp
new file mode 100644
index 0000000..eb91ef2
--- /dev/null
+++ b/src/glib/goption.cpp
@@ -0,0 +1,70 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file goption.cpp
+///
+
+#include "gdef.h"
+#include "goption.h"
+
+G::Option::Option( char c_in , const std::string & name_in , const std::string & description_in ,
+	const std::string & description_extra_in , Multiplicity value_multiplicity_in ,
+	const std::string & vd_in , unsigned int level_in ) :
+		c(c_in) ,
+		name(name_in) ,
+		description(description_in) ,
+		description_extra(description_extra_in) ,
+		value_multiplicity(value_multiplicity_in) ,
+		hidden(description_in.empty()||level_in==0U) ,
+		value_description(vd_in) ,
+		level(level_in) ,
+		main_tag(0U) ,
+		tag_bits(0U)
+{
+}
+
+G::Option::Option( char c_in , const char * name_in , const char * description_in ,
+	const char * description_extra_in , Multiplicity value_multiplicity_in ,
+	const char * vd_in , unsigned int level_in , unsigned int main_tag_in ,
+	unsigned int tag_bits_in ) :
+		c(c_in) ,
+		name(name_in) ,
+		description(description_in) ,
+		description_extra(description_extra_in) ,
+		value_multiplicity(value_multiplicity_in) ,
+		hidden(*description_in=='\0'||level_in==0U) ,
+		value_description(vd_in) ,
+		level(level_in) ,
+		main_tag(main_tag_in) ,
+		tag_bits(main_tag_in|tag_bits_in)
+{
+}
+
+G::Option::Multiplicity G::Option::decode( const std::string & s )
+{
+	if( s == "0" )
+		return Multiplicity::zero ;
+	else if( s == "01" )
+		return Multiplicity::zero_or_one ;
+	else if( s == "1" )
+		return Multiplicity::one ;
+	else if( s == "2" )
+		return Multiplicity::many ;
+	else
+		return Multiplicity::error ;
+}
+
diff --git a/src/glib/goption.h b/src/glib/goption.h
new file mode 100644
index 0000000..706debe
--- /dev/null
+++ b/src/glib/goption.h
@@ -0,0 +1,87 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file goption.h
+///
+
+#ifndef G_OPTION_H
+#define G_OPTION_H
+
+#include "gdef.h"
+#include "gstringarray.h"
+#include <string>
+#include <utility>
+
+namespace G
+{
+	struct Option ;
+}
+
+//| \class G::Option
+/// A structure representing a G::Options command-line option.
+///
+struct G::Option
+{
+	enum class Multiplicity { zero , zero_or_one , one , many , error } ;
+	char c ;
+	std::string name ;
+	std::string description ;
+	std::string description_extra ;
+	Multiplicity value_multiplicity ;
+	bool hidden ;
+	std::string value_description ;
+	unsigned int level ;
+	unsigned int main_tag ;
+	unsigned int tag_bits ;
+
+	Option( char c , const std::string & name , const std::string & description ,
+		const std::string & description_extra , Multiplicity value_multiplicity ,
+		const std::string & vd , unsigned int level ) ;
+			///< Constructor taking strings.
+
+	Option( char c , const char * name , const char * description ,
+		const char * description_extra , Multiplicity value_multiplicity ,
+		const char * vd , unsigned int level ,
+		unsigned int main_tag , unsigned int tag_bits ) ;
+			///< Constructor taking c-strings and tags.
+
+	static Multiplicity decode( const std::string & ) ;
+		///< Decodes a multiplicity string into its enumeration.
+		///< Returns 'error' on error.
+
+	bool valued() const ;
+	bool defaulting() const ;
+	bool multivalued() const ;
+	bool visible() const ;
+	bool visible( std::pair<unsigned,unsigned> level_range , unsigned int main_tag = 0U , unsigned int tag_bits = 0U ) const ;
+} ;
+
+inline bool G::Option::valued() const { return value_multiplicity != Multiplicity::zero ; }
+inline bool G::Option::defaulting() const { return value_multiplicity == Option::Multiplicity::zero_or_one ; }
+inline bool G::Option::multivalued() const { return value_multiplicity == Option::Multiplicity::many ; }
+inline bool G::Option::visible() const { return visible( {1U,99U} ) ; }
+inline bool G::Option::visible( std::pair<unsigned,unsigned> level_range , unsigned int main_tag_in , unsigned int tag_bits_in ) const
+{
+	return
+		!hidden &&
+		level >= level_range.first &&
+		level <= level_range.second &&
+		( main_tag_in == 0U || main_tag_in == main_tag ) &&
+		( tag_bits_in == 0U || ( tag_bits_in & tag_bits ) != 0U ) ;
+}
+
+#endif
diff --git a/src/glib/goptional.h b/src/glib/goptional.h
index 551d5cc..5e0803e 100644
--- a/src/glib/goptional.h
+++ b/src/glib/goptional.h
@@ -40,7 +40,7 @@ public:
 	optional() noexcept(noexcept(T())) ;
 	explicit optional( const T & ) ;
 	optional( bool has_value , const T & value ) ; // not in std::optional()
-	void clear() noexcept ; // not in std::optional()
+	void clear() ; // not in std::optional()
 	bool has_value() const noexcept ;
 	explicit operator bool() const noexcept ;
 	const T & value() const ;
@@ -81,7 +81,7 @@ G::optional<T>::optional( bool has_value , const T & value ) :
 }
 
 template <typename T>
-void G::optional<T>::clear() noexcept
+void G::optional<T>::clear()
 {
 	m_has_value = false ;
 }
diff --git a/src/glib/goptionmap.cpp b/src/glib/goptionmap.cpp
index 04b4ed8..e13ab0d 100644
--- a/src/glib/goptionmap.cpp
+++ b/src/glib/goptionmap.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -20,23 +20,40 @@
 
 #include "gdef.h"
 #include "goptionmap.h"
+#include <algorithm>
 
 void G::OptionMap::insert( const Map::value_type & value )
 {
 	m_map.insert( value ) ;
 }
 
-void G::OptionMap::replace( const std::string & key , const std::string & value )
+G::OptionMap::Range G::OptionMap::findRange( string_view key ) const
 {
-	auto pair = m_map.equal_range( key ) ;
-	if( pair.first != pair.second )
-		m_map.erase( pair.first , pair.second ) ;
-	m_map.insert( Map::value_type(key,OptionValue(value)) ) ;
+	return m_map.equal_range( sv_to_string(key) ) ; // or c++14 'generic associative lookup' of string_view
 }
 
-void G::OptionMap::increment( const std::string & key )
+G::OptionMap::Map::iterator G::OptionMap::findFirst( string_view key )
 {
-	auto p = m_map.find( key ) ;
+	return m_map.find( sv_to_string(key) ) ; // or c++14 'generic associative lookup' of string_view
+}
+
+G::OptionMap::const_iterator G::OptionMap::find( string_view key ) const
+{
+	auto pair = findRange( key ) ;
+	return pair.first == pair.second ? m_map.end() : pair.first ;
+}
+
+void G::OptionMap::replace( string_view key , const std::string & value )
+{
+	auto pair = findRange( key ) ;
+	if( pair.first != pair.second )
+		m_map.erase( pair.first , pair.second ) ;
+	m_map.insert( Map::value_type(sv_to_string(key),OptionValue(value)) ) ;
+}
+
+void G::OptionMap::increment( string_view key )
+{
+	auto p = findFirst( key ) ;
 	if( p != m_map.end() )
 		(*p).second.increment() ;
 }
@@ -61,25 +78,15 @@ G::OptionMap::const_iterator G::OptionMap::cend() const
 	return end() ;
 }
 
-G::OptionMap::const_iterator G::OptionMap::find( const std::string & key ) const
-{
-	return m_map.find( key ) ;
-}
-
 void G::OptionMap::clear()
 {
 	m_map.clear() ;
 }
 
-bool G::OptionMap::contains( const char * key ) const
+bool G::OptionMap::contains( string_view key ) const
 {
-	return contains( std::string(key) ) ;
-}
-
-bool G::OptionMap::contains( const std::string & key ) const
-{
-	const Map::const_iterator end = m_map.end() ;
-	for( auto p = m_map.find(key) ; p != end && (*p).first == key ; ++p )
+	auto range = findRange( key ) ;
+	for( auto p = range.first ; p != range.second ; ++p )
 	{
 		if( (*p).second.isOff() )
 			continue ;
@@ -88,30 +95,35 @@ bool G::OptionMap::contains( const std::string & key ) const
 	return false ;
 }
 
-std::size_t G::OptionMap::count( const std::string & key ) const
+bool G::OptionMap::contains( const char * key ) const
+{
+	return contains( string_view(key) ) ;
+}
+
+bool G::OptionMap::contains( const std::string & key ) const
+{
+	return contains( string_view(key) ) ;
+}
+
+std::size_t G::OptionMap::count( string_view key ) const
 {
 	std::size_t n = 0U ;
-	auto pair = m_map.equal_range( key ) ;
+	auto pair = findRange( key ) ;
 	for( auto p = pair.first ; p != pair.second ; ++p )
 		n += (*p).second.count() ;
 	return n ;
 }
 
-std::string G::OptionMap::value( const char * key , const char * default_ ) const
+std::string G::OptionMap::value( string_view key , string_view default_ ) const
 {
-	return value( std::string(key) , default_ ? std::string(default_) : std::string() ) ;
-}
-
-std::string G::OptionMap::value( const std::string & key , const std::string & default_ ) const
-{
-	auto range = m_map.equal_range( key ) ;
+	auto range = findRange( key ) ;
 	if( range.first == range.second )
-		return default_ ;
+		return sv_to_string(default_) ;
 	else
 		return join( range.first , range.second , default_ ) ;
 }
 
-std::string G::OptionMap::join( Map::const_iterator p , Map::const_iterator end , const std::string & off_value ) const
+std::string G::OptionMap::join( Map::const_iterator p , Map::const_iterator end , string_view off_value ) const
 {
 	std::string result ;
 	const char * sep = "" ;
@@ -122,13 +134,8 @@ std::string G::OptionMap::join( Map::const_iterator p , Map::const_iterator end
 		if( (*p).second.isOn() )
 			return (*p).second.value() ;
 		if( (*p).second.isOff() )
-			return off_value ;
+			return sv_to_string(off_value) ;
 	}
 	return result ;
 }
 
-bool G::OptionMap::compare( const Map::value_type & pair1 , const Map::value_type & pair2 )
-{
-	return pair1.first < pair2.first ;
-}
-
diff --git a/src/glib/goptionmap.h b/src/glib/goptionmap.h
index 848917e..96f7bd5 100644
--- a/src/glib/goptionmap.h
+++ b/src/glib/goptionmap.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -26,6 +26,7 @@
 #include <string>
 #include <map>
 #include <algorithm>
+#include <functional> // std::less
 
 namespace G
 {
@@ -41,20 +42,21 @@ namespace G
 class G::OptionMap
 {
 public:
-	using Map = std::multimap<std::string,OptionValue> ;
+	using Map = std::multimap<std::string,OptionValue,std::less<std::string>> ; // NOLINT modernize-use-transparent-functors
 	using value_type = Map::value_type ;
 	using iterator = Map::iterator ;
 	using const_iterator = Map::const_iterator ;
 
 public:
 	void insert( const Map::value_type & ) ;
-		///< Inserts the key/value pair into the map. The ordering of values in
-		///< the map with the same key is in the order of insert()ion.
+		///< Inserts the key/value pair into the map. The ordering of values
+		///< in the map with the same key is in the order of insert()ion
+		///< (as guaranteed by std::multimap since c++ 2011).
 
-	void replace( const std::string & key , const std::string & value ) ;
+	void replace( string_view key , const std::string & value ) ;
 		///< Replaces all matching values with a single value.
 
-	void increment( const std::string & key ) ;
+	void increment( string_view key ) ;
 		///< Increments the repeat count for the given entry.
 
 	const_iterator begin() const ;
@@ -69,36 +71,38 @@ public:
 	const_iterator cend() const ;
 		///< Returns the off-the-end iterator.
 
-	const_iterator find( const std::string & ) const ;
+	const_iterator find( string_view ) const ;
 		///< Finds the map entry with the given key.
 
 	void clear() ;
 		///< Clears the map.
 
-	bool contains( const std::string & ) const ;
+	bool contains( string_view ) const ;
 		///< Returns true if the map contains the given key, but ignoring 'off'
 		///< option-values.
 
 	bool contains( const char * ) const ;
-		///< Overload taking a c-string.
+		///< Overload for c-string.
 
-	std::size_t count( const std::string & key ) const ;
+	bool contains( const std::string & ) const ;
+		///< Overload for std-string.
+
+	std::size_t count( string_view key ) const ;
 		///< Returns the total repeat count for all matching entries.
 		///< See G::OptionValue::count().
 
-	std::string value( const std::string & key , const std::string & default_ = std::string() ) const ;
+	std::string value( string_view key , string_view default_ = {} ) const ;
 		///< Returns the matching value, with concatentation into a comma-separated
-		///< list if multivalued. If there are any on/off option-values matching
-		///< the key then a single value is returned corresponding to the first
-		///< one, being G::Str::positive() if 'on' or the supplied default
-		///< if 'off'.
-
-	std::string value( const char * key , const char * default_ = nullptr ) const ;
-		///< Overload taking c-strings.
+		///< list if multivalued (with no escaping). If there are any on/off
+		///< option-values matching the key then a single value is returned
+		///< corresponding to the first one, being G::Str::positive() if 'on'
+		///< or the supplied default if 'off'.
 
 private:
-	std::string join( Map::const_iterator , Map::const_iterator , const std::string & ) const ;
-	static bool compare( const Map::value_type & , const Map::value_type & ) ;
+	using Range = std::pair<Map::const_iterator,Map::const_iterator> ;
+	Range findRange( string_view key ) const ;
+	Map::iterator findFirst( string_view key ) ;
+	std::string join( Map::const_iterator , Map::const_iterator , string_view ) const ;
 
 private:
 	Map m_map ;
diff --git a/src/glib/goptionparser.cpp b/src/glib/goptionparser.cpp
index 13e015f..b116376 100644
--- a/src/glib/goptionparser.cpp
+++ b/src/glib/goptionparser.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -25,7 +25,6 @@
 #include "gstr.h"
 #include "glog.h"
 #include <algorithm>
-#include <map>
 #include <sstream>
 #include <stdexcept>
 #include <utility>
@@ -228,7 +227,7 @@ bool G::OptionParser::isAnOptionSet( const std::string & arg )
 void G::OptionParser::errorDubiousValue( const std::string & name , const std::string & value )
 {
 	std::string s = str(
-		format(G::gettext("%1% is probably a mistake, use %2% or %3%")) %
+		format(txt("%1% is probably a mistake, use %2% or %3%")) %
 			("\"--"+name+" "+value+"\"") %
 			("\"--"+name+"=... "+value+"\"") %
 			("\"--"+name+"="+value+"\"") ) ;
@@ -237,47 +236,47 @@ void G::OptionParser::errorDubiousValue( const std::string & name , const std::s
 
 void G::OptionParser::errorDuplicate( char c )
 {
-	error( str( format(gettext("duplicate use of %1%")) % ("\"-"+std::string(1U,c)+"\"") ) ) ;
+	error( str( format(txt("duplicate use of %1%")) % ("\"-"+std::string(1U,c)+"\"") ) ) ;
 }
 
 void G::OptionParser::errorDuplicate( const std::string & name )
 {
-	error( str( format(gettext("duplicate use of %1%")) % ("\"--"+name+"\"") ) ) ;
+	error( str( format(txt("duplicate use of %1%")) % ("\"--"+name+"\"") ) ) ;
 }
 
 void G::OptionParser::errorExtraValue( char c , const std::string & )
 {
-	error( str( format(gettext("cannot give a value with %1%")) % ("\"-"+std::string(1U,c)+"\"") ) ) ;
+	error( str( format(txt("cannot give a value with %1%")) % ("\"-"+std::string(1U,c)+"\"") ) ) ;
 }
 
 void G::OptionParser::errorExtraValue( const std::string & name , const std::string & value )
 {
-	error( str( format(gettext("cannot give a value with %1% (%2%)")) % ("\"--"+name+"\"") % value ) ) ;
+	error( str( format(txt("cannot give a value with %1% (%2%)")) % ("\"--"+name+"\"") % value ) ) ;
 }
 
 void G::OptionParser::errorNoValue( char c )
 {
-	error( str( format(gettext("no value supplied for %1%")) % ("-"+std::string(1U,c)) ) ) ;
+	error( str( format(txt("no value supplied for %1%")) % ("-"+std::string(1U,c)) ) ) ;
 }
 
 void G::OptionParser::errorNoValue( const std::string & name )
 {
-	error( str( format(gettext("no value supplied for %1%")) % ("\"--"+name+"\"") ) ) ;
+	error( str( format(txt("no value supplied for %1%")) % ("\"--"+name+"\"") ) ) ;
 }
 
 void G::OptionParser::errorUnknownOption( char c )
 {
-	error( str( format(gettext("invalid option: %1%")) % ("\"-"+std::string(1U,c)+"\"") ) ) ;
+	error( str( format(txt("invalid option: %1%")) % ("\"-"+std::string(1U,c)+"\"") ) ) ;
 }
 
 void G::OptionParser::errorUnknownOption( const std::string & name )
 {
-	error( str( format(gettext("invalid option: %1%")) % ("\"--"+name+"\"") ) ) ;
+	error( str( format(txt("invalid option: %1%")) % ("\"--"+name+"\"") ) ) ;
 }
 
 void G::OptionParser::errorConflict( const std::string & name )
 {
-	error( str( format(gettext("conflicting values: %1%")) % ("\"--"+name+"\"") ) ) ;
+	error( str( format(txt("conflicting values: %1%")) % ("\"--"+name+"\"") ) ) ;
 }
 
 void G::OptionParser::error( const std::string & s )
diff --git a/src/glib/goptionparser.h b/src/glib/goptionparser.h
index fb2675a..9126698 100644
--- a/src/glib/goptionparser.h
+++ b/src/glib/goptionparser.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,12 +22,11 @@
 #define G_OPTION_PARSER_H
 
 #include "gdef.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "goptions.h"
 #include "goptionvalue.h"
 #include "goptionmap.h"
 #include <string>
-#include <map>
 
 namespace G
 {
@@ -92,8 +91,8 @@ public:
 	~OptionParser() = default ;
 	OptionParser( const OptionParser & ) = delete ;
 	OptionParser( OptionParser && ) = delete ;
-	void operator=( const OptionParser & ) = delete ;
-	void operator=( OptionParser && ) = delete ;
+	OptionParser & operator=( const OptionParser & ) = delete ;
+	OptionParser & operator=( OptionParser && ) = delete ;
 
 private:
 	bool haveSeen( const std::string & ) const ;
diff --git a/src/glib/goptions.cpp b/src/glib/goptions.cpp
index 57af940..d348cbf 100644
--- a/src/glib/goptions.cpp
+++ b/src/glib/goptions.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -20,11 +20,8 @@
 
 #include "gdef.h"
 #include "gstr.h"
-#include "gstringwrap.h"
 #include "ggettext.h"
-#include "gassert.h"
 #include "goptions.h"
-#include "genvironment.h"
 #include <algorithm>
 
 G::Options::Options()
@@ -33,7 +30,6 @@ G::Options::Options()
 G::Options::Options( const std::string & spec , char sep_major , char sep_minor , char escape )
 {
 	parseSpec( spec , sep_major , sep_minor , escape ) ;
-	std::sort( m_names.begin() , m_names.end() ) ;
 }
 
 void G::Options::parseSpec( const std::string & spec , char sep_major , char sep_minor , char escape )
@@ -41,7 +37,7 @@ void G::Options::parseSpec( const std::string & spec , char sep_major , char sep
 	// split into separate options
 	StringArray spec_items ;
 	spec_items.reserve( 40U ) ;
-	Str::splitIntoFields( spec , spec_items , {&sep_major,1U} , escape , false ) ;
+	Str::splitIntoFields( spec , spec_items , sep_major , escape , false ) ;
 
 	// for each option
 	for( auto & spec_item : spec_items )
@@ -49,64 +45,73 @@ void G::Options::parseSpec( const std::string & spec , char sep_major , char sep
 		// split into separate fields
 		if( spec_item.empty() ) continue ;
 		StringArray inner_parts ;
-		inner_parts.reserve( 7U ) ;
-		Str::splitIntoFields( spec_item , inner_parts , {&sep_minor,1U} , escape ) ;
-		if( inner_parts.size() != 7U )
-		{
-			std::ostringstream ss ;
-			ss << "[" << spec_item << "] (" << sep_minor << ")" ;
-			throw InvalidSpecification( ss.str() ) ;
-		}
+		inner_parts.reserve( 10U ) ;
+		Str::splitIntoFields( spec_item , inner_parts , sep_minor , escape ) ;
 
-		add( inner_parts ) ;
+		if( inner_parts.size() < 7U )
+			throw InvalidSpecification( std::string(1U,'[').append(G::Str::join(",",inner_parts)).append(1U,']') ) ;
+
+		std::string short_form = inner_parts[0] ;
+		char c = short_form.empty() ? '\0' : short_form[0U] ;
+		unsigned int level = Str::toUInt( inner_parts[6U] ) ;
+
+		Option::Multiplicity multiplicity = Option::decode( inner_parts[4U] ) ;
+		if( multiplicity == Option::Multiplicity::error )
+			throw InvalidSpecification( std::string(1U,'[').append(G::Str::join(",",inner_parts)).append(1U,']') ) ;
+
+		Option opt( c , inner_parts[1U] , inner_parts[2U] , inner_parts[3U] ,
+			multiplicity , inner_parts[5U] , level ) ;
+
+		addOption( opt , sep_minor , escape ) ;
 	}
 }
 
-void G::Options::add( StringArray spec_parts )
+void G::Options::add( Options & options , char c , const char * name , const char * text ,
+	const char * more , Option::Multiplicity m , const char * argname ,
+	unsigned int level , unsigned int main_tag , unsigned int tag_bits )
 {
-	if( spec_parts.size() != 7U )
-		throw InvalidSpecification( "[" + G::Str::join(",",spec_parts) + "]" ) ;
-
-	unsigned int level = Str::toUInt( spec_parts[6U] ) ;
-	std::string short_form = spec_parts[0] ;
-	char c = short_form.empty() ? '\0' : short_form.at(0U) ;
-
-	addImp( spec_parts[1U] , c , spec_parts[2U] ,
-		spec_parts[3U] , spec_parts[4U] , spec_parts[5U] , level ) ;
+	options.add( Option(c,name,G::gettext(text),more,m,argname,level,main_tag,main_tag|tag_bits) ) ;
 }
 
-void G::Options::add( StringArray spec_parts , char sep , char escape )
+void G::Options::add( const Option & opt , char sep , char escape )
 {
-	if( spec_parts.size() != 6U )
-		throw InvalidSpecification( "[" + G::Str::join(",",spec_parts) + "]" ) ;
-
-	StringArray sub_parts ;
-	sub_parts.reserve( 2U ) ;
-	Str::splitIntoFields( spec_parts[2U] , sub_parts , {&sep,1U} , escape ) ;
-	if( sub_parts.empty() || sub_parts.size() > 2U )
-		throw InvalidSpecification( G::Str::join(",",spec_parts) ) ;
-
-	spec_parts[2U] = sub_parts[0U] ;
-	spec_parts.insert( spec_parts.begin()+3U , sub_parts.size() == 2U ? sub_parts[1U] : std::string() ) ;
-
-	add( spec_parts ) ;
+	addOption( opt , sep , escape ) ;
 }
 
-void G::Options::addImp( const std::string & name , char c ,
-	const std::string & description , const std::string & description_extra ,
-	const std::string & value_multiplicity , const std::string & value_description , unsigned int level )
+void G::Options::addOption( Option opt , char sep , char escape )
 {
-	std::pair<Map::iterator,bool> rc = m_map.insert( std::make_pair( name ,
-		Option(c,name,description,description_extra,value_multiplicity,value_description,level) ) ) ;
-	if( ! rc.second )
+	if( sep )
+	{
+		// if the description is in two parts separated by 'sep' and the
+		// extra-description is empty then take the first half as the
+		// description and the second part as the extra-description -- this
+		// allows the description to be translatable as a single string
+		//
+		StringArray sub_parts ;
+		sub_parts.reserve( 2U ) ;
+		Str::splitIntoFields( opt.description , sub_parts , sep , escape ) ;
+		if( sub_parts.empty() || sub_parts.size() > 2U || ( sub_parts.size()==2U && !opt.description_extra.empty() ) )
+			throw InvalidSpecification() ;
+		if( sub_parts.size() == 2U )
+		{
+			opt.description = sub_parts[0] ;
+			opt.description_extra = sub_parts[1] ;
+		}
+	}
+
+	auto range = std::equal_range( m_list.begin() , m_list.end() , opt ,
+		[](const Option & a, const Option & b){ return a.name < b.name ; } ) ;
+
+	if( range.first != range.second )
 		throw InvalidSpecification( "duplication" ) ;
-	m_names.insert( std::lower_bound(m_names.begin(),m_names.end(),name) , name ) ;
+
+	m_list.insert( range.first , opt ) ;
 }
 
 bool G::Options::defaulting( const std::string & name ) const
 {
-	auto p = m_map.find( name ) ;
-	return p == m_map.end() ? false : ( (*p).second.value_multiplicity == Option::Multiplicity::zero_or_one ) ;
+	auto p = find( name ) ;
+	return p == m_list.end() ? false : (*p).defaulting() ;
 }
 
 bool G::Options::valued( char c ) const
@@ -116,8 +121,8 @@ bool G::Options::valued( char c ) const
 
 bool G::Options::valued( const std::string & name ) const
 {
-	auto p = m_map.find( name ) ;
-	return p == m_map.end() ? false : ( (*p).second.value_multiplicity != Option::Multiplicity::zero ) ;
+	auto p = find( name ) ;
+	return p == m_list.end() ? false : (*p).valued() ;
 }
 
 bool G::Options::unvalued( const std::string & name ) const
@@ -132,18 +137,14 @@ bool G::Options::multivalued( char c ) const
 
 bool G::Options::multivalued( const std::string & name ) const
 {
-	auto p = m_map.find( name ) ;
-	return p == m_map.end() ? false : ( (*p).second.value_multiplicity == Option::Multiplicity::many ) ;
+	auto p = find( name ) ;
+	return p == m_list.end() ? false : (*p).multivalued() ;
 }
 
 bool G::Options::visible( const std::string & name , unsigned int level , bool level_exact ) const
 {
-	auto p = m_map.find( name ) ;
-	if( p == m_map.end() ) return false ;
-	return
-		level_exact ?
-			( !(*p).second.hidden && (*p).second.level == level ) :
-			( !(*p).second.hidden && (*p).second.level <= level ) ;
+	auto p = find( name ) ;
+	return p == m_list.end() ? false : (*p).visible({level_exact?level:1U,level}) ;
 }
 
 bool G::Options::visible( const std::string & name ) const
@@ -153,338 +154,31 @@ bool G::Options::visible( const std::string & name ) const
 
 bool G::Options::valid( const std::string & name ) const
 {
-	return m_map.find(name) != m_map.end() ;
+	return find(name) != m_list.end() ;
 }
 
 std::string G::Options::lookup( char c ) const
 {
-	for( auto p = m_map.begin() ; c != '\0' && p != m_map.end() ; ++p )
+	for( auto p = m_list.begin() ; c != '\0' && p != m_list.end() ; ++p )
 	{
-		if( (*p).second.c == c )
-			return (*p).second.name ;
+		if( (*p).c == c )
+			return (*p).name ;
 	}
-	return std::string() ;
+	return {} ;
 }
 
-const G::StringArray & G::Options::names() const
+G::Options::List::const_iterator G::Options::find( const std::string & name ) const
 {
-	return m_names ;
-}
-
-// --
-
-namespace G
-{
-	namespace OptionsLayoutImp
+	for( auto p = m_list.begin() ; p != m_list.end() ; ++p )
 	{
-		unsigned int widthDefault() ;
+		if( (*p).name == name )
+			return p ;
 	}
+	return m_list.end() ;
 }
 
-G::OptionsLayout::OptionsLayout() :
-	column(30U) ,
-	width(0U) ,
-	width2(0U) ,
-	margin(2U) ,
-	level(99U) ,
-	level_exact(false) ,
-	extra(false) ,
-	alt_usage(false)
+const std::vector<G::Option> & G::Options::list() const
 {
-	width = width2 = OptionsLayoutImp::widthDefault() ;
-}
-
-G::OptionsLayout::OptionsLayout( std::size_t column_ ) :
-	column(column_) ,
-	width(0U) ,
-	width2(0U) ,
-	margin(2U) ,
-	level(99U) ,
-	level_exact(false) ,
-	extra(false) ,
-	alt_usage(false)
-{
-	width = width2 = OptionsLayoutImp::widthDefault() ;
-}
-
-G::OptionsLayout::OptionsLayout( std::size_t column_ , std::size_t width_ ) :
-	column(column_) ,
-	width(width_) ,
-	width2(width_) ,
-	margin(2U) ,
-	level(99U) ,
-	level_exact(false) ,
-	extra(false) ,
-	alt_usage(false)
-{
-	width = width2 = OptionsLayoutImp::widthDefault() ;
-}
-
-unsigned int G::OptionsLayoutImp::widthDefault()
-{
-	return Str::toUInt( Environment::get("COLUMNS",std::string()) , "79" ) ;
-}
-
-// --
-
-std::string G::Options::usageSummaryPartOne( const Layout & layout ) const
-{
-	// summarise the single-character switches, excluding those which take a value
-	std::ostringstream ss ;
-	bool first = true ;
-	for( const auto & name : m_names )
-	{
-		auto spec_p = m_map.find( name ) ;
-		if( (*spec_p).second.c != '\0' && !valued(name) && visible(name,layout.level,layout.level_exact) )
-		{
-			if( first )
-				ss << "[-" ;
-			first = false ;
-			ss << (*spec_p).second.c ;
-		}
-	}
-
-	std::string s = ss.str() ;
-	if( s.length() ) s.append( "] " ) ;
-	return s ;
-}
-
-std::string G::Options::usageSummaryPartTwo( const Layout & layout ) const
-{
-	std::ostringstream ss ;
-	const char * sep = "" ;
-	for( const auto & name : m_names )
-	{
-		if( visible(name,layout.level,layout.level_exact) )
-		{
-			auto spec_p = m_map.find( name ) ;
-			ss << sep << "[" ;
-			if( (*spec_p).second.name.length() )
-			{
-				ss << "--" << (*spec_p).second.name ;
-			}
-			else
-			{
-				G_ASSERT( (*spec_p).second.c != '\0' ) ;
-				ss << "-" << (*spec_p).second.c ;
-			}
-			if( (*spec_p).second.value_multiplicity != Option::Multiplicity::zero )
-			{
-				std::string vd = (*spec_p).second.value_description ;
-				if( vd.empty() ) vd = "value" ;
-				ss << "=<" << vd << ">" ;
-			}
-			ss << "]" ;
-			sep = " " ;
-		}
-	}
-	return ss.str() ;
-}
-
-std::string G::Options::usageHelpSyntax( Map::const_iterator spec_p ) const
-{
-	std::string syntax ;
-	if( (*spec_p).second.c != '\0' )
-	{
-		syntax.append( "-" ) ;
-		syntax.append( 1U , (*spec_p).second.c ) ;
-		if( (*spec_p).second.name.length() )
-			syntax.append( ", " ) ;
-	}
-	if( (*spec_p).second.name.length() )
-	{
-		syntax.append( "--" ) ;
-		syntax.append( (*spec_p).second.name ) ;
-	}
-	if( (*spec_p).second.value_multiplicity != Option::Multiplicity::zero )
-	{
-		bool defaulting = (*spec_p).second.value_multiplicity == Option::Multiplicity::zero_or_one ;
-		std::string vd = (*spec_p).second.value_description ;
-		if( vd.empty() ) vd = "value" ;
-		if( defaulting ) syntax.append( "[" ) ;
-		syntax.append( "=<" ) ;
-		syntax.append( vd ) ;
-		syntax.append( ">" ) ;
-		if( defaulting ) syntax.append( "]" ) ;
-	}
-	syntax.append( 1U , ' ' ) ;
-	return syntax ;
-}
-
-std::string G::Options::usageHelpDescription( Map::const_iterator spec_p , const Layout & layout ) const
-{
-	std::string description = (*spec_p).second.description ;
-	if( layout.extra )
-		description.append( (*spec_p).second.description_extra ) ;
-	return description ;
-}
-
-std::string G::Options::usageHelpSeparator( const Layout & layout , std::size_t syntax_length ) const
-{
-	std::string separator ;
-	if( !layout.separator.empty() )
-		separator = layout.separator ;
-	else if( (layout.margin+syntax_length) > layout.column )
-		separator = std::string( 1U , ' ' ) ;
-	else
-		separator = std::string( layout.column-syntax_length-layout.margin , ' ' ) ;
-	return separator ;
-}
-
-std::string G::Options::usageHelpWrap( const Layout & layout , const std::string & line_in ,
-	const std::string & margin ) const
-{
-	std::string line( line_in ) ;
-	std::size_t wrap_width = layout.width>layout.margin ? (layout.width-layout.margin) : 1U ;
-	bool separator_is_tab = layout.separator.length() == 1U && layout.separator.at(0U) == '\t' ;
-	if( separator_is_tab )
-	{
-		std::string prefix_other = std::string(layout.margin,' ').append(1U,'\t') ;
-		line = margin + StringWrap::wrap( line , std::string() , prefix_other ,
-			wrap_width , layout.width2 , true ) ;
-	}
-	else if( !layout.separator.empty() )
-	{
-		// wrap with a one-space indent for wrapped descriptions wrt. the syntax
-		if( line.length() > layout.width )
-		{
-			std::string prefix_other( layout.margin+1U , ' ' ) ;
-			line = margin + StringWrap::wrap( line , std::string() , prefix_other ,
-				wrap_width , layout.width2 , true ) ;
-		}
-	}
-	else
-	{
-		std::string prefix_other( layout.column , ' ' ) ;
-		line = margin + StringWrap::wrap( line , std::string() , prefix_other ,
-			wrap_width , layout.width2 , true ) ;
-	}
-	return line ;
-}
-
-std::size_t G::Options::longestSubLine( const std::string & s )
-{
-	std::size_t result = 0U ;
-	std::size_t n = 0U ;
-	for( auto c : s )
-	{
-		if( c == '\n' )
-		{
-			if( n > result )
-				result = n ;
-			n = 0 ;
-		}
-		else
-		{
-			n++ ;
-		}
-	}
-	return result ;
-}
-
-std::string G::Options::usageHelp( const Layout & layout ) const
-{
-	std::string result = usageHelpImp( layout ) ;
-
-	// check for width overflow even after wrapping, which can
-	// happen as 'layout.width' shrinks towards 'layout.column'
-	if( layout.width && layout.column && layout.separator.empty() &&
-		layout.width <= (layout.column+20) )
-	{
-		std::size_t longest = longestSubLine( result ) ;
-		if( longest > layout.width )
-		{
-			// give up on columns and make the description part wrap
-			// onto a completely new line by setting a huge separator
-			Layout new_layout( layout ) ;
-			new_layout.separator = std::string( layout.column+layout.column , ' ' ) ;
-			result = usageHelpImp( new_layout ) ;
-		}
-	}
-
-	return result ;
-}
-
-std::string G::Options::usageHelpImp( const Layout & layout ) const
-{
-	std::string result ;
-	for( const auto & name : m_names )
-	{
-		if( visible(name,layout.level,layout.level_exact) )
-		{
-			auto spec_p = m_map.find( name ) ;
-
-			std::string margin( layout.margin , ' ' ) ;
-			std::string syntax = usageHelpSyntax( spec_p ) ;
-			std::string description = usageHelpDescription( spec_p , layout ) ;
-			std::string separator = usageHelpSeparator( layout , syntax.length() ) ;
-
-			std::string line ;
-			line.append(margin).append(syntax).append(separator).append(description) ;
-
-			if( layout.width )
-				line = usageHelpWrap( layout , line , margin ) ;
-
-			line.append( 1U , '\n' ) ;
-			result.append( line ) ;
-		}
-	}
-	return result ;
-}
-
-void G::Options::showUsage( const Layout & layout , std::ostream & stream ,
-	const std::string & exe , const std::string & args ) const
-{
-	stream
-		<< usageSummary(layout,exe,args) << std::endl
-		<< std::endl
-		<< usageHelp(layout) ;
-}
-
-std::string G::Options::usageSummary( const Layout & layout ,
-	const std::string & exe , const std::string & args ) const
-{
-	const char * usage = gettext( "usage: " ) ;
-	const char * alt_usage = gettext( "abbreviated usage: " ) ;
-	std::string s = std::string()
-		.append(layout.alt_usage?alt_usage:usage)
-		.append(exe)
-		.append(" ")
-		.append(usageSummaryPartOne(layout))
-		.append(usageSummaryPartTwo(layout))
-		.append(args.empty()||args.at(0U)==' '?"":" ")
-		.append(args) ;
-	std::string indent( 2U , ' ' ) ;
-	return layout.width == 0U ? s : StringWrap::wrap( s , "" , indent , layout.width , 0U , true ) ;
-}
-
-// ==
-
-G::Options::Option::Option( char c_ , const std::string & name_ , const std::string & description_ ,
-	const std::string & description_extra_ , const std::string & value_multiplicity_ ,
-	const std::string & vd_ , unsigned int level_ ) :
-		c(c_) ,
-		name(name_) ,
-		description(description_) ,
-		description_extra(description_extra_) ,
-		value_multiplicity(decode(value_multiplicity_)) ,
-		hidden(description_.empty()||level_==0U) ,
-		value_description(vd_) ,
-		level(level_)
-{
-}
-
-G::Options::Option::Multiplicity G::Options::Option::decode( const std::string & s )
-{
-	if( s == "0" )
-		return Multiplicity::zero ;
-	else if( s == "01" )
-		return Multiplicity::zero_or_one ;
-	else if( s == "1" )
-		return Multiplicity::one ;
-	else if( s == "2" )
-		return Multiplicity::many ;
-	else
-		throw InvalidSpecification( "multiplicity" ) ;
+	return m_list ;
 }
 
diff --git a/src/glib/goptions.h b/src/glib/goptions.h
index a1c3bcb..77ffed8 100644
--- a/src/glib/goptions.h
+++ b/src/glib/goptions.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,78 +22,64 @@
 #define G_OPTIONS_H
 
 #include "gdef.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gexception.h"
+#include "goption.h"
 #include <string>
-#include <map>
 
 namespace G
 {
 	class Options ;
-	struct OptionsLayout ;
 }
 
-//| \class G::OptionsLayout
-/// Describes the layout for G::Options output.
-///
-struct G::OptionsLayout
-{
-	std::string separator ; ///< separator between syntax and description
-	std::size_t column ; ///< left hand column width if no separator (includes margin)
-	std::size_t width ; ///< overall width for wrapping, or zero for none
-	std::size_t width2 ; ///< width after the first line, or zero for 'width'
-	std::size_t margin ; ///< spaces to the left of the syntax part
-	unsigned int level ; ///< show options at-or-below this level
-	bool level_exact ; ///< .. or exactly at that level
-	bool extra ; ///< include descriptions' extra text
-	bool alt_usage ; ///< use alternate "usage:" string
-	OptionsLayout() ;
-	explicit OptionsLayout( std::size_t column ) ;
-	OptionsLayout( std::size_t column , std::size_t width ) ;
-	OptionsLayout & set_column( std::size_t ) ;
-	OptionsLayout & set_extra( bool = true ) ;
-	OptionsLayout & set_level( unsigned int ) ;
-	OptionsLayout & set_level_if( bool , unsigned int ) ;
-	OptionsLayout & set_level_exact( bool = true ) ;
-	OptionsLayout & set_alt_usage( bool = true ) ;
-} ;
-
 //| \class G::Options
-/// A class to represent allowed command-line options and to provide command-line
-/// usage text.
+/// A class to assemble a list of command-line options and provide access
+/// by name.
 ///
 class G::Options
 {
 public:
-	using Layout = OptionsLayout ;
-	G_EXCEPTION( InvalidSpecification , "invalid options specification string" ) ;
+	G_EXCEPTION( InvalidSpecification , tx("invalid options specification string") ) ;
 
 	explicit Options( const std::string & spec , char sep_major = '|' , char sep_minor = '!' , char escape = '^' ) ;
 		///< Constructor taking a specification string.
 		///<
-		///< Uses specifications like "p!port!defines the port number!!1!port!1|v!verbose!shows more logging!!0!!1"
-		///< made up of (1) an optional single-character-option-letter, (2) a multi-character-option-name
-		///< (3) an option-description, (4) optional option-description-extra text, (5) a value-type
-		///< (with '0' for unvalued, '1' for a single value, '2' for a comma-separated list (possibly
-		///< multiple times), or '01' for a defaultable single value) or (6) a value-description
-		///< (unless unvalued), and (7) a level enumeration.
+		///< Uses specifications like
+		///< "p!port!the port! for listening!1!port!1|v!verbose!more logging! and help!0!!1"
+		///< made up of (1) an optional single-character-option-letter,
+		///< (2) a multi-character-option-name (3) an option-description,
+		///< (4) optional option-description-extra text, (5) a value-type
+		///< (with '0' for unvalued, '1' for a single value, '2' for a
+		///< comma-separated list (possibly multiple times), or '01'
+		///< for a defaultable single value) or (6) a value-description
+		///< (unless unvalued), (7) a level enumeration, and optional
+		///< trailing tags.
 		///<
-		///< By convention mainstream options should have a level of 1, and obscure ones level 2 and above.
-		///< If the option-description field is empty or if the level is zero then the option is hidden.
+		///< Typically mainstream options are given a level of 1, and
+		///< obscure ones level 2 and above. If the option-description
+		///< field is empty or if the level is zero then the option
+		///< is hidden.
 
 	Options() ;
 		///< Default constructor for no options.
 
-	void add( StringArray ) ;
-		///< Adds one component of the specification, broken down into its seven
-		///< separate parts.
+	static void add( Options & , char c , const char * name , const char * text ,
+        const char * more , Option::Multiplicity m , const char * argname ,
+		unsigned int level , unsigned int main_tag , unsigned int tag_bits = 0U ) ;
+			///< A convenience function that constructs an Option object
+			///< with the trailing arguments and then calls add(Option)
+			///< on the Options object. The 'text' string is passed through
+			///< G::gettext() and should therefore normally be marked
+			///< for translation with G::tx().
 
-	void add( StringArray , char sep , char escape = '\\' ) ;
-		///< Adds one component of the specification broken down into six separate
-		///< parts with fields 3 and 4 joined by the given separator character.
+	void add( const Option & , char sep = '!' , char escape = '\\' ) ;
+		///< Adds one component of the specification. If the 'description'
+		///< contains the unescaped 'sep' character then it is split
+		///< into two parts and the second part replaces the
+		///< 'description_extra', which must be empty.
 
-	const StringArray & names() const ;
-		///< Returns the sorted list of long-form option names.
+	const std::vector<Option> & list() const ;
+		///< Returns the sorted list of option structures.
 
 	std::string lookup( char c ) const ;
 		///< Converts from short-form option character to the corresponding
@@ -142,72 +128,14 @@ public:
 		///< taking its default (empty) value followed by a separate
 		///< argument 'bar'.
 
-	std::string usageSummary( const Layout & ,
-		const std::string & exe , const std::string & args = std::string() ) const ;
-			///< Returns a one-line (or line-wrapped) usage summary, as
-			///< "usage: <exe> <options> <args>". The 'args' parameter
-			///< should represent the non-option arguments (with a
-			///< leading space), like " <foo> [<bar>]".
-			///<
-			///< Eg:
-			///< \code
-			///< std::cout << options.usageSummary(
-			///<   OptionsLayout().set_level_if(!verbose,1U).set_extra(verbose) ,
-			///<   getopt.args().prefix() , " <arg> [<arg> ...]" ) << std::endl ;
-			///< \endcode
-
-	std::string usageHelp( const Layout & ) const ;
-		///< Returns a multi-line string giving help on each option.
-
-	void showUsage( const Layout & , std::ostream & stream ,
-		const std::string & exe , const std::string & args = std::string() ) const ;
-			///< Streams out multi-line usage text using usageSummary() and
-			///< usageHelp().
-
-private:
-	struct Option
-	{
-		enum class Multiplicity { zero , zero_or_one , one , many } ;
-		char c ;
-		std::string name ;
-		std::string description ;
-		std::string description_extra ;
-		Multiplicity value_multiplicity ;
-		bool hidden ;
-		std::string value_description ;
-		unsigned int level ;
-
-		Option( char c_ , const std::string & name_ , const std::string & description_ ,
-			const std::string & description_extra_ , const std::string & multiplicity_ ,
-			const std::string & vd_ , unsigned int level_ ) ;
-		static Multiplicity decode( const std::string & ) ;
-	} ;
-	using Map = std::map<std::string,Option> ;
-
 private:
+	using List = std::vector<Option> ;
 	void parseSpec( const std::string & spec , char , char , char ) ;
-	void addImp( const std::string & , char c , const std::string & , const std::string & ,
-		const std::string & , const std::string & , unsigned int ) ;
-	std::string usageSummaryPartOne( const Layout & ) const ;
-	std::string usageSummaryPartTwo( const Layout & ) const ;
-	std::string usageHelpSyntax( Map::const_iterator ) const ;
-	std::string usageHelpDescription( Map::const_iterator , const Layout & ) const ;
-	std::string usageHelpSeparator( const Layout & , std::size_t syntax_length ) const ;
-	std::string usageHelpWrap( const Layout & , const std::string & line_in ,
-		const std::string & ) const ;
-	std::string usageHelpImp( const Layout & ) const ;
-	static std::size_t longestSubLine( const std::string & ) ;
+	void addOption( Option , char , char ) ;
+	List::const_iterator find( const std::string & ) const ;
 
 private:
-	StringArray m_names ; // sorted
-	Map m_map ;
+	List m_list ;
 } ;
 
-inline G::OptionsLayout & G::OptionsLayout::set_column( std::size_t c ) { column = c ; return *this ; }
-inline G::OptionsLayout & G::OptionsLayout::set_extra( bool e ) { extra = e ; return *this ; }
-inline G::OptionsLayout & G::OptionsLayout::set_level( unsigned int l ) { level = l ; return *this ; }
-inline G::OptionsLayout & G::OptionsLayout::set_level_if( bool b , unsigned int l ) { if(b) level = l ; return *this ; }
-inline G::OptionsLayout & G::OptionsLayout::set_level_exact( bool le ) { level_exact = le ; return *this ; }
-inline G::OptionsLayout & G::OptionsLayout::set_alt_usage( bool au ) { alt_usage = au ; return *this ; }
-
 #endif
diff --git a/src/glib/goptionsusage.cpp b/src/glib/goptionsusage.cpp
new file mode 100644
index 0000000..e401198
--- /dev/null
+++ b/src/glib/goptionsusage.cpp
@@ -0,0 +1,328 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file goptionsusage.cpp
+///
+
+#include "gdef.h"
+#include "goptionsusage.h"
+#include "genvironment.h"
+#include "ggettext.h"
+#include "gstr.h"
+#include "gstringwrap.h"
+#include "gassert.h"
+#include <algorithm>
+
+G::OptionsUsage::OptionsUsage( const std::vector<Option> & options , std::function<bool(const Option&,const Option&)> sort_fn ) :
+	m_options(options)
+{
+	if( sort_fn )
+		std::sort( m_options.begin() , m_options.end() , sort_fn ) ;
+}
+
+std::string G::OptionsUsage::summary( const Config & config_in ,
+	const std::string & exe , const std::string & args ) const
+{
+	Config config = config_in ;
+	config.setDefaults() ;
+
+	const char * usage = txt( "usage: " ) ;
+	const char * alt_usage = txt( "abbreviated usage: " ) ;
+	std::string s = std::string()
+		.append(config.alt_usage?alt_usage:usage)
+		.append(exe)
+		.append(" ")
+		.append(summaryPartOne(config))
+		.append(summaryPartTwo(config))
+		.append(args.empty()||args.at(0U)==' '?"":" ")
+		.append(args) ;
+	std::string indent( 2U , ' ' ) ;
+	return config.width == 0U ? s : StringWrap::wrap( s , "" , indent , config.width , 0U , true ) ;
+}
+
+std::string G::OptionsUsage::help( const Config & config_in , bool * overflow_p ) const
+{
+	Config config = config_in ;
+	config.setDefaults() ;
+	config.setWidthsWrtMargin() ;
+
+	if( overflow_p == nullptr )
+	{
+		bool overflow = false ;
+		std::string s = helpImp( config , &overflow ) ;
+		if( overflow )
+			s = helpImp( config , &overflow ) ;
+		return s ;
+	}
+	else
+	{
+		return helpImp( config , overflow_p ) ;
+	}
+}
+
+void G::OptionsUsage::output( const Config & config , std::ostream & stream ,
+	const std::string & exe , const std::string & args ) const
+{
+	stream
+		<< summary(config,exe,args) << std::endl
+		<< std::endl
+		<< help(config) ;
+}
+
+std::string G::OptionsUsage::summaryPartOne( const Config & config ) const
+{
+	// summarise the single-character switches, excluding those which take a value
+	std::ostringstream ss ;
+	bool first = true ;
+	for( const auto & option : m_options )
+	{
+		if( option.c != '\0' && !option.valued() && option.visible({config.level_min,config.level_max},config.main_tag,config.tag_bits) )
+		{
+			if( first )
+				ss << "[-" ;
+			first = false ;
+			ss << option.c ;
+		}
+	}
+
+	std::string s = ss.str() ;
+	if( s.length() ) s.append( "] " ) ;
+	return s ;
+}
+
+std::string G::OptionsUsage::summaryPartTwo( const Config & config ) const
+{
+	std::ostringstream ss ;
+	const char * sep = "" ;
+	for( const auto & option : m_options )
+	{
+		if( option.visible({config.level_min,config.level_max},config.main_tag,config.tag_bits) )
+		{
+			ss << sep << "[" ;
+			if( option.name.length() )
+			{
+				ss << "--" << option.name ;
+			}
+			else
+			{
+				G_ASSERT( option.c != '\0' ) ;
+				ss << "-" << option.c ;
+			}
+			if( option.valued() )
+			{
+				std::string vd = option.value_description ;
+				if( vd.empty() ) vd = "value" ;
+				ss << "=<" << vd << ">" ;
+			}
+			ss << "]" ;
+			sep = " " ;
+		}
+	}
+	return ss.str() ;
+}
+
+std::string G::OptionsUsage::helpImp( const Config & config , bool * overflow_p ) const
+{
+	std::string result ;
+	for( const auto & option : m_options )
+	{
+		if( option.visible({config.level_min,config.level_max},config.main_tag,config.tag_bits) )
+		{
+			std::string option_help = optionHelp( config , option , overflow_p ) ;
+			result.append( option_help ) ;
+			result.append( 1U , '\n' ) ;
+		}
+	}
+	return result ;
+}
+
+std::string G::OptionsUsage::optionHelp( const Config & config , const Option & option , bool * overflow_p ) const
+{
+	char placeholder = '\x01' ;
+	std::string syntax = helpSyntax( option , placeholder ) ;
+	std::string description = helpDescription( option , config ) ;
+	std::string separator = helpSeparator( config , syntax.length() ) ;
+
+	// concatentate and wrap
+	std::string line = helpWrap( config , syntax , separator , description , overflow_p ) ;
+
+	// add a margin
+	if( config.margin )
+	{
+		std::string margin = std::string( config.margin , m_space_margin ) ;
+		G::Str::replaceAll( line , "\n" , std::string(1U,'\n').append(margin) ) ;
+		line = margin + line ;
+	}
+
+	// fix up the placeholders
+	G::Str::replace( line , placeholder , m_space_placeholder ) ;
+
+	return line ;
+}
+
+std::string G::OptionsUsage::helpWrap( const Config & config , const std::string & syntax ,
+	const std::string & separator , const std::string & description , bool * overflow_p ) const
+{
+	std::string text = std::string(syntax).append(separator).append(description) ;
+	if( config.width == 0 )
+	{
+		// no wrapping
+		return text ;
+	}
+	else if( config.separator == "\t" )
+	{
+		// wrapped lines are indented with a tab
+		return StringWrap::wrap( text , "" , "\t" ,
+			config.width , config.width2 , true ) ;
+	}
+	else if( config.separator.empty() && !(overflow_p && *overflow_p) )
+	{
+		// no separator so wrapped lines are indented to the required column
+		std::string s = StringWrap::wrap( text , "" , helpPadding(config) ,
+			config.width , config.width2 , true ) ;
+
+		if( overflow_p && !*overflow_p && config.overflow )
+			*overflow_p = ( longestSubLine(s) + config.margin ) < ( config.column + config.overflow ) ;
+
+		return s ;
+	}
+	else if( overflow_p && *overflow_p )
+	{
+		// overflow format -- use a very large separator so the description is
+		// bumped onto a new line with one leading space on all wrapped lines
+		std::size_t n = config.column + config.column + 99U ;
+		text = std::string(syntax).append(n,m_space_overflow).append(description) ;
+		return StringWrap::wrap( text , "" , std::string(config.overflow_spaces,m_space_overflow) ,
+			config.width , config.width2 , true ) ;
+	}
+	else
+	{
+		// separator defined -- no column for the wrapped lines to indent
+		// to -- just add (typically) one leading space to wrapped lines
+		return StringWrap::wrap( text , "" , std::string(config.separator_spaces,m_space_separator) ,
+			config.width , config.width2 , true ) ;
+	}
+}
+
+std::string G::OptionsUsage::helpSyntax( const Option & option , char placeholder ) const
+{
+	std::string syntax ;
+	if( option.c != '\0' )
+	{
+		syntax.append( 1U , '-' ) ;
+		syntax.append( 1U , option.c ) ;
+		if( option.name.length() )
+			syntax.append( ", " ) ;
+	}
+	else
+	{
+		syntax.append( 4U , placeholder ) ;
+	}
+	if( option.name.length() )
+	{
+		syntax.append( "--" ) ;
+		syntax.append( option.name ) ;
+	}
+	if( option.valued() )
+	{
+		std::string vd = option.value_description ;
+		if( vd.empty() ) vd = "value" ;
+		if( option.defaulting() ) syntax.append( "[" ) ;
+		syntax.append( "=<" ) ;
+		syntax.append( vd ) ;
+		syntax.append( ">" ) ;
+		if( option.defaulting() ) syntax.append( "]" ) ;
+	}
+	return syntax ;
+}
+
+std::string G::OptionsUsage::helpDescription( const Option & option , const Config & config ) const
+{
+	std::string description = option.description ;
+	if( config.extra )
+		description.append( option.description_extra ) ;
+	return description ;
+}
+
+std::string G::OptionsUsage::helpSeparator( const Config & config , std::size_t syntax_length ) const
+{
+	if( !config.separator.empty() )
+		return config.separator ;
+	else if( (config.margin+syntax_length) >= config.column )
+		return std::string( 1U , m_space_separator ) ;
+	else
+		return std::string( config.column-syntax_length-config.margin , m_space_separator ) ;
+}
+
+std::string G::OptionsUsage::helpPadding( const Config & config ) const
+{
+	std::size_t n = std::max( std::size_t(1U) , config.column - std::min(config.column,config.margin) ) ;
+	return std::string( n , m_space_padding ) ;
+}
+
+std::size_t G::OptionsUsage::longestSubLine( const std::string & s )
+{
+	std::size_t result = 0U ;
+	bool result_set = false ;
+	std::size_t n = 0U ;
+	for( auto c : s )
+	{
+		if( c == '\n' )
+		{
+			if( n > result )
+				result = n , result_set = true ;
+			n = 0 ;
+		}
+		else
+		{
+			n++ ;
+		}
+	}
+	return result_set ? result : s.length() ;
+}
+
+G::OptionsUsage::SortFn G::OptionsUsage::sort()
+{
+	return []( const Option & a , const Option & b ){
+		// sort by level, then by name
+		return a.level == b.level ? G::Str::iless(a.name,b.name) : ( a.level < b.level ) ;
+	} ;
+}
+
+// ==
+
+G::OptionsUsage::Config & G::OptionsUsage::Config::setDefaults()
+{
+	bool default1 = width == Config::default_ ;
+	bool default2 = width2 == Config::default_ ;
+	std::size_t wenv = (default1||default2) ? Str::toUInt( Environment::get("COLUMNS",{}) , "79" ) : 0U ;
+	if( default1 ) width = wenv ;
+	if( default2 ) width2 = wenv ;
+	return *this ;
+}
+
+G::OptionsUsage::Config & G::OptionsUsage::Config::setWidthsWrtMargin()
+{
+	// modify the given widths to pass to StringWrap::wrap()
+	width -= std::min( width , margin ) ;
+	width = std::max( width , std::size_t(1U) ) ;
+	width2 -= std::min( width2 , margin ) ;
+	width2 = std::max( width2 , std::size_t(1U) ) ;
+	return *this ;
+}
+
+
diff --git a/src/glib/goptionsusage.h b/src/glib/goptionsusage.h
new file mode 100644
index 0000000..38dcd85
--- /dev/null
+++ b/src/glib/goptionsusage.h
@@ -0,0 +1,176 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file goptionsusage.h
+///
+
+#ifndef G_OPTIONS_USAGE_H
+#define G_OPTIONS_USAGE_H
+
+#include "gdef.h"
+#include "goptions.h"
+#include <functional>
+#include <string>
+#include <vector>
+
+namespace G
+{
+	class OptionsUsage ;
+}
+
+//| \class G::OptionsUsage
+/// Provides help text for a set of options.
+///
+/// If configured with a fixed separator the help() text is
+/// formatted as:
+/// \code
+///  <margin><syntax><separator><detail-to-width1>
+///  <margin><separator-spaces><more-detail-to-width2>
+/// \endcode
+///
+/// Or with a tab separator:
+/// \code
+///  <margin><syntax><TAB><detail-to-width1>
+///  <margin><TAB><more-detail-to-width2>
+/// \endcode
+///
+/// Or with a two-column layout:
+/// \code
+///  <margin><syntax><spaces-to-column><detail-to-width1>
+///  <margin><spaces-to-column><more-detail-to-width2>
+/// \endcode
+///
+/// Or two-column layout in 'overflow' mode:
+/// \code
+///  <margin><syntax>
+///  <margin><overflow-spaces><detail-to-width2>
+///  <margin><overflow-spaces><more-detail-to-width2>
+/// \endcode
+///
+class G::OptionsUsage
+{
+public:
+	struct Config /// A configuration structure for G::OptionsUsage.
+	{
+		static constexpr std::size_t default_ = static_cast<std::size_t>(-1) ;
+
+		std::string separator ; ///< separator between syntax and description
+		std::size_t separator_spaces {1U} ; ///< extra spaces on wrapped lines if using a separator
+		std::size_t column {30U} ; ///< left hand column width if no separator (includes margin)
+		std::size_t width {default_} ; ///< overall width for wrapping, or zero for none
+		std::size_t width2 {default_} ; ///< width after the first line, or zero for 'width'
+		std::size_t margin {2U} ; ///< spaces added to the left
+		std::size_t overflow {20U} ; ///< use 'overflow' format if rhs is squashed down to this
+		std::size_t overflow_spaces {6U} ; ///< 'overflow' format extra spaces on wrapped lines
+
+		bool extra {false} ; ///< include descriptions' extra text
+		bool alt_usage {false} ; ///< use alternate "usage:" string
+
+		unsigned int level_max {99U} ; ///< show options at-or-below this level
+		unsigned int level_min {1U} ; ///< .. and at-or-above this level
+		unsigned int main_tag {0U} ; ///< show options with this main tag, or zero for all
+		unsigned int tag_bits {0U} ; ///< show options with matching tag bits, or zero for all
+
+		Config & set_separator( const std::string & ) ;
+		Config & set_column( std::size_t ) ;
+		Config & set_width( std::size_t ) ;
+		Config & set_width2( std::size_t ) ;
+		Config & set_margin( std::size_t ) ;
+		Config & set_extra( bool = true ) ;
+		Config & set_alt_usage( bool = true ) ;
+
+		Config & set_level_max( unsigned int ) ;
+		Config & set_level_min( unsigned int ) ;
+		Config & set_main_tag( unsigned int ) ;
+		Config & set_tag_bits( unsigned int ) ;
+		Config & setDefaults() ;
+		Config & setWidthsWrtMargin() ;
+		Config & setOverflowFormat( char = ' ' ) ;
+	} ;
+
+	using SortFn = std::function<bool(const Option&,const Option&)> ;
+
+	explicit OptionsUsage( const std::vector<Option> & , SortFn = sort() ) ;
+		///< Constructor.
+
+	std::string summary( const Config & , const std::string & exe ,
+		const std::string & args = {} ) const ;
+			///< Returns a one-line (or line-wrapped) usage summary, as
+			///< "usage: <exe> <options> <args>". The 'args' parameter
+			///< should represent the non-option arguments (with a
+			///< leading space), like " <foo> [<bar>]".
+			///<
+			///< Eg:
+			///< \code
+			///< std::cout << usage.summary(
+			///<   OptionsUsage::Config().set_level_max(verbose?1U:99U).set_extra(verbose) ,
+			///<   getopt.args().prefix() , " <arg> [<arg> ...]" ) << std::endl ;
+			///< \endcode
+
+	std::string help( const Config & , bool * overflow_p = nullptr ) const ;
+		///< Returns a multi-line string giving help on each option.
+		///< Use the optional overflow flag if using help() for separate
+		///< sections that should have the same layout: initialise to
+		///< false, call help() for each section and discard the result,
+		///< then call help() again for each section.
+
+	void output( const Config & , std::ostream & stream ,
+		const std::string & exe , const std::string & args = {} ) const ;
+			///< Streams out multi-line usage text using summary() and
+			///< help().
+
+	static SortFn sort() ;
+		///< Returns the default sort function.
+
+private:
+	std::string summaryPartOne( const Config & ) const ;
+	std::string summaryPartTwo( const Config & ) const ;
+	std::string helpSyntax( const Option & , char ) const ;
+	std::string helpDescription( const Option & , const Config & ) const ;
+	std::string helpSeparator( const Config & , std::size_t syntax_length ) const ;
+	std::string helpPadding( const Config & ) const ;
+	std::string helpImp( const Config & , bool * = nullptr ) const ;
+	std::string optionHelp( const Config & , const Option & option , bool * ) const ;
+	std::string helpWrap( const Config & , const std::string & separator ,
+		const std::string & syntax , const std::string & description , bool * ) const ;
+	static std::size_t longestSubLine( const std::string & ) ;
+	static Config setDefaults( const Config & ) ;
+	static Config setWidthsWrtMargin( const Config & ) ;
+
+private:
+	std::vector<Option> m_options ;
+	char m_space_margin {' '} ;
+	char m_space_separator {' '} ;
+	char m_space_indent {' '} ;
+	char m_space_padding {' '} ;
+	char m_space_overflow {' '} ;
+	char m_space_placeholder {' '} ;
+} ;
+
+inline G::OptionsUsage::Config & G::OptionsUsage::Config::set_separator( const std::string & s ) { separator = s ; return *this ; }
+inline G::OptionsUsage::Config & G::OptionsUsage::Config::set_column( std::size_t n ) { column  = n ; return *this ; }
+inline G::OptionsUsage::Config & G::OptionsUsage::Config::set_width( std::size_t n ) { width = n ; return *this ; }
+inline G::OptionsUsage::Config & G::OptionsUsage::Config::set_width2( std::size_t n ) { width2 = n ; return *this ; }
+inline G::OptionsUsage::Config & G::OptionsUsage::Config::set_margin( std::size_t n ) { margin = n ; return *this ; }
+inline G::OptionsUsage::Config & G::OptionsUsage::Config::set_extra( bool b ) { extra = b ; return *this ; }
+inline G::OptionsUsage::Config & G::OptionsUsage::Config::set_alt_usage( bool b ) { alt_usage = b ; return *this ; }
+inline G::OptionsUsage::Config & G::OptionsUsage::Config::set_level_max( unsigned int n ) { level_max = n ; return *this ; }
+inline G::OptionsUsage::Config & G::OptionsUsage::Config::set_level_min( unsigned int n ) { level_min = n ; return *this ; }
+inline G::OptionsUsage::Config & G::OptionsUsage::Config::set_main_tag( unsigned int n ) { main_tag = n ; return *this ; }
+inline G::OptionsUsage::Config & G::OptionsUsage::Config::set_tag_bits( unsigned int n ) { tag_bits = n ; return *this ; }
+
+#endif
diff --git a/src/glib/goptionvalue.h b/src/glib/goptionvalue.h
index ed1736d..ea5c46a 100644
--- a/src/glib/goptionvalue.h
+++ b/src/glib/goptionvalue.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gpam.h b/src/glib/gpam.h
index 2c9a5e6..1aebc8e 100644
--- a/src/glib/gpam.h
+++ b/src/glib/gpam.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -152,8 +152,8 @@ public:
 public:
 	Pam( const Pam & ) = delete ;
 	Pam( Pam && ) = delete ;
-	void operator=( const Pam & ) = delete ;
-	void operator=( Pam && ) = delete ;
+	Pam & operator=( const Pam & ) = delete ;
+	Pam & operator=( Pam && ) = delete ;
 
 private:
 	std::unique_ptr<PamImp> m_imp ;
diff --git a/src/glib/gpam_linux.cpp b/src/glib/gpam_linux.cpp
index 3fb3841..d5566d2 100644
--- a/src/glib/gpam_linux.cpp
+++ b/src/glib/gpam_linux.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gpam_none.cpp b/src/glib/gpam_none.cpp
index e62148b..6aad2a5 100644
--- a/src/glib/gpam_none.cpp
+++ b/src/glib/gpam_none.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gpath.cpp b/src/glib/gpath.cpp
index b986d40..b68d84a 100644
--- a/src/glib/gpath.cpp
+++ b/src/glib/gpath.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,51 +21,60 @@
 #include "gdef.h"
 #include "gpath.h"
 #include "gstr.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gstringview.h"
 #include "gassert.h"
 #include <algorithm> // std::swap()
 #include <utility> // std::swap()
 
-//| \class G::PathImp
-/// A private implementation class used by G::Path providing a set of
-/// static methods. Supports both posix-style and windows-style paths
-/// at run-time, with only the default selected at compile-time.
-///
-class G::PathImp
+namespace G
 {
-public:
-	static bool use_posix ;
-	using pos_t = std::string::size_type ;
-
-	static string_view windows_sep()
+	namespace PathImp /// An implementation namespace for G::Path.
 	{
-		return {"\\",1U} ;
+		enum class Platform { Unix , Windows } ;
+		template <Platform> struct PathPlatform /// A class template specialised by o/s in the implementation of G::Path.
+			{} ;
+		template <> struct G::PathImp::PathPlatform<Platform::Unix> ;
+		template <> struct G::PathImp::PathPlatform<Platform::Windows> ;
 	}
-	static pos_t windows_slashpos( const std::string & s )
+}
+
+template <>
+struct G::PathImp::PathPlatform<G::PathImp::Platform::Windows> /// A windows specialisation of G::PathImp::PathPlatform used by G::Path.
+{
+	static string_view sep() noexcept
+	{
+		return { "\\" , 1U } ;
+	}
+	static std::size_t slashpos( const std::string & s ) noexcept
 	{
 		return s.rfind('\\') ;
 	}
-	static bool windows_simple( const std::string & s )
+	static bool simple( const std::string & s ) noexcept
 	{
 		return s.find('/') == std::string::npos && s.find('\\') == std::string::npos ;
 	}
-	static bool windows_absolute( const std::string & s )
+	static bool isdrive( const std::string & s ) noexcept
 	{
-		return
-			( s.length() >= 3U && s.at(1U) == ':' && s.at(2U) == '\\' ) ||
-			( s.length() >= 1U && s.at(0U) == '\\' ) ;
+		return s.length() == 2U && s[1] == ':' ;
 	}
-	static pos_t windows_rootsize( const std::string & s , std::size_t chars , std::size_t parts )
+	static bool absolute( const std::string & s ) noexcept
+	{
+		// TODO use rootsize()
+		return
+			( s.length() >= 3U && s[1] == ':' && s[2] == '\\' ) ||
+			( s.length() >= 1U && s[0] == '\\' ) ;
+	}
+	static std::size_t rootsizeImp( const std::string & s , std::size_t chars , std::size_t parts ) noexcept
 	{
 		G_ASSERT( s.length() >= chars ) ;
 		G_ASSERT( parts == 1U || parts == 2U ) ;
-		pos_t pos = s.find( '\\' , chars ) ;
+		std::size_t pos = s.find( '\\' , chars ) ;
 		if( parts == 2U && pos != std::string::npos )
 			pos = s.find( '\\' , pos+1U ) ;
 		return pos == std::string::npos ? s.length() : pos ;
 	}
-	static pos_t windows_rootsize( const std::string & s )
+	static std::size_t rootsize( const std::string & s ) noexcept
 	{
 		if( s.empty() )
 			return 0U ;
@@ -73,185 +82,187 @@ public:
 			return 3U ; // C:|...
 		if( s.length() >= 2U && s.at(1U) == ':' )
 			return 2U ; // C:...
-		if( s.find("\\\\?\\UNC\\") == 0U )
-			return windows_rootsize(s,8U,2U) ; // ||?|UNC|server|volume|...
-		if( s.find("\\\\?\\") == 0U && s.size() > 5U && s.at(5U) == ':' )
-			return windows_rootsize(s,4U,1U) ; // ||?|C:|...
-		if( s.find("\\\\?\\") == 0U )
-			return windows_rootsize(s,4U,2U) ; // ||?|server|volume|...
-		if( s.find("\\\\.\\") == 0U )
-			return windows_rootsize(s,4U,1U) ; // ||.|dev|...
-		if( s.find("\\\\") == 0U )
-			return windows_rootsize(s,2U,2U) ; // ||server|volume|...
+		if( s.find(R"(\\?\UNC\)",0U,8U) == 0U )
+			return rootsizeImp(s,8U,2U) ; // ||?|UNC|server|volume|...
+		if( s.find(R"(\\?\)",0U,4U) == 0U && s.size() > 5U && s.at(5U) == ':' )
+			return rootsizeImp(s,4U,1U) ; // ||?|C:|...
+		if( s.find(R"(\\?\)",0U,4U) == 0U )
+			return rootsizeImp(s,4U,2U) ; // ||?|server|volume|...
+		if( s.find(R"(\\.\)",0U,4U) == 0U )
+			return rootsizeImp(s,4U,1U) ; // ||.|dev|...
+		if( s.find("\\\\",0U,2U) == 0U )
+			return rootsizeImp(s,2U,2U) ; // ||server|volume|...
 		if( s.find('\\') == 0U )
 			return 1U ; // |...
 		return 0U ;
 	}
-	static void windows_normalise( std::string & s )
+	static void normalise( std::string & s )
 	{
-		Str::replaceAll( s , "/" , "\\" ) ;
-		bool special = s.find("\\\\") == 0U ;
-		while( Str::replaceAll( s , "\\\\" , "\\" ) ) {;}
-		if( special ) s = "\\" + s ;
+		Str::replaceAll( s , "/"_sv , "\\"_sv ) ;
+		bool special = s.find("\\\\",0U,2U) == 0U ;
+		while( Str::replaceAll( s , "\\\\"_sv , "\\"_sv ) ) {;}
+		if( special ) s.insert( 0U , 1U , '\\' ) ;
 
 		while( s.length() > 1U )
 		{
-			pos_t pos = s.rfind('\\') ;
+			std::size_t pos = s.rfind('\\') ;
 			if( pos == std::string::npos ) break ;
 			if( (pos+1U) != s.length() ) break ;
-			if( pos < windows_rootsize(s) ) break ;
+			if( pos < rootsize(s) ) break ;
 			s.resize( pos ) ;
 		}
 	}
-	static std::string windows_null()
+	static std::string null()
 	{
 		return "NUL" ;
 	}
+} ;
 
-	static string_view posix_sep()
+template <>
+struct G::PathImp::PathPlatform<G::PathImp::Platform::Unix> /// A unix specialisation of G::PathImp::PathPlatform used by G::Path.
+{
+	static string_view sep() noexcept
 	{
-		return {"/",1U} ;
+		return { "/" , 1U } ;
 	}
-	static pos_t posix_slashpos( const std::string & s )
+	static std::size_t slashpos( const std::string & s ) noexcept
 	{
 		return s.rfind('/') ;
 	}
-	static bool posix_simple( const std::string & s )
+	static bool simple( const std::string & s ) noexcept
 	{
 		return s.find('/') == std::string::npos ;
 	}
-	static void posix_normalise( std::string & s )
+	static bool isdrive( const std::string & ) noexcept
 	{
-		while( Str::replaceAll( s , "//" , "/" ) ) {;}
-		while( s.length() > 1U && s.at(s.length()-1U) == '/' ) s.resize(s.length()-1U) ;
-	}
-	static bool posix_absolute( const std::string & s )
-	{
-		return !s.empty() && s.at(0U) == '/' ;
-	}
-	static pos_t posix_rootsize( const std::string & s )
-	{
-		return s.empty() || s.at(0U) != '/' ? 0U : 1U ;
-	}
-	static std::string posix_null()
-	{
-		return "/dev/null" ;
-	}
-
-	static string_view sep()
-	{
-		return use_posix ? posix_sep() : windows_sep() ;
+		return false ;
 	}
 	static void normalise( std::string & s )
 	{
-		use_posix ? posix_normalise(s) : windows_normalise(s) ;
+		while( Str::replaceAll( s , "//"_sv , "/"_sv ) ) {;}
+		while( s.length() > 1U && s.at(s.length()-1U) == '/' ) s.resize(s.length()-1U) ;
 	}
-	static bool simple( const std::string & s )
+	static bool absolute( const std::string & s ) noexcept
 	{
-		return use_posix ? posix_simple(s) : windows_simple(s) ;
+		return !s.empty() && s[0] == '/' ;
 	}
-	static bool absolute( const std::string & s )
+	static std::size_t rootsize( const std::string & s ) noexcept
 	{
-		return use_posix ? posix_absolute(s) : windows_absolute(s) ;
+		return s.empty() || s[0] != '/' ? 0U : 1U ;
 	}
 	static std::string null()
 	{
-		return use_posix ? posix_null() : windows_null() ;
+		return "/dev/null" ;
 	}
-	static pos_t rootsize( const std::string & s )
-	{
-		return use_posix ? posix_rootsize(s) : windows_rootsize(s) ;
-	}
-	static pos_t slashpos( const std::string & s )
-	{
-		return use_posix ? posix_slashpos(s) : windows_slashpos(s) ;
-	}
-	static pos_t dotpos( const std::string & s )
-	{
-		const pos_t npos = std::string::npos ;
-		const pos_t sp = slashpos( s ) ;
-		const pos_t dp = s.rfind( '.' ) ;
-		if( dp == npos )
-			return npos ;
-		else if( sp == npos )
-			return dp ;
-		else if( dp < sp )
-			return npos ;
-		else
-			return dp ;
-	}
-
-	static void splitInto( const std::string & str , StringArray & a )
-	{
-		pos_t rs = rootsize(str) ;
-		if( str.empty() )
-		{
-		}
-		else if( rs != 0U ) // ie. absolute or like "c:foo"
-		{
-			std::string root = str.substr( 0U , rs ) ;
-			Str::splitIntoTokens( Str::tail(str,rs-1U,std::string()) , a , sep() ) ;
-			a.insert( a.begin() , root ) ;
-		}
-		else
-		{
-			Str::splitIntoTokens( str , a , sep() ) ;
-		}
-	}
-
-	static bool purge( StringArray & a )
-	{
-		const std::string dot( 1U , '.' ) ;
-		a.erase( std::remove( a.begin() , a.end() , std::string() ) , a.end() ) ;
-		std::size_t n = a.size() ;
-		a.erase( std::remove( a.begin() , a.end() , dot ) , a.end() ) ;
-		const bool all_dots = a.empty() && n != 0U ;
-		return all_dots ;
-	}
-
-	static std::string join( StringArray::const_iterator p , StringArray::const_iterator end )
-	{
-		std::string str ;
-		int i = 0 ;
-		for( ; p != end ; ++p , i++ )
-		{
-			bool drive = !use_posix && str.length() == 2U && str.at(1U) == ':' ;
-			bool last_is_slash = !str.empty() &&
-				( str.at(str.length()-1U) == '/' || str.at(str.length()-1U) == '\\' ) ;
-			if( i == 1 && (drive || last_is_slash) )
-				;
-			else if( i != 0 )
-				str.append( sep().data() , sep().size() ) ;
-			str.append( *p ) ;
-		}
-		return str ;
-	}
-
-	static std::string join( const StringArray & a )
-	{
-		return join( a.begin() , a.end() ) ;
-	}
-
-public:
-	PathImp() = delete ;
 } ;
 
-#ifdef G_WINDOWS
-bool G::PathImp::use_posix = false ;
-#else
-bool G::PathImp::use_posix = true ;
-#endif
+namespace G
+{
+	namespace PathImp
+	{
+		static bool use_posix = !G::is_windows() ; // gdef.h // NOLINT bogus cert-err58-cpp
+		using U = PathPlatform<Platform::Unix> ;
+		using W = PathPlatform<Platform::Windows> ;
+		static void usePosix() { use_posix = true ; }
+		static void useWindows() { use_posix = false ; }
+		static string_view sep() { return use_posix ? U::sep() : W::sep() ; }
+		static void normalise( std::string & s ) { use_posix ? U::normalise(s) : W::normalise(s) ; }
+		static bool simple( const std::string & s ) { return use_posix ? U::simple(s) : W::simple(s) ; }
+		static bool isdrive( const std::string & s ) { return use_posix ? U::isdrive(s) : W::isdrive(s) ; }
+		static bool absolute( const std::string & s ) { return use_posix ? U::absolute(s) : W::absolute(s); }
+		static std::string null() { return use_posix ? U::null() : W::null() ; }
+		static std::size_t rootsize( const std::string & s ) { return use_posix ? U::rootsize(s) : W::rootsize(s) ; }
+		static std::size_t slashpos( const std::string & s ) { return use_posix ? U::slashpos(s) : W::slashpos(s) ; }
+	}
+}
+
+namespace G
+{
+	namespace PathImp
+	{
+		static std::size_t dotpos( const std::string & s ) noexcept
+		{
+			const std::size_t npos = std::string::npos ;
+			const std::size_t sp = slashpos( s ) ;
+			const std::size_t dp = s.rfind( '.' ) ;
+			if( dp == npos )
+				return npos ;
+			else if( sp == npos )
+				return dp ;
+			else if( dp < sp )
+				return npos ;
+			else
+				return dp ;
+		}
+
+		static void splitInto( const std::string & str , StringArray & a )
+		{
+			std::size_t rs = rootsize( str ) ;
+			if( str.empty() )
+			{
+			}
+			else if( rs != 0U ) // ie. absolute or like "c:foo"
+			{
+				std::string root = str.substr( 0U , rs ) ;
+				Str::splitIntoTokens( Str::tail(str,rs-1U,std::string()) , a , sep() ) ;
+				a.insert( a.begin() , root ) ;
+			}
+			else
+			{
+				Str::splitIntoTokens( str , a , sep() ) ;
+			}
+		}
+
+		static bool purge( StringArray & a )
+		{
+			const std::string dot( 1U , '.' ) ;
+			a.erase( std::remove( a.begin() , a.end() , std::string() ) , a.end() ) ;
+			std::size_t n = a.size() ;
+			a.erase( std::remove( a.begin() , a.end() , dot ) , a.end() ) ;
+			const bool all_dots = a.empty() && n != 0U ;
+			return all_dots ;
+		}
+
+		static std::string join( StringArray::const_iterator p , StringArray::const_iterator end )
+		{
+			std::string str ;
+			int i = 0 ;
+			for( ; p != end ; ++p , i++ )
+			{
+				bool drive = isdrive( str ) ;
+				bool last_is_slash = !str.empty() &&
+					( str.at(str.length()-1U) == '/' || str.at(str.length()-1U) == '\\' ) ;
+				if( i == 1 && (drive || last_is_slash) )
+					;
+				else if( i != 0 )
+					str.append( sep().data() , sep().size() ) ;
+				str.append( *p ) ;
+			}
+			return str ;
+		}
+
+		static std::string join( const StringArray & a )
+		{
+			return join( a.begin() , a.end() ) ;
+		}
+
+		static bool string_less( const std::string & a , const std::string & b ) noexcept
+		{
+			return a.compare(b) < 0 ; // uses std::char_traits<char>::compare()
+		}
+	}
+}
 
 // ==
 
 void G::Path::setPosixStyle()
 {
-	PathImp::use_posix = true ;
+	PathImp::usePosix() ;
 }
 
 void G::Path::setWindowsStyle()
 {
-	PathImp::use_posix = false ;
+	PathImp::useWindows() ;
 }
 
 G::Path::Path()
@@ -269,6 +280,12 @@ G::Path::Path( const char * path ) :
 	PathImp::normalise( m_str ) ;
 }
 
+G::Path::Path( string_view path ) :
+	m_str(sv_to_string(path))
+{
+	PathImp::normalise( m_str ) ;
+}
+
 G::Path::Path( const Path & path , const std::string & tail ) :
 	m_str(path.m_str)
 {
@@ -307,7 +324,7 @@ G::Path::Path( std::initializer_list<std::string> args )
 
 G::Path G::Path::nullDevice()
 {
-	return Path( PathImp::null() ) ;
+	return { PathImp::null() } ;
 }
 
 bool G::Path::simple() const
@@ -315,12 +332,12 @@ bool G::Path::simple() const
 	return dirname().empty() ;
 }
 
-bool G::Path::isAbsolute() const
+bool G::Path::isAbsolute() const noexcept
 {
 	return PathImp::absolute( m_str ) ;
 }
 
-bool G::Path::isRelative() const
+bool G::Path::isRelative() const noexcept
 {
 	return !isAbsolute() ;
 }
@@ -338,22 +355,22 @@ G::Path G::Path::dirname() const
 	StringArray a ;
 	PathImp::splitInto( m_str , a ) ;
 	PathImp::purge( a ) ;
-	if( a.empty() ) return Path() ;
+	if( a.empty() ) return {} ;
 	a.pop_back() ;
 	return join( a ) ;
 }
 
 G::Path G::Path::withoutExtension() const
 {
-	std::string::size_type sp = PathImp::slashpos(m_str) ;
-	std::string::size_type dp = PathImp::dotpos(m_str) ;
+	std::string::size_type sp = PathImp::slashpos( m_str ) ;
+	std::string::size_type dp = PathImp::dotpos( m_str ) ;
 	if( dp != std::string::npos )
 	{
 		std::string result = m_str ;
 		result.resize( dp ) ;
 		if( (sp == std::string::npos && dp == 0U) || ((sp+1U) == dp) )
 			result.append(".") ; // special case
-		return Path( result ) ;
+		return { result } ;
 	}
 	else
 	{
@@ -364,12 +381,28 @@ G::Path G::Path::withoutExtension() const
 G::Path G::Path::withExtension( const std::string & ext ) const
 {
 	std::string result = m_str ;
-	std::string::size_type dp = PathImp::dotpos(m_str) ;
+	std::string::size_type dp = PathImp::dotpos( m_str ) ;
 	if( dp != std::string::npos )
 		result.resize( dp ) ;
 	result.append( 1U , '.' ) ;
 	result.append( ext ) ;
-	return Path( result ) ;
+	return { result } ;
+}
+
+G::Path G::Path::withoutRoot() const
+{
+	if( isAbsolute() )
+	{
+		StringArray a ;
+		PathImp::splitInto( m_str , a ) ;
+		G_ASSERT( !a.empty() ) ;
+		a.erase( a.begin() ) ;
+		return a.empty() ? Path("."_sv) : join( a ) ;
+	}
+	else
+	{
+		return *this ;
+	}
 }
 
 void G::Path::pathAppend( const std::string & tail )
@@ -407,8 +440,8 @@ G::StringArray G::Path::split() const
 
 G::Path G::Path::join( const G::StringArray & a )
 {
-	if( a.empty() ) return Path() ;
-	return Path( PathImp::join(a) ) ;
+	if( a.empty() ) return {} ;
+	return { PathImp::join(a) } ;
 }
 
 G::Path G::Path::join( const G::Path & p1 , const G::Path & p2 )
@@ -475,11 +508,6 @@ void G::Path::swap( Path & other ) noexcept
 	swap( m_str , other.m_str ) ;
 }
 
-static bool string_less( const std::string & a , const std::string & b )
-{
-	return a.compare(b) < 0 ; // uses std::char_traits<char>::compare()
-}
-
 bool G::Path::less( const G::Path & a , const G::Path & b )
 {
 	StringArray a_parts = a.split() ;
@@ -487,7 +515,7 @@ bool G::Path::less( const G::Path & a , const G::Path & b )
 	return std::lexicographical_compare(
 		a_parts.begin() , a_parts.end() ,
 		b_parts.begin() , b_parts.end() ,
-		string_less ) ;
+		PathImp::string_less ) ;
 }
 
 G::Path G::Path::difference( const G::Path & root_in , const G::Path & path_in )
@@ -500,16 +528,16 @@ G::Path G::Path::difference( const G::Path & root_in , const G::Path & path_in )
 	if( path_parts.size() == 1U && path_parts.at(0U) == "." ) path_parts.clear() ;
 
 	if( path_parts.size() < root_parts.size() )
-		return Path() ;
+		return {} ;
 
 	using Pair = std::pair<StringArray::iterator,StringArray::iterator> ;
 	Pair p = std::mismatch( root_parts.begin() , root_parts.end() , path_parts.begin() ) ;
 
 	if( p.first == root_parts.end() && p.second == path_parts.end() )
-		return Path(".") ;
+		return { "." } ;
 	else if( p.first != root_parts.end() )
-		return Path() ;
+		return {} ;
 	else
-		return Path( PathImp::join(p.second,path_parts.end()) ) ;
+		return { PathImp::join(p.second,path_parts.end()) } ;
 }
 
diff --git a/src/glib/gpath.h b/src/glib/gpath.h
index b5f70b4..b3e9214 100644
--- a/src/glib/gpath.h
+++ b/src/glib/gpath.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,7 +22,8 @@
 #define G_PATH_H
 
 #include "gdef.h"
-#include "gstrings.h"
+#include "gstringarray.h"
+#include "gstringview.h"
 #include <string>
 #include <iostream>
 #include <initializer_list>
@@ -30,7 +31,7 @@
 namespace G
 {
 	class Path ;
-	class PathImp ;
+	class PathFriend ;
 }
 
 //| \class G::Path
@@ -78,8 +79,11 @@ public:
 	Path( const std::string & path ) ;
 		///< Implicit constructor from a string.
 
+	Path( string_view path ) ;
+		///< Implicit constructor from a string view.
+
 	Path( const char * path ) ;
-		///< Implicit constructor from a c-style string.
+		///< Implicit constructor from a c string.
 
 	Path( const Path & path , const std::string & tail ) ;
 		///< Constructor with an implicit pathAppend().
@@ -132,14 +136,19 @@ public:
 
 	Path withoutExtension() const ;
 		///< Returns a path without the basename extension, if any.
-		///< As a special case, a basename() that starts with a dot
-		///< is replaced by a single dot. Prefer withExtension()
-		///< where appropriate to avoid this.
+		///< Returns this path if there is no dot in the basename.
+		///< As a special case, a basename() like ".foo" ends up as
+		///< "."; prefer withExtension() where appropriate to avoid
+		///< this.
 
-	bool isAbsolute() const ;
+	Path withoutRoot() const ;
+		///< Returns a path without the root part. This has no effect
+		///< if the path isRelative().
+
+	bool isAbsolute() const noexcept ;
 		///< Returns !isRelative().
 
-	bool isRelative() const ;
+	bool isRelative() const noexcept ;
 		///< Returns true if the path is a relative path or empty().
 
 	void pathAppend( const std::string & tail ) ;
@@ -195,7 +204,7 @@ public:
 		///< UTF-8 paths.
 
 private:
-	friend class G::PathImp ;
+	friend class G::PathFriend ;
 	std::string m_str ;
 } ;
 
diff --git a/src/glib/gpidfile.cpp b/src/glib/gpidfile.cpp
index f997bf3..70c43b4 100644
--- a/src/glib/gpidfile.cpp
+++ b/src/glib/gpidfile.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -33,9 +33,14 @@
 G::PidFile::PidFile()
 = default;
 
+G::PidFile::PidFile( const Path & path ) :
+	m_path((!path.empty()&&path.isRelative())?Path::join(Process::cwd(),path):path)
+{
+}
+
 G::PidFile::~PidFile()
 {
-	if( valid() )
+	if( !m_path.empty() )
 	{
 		bool done = cleanup( SignalSafe() , m_path.cstr() ) ;
 		if( !done )
@@ -46,14 +51,10 @@ G::PidFile::~PidFile()
 	}
 }
 
-G::PidFile::PidFile( const Path & path ) :
-	m_path(path)
+void G::PidFile::mkdir()
 {
-}
-
-void G::PidFile::init( const Path & path )
-{
-	m_path = path ;
+	if( !m_path.empty() )
+		File::mkdir( m_path.dirname() , std::nothrow ) ;
 }
 
 void G::PidFile::create( const Path & pid_file )
@@ -74,7 +75,7 @@ void G::PidFile::create( const Path & pid_file )
 
 		// (leak only if necessary)
 		static constexpr std::size_t buffer_size = 60U ; // eg. "/var/run/whatever/whatever.pid"
-		static std::array<char,buffer_size> buffer ;
+		static std::array<char,buffer_size> buffer {} ;
 		const char * cleanup_arg = &buffer[0] ;
 		if( buffer[0] == '\0' && pid_file.size() < buffer.size() )
 			G::Str::strncpy_s( &buffer[0] , buffer.size() , pid_file.cstr() , pid_file.size() ) ;
@@ -92,7 +93,7 @@ G::Process::Id G::PidFile::read( SignalSafe , const char * path ) noexcept
 		return Process::Id::invalid() ;
 
 	constexpr std::size_t buffer_size = 11U ;
-	std::array<char,buffer_size> buffer ; // NOLINT cppcoreguidelines-pro-type-member-init
+	std::array<char,buffer_size> buffer {} ;
 	buffer[0U] = '\0' ;
 
 	ssize_t rc = File::read( fd , &buffer[0] , buffer_size-1U ) ;
@@ -123,15 +124,9 @@ bool G::PidFile::cleanup( SignalSafe safe , const char * path ) noexcept
 	}
 }
 
-void G::PidFile::check()
-{
-	if( valid() && ! m_path.isAbsolute() )
-		throw Error(std::string("must be an absolute path: ")+m_path.str()) ;
-}
-
 void G::PidFile::commit()
 {
-	if( valid() )
+	if( !m_path.empty() )
 	{
 		create( m_path ) ;
 		m_committed = true ;
@@ -148,8 +143,3 @@ G::Path G::PidFile::path() const
 	return m_path ;
 }
 
-bool G::PidFile::valid() const
-{
-	return !m_path.empty() ;
-}
-
diff --git a/src/glib/gpidfile.h b/src/glib/gpidfile.h
index 590ad1d..be9c5b5 100644
--- a/src/glib/gpidfile.h
+++ b/src/glib/gpidfile.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -56,7 +56,7 @@ namespace G
 class G::PidFile
 {
 public:
-	G_EXCEPTION( Error , "invalid pid file" ) ;
+	G_EXCEPTION( Error , tx("invalid pid file") ) ;
 
 	static bool cleanup( SignalSafe , const char * path ) noexcept ;
 		///< Deletes the specified pid file if it contains this
@@ -70,51 +70,44 @@ public:
 		///< Signal-safe, reentrant implementation.
 
 	explicit PidFile( const Path & pid_file_path ) ;
-		///< Constructor. The path should normally be an
-		///< absolute path. Use commit() to actually create
-		///< the file.
+		///< Constructor. A relative path is converted to
+		///< an absolute path using the cwd. Use commit()
+		///< to actually create the file.
 
 	PidFile() ;
 		///< Default constructor. Constructs a do-nothing
-		///< object. Initialise with init().
-
-	void init( const Path & pid_file_path ) ;
-		///< Used after default construction to make the object
-		///< active. Use commit() to actually create the file.
+		///< object.
 
 	~PidFile() ;
 		///< Destructor. Calls cleanup() to delete the file.
 
+	void mkdir() ;
+		///< Creates the directory if it does not already exist.
+		///<
+		///< The caller should switch effective user-id and
+		///< umask as necessary.
+
 	void commit() ;
-		///< Creates the file and installs signal handlers to
-		///< cleanup() the file on abnormal process termination.
+		///< Creates the pid file if a path has been defined.
+		///< Also installs signal handlers to cleanup() the
+		///< file on abnormal process termination. Throws
+		///< on error.
 		///<
-		///< Does nothing if no pid file path has been defined.
-		///< Throws on error.
-		///<
-		///< The caller is responsible for setting the file
-		///< ownership and permissions by switching effecive
-		///< user-id and umask.
+		///< The caller should switch effective user-id and
+		///< umask as necessary.
 
 	bool committed() const ;
 		///< Returns true if commit() has been called with
 		///< a valid path().
 
-	void check() ;
-		///< Throws an exception if the path is not absolute.
-		///< The use of G::Daemon normally requires an absolute
-		///< path because it may change the current working
-		///< directory.
-
 	Path path() const ;
-		///< Returns the path as supplied to the constructor
-		///< or init().
+		///< Returns the full path of the file.
 
 public:
 	PidFile( const PidFile & ) = delete ;
 	PidFile( PidFile && ) = delete ;
-	void operator=( const PidFile & ) = delete ;
-	void operator=( PidFile && ) = delete ;
+	PidFile & operator=( const PidFile & ) = delete ;
+	PidFile & operator=( PidFile && ) = delete ;
 
 private:
 	static void create( const Path & pid_file ) ;
diff --git a/src/glib/gprocess.h b/src/glib/gprocess.h
index f7c07c9..ab34516 100644
--- a/src/glib/gprocess.h
+++ b/src/glib/gprocess.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -26,9 +26,12 @@
 #include "gidentity.h"
 #include "gpath.h"
 #include "gstr.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gsignalsafe.h"
+#include <memory>
 #include <iostream>
+#include <limits>
+#include <type_traits>
 #include <string>
 #include <new>
 
@@ -45,10 +48,11 @@ namespace G
 class G::Process
 {
 public:
-	G_EXCEPTION( CannotChangeDirectory , "cannot change directory" ) ;
-	G_EXCEPTION( InvalidId , "invalid process-id string" ) ;
-	G_EXCEPTION( UidError , "cannot set uid" ) ;
-	G_EXCEPTION( GidError , "cannot set gid" ) ;
+	G_EXCEPTION( CannotChangeDirectory , tx("cannot change directory") ) ;
+	G_EXCEPTION( InvalidId , tx("invalid process-id string") ) ;
+	G_EXCEPTION( UidError , tx("cannot set uid") ) ;
+	G_EXCEPTION( GidError , tx("cannot set gid") ) ;
+	G_EXCEPTION( GetCwdError , tx("cannot get current working directory") ) ;
 	class Id ;
 	class Umask ;
 	class UmaskImp ;
@@ -75,9 +79,12 @@ public:
 		///< (Beware of destructors of c++ temporaries disrupting
 		///< the global errno value.)
 
+	static void errno_( int e_new ) noexcept ;
+		///< Sets the process's 'errno' value.
+
 	static int errno_( const SignalSafe & , int e_new ) noexcept ;
 		///< Sets the process's 'errno' value. Returns the old
-		///< value. Used in signal handlers.
+		///< value. Typically used in signal handlers.
 
 	static std::string strerror( int errno_ ) ;
 		///< Translates an 'errno' value into a meaningful diagnostic string.
@@ -147,6 +154,18 @@ public:
 		std::string str() const ;
 		bool operator==( const Id & ) const noexcept ;
 		bool operator!=( const Id & ) const noexcept ;
+		template <typename T> T value(
+			typename std::enable_if
+				<std::numeric_limits<T>::max() >= std::numeric_limits<pid_t>::max()>
+			::type * = 0 ) const noexcept
+		{
+			static_assert( sizeof(T) >= sizeof(pid_t) , "" ) ;
+			return static_cast<T>( m_pid ) ;
+		}
+		template <typename T> T seed() const noexcept
+		{
+			return static_cast<T>( m_pid ) ;
+		}
 
 	private:
 		friend class NewProcess ;
@@ -157,16 +176,29 @@ public:
 	class Umask /// Used to temporarily modify the process umask.
 	{
 	public:
-		enum class Mode { Readable , Tighter , Tightest , GroupOpen , Open } ;
+		enum class Mode
+		{
+			NoChange , // typically 0022
+			TightenOther , // -......---
+			LoosenGroup , // -...rwx...
+			Readable , // 0022 -rw-r--r-- for open(0666) and -rwxr-xr-x for mkdir(0777)
+			Tighter ,  // 0007 -rw-rw---- for open(0666) and -rwxrwx--- for mkdir(0777)
+			Tightest , // 0077 -rw------- for open(0666) and -rwx------ for mkdir(0777)
+			GroupOpen ,// 0002 -rw-rw-r-- for open(0666) and -rwxrwxr-x for mkdir(0777)
+			Open       // 0000 -rw-rw-rw- for open(0666) and -rwxrwxrwx for mkdir(0777)
+		} ;
 		explicit Umask( Mode ) ;
 		~Umask() ;
 		static void set( Mode ) ;
-		static void tighten() ; // no "other" access, user and group unchanged
+		static void tightenOther() ; // deny "other" access, user and group unchanged
+		static void loosenGroup() ; // allow group access, user and "other" unchanged
 		Umask( const Umask & ) = delete ;
 		Umask( Umask && ) = delete ;
-		void operator=( const Umask & ) = delete ;
-		void operator=( Umask && ) = delete ;
-		private: std::unique_ptr<UmaskImp> m_imp ;
+		Umask & operator=( const Umask & ) = delete ;
+		Umask & operator=( Umask && ) = delete ;
+
+	private:
+		std::unique_ptr<UmaskImp> m_imp ;
 	} ;
 
 public:
diff --git a/src/glib/gprocess_unix.cpp b/src/glib/gprocess_unix.cpp
index 1fc7fe5..d114a5a 100644
--- a/src/glib/gprocess_unix.cpp
+++ b/src/glib/gprocess_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -38,10 +38,12 @@ namespace G
 {
 	namespace ProcessImp
 	{
+		G_EXCEPTION_CLASS( DevNullError , tx("cannot open /dev/null") ) ;
+		G_EXCEPTION_CLASS( IdentityError , tx("cannot change process identity") ) ;
 		void noCloseOnExec( int fd ) noexcept ;
 		void reopen( int fd , int mode ) ;
 		mode_t umaskValue( G::Process::Umask::Mode mode ) ;
-		bool readlink_( const char * path , std::string & value ) ;
+		bool readlink_( string_view path , std::string & value ) ;
 		bool setRealUser( Identity id , std::nothrow_t ) noexcept ;
 		bool setRealGroup( Identity id , std::nothrow_t ) noexcept ;
 		void setEffectiveUser( Identity id ) ;
@@ -58,10 +60,12 @@ namespace G
 	}
 }
 
-class G::Process::UmaskImp /// A private implemetation class for G::Process::Umask that hides mode_t.
+class G::Process::UmaskImp
 {
 public:
 	mode_t m_old_mode ;
+	static mode_t set( Process::Umask::Mode ) noexcept ;
+	static void set( mode_t ) noexcept ;
 } ;
 
 // ==
@@ -117,6 +121,11 @@ int G::Process::errno_( const SignalSafe & ) noexcept
 	return errno ; // possible macro, not ::errno or std::errno
 }
 
+void G::Process::errno_( int e_new ) noexcept
+{
+	errno = e_new ;
+}
+
 int G::Process::errno_( const SignalSafe & , int e_new ) noexcept
 {
 	int e_old = errno ;
@@ -198,7 +207,7 @@ std::string G::Process::cwd( bool no_throw )
 		}
 	}
 	if( result.empty() && !no_throw )
-		throw std::runtime_error( "getcwd() failed" ) ;
+		throw GetCwdError() ;
 	return result ;
 }
 
@@ -259,25 +268,57 @@ bool G::Process::Id::operator!=( const Id & other ) const noexcept
 
 // ==
 
+void G::Process::UmaskImp::set( mode_t mode ) noexcept
+{
+	GDEF_IGNORE_RETURN ::umask( mode ) ;
+}
+
+mode_t G::Process::UmaskImp::set( Umask::Mode mode ) noexcept
+{
+	mode_t old = ::umask( 2 ) ;
+	mode_t new_ = old ;
+	if( mode == Umask::Mode::Tightest )
+		new_ = 0077 ; // -rw-------
+	else if( mode == Umask::Mode::Tighter )
+		new_ = 0007 ;  // -rw-rw----
+	else if( mode == Umask::Mode::Readable )
+		new_ = 0022 ; // -rw-r--r--
+	else if( mode == Umask::Mode::GroupOpen )
+		new_ = 0002 ; // -rw-rw-r--
+	else if( mode == Umask::Mode::TightenOther )
+		new_ = old | mode_t(007) ;
+	else if( mode == Umask::Mode::LoosenGroup )
+		new_ = old & ~mode_t(070) ;
+	else if( mode == Umask::Mode::Open )
+		new_ = 0 ; // -rw-rw-rw-
+	set( new_ ) ;
+	return old ;
+}
+
 G::Process::Umask::Umask( Mode mode ) :
 	m_imp(std::make_unique<UmaskImp>())
 {
-	m_imp->m_old_mode = ::umask( ProcessImp::umaskValue(mode) ) ;
+	m_imp->m_old_mode = UmaskImp::set( mode ) ;
 }
 
 G::Process::Umask::~Umask()
 {
-	GDEF_IGNORE_RETURN ::umask( m_imp->m_old_mode ) ;
+	UmaskImp::set( m_imp->m_old_mode ) ;
 }
 
 void G::Process::Umask::set( Mode mode )
 {
-	GDEF_IGNORE_RETURN ::umask( ProcessImp::umaskValue(mode) ) ;
+	UmaskImp::set( mode ) ;
 }
 
-void G::Process::Umask::tighten()
+void G::Process::Umask::tightenOther()
 {
-	::umask( ::umask(2) | mode_t(7) ) ; // -xxxxxx---
+	set( Mode::TightenOther ) ;
+}
+
+void G::Process::Umask::loosenGroup()
+{
+	set( Mode::LoosenGroup ) ;
 }
 
 // ==
@@ -289,8 +330,8 @@ void G::ProcessImp::noCloseOnExec( int fd ) noexcept
 
 void G::ProcessImp::reopen( int fd , int mode )
 {
-	int fd_null = ::open( Path::nullDevice().cstr() , mode ) ;
-	if( fd_null < 0 ) throw std::runtime_error( "cannot open /dev/null" ) ;
+	int fd_null = ::open( Path::nullDevice().cstr() , mode ) ; // NOLINT
+	if( fd_null < 0 ) throw DevNullError() ;
 	::dup2( fd_null , fd ) ;
 	::close( fd_null ) ;
 }
@@ -302,13 +343,12 @@ mode_t G::ProcessImp::umaskValue( Process::Umask::Mode mode )
 	if( mode == Process::Umask::Mode::Tighter ) m = 0117 ;  // -rw-rw----
 	if( mode == Process::Umask::Mode::Readable ) m = 0133 ; // -rw-r--r--
 	if( mode == Process::Umask::Mode::GroupOpen ) m = 0113 ;// -rw-rw-r--
-	if( mode == Process::Umask::Mode::Open ) m = 0111 ;     // -rw-rw-rw-
 	return m ;
 }
 
-bool G::ProcessImp::readlink_( const char * path , std::string & value )
+bool G::ProcessImp::readlink_( string_view path , std::string & value )
 {
-	Path target = File::readlink( path , std::nothrow ) ;
+	Path target = File::readlink( Path(path) , std::nothrow ) ;
 	if( !target.empty() ) value = target.str() ;
 	return !target.empty() ;
 }
@@ -428,7 +468,7 @@ bool G::ProcessImp::setEffectiveGroup( Identity id , std::nothrow_t ) noexcept
 void G::ProcessImp::throwError()
 {
 	// typically we are about to std::terminate() so make sure there is an error message
-	G_ERROR( "G::ProcessImp::throwError: failed to give up process privileges" ) ;
-	throw G::Exception( "cannot give up process privileges" ) ;
+	G_ERROR( "G::ProcessImp::throwError: failed to change process identity" ) ;
+	throw IdentityError() ;
 }
 
diff --git a/src/glib/gprocess_win32.cpp b/src/glib/gprocess_win32.cpp
index 7a76099..1aa45ad 100644
--- a/src/glib/gprocess_win32.cpp
+++ b/src/glib/gprocess_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -59,7 +59,7 @@ bool G::Process::Id::operator!=( const Id & rhs ) const noexcept
 
 // ===
 
-void G::Process::closeFiles( bool keep_stderr )
+void G::Process::closeFiles( bool /*keep_stderr*/ )
 {
 	std::cout << std::flush ;
 	std::cerr << std::flush ;
@@ -92,7 +92,12 @@ int G::Process::errno_( const SignalSafe & ) noexcept
 	return e ;
 }
 
-int G::Process::errno_( const SignalSafe & signal_safe , int e ) noexcept
+void G::Process::errno_( int e ) noexcept
+{
+	_set_errno( e ) ;
+}
+
+int G::Process::errno_( const SignalSafe & , int e ) noexcept
 {
 	int old = errno_( SignalSafe() ) ;
 	_set_errno( e ) ;
@@ -103,7 +108,7 @@ std::string G::Process::strerror( int errno_ )
 {
 	std::vector<char> buffer( 80U , '\0' ) ;
 	if( strerror_s( &buffer[0] , buffer.size()-1U , errno_ ) || buffer.at(0U) == '\0' )
-		return "unknown error" ;
+		return std::string("unknown error (").append(G::Str::fromInt(errno_)).append(1U,')') ;
 	std::string s( &buffer[0] ) ;
 	return Str::isPrintableAscii(s) ? Str::lower(s) : s ;
 }
@@ -123,7 +128,7 @@ void G::Process::beOrdinaryForExec( Identity ) noexcept
 	// not implemented
 }
 
-void G::Process::beSpecial( Identity identity , bool )
+void G::Process::beSpecial( Identity , bool )
 {
 	// not implemented -- see also RevertToSelf()
 }
@@ -167,7 +172,7 @@ std::string G::Process::cwd( bool no_throw )
 	if( p == nullptr )
 	{
 		if( !no_throw )
-			throw std::runtime_error( "getcwd() failed" ) ;
+			throw GetCwdError() ;
 		return std::string() ;
 	}
 	else
@@ -196,3 +201,13 @@ void G::Process::Umask::set( Process::Umask::Mode )
 	// not implemented
 }
 
+void G::Process::Umask::tightenOther()
+{
+	// not implemented
+}
+
+void G::Process::Umask::loosenGroup()
+{
+	// not implemented
+}
+
diff --git a/src/glib/grandom.cpp b/src/glib/grandom.cpp
index b921e99..b62f744 100644
--- a/src/glib/grandom.cpp
+++ b/src/glib/grandom.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -20,6 +20,7 @@
 
 #include "gdef.h"
 #include "grandom.h"
+#include "gprocess.h"
 #include <ctime>
 #include <chrono>
 #include <random>
@@ -44,7 +45,9 @@ unsigned int G::Random::rand( unsigned int start , unsigned int end )
 		auto tp = std::chrono::high_resolution_clock::now() ;
 		auto seed_2 = static_cast<seed_t>( tp.time_since_epoch().count() ) ;
 
-		std::seed_seq seq{ seed_1 , seed_2 } ;
+		seed_t seed_3 = G::Process::Id().seed<seed_t>() ;
+
+		std::seed_seq seq{ seed_1 , seed_2 , seed_3 } ;
 		e.seed( seq ) ;
 		seeded = true ;
 	}
diff --git a/src/glib/grandom.h b/src/glib/grandom.h
index 3c13186..88156ab 100644
--- a/src/glib/grandom.h
+++ b/src/glib/grandom.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/greadwrite.cpp b/src/glib/greadwrite.cpp
index 492d977..50011c4 100644
--- a/src/glib/greadwrite.cpp
+++ b/src/glib/greadwrite.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/greadwrite.h b/src/glib/greadwrite.h
index 1d8722e..1c5d7a3 100644
--- a/src/glib/greadwrite.h
+++ b/src/glib/greadwrite.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/groot.cpp b/src/glib/groot.cpp
index 473eeff..d75ce7e 100644
--- a/src/glib/groot.cpp
+++ b/src/glib/groot.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -61,7 +61,7 @@ G::Root::~Root() // NOLINT bugprone-exception-escape
 		m_this = nullptr ;
 		int e_saved = Process::errno_() ;
 		Process::beOrdinary( m_nobody , m_change_group ) ; // can throw - std::terminate is correct
-		Process::errno_( SignalSafe() , e_saved ) ;
+		Process::errno_( e_saved ) ;
 	}
 }
 
diff --git a/src/glib/groot.h b/src/glib/groot.h
index 2a66de4..2d2284f 100644
--- a/src/glib/groot.h
+++ b/src/glib/groot.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -65,7 +65,7 @@ public:
 		///< group-id or not.
 
 	~Root() ; // NOLINT
-		///< Desctructor. Releases special privileges if this instance acquired them.
+		///< Destructor. Releases special privileges if this instance acquired them.
 		///< The implementation uses G::Process::beOrdinary(). Errors from seteuid()
 		///< will call Process::terminate().
 
@@ -89,8 +89,8 @@ public:
 public:
 	Root( const Root & ) = delete ;
 	Root( Root && ) = delete ;
-	void operator=( const Root & ) = delete ;
-	void operator=( Root && ) = delete ;
+	Root & operator=( const Root & ) = delete ;
+	Root & operator=( Root && ) = delete ;
 
 private:
 	void check() ;
diff --git a/src/glib/gscope.h b/src/glib/gscope.h
index d49c879..4e86630 100644
--- a/src/glib/gscope.h
+++ b/src/glib/gscope.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -58,8 +58,8 @@ public:
 public:
 	ScopeExit( const ScopeExit & ) = delete ;
 	ScopeExit( ScopeExit && ) = delete ;
-	void operator=( const ScopeExit & ) = delete ;
-	void operator=( ScopeExit && ) = delete ;
+	ScopeExit & operator=( const ScopeExit & ) = delete ;
+	ScopeExit & operator=( ScopeExit && ) = delete ;
 
 private:
 	std::function<void()> m_fn ;
@@ -88,8 +88,8 @@ public:
 public:
 	ScopeExitSetFalse( const ScopeExitSetFalse & ) = delete ;
 	ScopeExitSetFalse( ScopeExitSetFalse && ) = delete ;
-	void operator=( const ScopeExitSetFalse & ) = delete ;
-	void operator=( ScopeExitSetFalse && ) = delete ;
+	ScopeExitSetFalse & operator=( const ScopeExitSetFalse & ) = delete ;
+	ScopeExitSetFalse & operator=( ScopeExitSetFalse && ) = delete ;
 
 private:
 	bool & m_bref ;
diff --git a/src/glib/gsignalsafe.h b/src/glib/gsignalsafe.h
index 54f5425..3f0e53c 100644
--- a/src/glib/gsignalsafe.h
+++ b/src/glib/gsignalsafe.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gsleep.h b/src/glib/gsleep.h
index 7311f9b..7a9d6ef 100644
--- a/src/glib/gsleep.h
+++ b/src/glib/gsleep.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,8 +24,6 @@
 #include "gdef.h"
 #include <cstdlib>
 
-/// A sleep() function.
-///
 #ifdef G_WINDOWS
 inline void sleep( int s )
 {
diff --git a/src/glib/gslot.cpp b/src/glib/gslot.cpp
index b018b0f..916869b 100644
--- a/src/glib/gslot.cpp
+++ b/src/glib/gslot.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gslot.h b/src/glib/gslot.h
index 118aad1..29ee7ef 100644
--- a/src/glib/gslot.h
+++ b/src/glib/gslot.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -27,6 +27,11 @@
 #include <functional>
 #include <memory>
 
+#ifdef emit
+// beware Qt
+#error invalid preprocessor definition of 'emit'
+#endif
+
 namespace G
 {
 	//| \namespace G::Slot
@@ -70,7 +75,7 @@ namespace G
 	///   std::function<void(int)> m_signal ;
 	///   void Source::raiseEvent()
 	///   {
-	///     if( m_signal ) m_signal( 123 ) ; // emit()
+	///     if( m_signal ) m_signal( 123 ) ;
 	///   }
 	/// } ;
 	///
@@ -79,12 +84,12 @@ namespace G
 	///   void onEvent( int n ) ;
 	///   Sink( Source & source ) : m_source(source)
 	///   {
-	///     check( !source.m_signal ) ; // throw if already connected
-	///     source.m_signal = std::bind_front(&Sink::onEvent,this) ; // connect(slot())
+	///     throw_if( !source.m_signal ) ;
+	///     source.m_signal = std::bind_front(&Sink::onEvent,this) ;
 	///   }
 	///   ~Sink()
 	///   {
-	///     m_source.m_signal = nullptr ; // disconnect()
+	///     m_source.m_signal = nullptr ;
 	///   }
 	///   Source & m_source ;
 	/// } ;
@@ -145,7 +150,7 @@ namespace G
 		///
 		struct SignalImp
 		{
-			G_EXCEPTION_CLASS( AlreadyConnected , "already connected" ) ;
+			G_EXCEPTION_CLASS( AlreadyConnected , tx("already connected") ) ;
 			SignalImp() = delete ;
 		} ;
 
@@ -199,9 +204,9 @@ namespace G
 			}
 			~Signal() = default ;
 			Signal( const Signal & ) = delete ;
-			Signal( Signal && ) = delete ;
-			void operator=( const Signal & ) = delete ;
-			void operator=( Signal && ) = delete ;
+			Signal( Signal && ) = default ;
+			Signal & operator=( const Signal & ) = delete ;
+			Signal & operator=( Signal && ) = default ;
 		} ;
 
 		/// A factory function for Slot objects.
@@ -211,20 +216,6 @@ namespace G
 			// or c++20: return std::function<void(Args...)>( std::bind_front(method,&sink) )
 			return Slot<Args...>( sink , method ) ;
 		}
-
-		// backwards compatible names...
-		using Signal0 = Signal<> ;
-		template <typename T> using Signal1 = Signal<T> ;
-		template <typename T1, typename T2> using Signal2 = Signal<T1,T2> ;
-		template <typename T1, typename T2, typename T3> using Signal3 = Signal<T1,T2,T3> ;
-		template <typename T1, typename T2, typename T3, typename T4> using Signal4 = Signal<T1,T2,T3,T4> ;
-		template <typename T1, typename T2, typename T3, typename T4, typename T5> using Signal5 = Signal<T1,T2,T3,T4,T5> ;
-		using Slot0 = Slot<> ;
-		template <typename T> using Slot1 = Slot<T> ;
-		template <typename T1, typename T2> using Slot2 = Slot<T1,T2> ;
-		template <typename T1, typename T2, typename T3> using Slot3 = Slot<T1,T2,T3> ;
-		template <typename T1, typename T2, typename T3, typename T4> using Slot4 = Slot<T1,T2,T3,T4> ;
-		template <typename T1, typename T2, typename T3, typename T4, typename T5> using Slot5 = Slot<T1,T2,T3,T4,T5> ;
 	}
 }
 #endif
diff --git a/src/glib/gstatemachine.h b/src/glib/gstatemachine.h
index 46a81a4..4bc4c9d 100644
--- a/src/glib/gstatemachine.h
+++ b/src/glib/gstatemachine.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -28,7 +28,7 @@
 namespace G
 {
 
-G_EXCEPTION_CLASS( StateMachine_Error , "invalid state machine transition" ) ;
+G_EXCEPTION_CLASS( StateMachine_Error , tx("invalid state machine transition") ) ;
 
 //| \class StateMachine
 /// A finite state machine class template.
diff --git a/src/glib/gstr.cpp b/src/glib/gstr.cpp
index baf2334..8176149 100644
--- a/src/glib/gstr.cpp
+++ b/src/glib/gstr.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -32,140 +32,128 @@
 #include <sstream>
 #include <cstring>
 #include <cerrno>
+#include <cmath>
 
 namespace G
 {
 	namespace StrImp /// An implementation namespace for G::Str.
 	{
-		static constexpr string_view chars_meta( "~<>[]*$|?\\(){}\"`'&;=" , nullptr ) ; // bash meta-chars plus "~"
+		#ifndef G_LIB_SMALL
+			static constexpr string_view chars_meta = "~<>[]*$|?\\(){}\"`'&;="_sv ; // bash meta-chars plus "~"
+		#endif
 
-		static constexpr string_view chars_alnum( "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-			"0123456789" "abcdefghijklmnopqrstuvwxyz" , nullptr ) ;
-		static_assert( chars_alnum.size() == 26U+10U+26U , "" ) ;
+		static constexpr string_view chars_alnum_ = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz_"_sv ;
+		static_assert( chars_alnum_.size() == 26U+10U+26U+1U , "" ) ;
 
-		static constexpr string_view chars_hexmap( "0123456789abcdef" , nullptr ) ;
+		static constexpr string_view chars_alnum( chars_alnum_.data() , chars_alnum_.size()-1U ) ;
+
+		static constexpr string_view chars_hexmap = "0123456789abcdef"_sv ;
 		static_assert( chars_hexmap.size() == 16U , "" ) ;
 
-		static constexpr string_view chars_ws( " \t\n\r" , nullptr ) ;
+		static constexpr string_view chars_ws = " \t\n\r"_sv ;
 		static_assert( chars_ws.size() == 4U , "" ) ;
 
-		bool isDigit( char c ) ;
-		bool isHex( char c ) ;
-		bool isPrintableAscii( char c ) ;
-		char toLower( char c )  ;
-		char toUpper( char c )  ;
-		unsigned short toUShort( const std::string & s , bool & overflow , bool & invalid ) ;
-		unsigned long toULong( const std::string & s , bool & overflow , bool & invalid ) ;
-		unsigned long toULongHex( const std::string & s , bool limited ) ;
-		unsigned int toUInt( const std::string & s , bool & overflow , bool & invalid ) ;
-		short toShort( const std::string & s , bool & overflow , bool & invalid ) ;
-		long toLong( const std::string & s , bool & overflow , bool & invalid ) ;
-		int toInt( const std::string & s , bool & overflow , bool & invalid ) ;
+		bool isDigit( char c ) noexcept ;
+		bool isHex( char c ) noexcept ;
+		bool isPrintableAscii( char c ) noexcept ;
+		bool isPrintable( char c ) noexcept ;
+		bool isSimple( char c ) noexcept ;
+		char toLower( char c ) noexcept ;
+		char toUpper( char c ) noexcept ;
+		unsigned short toUShort( string_view , bool & overflow , bool & invalid ) noexcept ;
+		unsigned long toULong( string_view , bool & overflow , bool & invalid ) noexcept ;
+		unsigned long toULongHex( string_view , bool limited ) ;
+		unsigned int toUInt( string_view , bool & overflow , bool & invalid ) noexcept ;
+		short toShort( string_view , bool & overflow , bool & invalid ) noexcept ;
+		long toLong( string_view , bool & overflow , bool & invalid ) noexcept ;
+		int toInt( string_view , bool & overflow , bool & invalid ) noexcept ;
+		template <typename U> string_view fromUnsignedToHex( U u , char * out_p ) noexcept ;
 		void strncpy( char * , const char * , std::size_t ) noexcept ;
-		void escape( std::string & s , char c_escape , const char * specials_in , const char * specials_out ,
-			bool with_nul ) ;
-		void readLineFrom( std::istream & stream , const std::string & eol , std::string & line ) ;
+		void readLineFrom( std::istream & stream , string_view eol , std::string & line ) ;
 		template <typename S, typename T, typename SV> void splitIntoTokens( const S & in , T & out , const SV & ws ) ;
 		template <typename S, typename T> void splitIntoTokens( const S & in , T & out , const S & ws , typename S::value_type esc ) ;
-		template <typename T> void splitIntoFields( const std::string & in , T & out , string_view ws ) ;
-		template <typename T> void splitIntoFields( const std::string & in_in , T & out , string_view ws ,
+		template <typename T> void splitIntoFields( string_view in , T & out , string_view ws ) ;
+		template <typename T> void splitIntoFields( string_view in_in , T & out , string_view ws ,
 			char escape , bool remove_escapes ) ;
-		template <typename T1, typename T2, typename P> bool equal4( T1 p1 , T1 end1 , T2 p2 , T2 end2 , P p ) ;
-		bool ilessc( char c1 , char c2 ) ;
-		bool iless( const std::string & a , const std::string & b ) ;
-		bool imatchc( char c1 , char c2 ) ;
+		bool ilessc( char c1 , char c2 ) noexcept ;
+		bool imatchc( char c1 , char c2 ) noexcept ;
 		bool imatch( const std::string & a , const std::string & b ) ;
-		bool match( const std::string & a , const std::string & b , bool ignore_case ) ;
 		template <typename T, typename V> T unique( T in , T end , V repeat , V replacement ) ;
 		bool inList( StringArray::const_iterator begin , StringArray::const_iterator end ,
 			const std::string & s , bool i ) ;
 		bool notInList( StringArray::const_iterator begin , StringArray::const_iterator end ,
 			const std::string & s , bool i ) ;
 		template <typename T> struct Joiner ;
-		void join( const std::string & , std::string & , const std::string & ) ;
+		void join( string_view , std::string & , string_view ) ;
 		template <typename Tout> std::size_t outputHex( Tout out , char c ) ;
 		template <typename Tout> std::size_t outputHex( Tout out , wchar_t c ) ;
 		template <typename Tout, typename Tchar> std::size_t outputPrintable( Tout , Tchar , Tchar , char , bool ) ;
 		struct InPlaceBackInserter ;
 		template <typename Tchar = char> struct PrintableAppender ;
+		bool allOf( string_view , bool (*)(char) ) noexcept ;
 	}
 }
 
-std::string G::Str::escaped( const std::string & s_in )
+bool G::StrImp::allOf( string_view s , bool (*fn)(char) ) noexcept
 {
-	std::string s( s_in ) ;
+	if( s.empty() ) return true ;
+	for( auto c : s )
+	{
+		if( !fn(c) )
+			return false ;
+	}
+	return true ;
+}
+
+#ifndef G_LIB_SMALL
+std::string G::Str::escaped( string_view s_in )
+{
+	if( s_in.empty() ) return {} ;
+	std::string s( s_in.data() , s_in.size() ) ;
 	escape( s ) ;
 	return s ;
 }
+#endif
 
-std::string G::Str::escaped( const std::string & s_in , char c_escape , const std::string & specials_in ,
-	const std::string & specials_out )
+std::string G::Str::escaped( string_view s_in , char c_escape , string_view specials_in , string_view specials_out )
 {
-	std::string s( s_in ) ;
+	if( s_in.empty() ) return {} ;
+	std::string s( s_in.data() , s_in.size() ) ;
 	escape( s , c_escape , specials_in , specials_out ) ;
 	return s ;
 }
 
-std::string G::Str::escaped( const std::string & s_in , char c_escape , const char * specials_in ,
-	const char * specials_out )
+void G::Str::escape( std::string & s , char c_escape , string_view specials_in , string_view specials_out )
 {
-	std::string s( s_in ) ;
-	escape( s , c_escape , specials_in , specials_out ) ;
-	return s ;
-}
-
-void G::StrImp::escape( std::string & s , char c_escape , const char * specials_in ,
-	const char * specials_out , bool with_nul )
-{
-	G_ASSERT( specials_in != nullptr ) ;
-	G_ASSERT( specials_out != nullptr && (std::strlen(specials_out)-std::strlen(specials_in)) <= 1U ) ;
+	G_ASSERT( specials_in.size() == specials_out.size() ) ;
 	std::size_t pos = 0U ;
 	for(;;)
 	{
 		char c_in = '\0' ;
-		pos = s.find_first_of( specials_in , pos ) ;
-		if( pos != std::string::npos )
-			c_in = s.at( pos ) ;
-		else if( with_nul )
-			pos = s.find( '\0' , pos ) ;
+		pos = s.find_first_of( specials_in.data() , pos , specials_in.size() ) ;
 		if( pos == std::string::npos )
 			break ;
+		else
+			c_in = s.at( pos ) ;
 
-		G_ASSERT( std::strchr(specials_in,c_in) != nullptr ) ;
-		const std::size_t special_index = std::strchr(specials_in,c_in) - specials_in ;
-		G_ASSERT( special_index < std::strlen(specials_out) ) ;
+		const std::size_t special_index = specials_in.find( c_in ) ;
+		char c_out = specials_out.at( special_index ) ;
 
 		s.insert( pos , 1U , c_escape ) ;
 		pos++ ;
-		s.at(pos) = specials_out[special_index] ;
+		s.at(pos) = c_out ;
 		pos++ ;
 	}
 }
 
 void G::Str::escape( std::string & s )
 {
-	namespace imp = G::StrImp ;
-	imp::escape( s , '\\' , "\\\r\n\t" , "\\rnt0" , true ) ;
-}
-
-void G::Str::escape( std::string & s , char c_escape , const char * specials_in , const char * specials_out )
-{
-	namespace imp = G::StrImp ;
-	bool with_nul = std::strlen(specials_in) != std::strlen(specials_out) ;
-	imp::escape( s , c_escape , specials_in , specials_out , with_nul ) ;
-}
-
-void G::Str::escape( std::string & s , char c_escape , const std::string & specials_in ,
-	const std::string & specials_out )
-{
-	namespace imp = G::StrImp ;
-	G_ASSERT( specials_in.length() == specials_out.length() ) ;
-	bool with_nul = !specials_in.empty() && specials_in.at(specials_in.length()-1U) == '\0' ;
-	imp::escape( s , c_escape , specials_in.c_str() , specials_out.c_str() , with_nul ) ;
+	Str::escape( s , '\\' , "\0\\\r\n\t"_sv , "0\\rnt"_sv ) ;
 }
 
 std::string G::Str::dequote( const std::string & s , char qq , char esc , string_view ws , string_view nbws )
 {
+	G_ASSERT( ws.size() == nbws.size() ) ;
 	std::string result ;
 	result.reserve( s.size() ) ;
 	bool in_quote = false ;
@@ -210,41 +198,45 @@ std::string G::Str::dequote( const std::string & s , char qq , char esc , string
 	return result ;
 }
 
+#ifndef G_LIB_SMALL
 void G::Str::unescape( std::string & s )
 {
-	unescape( s , '\\' , "rnt0" , "\r\n\t" ) ;
+	unescape( s , '\\' , "0rnt"_sv , "\0\r\n\t"_sv ) ;
 }
+#endif
 
-void G::Str::unescape( std::string & s , char c_escape , const char * specials_in , const char * specials_out )
+#ifndef G_LIB_SMALL
+void G::Str::unescape( std::string & s , char c_escape , string_view specials_in , string_view specials_out )
 {
-	G_ASSERT( specials_in != nullptr ) ;
-	G_ASSERT( specials_out != nullptr && (std::strlen(specials_in)-std::strlen(specials_out)) <= 1U ) ;
+	G_ASSERT( specials_in.size() == specials_out.size() ) ;
 	bool escaped = false ;
+	std::size_t cpos = 0U ;
 	auto out = s.begin() ; // output in-place
 	for( char & c_in : s )
 	{
-		const char * specials_in_p = std::strchr( specials_in , c_in ) ;
-		const char * specials_out_p = specials_in_p ? (specials_out+(specials_in_p-specials_in)) : nullptr ;
-		if( escaped && specials_out_p )
-			*out++ = *specials_out_p , escaped = false ;
-		else if( escaped && c_in == c_escape )
-			*out++ = c_escape , escaped = false ;
-		else if( escaped )
-			*out++ = c_in , escaped = false ;
-		else if( c_in == c_escape )
+		if( escaped && (cpos=specials_in.find(c_in)) != std::string::npos ) // was BS now 'n'
+			*out++ = specials_out.at(cpos) , escaped = false ; // emit NL
+		else if( escaped && c_in == c_escape ) // was BS now BS
+			*out++ = c_escape , escaped = false ; // emit BS
+		else if( escaped ) // was BS
+			*out++ = c_in , escaped = false ; // emit c
+		else if( c_in == c_escape ) // is BS
 			escaped = true ;
 		else
 			*out++ = c_in , escaped = false ;
 	}
 	if( out != s.end() ) s.erase( out , s.end() ) ;
 }
+#endif
 
+#ifndef G_LIB_SMALL
 std::string G::Str::unescaped( const std::string & s_in )
 {
 	std::string s( s_in ) ;
 	unescape( s ) ;
 	return s ;
 }
+#endif
 
 void G::Str::replace( std::string & s , char from , char to )
 {
@@ -255,36 +247,34 @@ void G::Str::replace( std::string & s , char from , char to )
 	}
 }
 
-void G::Str:: replace( StringArray & a , char from , char to )
+void G::Str::replace( StringArray & a , char from , char to )
 {
 	for( std::string & s : a )
 		replace( s , from , to ) ;
 }
 
-bool G::Str::replace( std::string & s , const std::string & from , const std::string & to , std::size_t * pos_p )
+bool G::Str::replace( std::string & s , string_view from , string_view to , std::size_t * pos_p )
 {
-	if( from.length() == 0 )
+	if( from.empty() )
 		return false ;
 
 	std::size_t pos = pos_p == nullptr ? 0 : *pos_p ;
-	if( pos >= s.length() )
+	if( pos >= s.size() )
 		return false ;
 
-	pos = s.find( from , pos ) ;
+	pos = s.find( from.data() , pos , from.size() ) ;
 	if( pos == std::string::npos )
-	{
 		return false ;
-	}
+	else if( to.empty() )
+		s.erase( pos , from.size() ) ;
 	else
-	{
-		s.replace( pos , from.length() , to ) ;
-		if( pos_p != nullptr )
-			*pos_p = pos + to.length() ;
-		return true ;
-	}
+		s.replace( pos , from.size() , to.data() , to.size() ) ;
+	if( pos_p != nullptr )
+		*pos_p = pos + to.size() ;
+	return true ;
 }
 
-unsigned int G::Str::replaceAll( std::string & s , const std::string & from , const std::string & to )
+unsigned int G::Str::replaceAll( std::string & s , string_view from , string_view to )
 {
 	unsigned int count = 0U ;
 	for( std::size_t pos = 0U ; replace(s,from,to,&pos) ; count++ )
@@ -292,26 +282,10 @@ unsigned int G::Str::replaceAll( std::string & s , const std::string & from , co
 	return count ;
 }
 
-unsigned int G::Str::replaceAll( std::string & s , const char * from , const char * to )
-{
-	if( s.find(from) != std::string::npos )
-	{
-		unsigned int count = 0U ;
-		std::string f( from ) ;
-		for( std::size_t pos = 0U ; replace(s,f,to,&pos) ; count++ )
-			{;} // no-op
-		return count ;
-	}
-	else
-	{
-		return 0U ;
-	}
-}
-
 std::string G::Str::replaced( const std::string & s , char from , char to )
 {
 	std::string result( s ) ;
-	replaceAll( result , std::string(1U,from) , std::string(1U,to) ) ;
+	replaceAll( result , {&from,1U} , {&to,1U} ) ;
 	return result ;
 }
 
@@ -320,7 +294,14 @@ void G::Str::removeAll( std::string & s , char c )
 	s.erase( std::remove_if( s.begin() , s.end() , [c](char x){return x==c;} ) , s.end() ) ;
 }
 
-std::string G::Str::only( const std::string & chars , const std::string & s )
+std::string G::Str::removedAll( const std::string & s_in , char c )
+{
+	std::string s( s_in ) ;
+	removeAll( s , c ) ;
+	return s ;
+}
+
+std::string G::Str::only( string_view chars , string_view s )
 {
 	std::string result ;
 	result.reserve( s.size() ) ;
@@ -336,26 +317,52 @@ std::string & G::Str::trimLeft( std::string & s , string_view ws , std::size_t l
 {
 	std::size_t n = s.find_first_not_of( ws.data() , 0U , ws.size() ) ;
 	if( limit != 0U && ( n == std::string::npos || n > limit ) )
-		n = limit >= s.length() ? std::string::npos : limit ;
+		n = limit >= s.size() ? std::string::npos : limit ;
 	if( n == std::string::npos )
-		s = std::string() ;
+		s.erase() ;
 	else if( n != 0U )
 		s.erase( 0U , n ) ;
 	return s ;
 }
 
+G::string_view G::Str::trimLeftView( string_view sv , string_view ws , std::size_t limit ) noexcept
+{
+	std::size_t n = sv.find_first_not_of( ws ) ;
+	if( limit != 0U && ( n == std::string::npos || n > limit ) )
+		n = limit >= sv.size() ? std::string::npos : limit ;
+	if( n == std::string::npos )
+		return sv.substr( std::nothrow , 0U , 0U ) ;
+	else if( n != 0U )
+		return sv.substr( std::nothrow , n ) ;
+	else
+		return sv ;
+}
+
 std::string & G::Str::trimRight( std::string & s , string_view ws , std::size_t limit )
 {
 	std::size_t n = s.find_last_not_of( ws.data() , std::string::npos , ws.size() ) ;
-	if( limit != 0U && ( n == std::string::npos || s.length() > (limit+n+1U) ) )
-		n = limit >= s.length() ? std::string::npos : (s.length()-limit-1U) ;
+	if( limit != 0U && ( n == std::string::npos || s.size() > (limit+n+1U) ) )
+		n = limit >= s.size() ? std::string::npos : (s.size()-limit-1U) ;
 	if( n == std::string::npos )
-		s = std::string() ;
-	else if( (n+1U) != s.length() )
+		s.erase() ;
+	else if( (n+1U) != s.size() )
 		s.resize( n + 1U ) ;
 	return s ;
 }
 
+G::string_view G::Str::trimRightView( string_view sv , string_view ws , std::size_t limit ) noexcept
+{
+	std::size_t n = sv.find_last_not_of( ws ) ;
+	if( limit != 0U && ( n == std::string::npos || sv.size() > (limit+n+1U) ) )
+		n = limit >= sv.size() ? std::string::npos : (sv.size()-limit-1U) ;
+	if( n == std::string::npos )
+		return sv.substr( std::nothrow , 0U , 0U ) ;
+	else if( (n+1U) != sv.size() )
+		return sv.substr( std::nothrow , 0U , n+1U ) ;
+	else
+		return sv ;
+}
+
 std::string & G::Str::trim( std::string & s , string_view ws )
 {
 	return trimLeft( trimRight(s,ws) , ws ) ;
@@ -372,125 +379,155 @@ std::string G::Str::trimmed( std::string && s , string_view ws )
 	return std::move( trimLeft(trimRight(s,ws),ws) ) ;
 }
 
-bool G::StrImp::isDigit( char c )
+G::string_view G::Str::trimmedView( string_view s , string_view ws ) noexcept
+{
+	return trimLeftView( trimRightView(s,ws) , ws ) ;
+}
+
+bool G::StrImp::isDigit( char c ) noexcept
 {
 	auto uc = static_cast<unsigned char>(c) ;
 	return uc >= 48U && uc <= 57U ;
 }
 
-bool G::StrImp::isHex( char c )
+bool G::StrImp::isHex( char c ) noexcept
 {
 	auto uc = static_cast<unsigned char>(c) ;
 	return ( uc >= 48U && uc <= 57U ) || ( uc >= 65U && uc <= 70U ) || ( uc >= 97U && uc <= 102U ) ;
 }
 
-bool G::StrImp::isPrintableAscii( char c )
+bool G::StrImp::isPrintableAscii( char c ) noexcept
 {
 	auto uc = static_cast<unsigned char>(c) ;
 	return uc >= 32U && uc < 127U ;
 }
 
-char G::StrImp::toLower( char c )
+bool G::StrImp::isPrintable( char c ) noexcept
+{
+	auto uc = static_cast<unsigned char>(c) ;
+	return ( uc >= 32U && uc < 127U ) || ( uc >= 0xa0 && uc < 0xff ) ;
+}
+
+bool G::StrImp::isSimple( char c ) noexcept
+{
+	auto uc = static_cast<unsigned char>(c) ;
+	return isDigit(c) || c == '-' || c == '_' ||
+		( uc >= 65U && uc <= 90U ) ||
+		( uc >= 97U && uc <= 122U ) ;
+}
+
+char G::StrImp::toLower( char c ) noexcept
 {
 	const auto uc = static_cast<unsigned char>(c) ;
 	return ( uc >= 65U && uc <= 90U ) ? static_cast<char>(c+'\x20') : c ;
 }
 
-char G::StrImp::toUpper( char c )
+char G::StrImp::toUpper( char c ) noexcept
 {
 	const auto uc = static_cast<unsigned char>(c) ;
 	return ( uc >= 97U && uc <= 122U ) ? static_cast<char>(c-'\x20') : c ;
 }
 
-bool G::Str::isNumeric( const std::string & s , bool allow_minus_sign )
+bool G::Str::isNumeric( string_view s , bool allow_minus_sign ) noexcept
 {
-	namespace imp = G::StrImp ;
-	const auto end = s.end() ;
-	auto p = s.begin() ;
-	if( allow_minus_sign && p != end && *p == '-' ) ++p ;
-	return std::all_of( p , end , imp::isDigit ) ;
+	bool bump = allow_minus_sign && s.size() > 1U && s[0] == '-' ;
+	return StrImp::allOf( bump?s.substr(std::nothrow,1U):s , StrImp::isDigit ) ; // (true if empty)
 }
 
-bool G::Str::isHex( const std::string & s )
+bool G::Str::isHex( string_view s ) noexcept
 {
-	namespace imp = G::StrImp ;
-	return std::all_of( s.begin() , s.end() , imp::isHex ) ;
+	return StrImp::allOf( s , StrImp::isHex ) ;
 }
 
-bool G::Str::isPrintableAscii( const std::string & s )
+bool G::Str::isPrintableAscii( string_view s ) noexcept
 {
-	namespace imp = G::StrImp ;
-	return std::all_of( s.begin() , s.end() , imp::isPrintableAscii ) ;
+	return StrImp::allOf( s , StrImp::isPrintableAscii ) ;
 }
 
-bool G::Str::isInt( const std::string & s )
+bool G::Str::isPrintable( string_view s ) noexcept
+{
+	return StrImp::allOf( s , StrImp::isPrintable ) ;
+}
+
+bool G::Str::isSimple( string_view s ) noexcept
+{
+	return StrImp::allOf( s , StrImp::isSimple ) ;
+}
+
+bool G::Str::isInt( string_view s ) noexcept
 {
-	namespace imp = G::StrImp ;
 	bool overflow = false ;
 	bool invalid = false ;
-	imp::toInt( s , overflow , invalid ) ;
+	StrImp::toInt( s , overflow , invalid ) ;
 	return !overflow && !invalid ;
 }
 
-bool G::Str::isUShort( const std::string & s )
+#ifndef G_LIB_SMALL
+bool G::Str::isUShort( string_view s ) noexcept
 {
-	namespace imp = G::StrImp ;
 	bool overflow = false ;
 	bool invalid = false ;
-	imp::toUShort( s , overflow , invalid ) ;
+	StrImp::toUShort( s , overflow , invalid ) ;
+	return !overflow && !invalid ;
+}
+#endif
+
+bool G::Str::isUInt( string_view s ) noexcept
+{
+	bool overflow = false ;
+	bool invalid = false ;
+	StrImp::toUInt( s , overflow , invalid ) ;
 	return !overflow && !invalid ;
 }
 
-bool G::Str::isUInt( const std::string & s )
+bool G::Str::isULong( string_view s ) noexcept
 {
-	namespace imp = G::StrImp ;
 	bool overflow = false ;
 	bool invalid = false ;
-	imp::toUInt( s , overflow , invalid ) ;
-	return !overflow && !invalid ;
-}
-
-bool G::Str::isULong( const std::string & s )
-{
-	namespace imp = G::StrImp ;
-	bool overflow = false ;
-	bool invalid = false ;
-	imp::toULong( s , overflow , invalid ) ;
+	StrImp::toULong( s , overflow , invalid ) ;
 	return !overflow && !invalid ;
 }
 
+#ifndef G_LIB_SMALL
 std::string G::Str::fromBool( bool b )
 {
 	return b ? "true" : "false" ;
 }
+#endif
 
+#ifndef G_LIB_SMALL
 std::string G::Str::fromDouble( double d )
 {
+	if( std::isnan(d) ) return "nan" ;
+	if( std::isinf(d) ) return "inf" ;
 	std::ostringstream ss ;
 	ss << std::setprecision(16) << d ;
 	return ss.str() ;
 }
+#endif
 
-bool G::Str::toBool( const std::string & s )
+#ifndef G_LIB_SMALL
+bool G::Str::toBool( string_view s )
 {
-	std::string str = lower( s ) ;
 	bool result = true ;
-	if( str == "true" )
+	if( imatch( s , "true"_sv ) )
 		{;}
-	else if( str == "false" )
+	else if( imatch( s , "false"_sv ) )
 		result = false ;
 	else
-		throw InvalidFormat( "expected true/false" , s ) ;
+		throw InvalidFormat( "expected true/false" , sv_to_string(s) ) ;
 	return result ;
 }
+#endif
 
+#ifndef G_LIB_SMALL
 double G::Str::toDouble( const std::string & s )
 {
 	try
 	{
 		std::size_t end = 0U ;
 		double result = std::stod( s , &end ) ;
-		if( end == 0U || end == s.size() )
+		if( end != s.size() )
 			throw InvalidFormat( "expected floating point number" , s ) ;
 		return result ;
 	}
@@ -503,21 +540,48 @@ double G::Str::toDouble( const std::string & s )
 	 	throw Overflow( s ) ;
 	}
 }
+#endif
 
-int G::Str::toInt( const std::string & s )
+#ifndef G_LIB_SMALL
+float G::Str::toFloat( const std::string & s )
+{
+	try
+	{
+		std::size_t end = 0U ;
+		float result = std::stof( s , &end ) ;
+		if( end != s.size() )
+			throw InvalidFormat( "expected floating point number" , s ) ;
+		return result ;
+	}
+	catch( std::invalid_argument & )
+	{
+		throw InvalidFormat( "expected floating point number" , s ) ;
+	}
+	catch( std::out_of_range & )
+	{
+	 	throw Overflow( s ) ;
+	}
+}
+#endif
+
+int G::Str::toInt( string_view s )
 {
-	namespace imp = G::StrImp ;
 	bool overflow = false ;
 	bool invalid = false ;
-	int result = imp::toInt( s , overflow , invalid ) ;
+	int result = StrImp::toInt( s , overflow , invalid ) ;
 	if( invalid )
-		throw InvalidFormat( "expected integer" , s ) ;
+		throw InvalidFormat( "expected integer" , sv_to_string(s) ) ;
 	if( overflow )
-		throw Overflow( s ) ;
+		throw Overflow( sv_to_string(s) ) ;
 	return result ;
 }
 
-int G::StrImp::toInt( const std::string & s , bool & overflow , bool & invalid )
+int G::Str::toInt( string_view s1 , string_view s2 )
+{
+	return !s1.empty() && isInt(s1) ? toInt(s1) : toInt(s2) ;
+}
+
+int G::StrImp::toInt( string_view s , bool & overflow , bool & invalid ) noexcept
 {
 	long long_val = toLong( s , overflow , invalid ) ;
 	int result = static_cast<int>( long_val ) ;
@@ -526,55 +590,55 @@ int G::StrImp::toInt( const std::string & s , bool & overflow , bool & invalid )
 	return result ;
 }
 
-long G::Str::toLong( const std::string & s )
+#ifndef G_LIB_SMALL
+long G::Str::toLong( string_view s )
 {
-	namespace imp = G::StrImp ;
 	bool overflow = false ;
 	bool invalid = false ;
-	long result = imp::toLong( s , overflow , invalid ) ;
+	long result = StrImp::toLong( s , overflow , invalid ) ;
 	if( invalid )
-		throw InvalidFormat( "expected long integer" , s ) ;
+		throw InvalidFormat( "expected long integer" , sv_to_string(s) ) ;
 	if( overflow )
-		throw Overflow( s ) ;
+		throw Overflow( sv_to_string(s) ) ;
 	return result ;
 }
+#endif
 
-long G::StrImp::toLong( const std::string & s , bool & overflow , bool & invalid )
+long G::StrImp::toLong( string_view s , bool & overflow , bool & invalid ) noexcept
 {
-	try
-	{
-		std::size_t end = 0U ;
-		long result = std::stol( s , &end , 10 ) ;
-		if( end == 0U || end != s.size() )
-			invalid = true ;
-		return result ;
-	}
-	catch( std::invalid_argument & )
+	bool negative = !s.empty() && s[0] == '-' ;
+	bool positive = !s.empty() && s[0] == '+' ;
+	if( (negative || positive) && s.size() == 1U )
 	{
 		invalid = true ;
 		return 0L ;
 	}
-	catch( std::out_of_range & )
+	unsigned long ul = toULong( s.substr(std::nothrow,(negative||positive)?1U:0U) , overflow , invalid ) ;
+	static constexpr long long_max = std::numeric_limits<long>::max() ;
+	if( ul > long_max || (negative && (ul==long_max)) )
 	{
 		overflow = true ;
 		return 0L ;
 	}
+	return negative ? -static_cast<long>(ul) : static_cast<long>(ul) ;
 }
 
-short G::Str::toShort( const std::string & s )
+#ifndef G_LIB_SMALL
+short G::Str::toShort( string_view s )
 {
-	namespace imp = G::StrImp ;
 	bool overflow = false ;
 	bool invalid = false ;
-	short result = imp::toShort( s , overflow , invalid ) ;
+	short result = StrImp::toShort( s , overflow , invalid ) ;
 	if( invalid )
-		throw InvalidFormat( "expected short integer" , s ) ;
+		throw InvalidFormat( "expected short integer" , sv_to_string(s) ) ;
 	if( overflow )
-		throw Overflow( s ) ;
+		throw Overflow( sv_to_string(s) ) ;
 	return result ;
 }
+#endif
 
-short G::StrImp::toShort( const std::string & s , bool & overflow , bool & invalid )
+#ifndef G_LIB_SMALL
+short G::StrImp::toShort( string_view s , bool & overflow , bool & invalid ) noexcept
 {
 	long long_val = toLong( s , overflow , invalid ) ;
 	auto result = static_cast<short>( long_val ) ;
@@ -582,39 +646,45 @@ short G::StrImp::toShort( const std::string & s , bool & overflow , bool & inval
 		overflow = true ;
 	return result ;
 }
+#endif
 
-unsigned int G::Str::toUInt( const std::string & s1 , const std::string & s2 )
+unsigned int G::Str::toUInt( string_view s1 , string_view s2 )
 {
 	return !s1.empty() && isUInt(s1) ? toUInt(s1) : toUInt(s2) ;
 }
 
-unsigned int G::Str::toUInt( const std::string & s , Limited )
+unsigned int G::Str::toUInt( string_view s , unsigned int default_ )
+{
+	return !s.empty() && isUInt(s) ? toUInt(s) : default_ ;
+}
+
+#ifndef G_LIB_SMALL
+unsigned int G::Str::toUInt( string_view s , Limited )
 {
-	namespace imp = G::StrImp ;
 	bool overflow = false ;
 	bool invalid = false ;
-	unsigned int result = imp::toUInt( s , overflow , invalid ) ;
+	unsigned int result = StrImp::toUInt( s , overflow , invalid ) ;
 	if( invalid )
-		throw InvalidFormat( "expected unsigned integer" , s ) ;
+		throw InvalidFormat( "expected unsigned integer" , sv_to_string(s) ) ;
 	if( overflow )
 		result = std::numeric_limits<unsigned int>::max() ;
 	return result ;
 }
+#endif
 
-unsigned int G::Str::toUInt( const std::string & s )
+unsigned int G::Str::toUInt( string_view s )
 {
-	namespace imp = G::StrImp ;
 	bool overflow = false ;
 	bool invalid = false ;
-	unsigned int result = imp::toUInt( s , overflow , invalid ) ;
+	unsigned int result = StrImp::toUInt( s , overflow , invalid ) ;
 	if( invalid )
-		throw InvalidFormat( "expected unsigned integer" , s ) ;
+		throw InvalidFormat( "expected unsigned integer" , sv_to_string(s) ) ;
 	if( overflow )
-		throw Overflow( s ) ;
+		throw Overflow( sv_to_string(s) ) ;
 	return result ;
 }
 
-unsigned int G::StrImp::toUInt( const std::string & s , bool & overflow , bool & invalid )
+unsigned int G::StrImp::toUInt( string_view s , bool & overflow , bool & invalid ) noexcept
 {
 	unsigned long ulong_val = toULong( s , overflow , invalid ) ;
 	auto result = static_cast<unsigned int>( ulong_val ) ;
@@ -623,41 +693,43 @@ unsigned int G::StrImp::toUInt( const std::string & s , bool & overflow , bool &
 	return result ;
 }
 
-unsigned long G::Str::toULong( const std::string & s , Limited )
+unsigned long G::Str::toULong( string_view s , Limited )
 {
-	namespace imp = G::StrImp ;
 	bool overflow = false ;
 	bool invalid = false ;
-	unsigned long result = imp::toULong( s , overflow , invalid ) ;
+	unsigned long result = StrImp::toULong( s , overflow , invalid ) ;
 	if( invalid )
-		throw InvalidFormat( "expected unsigned long integer" , s ) ;
+		throw InvalidFormat( "expected unsigned long integer" , sv_to_string(s) ) ;
 	if( overflow )
 		result = std::numeric_limits<unsigned long>::max() ;
 	return result ;
 }
 
-unsigned long G::Str::toULong( const std::string & s , Hex , Limited )
+#ifndef G_LIB_SMALL
+unsigned long G::Str::toULong( string_view s , Hex , Limited )
 {
-	namespace imp = G::StrImp ;
-	return imp::toULongHex( s , true ) ;
+	return StrImp::toULongHex( s , true ) ;
 }
+#endif
 
-unsigned long G::Str::toULong( const std::string & s , Hex )
+#ifndef G_LIB_SMALL
+unsigned long G::Str::toULong( string_view s , Hex )
 {
-	namespace imp = G::StrImp ;
-	return imp::toULongHex( s , false ) ;
+	return StrImp::toULongHex( s , false ) ;
 }
+#endif
 
-unsigned long G::StrImp::toULongHex( const std::string & s , bool limited )
+#ifndef G_LIB_SMALL
+unsigned long G::StrImp::toULongHex( string_view s , bool limited )
 {
 	unsigned long n = 0U ;
 	if( s.empty() ) return 0U ;
-	std::size_t i0 = s.find_first_not_of('0') ;
+	std::size_t i0 = s.find_first_not_of( '0' ) ;
 	if( i0 == std::string::npos ) i0 = 0U ;
 	if( (s.size()-i0) > (sizeof(unsigned long)*2U) )
 	{
 		if( limited ) return ~0UL ;
-		throw Str::Overflow( s ) ;
+		throw Str::Overflow( sv_to_string(s) ) ;
 	}
 	for( std::size_t i = i0 ; i < s.size() ; i++ )
 	{
@@ -665,65 +737,74 @@ unsigned long G::StrImp::toULongHex( const std::string & s , bool limited )
 		if( c >= 97U && c <= 102U ) c -= 87U ;
 		else if( c >= 65U && c <= 70U ) c -= 55U ;
 		else if( c >= 48U && c <= 57U ) c -= 48U ;
-		else throw Str::InvalidFormat( "invalid hexadecimal" , s ) ;
+		else throw Str::InvalidFormat( "invalid hexadecimal" , sv_to_string(s) ) ;
 		n <<= 4U ;
 		n += c ;
 	}
 	return n ;
 }
+#endif
 
-unsigned long G::Str::toULong( const std::string & s )
+unsigned long G::Str::toULong( string_view s )
 {
-	namespace imp = G::StrImp ;
 	bool overflow = false ;
 	bool invalid = false ;
-	unsigned long result = imp::toULong( s , overflow , invalid ) ;
+	unsigned long result = StrImp::toULong( s , overflow , invalid ) ;
 	if( invalid )
-		throw InvalidFormat( "expected unsigned long integer" , s ) ;
+		throw InvalidFormat( "expected unsigned long integer" , sv_to_string(s) ) ;
 	else if( overflow )
-		throw Overflow( s ) ;
+		throw Overflow( sv_to_string(s) ) ;
 	return result ;
 }
 
-unsigned long G::Str::toULong( const std::string & s1 , const std::string & s2 )
+#ifndef G_LIB_SMALL
+unsigned long G::Str::toULong( string_view s1 , string_view s2 )
 {
 	return !s1.empty() && isULong(s1) ? toULong(s1) : toULong(s2) ;
 }
+#endif
 
-unsigned long G::StrImp::toULong( const std::string & s , bool & overflow , bool & invalid )
+unsigned long G::StrImp::toULong( string_view s , bool & overflow , bool & invalid ) noexcept
 {
 	// note that stoul()/strtoul() do too much in that they skip leading
-	// spaces, allow initial +/- (!) and are C-locale dependent
+	// spaces, allow initial +/- even for unsigned, and are C-locale
+	// dependent -- also there is no string_view version of std::stol()
+	// and std::strtol() requires a null-terminated string and so cannot
+	// take string_view::data()
+
 	return Str::toUnsigned<unsigned long>( s.data() , s.data()+s.size() , overflow , invalid ) ;
 }
 
-unsigned short G::Str::toUShort( const std::string & s , Limited )
+#ifndef G_LIB_SMALL
+unsigned short G::Str::toUShort( string_view s , Limited )
 {
-	namespace imp = G::StrImp ;
 	bool overflow = false ;
 	bool invalid = false ;
-	unsigned short result = imp::toUShort( s , overflow , invalid ) ;
+	unsigned short result = StrImp::toUShort( s , overflow , invalid ) ;
 	if( invalid )
-		throw InvalidFormat( "expected unsigned short integer" , s ) ;
+		throw InvalidFormat( "expected unsigned short integer" , sv_to_string(s) ) ;
 	if( overflow )
 		result = std::numeric_limits<unsigned short>::max() ;
 	return result ;
 }
+#endif
 
-unsigned short G::Str::toUShort( const std::string & s )
+#ifndef G_LIB_SMALL
+unsigned short G::Str::toUShort( string_view s )
 {
-	namespace imp = G::StrImp ;
 	bool overflow = false ;
 	bool invalid = false ;
-	unsigned short result = imp::toUShort( s , overflow , invalid ) ;
+	unsigned short result = StrImp::toUShort( s , overflow , invalid ) ;
 	if( invalid )
-		throw InvalidFormat( "expected unsigned short integer" , s ) ;
+		throw InvalidFormat( "expected unsigned short integer" , sv_to_string(s) ) ;
 	else if( overflow )
-		throw Overflow( s ) ;
+		throw Overflow( sv_to_string(s) ) ;
 	return result ;
 }
+#endif
 
-unsigned short G::StrImp::toUShort( const std::string & s , bool & overflow , bool & invalid )
+#ifndef G_LIB_SMALL
+unsigned short G::StrImp::toUShort( string_view s , bool & overflow , bool & invalid ) noexcept
 {
 	unsigned long ulong_val = toULong( s , overflow , invalid ) ;
 	auto result = static_cast<unsigned short>( ulong_val ) ;
@@ -731,29 +812,63 @@ unsigned short G::StrImp::toUShort( const std::string & s , bool & overflow , bo
 		overflow = true ;
 	return result ;
 }
+#endif
+
+#ifndef G_LIB_SMALL
+G::string_view G::Str::fromULongToHex( unsigned long u , char * out_p ) noexcept
+{
+	return StrImp::fromUnsignedToHex( u , out_p ) ;
+}
+#endif
+
+#ifndef G_LIB_SMALL
+G::string_view G::Str::fromULongLongToHex( unsigned long long u , char * out_p ) noexcept
+{
+	return StrImp::fromUnsignedToHex( u , out_p ) ;
+}
+#endif
+
+#ifndef G_LIB_SMALL
+template <typename U>
+G::string_view G::StrImp::fromUnsignedToHex( U u , char * out_p ) noexcept
+{
+	// (std::to_chars() is c++17 so do it long-hand)
+	static constexpr unsigned bytes = sizeof(U) ;
+	static constexpr unsigned bits = 8U * bytes ;
+	static constexpr unsigned buffer_size = bytes * 2U ;
+	static const char * map = "0123456789abcdef" ;
+	unsigned int shift = bits - 4U ;
+	char * out = out_p ;
+	for( unsigned i = 0 ; i < (bytes*2U) ; i++ ) // unrollable, no break
+	{
+		*out++ = map[(u>>shift) & 0xfUL] ;
+		shift -= 4U ;
+	}
+	string_view sv( out_p , buffer_size ) ;
+	return sv.substr( std::nothrow , std::min( sv.find_first_not_of('0') , static_cast<std::size_t>(buffer_size-1U) ) ) ;
+}
+#endif
 
 void G::Str::toLower( std::string & s )
 {
-	namespace imp = G::StrImp ;
-	std::transform( s.begin() , s.end() , s.begin() , imp::toLower ) ;
+	std::transform( s.begin() , s.end() , s.begin() , StrImp::toLower ) ;
 }
 
-std::string G::Str::lower( const std::string & in )
+std::string G::Str::lower( G::string_view in )
 {
-	std::string out = in ;
+	std::string out = sv_to_string( in ) ;
 	toLower( out ) ;
 	return out ;
 }
 
 void G::Str::toUpper( std::string & s )
 {
-	namespace imp = G::StrImp ;
-	std::transform( s.begin() , s.end() , s.begin() , imp::toUpper ) ;
+	std::transform( s.begin() , s.end() , s.begin() , StrImp::toUpper ) ;
 }
 
-std::string G::Str::upper( const std::string & in )
+std::string G::Str::upper( G::string_view in )
 {
-	std::string out = in ;
+	std::string out = sv_to_string( in ) ;
 	toUpper( out ) ;
 	return out ;
 }
@@ -761,25 +876,23 @@ std::string G::Str::upper( const std::string & in )
 template <typename Tout>
 std::size_t G::StrImp::outputHex( Tout out , char c )
 {
-	namespace imp = G::StrImp ;
 	std::size_t n = static_cast<unsigned char>( c ) ;
-	n &= 0xFFU ;
-	*out++ = imp::chars_hexmap[(n>>4U)%16U] ;
-	*out++ = imp::chars_hexmap[(n>>0U)%16U] ;
+	n &= 0xffU ;
+	*out++ = StrImp::chars_hexmap[(n>>4U)%16U] ;
+	*out++ = StrImp::chars_hexmap[(n>>0U)%16U] ;
 	return 2U ;
 }
 
 template <typename Tout>
 std::size_t G::StrImp::outputHex( Tout out , wchar_t c )
 {
-	namespace imp = G::StrImp ;
 	using uwchar_t = typename std::make_unsigned<wchar_t>::type ;
 	std::size_t n = static_cast<uwchar_t>( c ) ;
-	n &= 0xFFFFU ;
-	*out++ = imp::chars_hexmap[(n>>12U)%16U] ;
-	*out++ = imp::chars_hexmap[(n>>8U)%16U] ;
-	*out++ = imp::chars_hexmap[(n>>4U)%16U] ;
-	*out++ = imp::chars_hexmap[(n>>0U)%16U] ;
+	n &= 0xffffU ;
+	*out++ = StrImp::chars_hexmap[(n>>12U)%16U] ;
+	*out++ = StrImp::chars_hexmap[(n>>8U)%16U] ;
+	*out++ = StrImp::chars_hexmap[(n>>4U)%16U] ;
+	*out++ = StrImp::chars_hexmap[(n>>0U)%16U] ;
 	return 4U ;
 }
 
@@ -794,49 +907,36 @@ std::size_t G::StrImp::outputPrintable( Tout out , Tchar c , Tchar escape_in , c
 		*out++ = escape_out , n++ ;
 		*out++ = escape_out ;
 	}
-	else if( !eight_bit && uc >= 0x20U && uc < 0x7FU && uc != 0xFFU )
+	else if( !eight_bit && uc >= 0x20U && uc < 0x7fU )
 	{
 		*out++ = static_cast<char>(c) ;
 	}
-	else if( eight_bit && ( ( uc >= 0x20U && uc < 0x7FU ) || uc >= 0xA0 ) && uc != 0xFFU )
+	else if( eight_bit && ( ( uc >= 0x20U && uc < 0x7fU ) || ( uc >= 0Xa0 && uc < 0xffU ) ) )
 	{
 		*out++ = static_cast<char>(c) ;
 	}
 	else
 	{
 		*out++ = escape_out , n++ ;
+		char c_out = 'x' ;
 		if( uc == 10U )
-		{
-			*out++ = 'n' ;
-		}
+			c_out = 'n' ;
 		else if( uc == 13U )
-		{
-			*out++ = 'r' ;
-		}
+			c_out = 'r' ;
 		else if( uc == 9U )
-		{
-			*out++ = 't' ;
-		}
+			c_out = 't' ;
 		else if( uc == 0U )
-		{
-			*out++ = '0' ;
-		}
-		else
-		{
-			*out++ = 'x' ;
+			c_out = '0' ;
+		*out++ = c_out ;
+		if( c_out == 'x' )
 			n += outputHex( out , c ) ;
-		}
 	}
 	return n ;
 }
 
 template <typename Tchar>
-struct G::StrImp::PrintableAppender /// A character appender used by G::Str.
+struct G::StrImp::PrintableAppender /// An implementation class template for G::Str.
 {
-	std::string & s ;
-	const Tchar escape_in ;
-	const char escape_out ;
-	const bool eight_bit ;
 	PrintableAppender( std::string & s_ , Tchar escape_in_ , char escape_out_ , bool eight_bit_ ) :
 		s(s_) ,
 		escape_in(escape_in_) ,
@@ -848,13 +948,15 @@ struct G::StrImp::PrintableAppender /// A character appender used by G::Str.
 	{
 		outputPrintable( std::back_inserter(s) , c , escape_in , escape_out , eight_bit ) ;
 	}
+private:
+	std::string & s ;
+	const Tchar escape_in ;
+	const char escape_out ;
+	const bool eight_bit ;
 } ;
 
-struct G::StrImp::InPlaceBackInserter /// A character appender used by G::Str.
+struct G::StrImp::InPlaceBackInserter /// An implementation class for G::Str.
 {
-	std::string & m_s ;
-	std::size_t m_pos ;
-	std::size_t m_i{0U} ;
 	InPlaceBackInserter( std::string & s , std::size_t pos ) :
 		m_s(s) ,
 		m_pos(pos)
@@ -880,58 +982,123 @@ struct G::StrImp::InPlaceBackInserter /// A character appender used by G::Str.
 		return old ;
 	}
 	void operator++() = delete ;
+private:
+	std::string & m_s ;
+	std::size_t m_pos ;
+	std::size_t m_i{0U} ;
 } ;
 
 std::string G::Str::printable( const std::string & in , char escape )
 {
-	namespace imp = G::StrImp ;
 	std::string result ;
 	result.reserve( in.length() + (in.length()/8U) + 1U ) ;
-	std::for_each( in.begin() , in.end() , imp::PrintableAppender<>(result,escape,escape,true) ) ;
+	std::for_each( in.begin() , in.end() , StrImp::PrintableAppender<>(result,escape,escape,true) ) ;
 	return result ;
 }
 
 std::string G::Str::printable( std::string && s , char escape )
 {
-	namespace imp = G::StrImp ;
 	for( std::size_t pos = 0U ; pos < s.size() ; )
 	{
-		imp::InPlaceBackInserter out( s , pos ) ;
-		pos += imp::outputPrintable( out , s.at(pos) , escape , escape , true ) ;
+		StrImp::InPlaceBackInserter out( s , pos ) ;
+		pos += StrImp::outputPrintable( out , s.at(pos) , escape , escape , true ) ;
 	}
 	return std::move( s ) ;
 }
 
-std::string G::Str::toPrintableAscii( const std::string & in , char escape )
+std::string G::Str::printable( G::string_view in , char escape )
 {
-	namespace imp = G::StrImp ;
 	std::string result ;
 	result.reserve( in.length() + (in.length()/8U) + 1U ) ;
-	std::for_each( in.begin() , in.end() , imp::PrintableAppender<>(result,escape,escape,false) ) ;
+	std::for_each( in.begin() , in.end() , StrImp::PrintableAppender<>(result,escape,escape,true) ) ;
+	return result ;
+}
+
+std::string G::Str::toPrintableAscii( const std::string & in , char escape )
+{
+	std::string result ;
+	result.reserve( in.length() + (in.length()/8U) + 1U ) ;
+	std::for_each( in.begin() , in.end() ,
+		StrImp::PrintableAppender<>(result,escape,escape,false) ) ;
 	return result ;
 }
 
 std::string G::Str::toPrintableAscii( const std::wstring & in , wchar_t escape )
 {
-	namespace imp = G::StrImp ;
-	std::string result ;
-	result.reserve( in.length() + (in.length()/8U) + 1U ) ;
-	std::for_each( in.begin() , in.end() ,
-		imp::PrintableAppender<wchar_t>(result,escape,static_cast<char>(escape),false) ) ;
-	return result ;
+    std::string result ;
+    result.reserve( in.length() + (in.length()/8U) + 1U ) ;
+    std::for_each( in.begin() , in.end() ,
+        StrImp::PrintableAppender<wchar_t>(result,escape,static_cast<char>(escape),false) ) ;
+    return result ;
 }
 
 std::string G::Str::readLineFrom( std::istream & stream , const std::string & eol )
 {
 	std::string result ;
-	readLineFrom( stream , eol.empty() ? std::string(1U,'\n') : eol , result , true ) ;
+	readLineFrom( stream , eol.empty() ? string_view("\n",1U) : string_view(eol.data(),eol.size()) , result , true ) ;
 	return result ;
 }
 
-void G::StrImp::readLineFrom( std::istream & stream , const std::string & eol , std::string & line )
+void G::Str::readLineFrom( std::istream & stream , const std::string & eol , std::string & line , bool pre_erase )
 {
+	if( eol.empty() ) throw InvalidEol() ;
+	readLineFrom( stream , string_view(eol.data(),eol.size()) , line , pre_erase ) ;
+}
+
+void G::Str::readLineFrom( std::istream & stream , const char * eol , std::string & line , bool pre_erase )
+{
+	if( eol == nullptr || eol[0] == '\0' ) throw InvalidEol() ;
+	readLineFrom( stream , string_view(eol) , line , pre_erase ) ;
+}
+
+void G::Str::readLineFrom( std::istream & stream , string_view eol , std::string & line , bool pre_erase )
+{
+	if( eol.empty() )
+		throw InvalidEol() ;
+
+	if( pre_erase )
+		line.erase() ;
+
+	// this is a special speed optimisation for a two-character terminator with a one-character initial string ;-)
+	if( eol.size() == 2U && eol[0] != eol[1] && line.length() == 1U )
+	{
+		// save the initial character, use std::getline() for speed (terminating
+		// on the second character of the two-character terminator), check that the
+		// one-character terminator was actually part of the required two-character
+		// terminator, remove the first character of the two-character terminator,
+		// and finally re-insert the initial character
+		//
+		const char c = line[0] ;
+		line.erase() ; // since getline() doesnt erase it if already at eof
+		std::getline( stream , line , eol[1] ) ; // fast
+		const std::size_t line_length = line.length() ;
+		bool complete = line_length > 0U && line[line_length-1U] == eol[0] ;
+		if( complete )
+		{
+			line.resize( line_length - 1U ) ;
+			line.insert( 0U , &c , 1U ) ;
+		}
+		else
+		{
+			line.insert( 0U , &c , 1U ) ;
+			if( stream.good() )
+			{
+				line.append( 1U , eol[1] ) ;
+				StrImp::readLineFrom( stream , eol , line ) ;
+			}
+		}
+	}
+	else
+	{
+		StrImp::readLineFrom( stream , eol , line ) ;
+	}
+}
+
+void G::StrImp::readLineFrom( std::istream & stream , string_view eol , std::string & line )
+{
+	G_ASSERT( !eol.empty() ) ;
 	const std::size_t limit = line.max_size() ;
-	const std::size_t eol_length = eol.length() ;
+	const std::size_t eol_length = eol.size() ;
 	const char eol_final = eol.at( eol_length - 1U ) ;
 	std::size_t line_length = line.length() ;
 
@@ -962,7 +1129,7 @@ void G::StrImp::readLineFrom( std::istream & stream , const std::string & eol ,
 		if( line_length >= eol_length && c == eol_final )
 		{
 			const std::size_t offset = line_length - eol_length ;
-			if( line.find(eol,offset) == offset )
+			if( line.find(eol.data(),offset,eol.size()) == offset )
 			{
 				line.erase(offset) ;
 				break ;
@@ -973,49 +1140,6 @@ void G::StrImp::readLineFrom( std::istream & stream , const std::string & eol ,
 		stream.setstate( std::ios_base::failbit ) ;
 }
 
-void G::Str::readLineFrom( std::istream & stream , const std::string & eol , std::string & line , bool pre_erase )
-{
-	namespace imp = G::StrImp ;
-	G_ASSERT( eol.length() != 0U ) ;
-
-	if( pre_erase )
-		line.erase() ;
-
-	// this is a special speed optimisation for a two-character terminator with a one-character initial string ;-)
-	if( eol.length() == 2U && eol[0] != eol[1] && line.length() == 1U )
-	{
-		// save the initial character, use std::getline() for speed (terminating
-		// on the second character of the two-character terminator), check that the
-		// one-character terminator was actually part of the required two-character
-		// terminator, remove the first character of the two-character terminator,
-		// and finally re-insert the initial character
-		//
-		const char c = line[0] ;
-		line.erase() ; // since getline() doesnt erase it if already at eof
-		std::getline( stream , line , eol[1] ) ; // fast
-		const std::size_t line_length = line.length() ;
-		bool complete = line_length > 0U && line[line_length-1U] == eol[0] ;
-		if( complete )
-		{
-			line.resize( line_length - 1U ) ;
-			line.insert( 0U , &c , 1U ) ;
-		}
-		else
-		{
-			line.insert( 0U , &c , 1U ) ;
-			if( stream.good() )
-			{
-				line.append( 1U , eol[1] ) ;
-				imp::readLineFrom( stream , eol , line ) ;
-			}
-		}
-	}
-	else
-	{
-		imp::readLineFrom( stream , eol , line ) ;
-	}
-}
-
 template <typename S, typename T, typename SV>
 void G::StrImp::splitIntoTokens( const S & in , T & out , const SV & ws )
 {
@@ -1072,11 +1196,10 @@ void G::StrImp::splitIntoTokens( const S & in , T & out , const S & ws , typenam
 
 void G::Str::splitIntoTokens( const std::string & in , StringArray & out , string_view ws , char esc )
 {
-	namespace imp = G::StrImp ;
 	if( esc && in.find(esc) != std::string::npos )
-		imp::splitIntoTokens( in , out , sv_to_string(ws) , esc ) ;
+		StrImp::splitIntoTokens( in , out , sv_to_string(ws) , esc ) ;
 	else
-		imp::splitIntoTokens( in , out , ws ) ;
+		StrImp::splitIntoTokens( in , out , ws ) ;
 }
 
 G::StringArray G::Str::splitIntoTokens( const std::string & in , string_view ws , char esc )
@@ -1087,41 +1210,41 @@ G::StringArray G::Str::splitIntoTokens( const std::string & in , string_view ws
 }
 
 template <typename T>
-void G::StrImp::splitIntoFields( const std::string & in , T & out , string_view ws )
+void G::StrImp::splitIntoFields( string_view in , T & out , string_view ws )
 {
-	if( in.length() )
+	if( !in.empty() )
 	{
 		std::size_t start = 0U ;
 		std::size_t pos = 0U ;
 		for(;;)
 		{
-			if( pos >= in.length() ) break ;
+			if( pos >= in.size() ) break ;
 			pos = in.find_first_of( ws.data() , pos , ws.size() ) ;
 			if( pos == std::string::npos ) break ;
-			out.push_back( in.substr(start,pos-start) ) ;
+			out.push_back( sv_to_string(in.substr(start,pos-start)) ) ;
 			pos++ ;
 			start = pos ;
 		}
-		out.push_back( in.substr(start,pos-start) ) ;
+		out.push_back( sv_to_string(in.substr(start,pos-start)) ) ;
 	}
 }
 
 template <typename T>
-void G::StrImp::splitIntoFields( const std::string & in_in , T & out , string_view ws ,
+void G::StrImp::splitIntoFields( string_view in_in , T & out , string_view ws ,
 	char escape , bool remove_escapes )
 {
 	std::string ews ; // escape+whitespace
 	ews.reserve( ws.size() + 1U ) ;
 	ews.assign( ws.data() , ws.size() ) ;
 	if( escape != '\0' ) ews.append( 1U , escape ) ;
-	if( in_in.length() )
+	if( !in_in.empty() )
 	{
-		std::string in = in_in ;
+		std::string in = sv_to_string( in_in ) ;
 		std::size_t start = 0U ;
 		std::size_t pos = 0U ;
 		for(;;)
 		{
-			if( pos >= in.length() ) break ;
+			if( pos >= in.size() ) break ;
 			pos = in.find_first_of( ews , pos ) ;
 			if( pos == std::string::npos ) break ;
 			if( in.at(pos) == escape )
@@ -1143,104 +1266,82 @@ void G::StrImp::splitIntoFields( const std::string & in_in , T & out , string_vi
 	}
 }
 
-void G::Str::splitIntoFields( const std::string & in , StringArray & out , string_view ws ,
+void G::Str::splitIntoFields( string_view in , StringArray & out , char sep ,
 	char escape , bool remove_escapes )
 {
-	namespace imp = G::StrImp ;
-	imp::splitIntoFields( in , out , ws , escape , remove_escapes ) ;
+	StrImp::splitIntoFields( in , out , string_view(&sep,1U) , escape , remove_escapes ) ;
 }
 
-G::StringArray G::Str::splitIntoFields( const std::string & in , string_view ws )
+G::StringArray G::Str::splitIntoFields( string_view in , char sep )
 {
-	namespace imp = G::StrImp ;
 	G::StringArray out ;
-	imp::splitIntoFields( in , out , ws ) ;
+	StrImp::splitIntoFields( in , out , string_view(&sep,1U) ) ;
 	return out ;
 }
 
 template <typename T>
-struct G::StrImp::Joiner /// A sub-string joiner used by G::Str.
+struct G::StrImp::Joiner /// An implementation class template for G::Str.
 {
-	T & result ;
-	const T & sep ;
-	bool & first ;
-	Joiner( T & result_ , const T & sep_ , bool & first_ ) :
+	Joiner( T & result_ , string_view sep_ , bool & first_ ) :
 		result(result_) ,
 		sep(sep_) ,
 		first(first_)
 	{
-		first = true ;
+		first_ = true ;
 	}
 	void operator()( const T & s )
 	{
-		if( !first ) result.append( sep ) ;
+		if( !first ) result.append( sep.data() , sep.size() ) ;
 		result.append( s ) ;
 		first = false ;
 	}
+private:
+	T & result ;
+	string_view sep ;
+	bool & first ;
 } ;
 
-std::string G::Str::join( const std::string & sep , const StringMap & map ,
-	const std::string & pre_in , const std::string & post )
+std::string G::Str::join( string_view sep , const StringMap & map , string_view pre ,
+	string_view post )
 {
-	namespace imp = G::StrImp ;
-	std::string pre = pre_in.empty() ? std::string("=") : pre_in ;
 	std::string result ;
 	bool first = true ;
-	imp::Joiner<std::string> joiner( result , sep , first ) ;
+	StrImp::Joiner<std::string> joiner( result , sep , first ) ;
 	for( const auto & map_item : map )
-		joiner( std::string(map_item.first).append(pre).append(map_item.second).append(post) ) ;
+		joiner( std::string(map_item.first).append(pre.data(),pre.size()).append(map_item.second).append(post.data(),post.size()) ) ;
 	return result ;
 }
 
-std::string G::Str::join( const std::string & sep , const StringArray & strings )
+std::string G::Str::join( string_view sep , const StringArray & strings )
 {
-	namespace imp = G::StrImp ;
 	std::string result ;
 	bool first = true ;
-	std::for_each( strings.begin() , strings.end() , imp::Joiner<std::string>(result,sep,first) ) ;
+	std::for_each( strings.begin() , strings.end() , StrImp::Joiner<std::string>(result,sep,first) ) ;
 	return result ;
 }
 
-std::string G::Str::join( const std::string & sep , const std::set<std::string> & strings )
+std::string G::Str::join( string_view sep , string_view s1 , string_view s2 ,
+	string_view s3 , string_view s4 , string_view s5 , string_view s6 ,
+	string_view s7 , string_view s8 , string_view s9 )
 {
-	namespace imp = G::StrImp ;
 	std::string result ;
-	bool first = true ;
-	std::for_each( strings.begin() , strings.end() , imp::Joiner<std::string>(result,sep,first) ) ;
+	StrImp::join( sep , result , s1 ) ;
+	StrImp::join( sep , result , s2 ) ;
+	StrImp::join( sep , result , s3 ) ;
+	StrImp::join( sep , result , s4 ) ;
+	StrImp::join( sep , result , s5 ) ;
+	StrImp::join( sep , result , s6 ) ;
+	StrImp::join( sep , result , s7 ) ;
+	StrImp::join( sep , result , s8 ) ;
+	StrImp::join( sep , result , s9 ) ;
 	return result ;
 }
 
-std::string G::Str::join( const std::string & sep , const std::string & s1 , const std::string & s2 ,
-	const std::string & s3 , const std::string & s4 , const std::string & s5 , const std::string & s6 ,
-	const std::string & s7 , const std::string & s8 , const std::string & s9 )
-{
-	namespace imp = G::StrImp ;
-	std::string result ;
-	imp::join( sep , result , s1 ) ;
-	imp::join( sep , result , s2 ) ;
-	imp::join( sep , result , s3 ) ;
-	imp::join( sep , result , s4 ) ;
-	imp::join( sep , result , s5 ) ;
-	imp::join( sep , result , s6 ) ;
-	imp::join( sep , result , s7 ) ;
-	imp::join( sep , result , s8 ) ;
-	imp::join( sep , result , s9 ) ;
-	return result ;
-}
-
-void G::StrImp::join( const std::string & sep , std::string & result , const std::string & s )
+void G::StrImp::join( string_view sep , std::string & result , string_view s )
 {
 	if( !result.empty() && !s.empty() )
-		result.append( sep ) ;
-	result.append( s ) ;
-}
-
-std::set<std::string> G::Str::keySet( const StringMap & map )
-{
-	std::set<std::string> result ;
-	std::transform( map.begin() , map.end() , std::inserter(result,result.end()) ,
-		[](const StringMap::value_type & pair){return pair.first;} ) ;
-	return result ;
+		result.append( sep.data() , sep.size() ) ;
+	result.append( s.data() , s.size() ) ;
 }
 
 G::StringArray G::Str::keys( const StringMap & map )
@@ -1252,95 +1353,100 @@ G::StringArray G::Str::keys( const StringMap & map )
 	return result ;
 }
 
-G::string_view G::Str::ws()
+G::string_view G::Str::ws() noexcept
 {
-	namespace imp = G::StrImp ;
-	return imp::chars_ws ;
+	return StrImp::chars_ws ;
 }
 
-G::string_view G::Str::alnum()
+G::string_view G::Str::alnum() noexcept
 {
-	namespace imp = G::StrImp ;
-	return imp::chars_alnum ;
+	return StrImp::chars_alnum ;
 }
 
-G::string_view G::Str::meta()
+G::string_view G::Str::alnum_() noexcept
 {
-	namespace imp = G::StrImp ;
-	return imp::chars_meta ;
+	return StrImp::chars_alnum_ ;
 }
 
-std::string G::Str::head( const std::string & in , std::size_t pos , const std::string & default_ )
+#ifndef G_LIB_SMALL
+G::string_view G::Str::meta() noexcept
+{
+	return StrImp::chars_meta ;
+}
+#endif
+
+std::string G::Str::head( string_view in , std::size_t pos , string_view default_ )
 {
 	return
 		pos == std::string::npos ?
-			default_ :
-			( pos == 0U ? std::string() : ( pos >= in.length() ? in : in.substr(0U,pos) ) ) ;
+			sv_to_string(default_) :
+			( pos == 0U ? std::string() : sv_to_string( pos >= in.size() ? in : in.substr(0U,pos) ) ) ;
 }
 
-std::string G::Str::head( const std::string & in , const std::string & sep , bool default_empty )
+std::string G::Str::head( string_view in , string_view sep , bool default_empty )
 {
 	std::size_t pos = sep.empty() ? std::string::npos : in.find( sep ) ;
-	return head( in , pos , default_empty ? std::string() : in ) ;
+	return head( in , pos , default_empty ? string_view() : in ) ;
 }
 
-std::string G::Str::tail( const std::string & in , std::size_t pos , const std::string & default_ )
+G::string_view G::Str::headView( string_view in , std::size_t pos , string_view default_ ) noexcept
 {
 	return
 		pos == std::string::npos ?
 			default_ :
-			( (pos+1U) >= in.length() ? std::string() : in.substr(pos+1U) ) ;
+			( pos == 0U ? string_view(in.data(),std::size_t(0U)) : ( pos >= in.size() ? in : in.substr(std::nothrow,0U,pos) ) ) ;
 }
 
-std::string G::Str::tail( const std::string & in , const std::string & sep , bool default_empty )
+#ifndef G_LIB_SMALL
+G::string_view G::Str::headView( string_view in , string_view sep , bool default_empty ) noexcept
+{
+	std::size_t pos = sep.empty() ? std::string::npos : in.find( sep ) ;
+	return headView( in , pos , default_empty ? string_view(in.data(),std::size_t(0U)) : in ) ;
+}
+#endif
+
+std::string G::Str::tail( string_view in , std::size_t pos , string_view default_ )
+{
+	return
+		pos == std::string::npos ?
+			sv_to_string(default_) :
+			( (pos+1U) >= in.size() ? std::string() : sv_to_string(in.substr(pos+1U)) ) ;
+}
+
+std::string G::Str::tail( string_view in , string_view sep , bool default_empty )
 {
 	std::size_t pos = sep.empty() ? std::string::npos : in.find(sep) ;
-	if( pos != std::string::npos ) pos += (sep.length()-1U) ;
-	return tail( in , pos , default_empty ? std::string() : in ) ;
+	if( pos != std::string::npos ) pos += (sep.size()-1U) ;
+	return tail( in , pos , default_empty ? string_view() : in ) ;
 }
 
-bool G::Str::tailMatch( const std::string & in , const std::string & tail )
+G::string_view G::Str::tailView( string_view in , std::size_t pos , string_view default_ ) noexcept
+{
+	return
+		pos == std::string::npos ?
+			default_ :
+			( (pos+1U) >= in.size() ? string_view() : in.substr(std::nothrow,pos+1U) ) ;
+}
+
+G::string_view G::Str::tailView( string_view in , string_view sep , bool default_empty ) noexcept
+{
+	std::size_t pos = sep.empty() ? std::string::npos : in.find(sep) ;
+	if( pos != std::string::npos ) pos += (sep.size()-1U) ;
+	return tailView( in , pos , default_empty ? string_view() : in ) ;
+}
+
+bool G::Str::tailMatch( const std::string & in , string_view tail ) noexcept
 {
 	return
 		tail.empty() ||
-		( in.length() >= tail.length() && 0 == in.compare(in.length()-tail.length(),tail.length(),tail) ) ;
+		( in.size() >= tail.size() && 0 == in.compare(in.size()-tail.size(),tail.size(),tail.data()) ) ;
 }
 
-bool G::Str::tailMatch( const StringArray & in , const std::string & tail )
-{
-	return std::any_of( in.begin() , in.end() ,
-		[&tail](const std::string &x){return tailMatch(x,tail);} ) ;
-}
-
-bool G::Str::headMatch( const std::string & in , const char * head )
-{
-	if( head == nullptr || *head == '\0' ) return true ;
-	std::size_t head_length = std::strlen( head ) ;
-	return ( in.length() >= head_length && 0 == in.compare(0U,head_length,head) ) ;
-}
-
-bool G::Str::headMatch( const std::string & in , const std::string & head )
+bool G::Str::headMatch( const std::string & in , string_view head ) noexcept
 {
 	return
 		head.empty() ||
-		( in.length() >= head.length() && 0 == in.compare(0U,head.length(),head) ) ;
-}
-
-bool G::Str::headMatch( const StringArray & in , const std::string & head )
-{
-	return std::any_of( in.begin() , in.end() ,
-		[&head](const std::string &x){return headMatch(x,head);} ) ;
-}
-
-std::string G::Str::headMatchResidue( const StringArray & in , const std::string & head )
-{
-	const auto end = in.end() ;
-	for( auto p = in.begin() ; p != end ; ++p )
-	{
-		if( headMatch( *p , head ) )
-			return (*p).substr( head.length() ) ;
-	}
-	return std::string() ;
+		( in.size() >= head.size() && 0 == in.compare(0U,head.size(),head.data()) ) ;
 }
 
 std::string G::Str::positive()
@@ -1353,97 +1459,70 @@ std::string G::Str::negative()
 	return "no" ;
 }
 
-bool G::Str::isPositive( const std::string & s_in )
+bool G::Str::isPositive( string_view s_in ) noexcept
 {
-	std::string s = trimmed( lower(s_in) , ws() ) ;
-	return !s.empty() && ( s == "y" || s == "yes" || s == "t" || s == "true" || s == "1" || s == "on" ) ;
+	string_view s = trimmedView( s_in , ws() ) ;
+	return !s.empty() && (
+		s.imatch("y"_sv) || s.imatch("yes"_sv) || s.imatch("t"_sv) ||
+		s.imatch("true"_sv) || s.imatch("1"_sv) || s.imatch("on"_sv) ) ;
 }
 
-bool G::Str::isNegative( const std::string & s_in )
+bool G::Str::isNegative( string_view s_in ) noexcept
 {
-	std::string s = trimmed( lower(s_in) , ws() ) ;
-	return !s.empty() && ( s == "n" || s == "no" || s == "f" || s == "false" || s == "0" || s == "off" ) ;
+	string_view s = trimmedView( s_in , ws() ) ;
+	return !s.empty() && (
+		s.imatch("n"_sv) || s.imatch("no"_sv) || s.imatch("f"_sv) ||
+		s.imatch("false"_sv) || s.imatch("0"_sv) || s.imatch("off"_sv) ) ;
 }
 
-bool G::Str::match( const std::string & a , const std::string & b )
+bool G::Str::match( string_view a , string_view b ) noexcept
 {
 	return a == b ;
 }
 
-bool G::Str::match( const StringArray & a , const std::string & b )
-{
-	return std::find( a.begin() , a.end() , b ) != a.end() ;
-}
-
-template <typename T1, typename T2, typename P>
-bool G::StrImp::equal4( T1 p1 , T1 end1 , T2 p2 , T2 end2 , P p )
-{
-	// (std::equal with four iterators is c++14 or later)
-	for( ; p1 != end1 && p2 != end2 ; ++p1 , ++p2 )
-	{
-		if( !p(*p1,*p2) )
-			return false ;
-	}
-	return p1 == end1 && p2 == end2 ;
-}
-
-bool G::StrImp::ilessc( char c1 , char c2 )
+bool G::StrImp::ilessc( char c1 , char c2 ) noexcept
 {
 	if( c1 >= 'a' && c1 <= 'z' ) c1 -= '\x20' ;
 	if( c2 >= 'a' && c2 <= 'z' ) c2 -= '\x20' ;
 	return c1 < c2 ;
 }
 
-bool G::StrImp::iless( const std::string & a , const std::string & b )
+bool G::Str::iless( string_view a , string_view b ) noexcept
 {
-	return std::lexicographical_compare( a.begin() , a.end() , b.begin() , b.end() , StrImp::ilessc ) ;
+	return std::lexicographical_compare( a.begin() , a.end() , b.begin() , b.end() , StrImp::ilessc ) ; // noexcept?
 }
 
-bool G::Str::iless( const std::string & a , const std::string & b )
+bool G::StrImp::imatchc( char c1 , char c2 ) noexcept
 {
-	return StrImp::iless( a , b ) ;
+	return string_view(&c1,1U).imatch({&c2,1U}) ;
 }
 
-bool G::StrImp::imatchc( char c1 , char c2 )
-{
-	if( c1 >= 'A' && c1 <= 'Z' ) c1 += '\x20' ;
-	if( c2 >= 'A' && c2 <= 'Z' ) c2 += '\x20' ;
-	return c1 == c2 ;
-}
-
-bool G::Str::imatch( char c1 , char c2 )
+#ifndef G_LIB_SMALL
+bool G::Str::imatch( char c1 , char c2 ) noexcept
 {
 	return StrImp::imatchc( c1 , c2 ) ;
 }
+#endif
+
+bool G::Str::imatch( string_view a , string_view b ) noexcept
+{
+	return a.imatch( b ) ;
+}
 
 bool G::StrImp::imatch( const std::string & a , const std::string & b )
 {
-	return a.size() == b.size() && equal4( a.begin() , a.end() , b.begin() , b.end() , imatchc ) ;
+	return string_view(a).imatch( b ) ;
 }
 
-bool G::StrImp::match( const std::string & a , const std::string & b , bool ignore_case )
+std::size_t G::Str::ifind( string_view s , string_view key )
 {
-	return ignore_case ? imatch(a,b) : (a==b) ;
+	return ifindat( s , key , 0U ) ;
 }
 
-bool G::Str::imatch( const std::string & a , const std::string & b )
+std::size_t G::Str::ifindat( string_view s , string_view key , std::size_t pos )
 {
-	namespace imp = G::StrImp ;
-	return imp::imatch( a , b ) ;
-}
-
-bool G::Str::imatch( const StringArray & a , const std::string & b )
-{
-	namespace imp = G::StrImp ;
-	using namespace std::placeholders ;
-	return std::any_of( a.begin() , a.end() , std::bind(imp::imatch,_1,std::cref(b)) ) ;
-}
-
-std::size_t G::Str::ifind( const std::string & s , const std::string & key , std::size_t pos )
-{
-	namespace imp = G::StrImp ;
-	if( s.empty() || key.empty() || pos > s.length() ) return std::string::npos ;
-	auto p = std::search( s.begin()+pos , s.end() , key.begin() , key.end() , imp::imatchc ) ; // NOLINT narrowing
+	if( s.empty() || key.empty() || pos >= s.size() ) return std::string::npos ;
+	auto p = std::search( s.data()+pos , s.data()+s.size() , key.data() , key.data()+key.size() , StrImp::imatchc ) ; // NOLINT narrowing
 	return p == s.end() ? std::string::npos : std::distance(s.begin(),p) ;
 }
 
@@ -1471,9 +1550,8 @@ T G::StrImp::unique( T in , T end , V repeat , V replacement )
 
 std::string G::Str::unique( const std::string & s_in , char c , char r )
 {
-	namespace imp = G::StrImp ;
 	std::string s( s_in ) ;
-	s.erase( imp::unique( s.begin() , s.end() , c , r ) , s.end() ) ;
+	s.erase( StrImp::unique( s.begin() , s.end() , c , r ) , s.end() ) ;
 	return s ;
 }
 
@@ -1482,38 +1560,6 @@ std::string G::Str::unique( const std::string & s , char c )
 	return s.find(c) == std::string::npos ? s : unique( s , c , c ) ;
 }
 
-bool G::StrImp::inList( StringArray::const_iterator begin , StringArray::const_iterator end ,
-	const std::string & s , bool i )
-{
-	using namespace std::placeholders ;
-	return std::any_of( begin , end , std::bind(match,_1,std::cref(s),i) ) ;
-}
-
-bool G::StrImp::notInList( StringArray::const_iterator begin , StringArray::const_iterator end ,
-	const std::string & s , bool i )
-{
-	return !inList( begin , end , s , i ) ;
-}
-
-G::StringArray::iterator G::Str::keepMatch( StringArray::iterator begin , StringArray::iterator end ,
-	const StringArray & match_list , bool ignore_case )
-{
-	namespace imp = G::StrImp ;
-	using namespace std::placeholders ;
-	if( match_list.empty() ) return end ;
-	return std::remove_if( begin , end ,
-		std::bind(imp::notInList,match_list.begin(),match_list.end(),_1,ignore_case) ) ;
-}
-
-G::StringArray::iterator G::Str::removeMatch( StringArray::iterator begin , StringArray::iterator end ,
-	const StringArray & match_list , bool ignore_case )
-{
-	namespace imp = G::StrImp ;
-	using namespace std::placeholders ;
-	return std::remove_if( begin , end ,
-		std::bind(imp::inList,match_list.begin(),match_list.end(),_1,ignore_case) ) ;
-}
-
 void G::StrImp::strncpy( char * dst , const char * src , std::size_t n ) noexcept
 {
 	// (because 'strncpy considered dangerous' analytics)
@@ -1527,7 +1573,6 @@ void G::StrImp::strncpy( char * dst , const char * src , std::size_t n ) noexcep
 
 errno_t G::Str::strncpy_s( char * dst , std::size_t n_dst , const char * src , std::size_t count ) noexcept
 {
-	namespace imp = G::StrImp ;
 	if( dst == nullptr || n_dst == 0U )
 		return EINVAL ;
 
@@ -1543,7 +1588,7 @@ errno_t G::Str::strncpy_s( char * dst , std::size_t n_dst , const char * src , s
 
 	if( count == truncate && n >= n_dst )
 	{
-		imp::strncpy( dst , src , n_dst ) ;
+		StrImp::strncpy( dst , src , n_dst ) ;
 		dst[n_dst-1U] = '\0' ;
 		return 0 ; // STRUNCATE
 	}
@@ -1554,7 +1599,7 @@ errno_t G::Str::strncpy_s( char * dst , std::size_t n_dst , const char * src , s
 	}
 	else
 	{
-		imp::strncpy( dst , src , n ) ;
+		StrImp::strncpy( dst , src , n ) ;
 		dst[n] = '\0' ;
 		return 0 ;
 	}
diff --git a/src/glib/gstr.h b/src/glib/gstr.h
index 04dc7b7..cd2f979 100644
--- a/src/glib/gstr.h
+++ b/src/glib/gstr.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,15 +23,17 @@
 
 #include "gdef.h"
 #include "gexception.h"
-#include "gstrings.h"
+#include "gstringarray.h"
+#include "gstringmap.h"
 #include "gstringview.h"
 #include <string>
 #include <sstream>
 #include <iostream>
 #include <list>
 #include <vector>
-#include <set>
 #include <limits>
+#include <array>
+#include <algorithm>
 #include <type_traits>
 
 namespace G
@@ -45,9 +47,10 @@ namespace G
 class G::Str
 {
 public:
-	G_EXCEPTION_CLASS( Overflow , "string conversion error: over/underflow" ) ;
-	G_EXCEPTION_CLASS( InvalidFormat, "string conversion error: invalid format" ) ;
-	G_EXCEPTION_CLASS( NotEmpty, "internal error: string container not empty" ) ;
+	G_EXCEPTION_CLASS( Overflow , tx("string conversion error: over/underflow") ) ;
+	G_EXCEPTION_CLASS( InvalidFormat, tx("string conversion error: invalid format") ) ;
+	G_EXCEPTION_CLASS( NotEmpty, tx("internal error: string container not empty") ) ;
+	G_EXCEPTION( InvalidEol , tx("invalid end-of-line specifier") ) ;
 
 	struct Limited /// Overload discrimiator for G::Str::toUWhatever() requesting a range-limited result.
 		{} ;
@@ -55,11 +58,11 @@ public:
 	struct Hex /// Overload discrimiator for G::Str::toUWhatever() indicating hexadecimal strings.
 		{} ;
 
-	static bool replace( std::string & s , const std::string & from , const std::string & to ,
+	static bool replace( std::string & s , string_view from , string_view to ,
 		std::size_t * pos_p = nullptr ) ;
-			///< Replaces 'from' with 'to', starting at offset '*pos_p'.
-			///< Returns true if a substitution was made, and adjusts
-			///< '*pos_p' by to.length().
+			///< A string_view overload. Replaces 'from' with 'to', starting at
+			///< offset '*pos_p'. Returns true if a substitution was made,
+			///< and adjusts '*pos_p' by to.length().
 
 	static void replace( std::string & s , char from , char to ) ;
 		///< Replaces all 'from' characters with 'to'.
@@ -67,29 +70,38 @@ public:
 	static void replace( StringArray & , char from , char to ) ;
 		///< Replaces 'from' characters with 'to' in all the strings in the array.
 
-	static unsigned int replaceAll( std::string & s , const std::string & from , const std::string & to ) ;
+	static unsigned int replaceAll( std::string & s , string_view from , string_view to ) ;
 		///< Does a global replace on string 's', replacing all occurrences
 		///< of sub-string 'from' with 'to'. Returns the number of substitutions
 		///< made. Consider using in a while loop if 'from' is more than one
 		///< character.
 
-	static unsigned int replaceAll( std::string & s , const char * from , const char * to ) ;
-		///< A c-string overload, provided for performance reasons.
-
 	static std::string replaced( const std::string & s , char from , char to ) ;
 		///< Returns the string 's' with all occurrences of 'from' replaced by 'to'.
 
 	static void removeAll( std::string & , char ) ;
 		///< Removes all occurrences of the character from the string. See also only().
 
+	static std::string removedAll( const std::string & , char ) ;
+		///< Removes all occurrences of the character from the string and returns
+		///< the result. See also only().
+
 	static std::string & trimLeft( std::string & s , string_view ws , std::size_t limit = 0U ) ;
 		///< Trims the lhs of s, taking off up to 'limit' of the 'ws' characters.
 		///< Returns s.
 
+	static string_view trimLeftView( string_view , string_view ws , std::size_t limit = 0U ) noexcept ;
+		///< Trims the lhs of s, taking off up to 'limit' of the 'ws' characters.
+		///< Returns a view into the input string.
+
 	static std::string & trimRight( std::string & s , string_view ws , std::size_t limit = 0U ) ;
 		///< Trims the rhs of s, taking off up to 'limit' of the 'ws' characters.
 		///< Returns s.
 
+	static string_view trimRightView( string_view sv , string_view ws , std::size_t limit = 0U ) noexcept ;
+		///< Trims the rhs of s, taking off up to 'limit' of the 'ws' characters.
+		///< Returns a view into the input string.
+
 	static std::string & trim( std::string & s , string_view ws ) ;
 		///< Trims both ends of s, taking off any of the 'ws' characters.
 		///< Returns s.
@@ -100,31 +112,43 @@ public:
 	static std::string trimmed( std::string && s , string_view ws ) ;
 		///< Returns a trim()med version of s.
 
-	static bool isNumeric( const std::string & s , bool allow_minus_sign = false ) ;
+	static string_view trimmedView( string_view s , string_view ws ) noexcept ;
+		///< Returns a trim()med view of the input view.
+
+	static bool isNumeric( string_view s , bool allow_minus_sign = false ) noexcept ;
 		///< Returns true if every character is a decimal digit.
 		///< Empty strings return true.
 
-	static bool isHex( const std::string & s ) ;
+	static bool isHex( string_view s ) noexcept ;
 		///< Returns true if every character is a hexadecimal digit.
 		///< Empty strings return true.
 
-	static bool isPrintableAscii( const std::string & s ) ;
+	static bool isPrintableAscii( string_view s ) noexcept ;
 		///< Returns true if every character is a 7-bit, non-control
 		///< character (ie. 0x20<=c<0x7f). Empty strings return true.
 
-	static bool isUShort( const std::string & s ) ;
+	static bool isPrintable( string_view s ) noexcept ;
+		///< Returns true if every character is a non-control
+		///< character (ie. 0x20<=c<0x7f || 0xa0<=c<0xff).
+		///< Empty strings return true.
+
+	static bool isSimple( string_view s ) noexcept ;
+		///< Returns true if every character is alphanumeric or
+		///< "-" or "_". Empty strings return true.
+
+	static bool isUShort( string_view s ) noexcept ;
 		///< Returns true if the string can be converted into
 		///< an unsigned short without throwing an exception.
 
-	static bool isUInt( const std::string & s ) ;
+	static bool isUInt( string_view s ) noexcept ;
 		///< Returns true if the string can be converted into
 		///< an unsigned integer without throwing an exception.
 
-	static bool isULong( const std::string & s ) ;
+	static bool isULong( string_view s ) noexcept ;
 		///< Returns true if the string can be converted into
 		///< an unsigned long without throwing an exception.
 
-	static bool isInt( const std::string & s ) ;
+	static bool isInt( string_view s ) noexcept ;
 		///< Returns true if the string can be converted into
 		///< an integer without throwing an exception.
 
@@ -152,7 +176,25 @@ public:
 	static std::string fromUShort( unsigned short us ) ;
 		///< Converts unsigned short 'us' to a string.
 
-	static bool toBool( const std::string & s ) ;
+	static std::string fromULong( unsigned long , const Hex & ) ;
+		///< Converts an unsigned value to a lower-case
+		///< hex string with no leading zeros.
+
+	static std::string fromULongLong( unsigned long long , const Hex & ) ;
+		///< Converts an unsigned value to a lower-case
+		///< hex string with no leading zeros.
+
+	static string_view fromULongToHex( unsigned long , char * out ) noexcept ;
+		///< Low-level conversion from an unsigned value
+		///< to a lower-case hex string with no leading zeros.
+		///< The output buffer must be sizeof(long)*2.
+
+	static string_view fromULongLongToHex( unsigned long long , char * out ) noexcept ;
+		///< Low-level conversion from an unsigned value
+		///< to a lower-case hex string with no leading zeros.
+		///< The output buffer must be sizeof(long long)*2.
+
+	static bool toBool( string_view s ) ;
 		///< Converts string 's' to a bool.
 		///<
 		///< Exception: InvalidFormat
@@ -163,31 +205,41 @@ public:
 		///< Exception: Overflow
 		///< Exception: InvalidFormat
 
-	static int toInt( const std::string & s ) ;
+	static float toFloat( const std::string & s ) ;
+		///< Converts string 's' to a float.
+		///<
+		///< Exception: Overflow
+		///< Exception: InvalidFormat
+
+	static int toInt( string_view s ) ;
 		///< Converts string 's' to an int.
 		///<
 		///< Exception: Overflow
 		///< Exception: InvalidFormat
 
-	static long toLong( const std::string & s ) ;
+	static long toLong( string_view s ) ;
 		///< Converts string 's' to a long.
 		///<
 		///< Exception: Overflow
 		///< Exception: InvalidFormat
 
-	static short toShort( const std::string & s ) ;
+	static short toShort( string_view s ) ;
 		///< Converts string 's' to a short.
 		///<
 		///< Exception: Overflow
 		///< Exception: InvalidFormat
 
-	static unsigned int toUInt( const std::string & s ) ;
+	static unsigned int toUInt( string_view s ) ;
 		///< Converts string 's' to an unsigned int.
 		///<
 		///< Exception: Overflow
 		///< Exception: InvalidFormat
 
-	static unsigned int toUInt( const std::string & s , Limited ) ;
+	static int toInt( string_view s1 , string_view s2 ) ;
+		///< Overload that converts the first string if it can be converted
+		///< without throwing, or otherwise the second string.
+
+	static unsigned int toUInt( string_view s , Limited ) ;
 		///< Converts string 's' to an unsigned int.
 		///<
 		///< Very large numeric strings are limited to the maximum
@@ -195,11 +247,15 @@ public:
 		///<
 		///< Exception: InvalidFormat
 
-	static unsigned int toUInt( const std::string & s1 , const std::string & s2 ) ;
+	static unsigned int toUInt( string_view s1 , string_view s2 ) ;
 		///< Overload that converts the first string if it can be converted
 		///< without throwing, or otherwise the second string.
 
-	static unsigned long toULong( const std::string & s , Limited ) ;
+	static unsigned int toUInt( string_view s1 , unsigned int default_ ) ;
+		///< Overload that converts the string if it can be converted
+		///< without throwing, or otherwise returns the default value.
+
+	static unsigned long toULong( string_view s , Limited ) ;
 		///< Converts string 's' to an unsigned long.
 		///<
 		///< Very large numeric strings are limited to the maximum value
@@ -207,11 +263,11 @@ public:
 		///<
 		///< Exception: InvalidFormat
 
-	static unsigned long toULong( const std::string & s , Hex ) ;
+	static unsigned long toULong( string_view s , Hex ) ;
 		///< An overload for hexadecimal strings. To avoid exceptions
 		///< use isHex() and check the string length.
 
-	static unsigned long toULong( const std::string & s , Hex , Limited ) ;
+	static unsigned long toULong( string_view s , Hex , Limited ) ;
 		///< An overload for hexadecimal strings where overflow
 		///< results in the return of the maximum value. To avoid
 		///< exceptions use isHex().
@@ -225,19 +281,19 @@ public:
 	template <typename T> static T toUnsigned( const char * &p , const char * end ,
 		bool & overflow ) noexcept ;
 			///< Low-level conversion from an unsigned decimal string to a number.
-			///< Consumes charaters until the first invalid character.
+			///< Consumes characters until the first invalid character.
 
-	static unsigned long toULong( const std::string & s ) ;
+	static unsigned long toULong( string_view s ) ;
 		///< Converts string 's' to an unsigned long.
 		///<
 		///< Exception: Overflow
 		///< Exception: InvalidFormat
 
-	static unsigned long toULong( const std::string & s1 , const std::string & s2 ) ;
+	static unsigned long toULong( string_view s1 , string_view s2 ) ;
 		///< Overload that converts the first string if it can be converted
 		///< without throwing, or otherwise the second string.
 
-	static unsigned short toUShort( const std::string & s , Limited ) ;
+	static unsigned short toUShort( string_view s , Limited ) ;
 		///< Converts string 's' to an unsigned short.
 		///<
 		///< Very large numeric strings are limited to the maximum value
@@ -245,7 +301,7 @@ public:
 		///<
 		///< Exception: InvalidFormat
 
-	static unsigned short toUShort( const std::string & s ) ;
+	static unsigned short toUShort( string_view s ) ;
 		///< Converts string 's' to an unsigned short.
 		///<
 		///< Exception: Overflow
@@ -259,11 +315,11 @@ public:
 		///< Replaces all Latin-1 upper-case characters in string 's' by
 		///< lower-case characters.
 
-	static std::string upper( const std::string & s ) ;
+	static std::string upper( string_view ) ;
 		///< Returns a copy of 's' in which all Latin-1 lower-case characters
 		///< have been replaced by upper-case characters.
 
-	static std::string lower( const std::string & s ) ;
+	static std::string lower( string_view ) ;
 		///< Returns a copy of 's' in which all Latin-1 upper-case characters
 		///< have been replaced by lower-case characters.
 
@@ -271,7 +327,7 @@ public:
 		///< Returns a 7-bit printable representation of the given input string.
 
 	static std::string toPrintableAscii( const std::wstring & in , wchar_t escape = L'\\' ) ;
-		///< Returns a 7-bit printable representation of the given wide input string.
+		///< Returns a 7-bit printable representation of the given input string.
 
 	static std::string printable( const std::string & in , char escape = '\\' ) ;
 		///< Returns a printable representation of the given input string, using
@@ -283,46 +339,39 @@ public:
 		///< chacter code ranges 0x20 to 0x7e and 0xa0 to 0xfe inclusive.
 		///< Typically used to prevent escape sequences getting into log files.
 
-	static std::string only( const std::string & allow_chars , const std::string & s ) ;
-		///< Returns the 's' with all occurrences of the characters not appearing in
-		///< the fist string deleted.
+	static std::string printable( string_view in , char escape = '\\' ) ;
+		///< Returns a printable representation of the given input string, using
+		///< chacter code ranges 0x20 to 0x7e and 0xa0 to 0xfe inclusive.
+		///< Typically used to prevent escape sequences getting into log files.
 
-	static void escape( std::string & s , char c_escape , const std::string & specials_in ,
-		const std::string & specials_out ) ;
+	static std::string only( string_view allow_chars , string_view s ) ;
+		///< Returns the 's' with all occurrences of the characters not appearing in
+		///< the first string deleted.
+
+	static void escape( std::string & s , char c_escape , string_view specials_in ,
+		string_view specials_out ) ;
 			///< Prefixes each occurrence of one of the special-in characters with
 			///< the escape character and its corresponding special-out character.
 			///<
-			///< If the specials-in string contains the nul character it must be
-			///< at the end, otherwise the two specials strings must be the same
-			///< length. The specials-out string cannot contain the nul character.
+			///< The specials-in and specials-out strings must be the same size.
 			///<
 			///< The specials-in string should normally include the escape character
 			///< itself, otherwise unescaping will not recover the original.
 
-	static void escape( std::string & s , char c_escape , const char * specials_in ,
-		const char * specials_out ) ;
-			///< Overload for c-style 'special' strings.
-
 	static void escape( std::string & s ) ;
 		///< Overload for 'normal' backslash escaping of whitespace.
 
-	static std::string escaped( const std::string & , char c_escape , const std::string & specials_in ,
-		const std::string & specials_out ) ;
+	static std::string escaped( string_view , char c_escape , string_view specials_in ,
+		string_view specials_out ) ;
 			///< Returns the escape()d string.
 
-	static std::string escaped( const std::string & , char c_escape , const char * specials_in ,
-		const char * specials_out ) ;
-			///< Returns the escape()d string.
-
-	static std::string escaped( const std::string & ) ;
+	static std::string escaped( string_view ) ;
 		///< Returns the escape()d string.
 
-	static void unescape( std::string & s , char c_escape , const char * specials_in , const char * specials_out ) ;
+	static void unescape( std::string & s , char c_escape , string_view specials_in , string_view specials_out ) ;
 		///< Unescapes the string by replacing e-e with e, e-special-in with
-		///< special-out, and e-other with other.
-		///<
-		///< If the specials-out string includes the nul character then it must be at
-		///< the end, otherwise the two specials strings must be the same length.
+		///< special-out, and e-other with other. The specials-in and
+		///< specials-out strings must be the same length.
 
 	static void unescape( std::string & s ) ;
 		///< Overload for 'normal' unescaping where the string has backslash escaping
@@ -331,12 +380,12 @@ public:
 	static std::string unescaped( const std::string & s ) ;
 		///< Returns the unescape()d version of s.
 
-	static string_view meta() ;
+	static string_view meta() noexcept ;
 		///< Returns a list of shell meta-characters with a tilde as the
 		///< first character. Does not contain the nul character. This is
 		///< typically used with escape().
 
-	static std::string readLineFrom( std::istream & stream , const std::string & eol = std::string() ) ;
+	static std::string readLineFrom( std::istream & stream , const std::string & eol = {} ) ;
 		///< Reads a line from the stream using the given line terminator.
 		///< The line terminator is not part of the returned string.
 		///< The terminator defaults to the newline.
@@ -366,6 +415,18 @@ public:
 		bool pre_erase_result = true ) ;
 			///< An overload which avoids string copying.
 
+	static void readLineFrom( std::istream & stream , string_view eol , std::string & result ,
+		bool pre_erase_result = true ) ;
+			///< An overload using string_view for eol.
+
+	static void readLineFrom( std::istream & stream , const char * eol , std::string & result ,
+		bool pre_erase_result = true ) ;
+			///< An overload using c-string for eol.
+
+	static void readLineFrom( std::istream & stream , string_view eol , std::vector<char> & result ,
+		bool pre_erase_result = true ) ;
+			///< An overload for a vector buffer.
+
 	static void splitIntoTokens( const std::string & in , StringArray & out , string_view ws , char esc = '\0' ) ;
 		///< Splits the string into 'ws'-delimited tokens. The behaviour is like
 		///< strtok() in that adjacent delimiters count as one and leading and
@@ -380,8 +441,8 @@ public:
 	static StringArray splitIntoTokens( const std::string & in , string_view ws = Str::ws() , char esc = '\0' ) ;
 		///< Overload that returns by value.
 
-	static void splitIntoFields( const std::string & in , StringArray & out ,
-		string_view ws , char escape = '\0' ,
+	static void splitIntoFields( string_view in , StringArray & out ,
+		char sep , char escape = '\0' ,
 		bool remove_escapes = true ) ;
 			///< Splits the string into fields. Duplicated, leading and trailing
 			///< separator characters are all significant. The output array is
@@ -395,7 +456,7 @@ public:
 			///< unescaped escapes are used to prevent splitting but they remain
 			///< in the output.
 
-	static StringArray splitIntoFields( const std::string & in , string_view ws = Str::ws() ) ;
+	static StringArray splitIntoFields( string_view in , char sep ) ;
 		///< Overload that returns by value.
 
 	static std::string dequote( const std::string & , char qq = '\"' , char esc = '\\' ,
@@ -405,120 +466,108 @@ public:
 			///< "aaa-qq-bbb-esc-ws-ccc". Escaped whitespace characters within
 			///< quotes can optionally be converted to non-breaking equivalents.
 
-	static std::string join( const std::string & sep , const StringArray & strings ) ;
+	static std::string join( string_view sep , const StringArray & strings ) ;
 		///< Concatenates an array of strings with separators.
 
-	static std::string join( const std::string & sep , const std::set<std::string> & strings ) ;
-		///< Concatenates a set of strings with separators.
-
-	static std::string join( const std::string & sep , const std::string & s1 , const std::string & s2 ,
-		const std::string & s3 = std::string() , const std::string & s4 = std::string() , const std::string & s5 = std::string() ,
-		const std::string & s6 = std::string() , const std::string & s7 = std::string() , const std::string & s8 = std::string() ,
-		const std::string & s9 = std::string() ) ;
+	static std::string join( string_view sep , string_view s1 , string_view s2 ,
+		string_view s3 = {} , string_view s4 = {} , string_view s5 = {} ,
+		string_view s6 = {} , string_view s7 = {} , string_view s8 = {} ,
+		string_view s9 = {} ) ;
 			///< Concatenates a small number of strings with separators.
 			///< In this overload empty strings are ignored.
 
-	static std::string join( const std::string & sep , const StringMap & ,
-		const std::string & eq = std::string(1U,'=') , const std::string & tail = std::string() ) ;
+	static std::string join( string_view sep , const StringMap & , string_view eq ,
+		string_view tail = {} ) ;
 			///< Concatenates entries in a map, where an entry is "<key><eq><value><tail>".
 
-	static std::set<std::string> keySet( const StringMap & string_map ) ;
-		///< Extracts the keys from a map of strings.
-
 	static StringArray keys( const StringMap & string_map ) ;
 		///< Extracts the keys from a map of strings.
 
-	static std::string head( const std::string & in , std::size_t pos ,
-		const std::string & default_ = std::string() ) ;
+	static std::string head( string_view in , std::size_t pos , string_view default_ = {} ) ;
 			///< Returns the first part of the string up to just before the given position.
 			///< The character at pos is not returned. Returns the supplied default
 			///< if pos is npos. Returns the whole string if pos is one-or-more
 			///< off the end.
 
-	static std::string head( const std::string & in , const std::string & sep , bool default_empty = true ) ;
+	static std::string head( string_view , string_view sep , bool default_empty = true ) ;
 		///< Overload taking a separator string, and with the default
 		///< as either the input string or the empty string. If the
 		///< separator occurs more than once in the input then only the
 		///< first occurrence is relevant.
 
-	static std::string tail( const std::string & in , std::size_t pos ,
-		const std::string & default_ = std::string() ) ;
+	static string_view headView( string_view in , std::size_t pos , string_view default_ = {} ) noexcept ;
+		///< Like head() but returning a view into the input string.
+
+	static string_view headView( string_view in , string_view sep , bool default_empty = true ) noexcept ;
+		///< Like head() but returning a view into the input string.
+
+	static std::string tail( string_view in , std::size_t pos , string_view default_ = {} ) ;
 			///< Returns the last part of the string after the given position.
 			///< The character at pos is not returned. Returns the supplied default
 			///< if pos is npos. Returns the empty string if pos is one-or-more
 			///< off the end.
 
-	static std::string tail( const std::string & in , const std::string & sep , bool default_empty = true ) ;
+	static std::string tail( string_view in , string_view sep , bool default_empty = true ) ;
 		///< Overload taking a separator string, and with the default
 		///< as either the input string or the empty string. If the
 		///< separator occurs more than once in the input then only the
 		///< first occurrence is relevant.
 
-	static bool match( const std::string & , const std::string & ) ;
+	static string_view tailView( string_view in , std::size_t pos , string_view default_ = {} ) noexcept ;
+		///< Like tail() but returning a view into the input string.
+
+	static string_view tailView( string_view in , string_view sep , bool default_empty = true ) noexcept ;
+		///< Like tail() but returning a view into the input string.
+
+	static bool match( string_view , string_view ) noexcept ;
 		///< Returns true if the two strings are the same.
 
-	static bool match( const StringArray & , const std::string & ) ;
-		///< Returns true if any string in the array matches the given string.
-
-	static bool iless( const std::string & , const std::string & ) ;
+	static bool iless( string_view , string_view ) noexcept ;
 		///< Returns true if the first string is lexicographically less
 		///< than the first, after Latin-1 lower-case letters have been
 		///< folded to upper-case.
 
-	static bool imatch( char , char ) ;
+	static bool imatch( char , char ) noexcept ;
 		///< Returns true if the two characters are the same, ignoring Latin-1 case.
 
-	static bool imatch( const std::string & , const std::string & ) ;
+	static bool imatch( string_view , string_view ) noexcept ;
 		///< Returns true if the two strings are the same, ignoring Latin-1 case.
 		///< The locale is ignored.
 
-	static bool imatch( const StringArray & , const std::string & ) ;
-		///< Returns true if any string in the array matches the given string, ignoring
-		///< Latin-1 case. The locale is ignored.
-
-	static std::size_t ifind( const std::string & s , const std::string & key ,
-		std::size_t pos = 0U ) ;
+	static std::size_t ifind( string_view s , string_view key ) ;
 			///< Returns the position of the key in 's' using a Latin-1 case-insensitive
 			///< search. Returns std::string::npos if not found. The locale is ignored.
 
-	static bool tailMatch( const std::string & in , const std::string & ending ) ;
+	static std::size_t ifindat( string_view s , string_view key , std::size_t pos ) ;
+			///< Returns the position of the key in 's' at of after position 'pos'
+			///< using a Latin-1 case-insensitive search. Returns std::string::npos
+			///< if not found. The locale is ignored.
+
+	static bool tailMatch( const std::string & in , string_view ending ) noexcept ;
 		///< Returns true if the string has the given ending (or the given ending is empty).
 
-	static bool tailMatch( const StringArray & in , const std::string & ending ) ;
-		///< Returns true if any string in the array has the given ending
-		///< (or the given ending is empty).
-
-	static bool headMatch( const std::string & in , const std::string & head ) ;
+	static bool headMatch( const std::string & in , string_view head ) noexcept ;
 		///< Returns true if the string has the given start (or head is empty).
 
-	static bool headMatch( const std::string & in , const char * head ) ;
-		///< A c-string overload.
-
-	static bool headMatch( const StringArray & in , const std::string & head ) ;
-		///< Returns true if any string in the array has the given start
-		///< (or head is empty).
-
-	static std::string headMatchResidue( const StringArray & in , const std::string & head ) ;
-		///< Returns the unmatched part of the first string in the array that has
-		///< the given start. Returns the empty string if nothing matches or if
-		///< the first match is an exact match.
-
-	static string_view ws() ;
+	static string_view ws() noexcept ;
 		///< Returns a string of standard whitespace characters.
 
-	static string_view alnum() ;
+	static string_view alnum() noexcept ;
 		///< Returns a string of seven-bit alphanumeric characters, ie A-Z, a-z and 0-9.
 
+	static string_view alnum_() noexcept ;
+		///< Returns alnum() with an additional trailing underscore character.
+
 	static std::string positive() ;
 		///< Returns a default positive string. See isPositive().
 
 	static std::string negative() ;
 		///< Returns a default negative string. See isNegative().
 
-	static bool isPositive( const std::string & ) ;
+	static bool isPositive( string_view ) noexcept ;
 		///< Returns true if the string has a positive meaning, such as "1", "true", "yes".
 
-	static bool isNegative( const std::string & ) ;
+	static bool isNegative( string_view ) noexcept ;
 		///< Returns true if the string has a negative meaning, such as "0", "false", "no".
 
 	static std::string unique( const std::string & s , char c , char r ) ;
@@ -529,19 +578,6 @@ public:
 		///< An overload that replaces repeated 'c' characters by
 		///< one 'c' character.
 
-	static StringArray::iterator keepMatch( StringArray::iterator begin , StringArray::iterator end ,
-		const StringArray & match_list , bool ignore_case = false ) ;
-			///< Removes items in the begin/end list that do not match any of the
-			///< elements in the match-list (whitelist), but keeps everything (by
-			///< returning 'end') if the match-list is empty. Returns an iterator
-			///< for erase().
-
-	static StringArray::iterator removeMatch( StringArray::iterator begin , StringArray::iterator end ,
-		const StringArray & match_list , bool ignore_case = false ) ;
-			///< Removes items in the begin/end list that match one of the elements
-			///< in the match-list (blocklist). (Removes nothing if the match-list is
-			///< empty.) Returns an iterator for erase().
-
 	static constexpr std::size_t truncate = (~(static_cast<std::size_t>(0U))) ;
 		///< A special value for the G::Str::strncpy_s() 'count' parameter.
 
@@ -593,6 +629,20 @@ std::string G::Str::fromUShort( unsigned short us )
 	return std::to_string( us ) ;
 }
 
+inline
+std::string G::Str::fromULong( unsigned long u , const Hex & )
+{
+	std::array <char,sizeof(u)*2U> buffer ; // NOLINT cppcoreguidelines-pro-type-member-init
+	return sv_to_string( fromULongToHex( u , &buffer[0] ) ) ;
+}
+
+inline
+std::string G::Str::fromULongLong( unsigned long long u , const Hex & )
+{
+	std::array <char,sizeof(u)*2U> buffer ; // NOLINT cppcoreguidelines-pro-type-member-init
+	return sv_to_string( fromULongLongToHex( u , &buffer[0] ) ) ;
+}
+
 template <typename T>
 T G::Str::toUnsigned( const char * p , const char * end , bool & overflow , bool & invalid ) noexcept
 {
diff --git a/src/glib/gstringarray.h b/src/glib/gstringarray.h
new file mode 100644
index 0000000..6a48ff6
--- /dev/null
+++ b/src/glib/gstringarray.h
@@ -0,0 +1,33 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file gstringarray.h
+///
+
+#ifndef G_STRING_ARRAY_H
+#define G_STRING_ARRAY_H
+
+#include "gdef.h"
+#include <string>
+#include <vector>
+
+namespace G
+{
+	using StringArray = std::vector<std::string> ; ///< A std::vector of std::strings.
+}
+
+#endif
diff --git a/src/glib/gstringfield.h b/src/glib/gstringfield.h
new file mode 100644
index 0000000..20107e5
--- /dev/null
+++ b/src/glib/gstringfield.h
@@ -0,0 +1,221 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file gstringfield.h
+///
+
+#ifndef G_STRING_FIELD_H
+#define G_STRING_FIELD_H
+
+#include "gdef.h"
+#include "gstringview.h"
+#include "gassert.h"
+#include <string>
+#include <algorithm>
+
+namespace G
+{
+	template <typename T> class StringFieldT ;
+	using StringField = StringFieldT<std::string> ;
+	using StringFieldView = StringFieldT<string_view> ;
+}
+
+//| \class G::StringFieldT
+/// A zero-copy string field iterator where the field separators
+/// are short fixed strings.
+///
+/// \code
+/// for( StringField f(s,"\r\n",2U) ; f ; ++f )
+///   std::cout << std::string_view(f.data(),f.size()) << "\n" ;
+/// \endcode
+///
+/// \see G::Str::splitIntoFields(), G::SubString
+///
+template <typename T>
+class G::StringFieldT
+{
+public:
+	using char_type = typename T::value_type ;
+
+	StringFieldT( const T & s , const char_type * sep , std::size_t sepn ) noexcept ;
+		///< Constructor. The parameters must stay valid
+		///< for the object lifefime.
+		///<
+		///< The rvalue overload is deleted to avoid passing a
+		///< temporary T that has been implicitly constructed from
+		///< something else. Temporary string_views constructed
+		///< from a string would be safe, but might be unsafe for
+		///< other types.
+
+	StringFieldT( const T & s , char_type sep ) noexcept ;
+		///< Constructor. The parameters must stay valid
+		///< for the object lifefime.
+
+	explicit operator bool() const noexcept ;
+		///< Returns true if a valid field.
+
+	bool valid() const noexcept ;
+		///< Returns true if a valid field.
+
+	T operator()() const noexcept(std::is_same<T,string_view>::value) ;
+		///< Returns the current field substring. Prefer data()
+		///< and size() to avoid copying.
+
+	StringFieldT<T> & operator++() noexcept ;
+		///< Moves to the next field.
+
+	const char_type * data() const noexcept ;
+		///< Returns the current field pointer.
+
+	std::size_t size() const noexcept ;
+		///< Returns the current field size.
+
+	bool first() const noexcept ;
+		///< Returns true if the current field is the first.
+
+	bool last() const noexcept ;
+		///< Returns true if the current field is the last.
+
+	std::size_t count() const noexcept ;
+		///< Returns the number of fields.
+
+public:
+	~StringFieldT() = default ;
+	StringFieldT( T && s , const char * , std::size_t ) = delete ;
+	StringFieldT( T && s , char ) = delete ;
+	StringFieldT( const StringFieldT<T> & ) = delete ;
+	StringFieldT( StringFieldT<T> && ) = delete ;
+	StringFieldT<T> & operator=( const StringFieldT<T> & ) = delete ;
+	StringFieldT<T> & operator=( StringFieldT<T> && ) = delete ;
+
+private:
+	const T & m_s ;
+	char m_c ;
+	const char_type * m_sep ;
+	std::size_t m_sepn ;
+	std::size_t m_fpos ;
+	std::size_t m_fendpos ;
+} ;
+
+namespace G
+{
+	namespace StringFieldImp
+	{
+		template <typename T> inline T substr( const T & s ,
+			std::size_t pos , std::size_t len ) noexcept(std::is_same<T,string_view>::value)
+		{
+			return s.substr( pos , len ) ;
+		}
+		template <> string_view inline substr<string_view>( const string_view & s ,
+			std::size_t pos , std::size_t len ) noexcept
+		{
+			return s.substr( std::nothrow , pos , len ) ;
+		}
+		static_assert( !noexcept(std::string().substr(0,0)) , "" ) ;
+		static_assert( noexcept(string_view().substr(std::nothrow,0,0)) , "" ) ;
+	}
+}
+
+template <typename T>
+G::StringFieldT<T>::StringFieldT( const T & s , const char_type * sep_p , std::size_t sep_n ) noexcept :
+	m_s(s) ,
+	m_c('\0') ,
+	m_sep(sep_p) ,
+	m_sepn(sep_n) ,
+	m_fpos(s.empty()?std::string::npos:0U) ,
+	m_fendpos(s.find(m_sep,0U,m_sepn))
+{
+}
+
+template <typename T>
+G::StringFieldT<T>::StringFieldT( const T & s , char_type sep ) noexcept :
+	m_s(s) ,
+	m_c(sep) ,
+	m_sep(&m_c) ,
+	m_sepn(1U) ,
+	m_fpos(s.empty()?std::string::npos:0U) ,
+	m_fendpos(s.find(m_sep,0U,m_sepn))
+{
+}
+
+template <typename T>
+const typename T::value_type * G::StringFieldT<T>::data() const noexcept
+{
+	G_ASSERT( m_fpos != std::string::npos ) ;
+	return m_s.data() + m_fpos ;
+}
+
+template <typename T>
+std::size_t G::StringFieldT<T>::size() const noexcept
+{
+	G_ASSERT( m_fpos != std::string::npos ) ;
+	return (m_fendpos==std::string::npos?m_s.size():m_fendpos) - m_fpos ;
+}
+
+template <typename T>
+G::StringFieldT<T>::operator bool() const noexcept
+{
+	return m_fpos != std::string::npos ;
+}
+
+template <typename T>
+bool G::StringFieldT<T>::valid() const noexcept
+{
+	return m_fpos != std::string::npos ;
+}
+
+template <typename T>
+T G::StringFieldT<T>::operator()() const noexcept(std::is_same<T,string_view>::value)
+{
+	if( m_fpos == std::string::npos ) return {} ;
+	return StringFieldImp::substr<T>( m_s , m_fpos , size() ) ;
+}
+
+template <typename T>
+G::StringFieldT<T> & G::StringFieldT<T>::operator++() noexcept
+{
+	m_fpos = m_fendpos ;
+	if( m_fpos != std::string::npos )
+	{
+		m_fpos = std::min( m_s.size() , m_fpos + m_sepn ) ;
+		m_fendpos = m_s.find( m_sep , m_fpos , m_sepn ) ; // documented as non-throwing
+	}
+	return *this ;
+}
+
+template <typename T>
+bool G::StringFieldT<T>::first() const noexcept
+{
+	return m_fpos == 0U ;
+}
+
+template <typename T>
+bool G::StringFieldT<T>::last() const noexcept
+{
+	return m_fendpos == std::string::npos ;
+}
+
+template <typename T>
+std::size_t G::StringFieldT<T>::count() const noexcept
+{
+	std::size_t n = 0U ;
+	for( StringFieldT<T> f( m_s , m_sep , m_sepn ) ; f ; ++f )
+		n++ ;
+	return n ;
+}
+
+#endif
diff --git a/src/glib/gstringlist.cpp b/src/glib/gstringlist.cpp
new file mode 100644
index 0000000..b911ebf
--- /dev/null
+++ b/src/glib/gstringlist.cpp
@@ -0,0 +1,113 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file gstringlist.cpp
+///
+
+#include "gdef.h"
+#include "gstringlist.h"
+#include "gstr.h"
+#include "gassert.h"
+#include <algorithm>
+#include <functional>
+#include <string>
+
+namespace G
+{
+	namespace StringListImp
+	{
+		bool inList( StringArray::const_iterator begin , StringArray::const_iterator end ,
+			const std::string & s , bool i ) ;
+		bool notInList( StringArray::const_iterator begin , StringArray::const_iterator end ,
+			const std::string & s , bool i ) ;
+		bool match( const std::string & a , const std::string & b , bool ignore_case ) ;
+	}
+}
+
+bool G::StringListImp::inList( StringArray::const_iterator begin , StringArray::const_iterator end ,
+	const std::string & s , bool ignore )
+{
+	using namespace std::placeholders ;
+	return std::any_of( begin , end , std::bind(match,_1,std::cref(s),ignore) ) ;
+}
+
+bool G::StringListImp::notInList( StringArray::const_iterator begin , StringArray::const_iterator end ,
+	const std::string & s , bool ignore_case )
+{
+	return !inList( begin , end , s , ignore_case ) ;
+}
+
+bool G::StringListImp::match( const std::string & a , const std::string & b , bool ignore_case )
+{
+	return ignore_case ? string_view(a).imatch( b ) : (a==b) ;
+}
+
+void G::StringList::keepMatch( StringArray & list , const StringArray & match_list , Ignore ignore )
+{
+	using namespace std::placeholders ;
+	if( !match_list.empty() )
+		list.erase(
+			std::remove_if( list.begin() , list.end() ,
+				std::bind(StringListImp::notInList,match_list.begin(),match_list.end(),_1,ignore==Ignore::Case) ) ,
+			list.end() ) ;
+}
+
+void G::StringList::removeMatch( StringArray & list , const StringArray & deny_list , Ignore ignore )
+{
+	using namespace std::placeholders ;
+	list.erase(
+		std::remove_if( list.begin() , list.end() ,
+			std::bind(StringListImp::inList,deny_list.begin(),deny_list.end(),_1,ignore==Ignore::Case) ) ,
+		list.end() ) ;
+}
+
+bool G::StringList::headMatch( const StringArray & in , string_view head )
+{
+	return std::any_of( in.begin() , in.end() ,
+		[&head](const std::string &x){return Str::headMatch(x,head);} ) ;
+}
+
+bool G::StringList::tailMatch( const StringArray & in , string_view tail )
+{
+	return std::any_of( in.begin() , in.end() ,
+		[&tail](const std::string &x){return Str::tailMatch(x,tail);} ) ;
+}
+
+std::string G::StringList::headMatchResidue( const StringArray & in , string_view head )
+{
+	const auto end = in.end() ;
+	for( auto p = in.begin() ; p != end ; ++p )
+	{
+		if( Str::headMatch( *p , head ) )
+			return (*p).substr( head.size() ) ;
+	}
+	return {} ;
+}
+
+bool G::StringList::match( const StringArray & a , const std::string & b )
+{
+	return std::find( a.begin() , a.end() , b ) != a.end() ;
+}
+
+bool G::StringList::imatch( const StringArray & a , const std::string & b )
+{
+	using namespace std::placeholders ;
+	string_view b_sv( b ) ;
+	return std::any_of( a.begin() , a.end() ,
+		[b_sv](const std::string & a_str){ return Str::imatch(a_str,b_sv) ; } ) ;
+}
+
diff --git a/src/glib/gstringlist.h b/src/glib/gstringlist.h
new file mode 100644
index 0000000..0157a58
--- /dev/null
+++ b/src/glib/gstringlist.h
@@ -0,0 +1,108 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file gstringlist.h
+///
+
+#ifndef G_STRING_LIST_H
+#define G_STRING_LIST_H
+
+#include "gdef.h"
+#include "gstr.h"
+#include "gstringarray.h"
+#include "gstringview.h"
+#include "goptional.h"
+#include <string>
+
+namespace G
+{
+	namespace StringList /// Utility functions for lists of strings.
+	{
+		enum class Ignore
+		{
+			Case ,
+			Nothing
+		} ;
+
+		void keepMatch( StringArray & list , const StringArray & allow_list ,
+			Ignore = Ignore::Nothing ) ;
+				///< Removes items in the list that do not match any entry
+				///< in the allow list. Optionally uses a case-insensitive
+				///< match.
+
+		void applyMatch( StringArray & list , const StringArray & allow_list ,
+			Ignore = Ignore::Nothing ) ;
+				///< Removes items in the list that do not match any entry
+				///< in the allow list and reorders the result to be the same
+				///< as the allow list. Optionally uses a case-insensitive
+				///< match.
+
+		void removeMatch( StringArray & list , const StringArray & deny_list ,
+			Ignore = Ignore::Nothing ) ;
+				///< Removes items in the list that match an entry
+				///< in the deny list. Optionally uses a case-insensitive
+				///< match.
+
+		bool headMatch( const StringArray & list , string_view head ) ;
+			///< Returns true if any string in the array has the given start
+			///< (or 'head' is empty).
+
+		bool tailMatch( const StringArray & list , string_view ending ) ;
+			///< Returns true if any string in the array has the given ending
+			///< (or the given ending is empty).
+
+		std::string headMatchResidue( const StringArray & list , string_view head ) ;
+			///< Returns the unmatched part of the first string in the array that has
+			///< the given start. Returns the empty string if nothing matches or if
+			///< the first match is an exact match for the whole string.
+
+		bool match( const StringArray & , const std::string & ) ;
+			///< Returns true if any string in the array matches the given string.
+
+		bool imatch( const StringArray & , const std::string & ) ;
+			///< Returns true if any string in the array matches the given string,
+			///< ignoring case.
+
+		struct Filter /// Filters a list of strings with allow and deny lists.
+		{
+			Filter( StringArray & list , Ignore ignore = Ignore::Case ) :
+				m_list(list)  ,
+				m_ignore(ignore)
+			{
+			}
+			Filter & allow( const optional<std::string> & a )
+			{
+				auto a_list = Str::splitIntoTokens( a.value_or({}) , "," ) ;
+				if( a.has_value() && a_list.empty() )
+					m_list.clear() ;
+				else
+					StringList::keepMatch( m_list , a_list , m_ignore ) ;
+				return *this ;
+			}
+			Filter & deny( const std::string & d )
+			{
+				auto d_list = Str::splitIntoTokens( d , "," ) ;
+				StringList::removeMatch( m_list , d_list , m_ignore ) ;
+				return *this ;
+			}
+			StringArray & m_list ;
+			Ignore m_ignore ;
+		} ;
+	}
+}
+
+#endif
diff --git a/src/glib/gstringmap.h b/src/glib/gstringmap.h
new file mode 100644
index 0000000..556c3e7
--- /dev/null
+++ b/src/glib/gstringmap.h
@@ -0,0 +1,33 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file gstringmap.h
+///
+
+#ifndef G_STRING_MAP_H
+#define G_STRING_MAP_H
+
+#include "gdef.h"
+#include <string>
+#include <map>
+
+namespace G
+{
+	using StringMap = std::map<std::string,std::string> ; ///< A std::map of std::strings.
+}
+
+#endif
diff --git a/src/glib/gstrings.h b/src/glib/gstrings.h
index e84e905..3bba2d8 100644
--- a/src/glib/gstrings.h
+++ b/src/glib/gstrings.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,14 +22,9 @@
 #define G_STRINGS_H
 
 #include "gdef.h"
-#include <string>
-#include <vector>
-#include <map>
+#include "gstringarray.h"
+#include "gstringmap.h"
 
-namespace G
-{
-	using StringArray = std::vector<std::string> ; ///< A std::vector of std::strings.
-	using StringMap = std::map<std::string,std::string> ; ///< A std::map of std::strings.
-}
+// empty
 
 #endif
diff --git a/src/glib/gstringtoken.h b/src/glib/gstringtoken.h
new file mode 100644
index 0000000..32973a0
--- /dev/null
+++ b/src/glib/gstringtoken.h
@@ -0,0 +1,211 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file gstringtoken.h
+///
+
+#ifndef G_STRING_TOKEN_H
+#define G_STRING_TOKEN_H
+
+#include "gdef.h"
+#include "gassert.h"
+#include "gstringview.h"
+#include <string>
+#include <type_traits>
+#include <algorithm>
+
+namespace G
+{
+	template <typename T> class StringTokenT ;
+	using StringToken = StringTokenT<std::string> ;
+	using StringTokenView = StringTokenT<string_view> ;
+}
+
+//| \class G::StringTokenT
+/// A zero-copy string token iterator where the token separators
+/// are runs of whitespace characters, with no support for escape
+/// characters. Leading and trailing whitespace are not significant.
+/// Empty whitespace yields a single token. Stepping beyond the
+/// last token is allowed.
+///
+/// \code
+/// for( StringToken t(s," \t",2U) ; t ; ++t )
+///   std::cout << t() << "\n" ;
+/// \endcode
+///
+/// \see G::Str::splitIntoTokens()
+///
+template <typename T>
+class G::StringTokenT
+{
+public:
+	using char_type = typename T::value_type ;
+
+	StringTokenT( const T & s , const char_type * ws , std::size_t wsn ) noexcept ;
+		///< Constructor. The parameters must stay valid for
+		///< the object lifefime.
+		///<
+		///< The rvalue overload is deleted to avoid passing a
+		///< temporary T that has been implicitly constructed from
+		///< something else. Temporary string_views constructed
+		///< from a string would be safe, but might be unsafe for
+		///< other types.
+
+	StringTokenT( const T & s , string_view ws ) noexcept ;
+		///< Constructor. The parameters must stay valid
+		///< for the object lifefime.
+
+	bool valid() const noexcept ;
+		///< Returns true if a valid token.
+
+	explicit operator bool() const noexcept ;
+		///< Returns true if a valid token.
+
+	const char_type * data() const noexcept ;
+		///< Returns the current token pointer.
+
+	std::size_t size() const noexcept ;
+		///< Returns the current token size.
+
+	std::size_t pos() const noexcept ;
+		///< Returns the offset of data().
+
+	T operator()() const noexcept(std::is_same<T,string_view>::value) ;
+		///< Returns the current token substring.
+
+	StringTokenT<T> & operator++() noexcept ;
+		///< Moves to the next token.
+
+	StringTokenT<T> & next() noexcept ;
+		///< Moves to the next token.
+
+public:
+	~StringTokenT() = default ;
+	StringTokenT( T && s , const char_type * , std::size_t ) = delete ;
+	StringTokenT( T && s , string_view ) = delete ;
+	StringTokenT( const StringTokenT<T> & ) = delete ;
+	StringTokenT( StringTokenT<T> && ) = delete ;
+	StringTokenT<T> & operator=( const StringTokenT<T> & ) = delete ;
+	StringTokenT<T> & operator=( StringTokenT<T> && ) = delete ;
+
+private:
+	static constexpr std::size_t npos = T::npos ;
+	const T & m_s ;
+	const char_type * m_ws ;
+	std::size_t m_wsn ;
+	std::size_t m_pos ;
+	std::size_t m_endpos ;
+} ;
+
+namespace G
+{
+	namespace StringTokenImp
+	{
+		template <typename T> inline T substr( const T & s ,
+			std::size_t pos , std::size_t len ) noexcept(std::is_same<T,string_view>::value)
+		{
+			return s.substr( pos , len ) ;
+		}
+		template <> inline string_view substr<string_view>( const string_view & s ,
+			std::size_t pos , std::size_t len ) noexcept
+		{
+			return s.substr( std::nothrow , pos , len ) ;
+		}
+		static_assert( !noexcept(std::string().substr(0,0)) , "" ) ;
+		static_assert( noexcept(string_view().substr(std::nothrow,0,0)) , "" ) ;
+	}
+}
+
+template <typename T>
+G::StringTokenT<T>::StringTokenT( const T & s , const char_type * ws , std::size_t wsn ) noexcept :
+	m_s(s) ,
+	m_ws(ws) ,
+	m_wsn(wsn) ,
+	m_pos(s.empty()?npos:s.find_first_not_of(m_ws,0U,m_wsn)) ,
+	m_endpos(s.find_first_of(m_ws,m_pos,m_wsn))
+{
+	G_ASSERT( !(s.empty()) || ( m_pos == npos && m_endpos == npos ) ) ;
+	G_ASSERT( !(!s.empty() && wsn==0U) || ( m_pos == 0U && m_endpos == npos ) ) ;
+	G_ASSERT( !(m_pos == npos) || m_endpos == npos ) ;
+}
+
+template <typename T>
+G::StringTokenT<T>::StringTokenT( const T & s , string_view ws ) noexcept :
+	m_s(s) ,
+	m_ws(ws.data()) ,
+	m_wsn(ws.size()) ,
+	m_pos(s.empty()?npos:s.find_first_not_of(m_ws,0U,m_wsn)) ,
+	m_endpos(s.find_first_of(m_ws,m_pos,m_wsn))
+{
+}
+
+template <typename T>
+const typename T::value_type * G::StringTokenT<T>::data() const noexcept
+{
+	//static_assert( __cplusplus >= 201100 , "" ) ; // broken on msvc
+	return m_s.data() + (m_pos==npos?0U:m_pos) ;
+}
+
+template <typename T>
+std::size_t G::StringTokenT<T>::size() const noexcept
+{
+	return (m_endpos==npos?m_s.size():m_endpos) - m_pos ;
+}
+
+template <typename T>
+std::size_t G::StringTokenT<T>::pos() const noexcept
+{
+	return m_pos == npos ? 0U : m_pos ;
+}
+
+template <typename T>
+G::StringTokenT<T>::operator bool() const noexcept
+{
+	return m_pos != npos ;
+}
+
+template <typename T>
+bool G::StringTokenT<T>::valid() const noexcept
+{
+	return m_pos != npos ;
+}
+
+template <typename T>
+T G::StringTokenT<T>::operator()() const noexcept(std::is_same<T,string_view>::value)
+{
+	using string_type = T ;
+	return m_pos == npos ? string_type{} : StringTokenImp::substr( m_s , m_pos , size() ) ;
+}
+
+template <typename T>
+G::StringTokenT<T> & G::StringTokenT<T>::operator++() noexcept
+{
+	m_pos = m_s.find_first_not_of( m_ws , m_endpos , m_wsn ) ;
+	m_endpos = m_s.find_first_of( m_ws , m_pos , m_wsn ) ;
+	G_ASSERT( !(m_s.empty()) || ( m_pos == npos && m_endpos == npos ) ) ;
+	G_ASSERT( !(!m_s.empty() && m_wsn==0U) || ( m_pos == npos && m_endpos == npos ) ) ;
+	G_ASSERT( !(m_pos == npos) || m_endpos == npos ) ;
+	return *this ;
+}
+
+template <typename T>
+G::StringTokenT<T> & G::StringTokenT<T>::next() noexcept
+{
+	return ++(*this) ;
+}
+
+#endif
diff --git a/src/glib/gstringview.cpp b/src/glib/gstringview.cpp
new file mode 100644
index 0000000..d386f71
--- /dev/null
+++ b/src/glib/gstringview.cpp
@@ -0,0 +1,217 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file gstringview.cpp
+///
+
+#include "gdef.h"
+#include "gstringview.h"
+
+std::string G::string_view::sv_to_string_imp() const
+{
+	return empty() ? std::string() : std::string( m_p , m_n ) ;
+}
+
+int G::string_view::compare( const string_view & other ) const noexcept
+{
+	int rc = ( empty() || other.empty() ) ? 0 : std::char_traits<char>::compare( m_p , other.m_p , std::min(m_n,other.m_n) ) ;
+	return rc == 0 ? ( m_n < other.m_n ? -1 : (m_n==other.m_n?0:1) ) : rc ;
+}
+
+bool G::string_view::imatch( const string_view & other ) const noexcept
+{
+	if( empty() || other.empty() ) return empty() && other.empty() ;
+	if( size() != other.size() ) return false ;
+	const char * const end = m_p + m_n ;
+	const char * q = other.m_p ;
+	for( const char * p = m_p ; p != end ; ++p , ++q )
+	{
+		char c1 = *p ;
+		char c2 = *q ;
+		if( c1 >= 'A' && c1 <= 'Z' ) c1 += '\x20' ;
+		if( c2 >= 'A' && c2 <= 'Z' ) c2 += '\x20' ;
+		if( c1 != c2 ) return false ;
+	}
+	return true ;
+}
+
+G::string_view G::string_view::substr( std::size_t pos , std::size_t count ) const
+{
+	if( (empty() && pos!=0U) || pos > m_n ) throw std::out_of_range( "string_view::substr" ) ;
+	if( pos == m_n ) return string_view( m_p , std::size_t(0U) ) ; // (more than the standard requires)
+	return string_view( m_p + pos , std::min(m_n-pos,count) ) ;
+}
+
+G::string_view G::string_view::substr( std::nothrow_t , std::size_t pos , std::size_t count ) const noexcept
+{
+	if( pos >= m_n ) return string_view( m_p , std::size_t(0U) ) ;
+	return string_view( m_p + pos , std::min(m_n-pos,count) ) ;
+}
+
+std::size_t G::string_view::find( char c , std::size_t pos ) const noexcept
+{
+	if( empty() || pos >= m_n ) return std::string::npos ;
+	const char * p = m_p + pos ;
+	std::size_t n = m_n - pos ;
+	for( ; n ; p++ , n-- , pos++ )
+	{
+		if( *p == c )
+			return pos ;
+	}
+	return std::string::npos ;
+}
+
+std::size_t G::string_view::find( const char * substr_p , std::size_t pos , std::size_t substr_n ) const
+{
+	return find( string_view(substr_p,substr_n) , pos ) ;
+}
+
+std::size_t G::string_view::find( string_view substr , std::size_t pos ) const
+{
+	if( empty() || pos >= m_n ) return std::string::npos ;
+	if( substr.empty() ) return pos ;
+	auto const end = m_p + m_n ;
+	auto p = std::search( m_p+pos , end , substr.m_p , substr.m_p+substr.m_n ) ;
+	return p == end ? std::string::npos : std::distance(m_p,p) ;
+}
+
+std::size_t G::string_view::find_first_of( const char * chars , std::size_t pos , std::size_t chars_size ) const noexcept
+{
+	return find_first_of( string_view(chars,chars_size) , pos ) ;
+}
+
+std::size_t G::string_view::find_first_of( string_view chars , std::size_t pos ) const noexcept
+{
+	if( empty() || pos >= m_n || chars.empty() ) return std::string::npos ;
+	const char * p = m_p + pos ;
+	std::size_t n = m_n - pos ;
+	for( ; n ; p++ , n-- , pos++ )
+	{
+		const std::size_t i_end = chars.size() ;
+		for( std::size_t i = 0U ; i < i_end ; i++ )
+		{
+			if( *p == chars[i] )
+				return pos ;
+		}
+	}
+	return std::string::npos ;
+}
+
+std::size_t G::string_view::find_first_not_of( char c , std::size_t pos ) const noexcept
+{
+	if( empty() || pos >= m_n ) return std::string::npos ;
+	const char * p = m_p + pos ;
+	std::size_t n = m_n - pos ;
+	for( ; n ; p++ , n-- , pos++ )
+	{
+		if( *p != c )
+			return pos ;
+	}
+	return std::string::npos ;
+}
+
+std::size_t G::string_view::find_first_not_of( const char * chars , std::size_t pos , std::size_t chars_size ) const noexcept
+{
+	return find_first_not_of( string_view(chars,chars_size) , pos ) ;
+}
+
+std::size_t G::string_view::find_first_not_of( string_view chars , std::size_t pos ) const noexcept
+{
+	if( empty() || pos >= m_n ) return std::string::npos ;
+	const char * p = m_p + pos ;
+	std::size_t n = m_n - pos ;
+	for( ; n ; p++ , n-- , pos++ )
+	{
+		bool match = false ;
+		const std::size_t i_end = chars.size() ;
+		for( std::size_t i = 0U ; !match && i < i_end ; i++ )
+		{
+			if( *p == chars[i] )
+				match = true ;
+		}
+		if( !match )
+			return pos ;
+	}
+	return std::string::npos ;
+}
+
+std::size_t G::string_view::find_last_of( const char * chars , std::size_t pos , std::size_t chars_size ) const noexcept
+{
+	return find_last_of( string_view(chars,chars_size) , pos ) ;
+}
+
+std::size_t G::string_view::find_last_of( string_view chars , std::size_t pos ) const noexcept
+{
+	if( empty() ) return std::string::npos ;
+	if( pos >= m_n ) pos = m_n - 1U ;
+	const char * p = data() + pos ;
+	std::size_t count = pos ;
+	for( std::size_t n = 0U ; n <= count ; n++ , p-- , pos-- )
+	{
+		bool match = false ;
+		const std::size_t i_end = chars.size() ;
+		for( std::size_t i = 0U ; !match && i < i_end ; i++ )
+		{
+			if( *p == chars[i] )
+				match = true ;
+		}
+		if( match )
+			return pos ;
+	}
+	return std::string::npos ;
+}
+
+std::size_t G::string_view::find_last_not_of( const char * chars , std::size_t pos , std::size_t chars_size ) const noexcept
+{
+	return find_last_not_of( string_view(chars,chars_size) , pos ) ;
+}
+
+std::size_t G::string_view::find_last_not_of( string_view chars , std::size_t pos ) const noexcept
+{
+	if( empty() ) return std::string::npos ;
+	if( pos >= m_n ) pos = m_n - 1U ;
+	const char * p = data() + pos ;
+	std::size_t count = pos ;
+	for( std::size_t n = 0U ; n <= count ; n++ , p-- , pos-- )
+	{
+		bool match = false ;
+		const std::size_t i_end = chars.size() ;
+		for( std::size_t i = 0U ; !match && i < i_end ; i++ )
+		{
+			if( *p == chars[i] )
+				match = true ;
+		}
+		if( !match )
+			return pos ;
+	}
+	return std::string::npos ;
+}
+
+std::size_t G::string_view::rfind( char c , std::size_t pos ) const noexcept
+{
+	if( empty() || pos == 0U ) return std::string::npos ;
+	if( pos == std::string::npos || pos > m_n ) pos = m_n ;
+	const char * p = m_p + pos - 1U ;
+	std::size_t n = pos - 1U ;
+	for( ; n ; n-- , p-- )
+	{
+		if( *p == c )
+			return n ;
+	}
+	return std::string::npos ;
+}
+
diff --git a/src/glib/gstringview.h b/src/glib/gstringview.h
index cc02349..b19b6b4 100644
--- a/src/glib/gstringview.h
+++ b/src/glib/gstringview.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -25,190 +25,87 @@
 #include <algorithm>
 #include <stdexcept>
 #include <ostream>
+#include <string>
 #include <cstring>
+#include <new>
 
 namespace G
 {
-	template <typename Tchar> class basic_string_view ;
-	using string_view = basic_string_view<char> ;
-	using wstring_view = basic_string_view<wchar_t> ;
-
-	namespace StringViewImp /// An implementation namespace for G::basic_string_view.
-	{
-		constexpr unsigned int strlen_constexpr( const char * p ) noexcept
-		{
-			return *p ? (strlen_constexpr(p+1)+1U) : 0U ;
-		}
-		constexpr unsigned int strlen_constexpr( const wchar_t * p ) noexcept
-		{
-			return *p ? (strlen_constexpr(p+1)+1U) : 0U ;
-		}
-		inline std::size_t strlen( const char * p ) noexcept
-		{
-			return std::strlen( p ) ;
-		}
-		inline std::size_t strlen( const wchar_t * p ) noexcept
-		{
-			return std::wcslen( p ) ;
-		}
-		constexpr bool same( std::size_t n , const char * p1 , const char * p2 ) noexcept
-		{
-			return n == 0U ? true : ( *p1 == *p2 && same( n-1U , p1+1 , p2+1 ) ) ;
-		}
-	}
+	class string_view ;
 }
 
-//| \class G::basic_string_view
-/// A class template like c++17's std::basic_string_view.
+//| \class G::string_view
+/// A class like c++17's std::string_view.
 ///
-/// Compared to std::basic_string_view there is an extra free function
-/// for conversion to std::basic_string (G::sv_to_string()) and an
-/// extra constructor overload for constinit initialisation:
-/// \code
-///  static constinit G::string_view sv( "foo" , nullptr ) ;
-/// \endcode
+/// Unlike std::string_view there is (1) an extra free function
+/// "sv_to_string()" for conversion to std::string, (2) an implicit
+/// conversion constructor from std::string since std::string has
+/// its convertion operator "operator sv()", (3) some nothrow_t
+/// noexept overloads, and (4) a case-insensitive match function
+/// "imatch()".
 ///
-template <typename Tchar>
-class G::basic_string_view
+class G::string_view
 {
 public:
-	using traits = std::char_traits<Tchar> ;
-	using iterator = const Tchar * ;
-	using const_iterator = const Tchar * ;
+	using traits = std::char_traits<char> ;
+	using iterator = const char * ;
+	using const_iterator = const char * ;
 	using size_type = std::size_t ;
 	using difference_type = std::ptrdiff_t ;
-	using value_type = Tchar ;
+	using value_type = char ;
 	static constexpr std::size_t npos = std::size_t(-1) ;
-	basic_string_view() noexcept = default ;
-	constexpr basic_string_view( const Tchar * p , std::size_t n ) noexcept :
-		m_p(p) ,
-		m_n(n)
-	{
-	}
-	basic_string_view( const Tchar * p ) noexcept /*implicit*/ :
-		m_p(p) ,
-		m_n(p?StringViewImp::strlen(p):0U)
-	{
-	}
-	constexpr basic_string_view( const Tchar * p , std::nullptr_t ) noexcept :
-		m_p(p) ,
-		m_n(p?StringViewImp::strlen_constexpr(p):0U)
-	{
-	}
-	constexpr static bool same( basic_string_view a , basic_string_view b ) noexcept
-	{
-		return a.size() == b.size() && ( a.empty() || StringViewImp::same( a.size() , a.data() , b.data() ) ) ;
-	}
+	string_view() noexcept = default ;
+	constexpr string_view( const char * p , std::size_t n ) noexcept : m_p(p) , m_n(n) {}
+	string_view( const char * p ) noexcept /*implicit*/ : m_p(p) , m_n(p?std::strlen(p):0U) {}
+	string_view( const std::string & s ) noexcept /* implicit */ : m_p(s.data()) , m_n(s.size()) {}
 	constexpr std::size_t size() const noexcept { return m_n ; }
 	constexpr std::size_t length() const noexcept { return m_n ; }
-	constexpr const Tchar * data() const noexcept { return m_p ; }
+	constexpr const char * data() const noexcept { return m_p ; }
 	constexpr bool empty() const noexcept { return m_n == 0U ; }
-	void swap( basic_string_view<Tchar> & other ) noexcept { std::swap(m_p,other.m_p) ; std::swap(m_n,other.m_n) ; }
-	constexpr const Tchar & operator[]( std::size_t i ) const { return m_p[i] ; }
-	const Tchar & at( std::size_t i ) const { if( i >= m_n ) throw std::out_of_range("string_view") ; return m_p[i] ; }
-	const Tchar * begin() const noexcept { return empty() ? nullptr : m_p ; }
-	const Tchar * cbegin() const noexcept { return empty() ? nullptr : m_p ; }
-	const Tchar * end() const noexcept { return empty() ? nullptr : (m_p+m_n) ; }
-	const Tchar * cend() const noexcept { return empty() ? nullptr : (m_p+m_n) ; }
-	bool operator==( const basic_string_view<Tchar> & other ) const noexcept { return compare(other) == 0 ; }
-	bool operator!=( const basic_string_view<Tchar> & other ) const noexcept { return compare(other) != 0 ; }
-	bool operator<( const basic_string_view<Tchar> & other ) const noexcept { return compare(other) < 0 ; }
-	bool operator<=( const basic_string_view<Tchar> & other ) const noexcept { return compare(other) <= 0 ; }
-	bool operator>( const basic_string_view<Tchar> & other ) const noexcept { return compare(other) > 0 ; }
-	bool operator>=( const basic_string_view<Tchar> & other ) const noexcept { return compare(other) >= 0 ; }
-	int compare( const basic_string_view<Tchar> & other ) const noexcept
-	{
-		int rc = ( empty() || other.empty() ) ? 0 : std::char_traits<Tchar>::compare( m_p , other.m_p , std::min(m_n,other.m_n) ) ;
-		return rc == 0 ? ( m_n < other.m_n ? -1 : (m_n==other.m_n?0:1) ) : rc ;
-	}
-	string_view substr( std::size_t pos , std::size_t count = npos ) const
-	{
-		if( empty() || pos > m_n ) throw std::out_of_range( "string_view" ) ;
-		return string_view( m_p + pos , std::min(m_n-pos,count) ) ;
-	}
-	std::size_t find( Tchar c ) const noexcept
-	{
-		if( empty() ) return std::string::npos ;
-		const Tchar * p = m_p ;
-		std::size_t n = m_n ;
-		for( std::size_t pos = 0U ; n ; p++ , n-- , pos++ )
-		{
-			if( *p == c )
-				return pos ;
-		}
-		return std::string::npos ;
-	}
-	std::size_t find( const Tchar * substr_p , std::size_t pos , std::size_t substr_n ) const
-	{
-		return find( basic_string_view<Tchar>(substr_p,substr_n) , pos ) ;
-	}
-	std::size_t find( basic_string_view<Tchar> substr , std::size_t pos = 0U ) const
-	{
-		if( empty() || pos >= m_n ) return std::string::npos ;
-		if( substr.empty() ) return pos ;
-		auto const end = m_p + m_n ;
-		auto p = std::search( m_p+pos , end , substr.m_p , substr.m_p+substr.m_n ) ;
-		return p == end ? std::string::npos : std::distance(m_p,p) ;
-	}
-	std::size_t find_first_of( const Tchar * chars , std::size_t pos , std::size_t chars_size ) const noexcept
-	{
-		return find_first_of( basic_string_view<Tchar>(chars,chars_size) , pos ) ;
-	}
-	std::size_t find_first_of( basic_string_view<Tchar> chars , std::size_t pos = 0U ) const noexcept
-	{
-		if( empty() || pos >= m_n || chars.empty() ) return std::string::npos ;
-		const Tchar * p = m_p + pos ;
-		std::size_t n = m_n - pos ;
-		for( ; n ; p++ , n-- , pos++ )
-		{
-			const std::size_t i_end = chars.size() ;
-			for( std::size_t i = 0U ; i < i_end ; i++ )
-			{
-				if( *p == chars[i] )
-					return pos ;
-			}
-		}
-		return std::string::npos ;
-	}
-	std::size_t find_first_not_of( const Tchar * chars , std::size_t pos , std::size_t chars_size ) const noexcept
-	{
-		return find_first_not_of( basic_string_view<Tchar>(chars,chars_size) , pos ) ;
-	}
-	std::size_t find_first_not_of( basic_string_view<Tchar> chars , std::size_t pos = 0U ) const noexcept
-	{
-		if( empty() || pos >= m_n || chars.empty() ) return std::string::npos ;
-		const Tchar * p = m_p + pos ;
-		std::size_t n = m_n - pos ;
-		for( ; n ; p++ , n-- , pos++ )
-		{
-			bool match = false ;
-			const std::size_t i_end = chars.size() ;
-			for( std::size_t i = 0U ; !match && i < i_end ; i++ )
-			{
-				if( *p == chars[i] )
-					match = true ;
-			}
-			if( !match )
-				return pos ;
-		}
-		return std::string::npos ;
-	}
-	std::basic_string<Tchar> sv_to_string_imp() const
-	{
-		return empty() ? std::basic_string<Tchar>() : std::basic_string<Tchar>( m_p , m_n ) ;
-	}
+	void swap( string_view & other ) noexcept { std::swap(m_p,other.m_p) ; std::swap(m_n,other.m_n) ; }
+	constexpr const char & operator[]( std::size_t i ) const { return m_p[i] ; }
+	const char & at( std::size_t i ) const { if( i >= m_n ) throw std::out_of_range("string_view::at") ; return m_p[i] ; }
+	const char * begin() const noexcept { return empty() ? nullptr : m_p ; }
+	const char * cbegin() const noexcept { return empty() ? nullptr : m_p ; }
+	const char * end() const noexcept { return empty() ? nullptr : (m_p+m_n) ; }
+	const char * cend() const noexcept { return empty() ? nullptr : (m_p+m_n) ; }
+	bool operator==( const string_view & other ) const noexcept { return compare(other) == 0 ; }
+	bool operator!=( const string_view & other ) const noexcept { return compare(other) != 0 ; }
+	bool operator<( const string_view & other ) const noexcept { return compare(other) < 0 ; }
+	bool operator<=( const string_view & other ) const noexcept { return compare(other) <= 0 ; }
+	bool operator>( const string_view & other ) const noexcept { return compare(other) > 0 ; }
+	bool operator>=( const string_view & other ) const noexcept { return compare(other) >= 0 ; }
+
+	int compare( const string_view & other ) const noexcept ;
+	bool imatch( const string_view & other ) const noexcept ;
+	string_view substr( std::size_t pos , std::size_t count = npos ) const ;
+	string_view substr( std::nothrow_t , std::size_t pos , std::size_t count = npos ) const noexcept ;
+	std::size_t find( char c , std::size_t pos = 0U ) const noexcept ;
+	std::size_t find( const char * substr_p , std::size_t pos , std::size_t substr_n ) const ;
+	std::size_t find( string_view substr , std::size_t pos = 0U ) const ;
+	std::size_t find_first_of( const char * chars , std::size_t pos , std::size_t chars_size ) const noexcept ;
+	std::size_t find_first_of( string_view chars , std::size_t pos = 0U ) const noexcept ;
+	std::size_t find_first_not_of( char c , std::size_t pos = 0U ) const noexcept ;
+	std::size_t find_first_not_of( const char * chars , std::size_t pos , std::size_t chars_size ) const noexcept ;
+	std::size_t find_first_not_of( string_view chars , std::size_t pos = 0U ) const noexcept ;
+	std::size_t find_last_of( const char * chars , std::size_t pos , std::size_t chars_size ) const noexcept ;
+	std::size_t find_last_of( string_view chars , std::size_t pos = std::string::npos ) const noexcept ;
+	std::size_t find_last_not_of( const char * chars , std::size_t pos , std::size_t chars_size ) const noexcept ;
+	std::size_t find_last_not_of( string_view chars , std::size_t pos = std::string::npos ) const noexcept ;
+	std::size_t rfind( char c , std::size_t pos = std::string::npos ) const noexcept ;
+	std::string sv_to_string_imp() const ;
 
 private:
-	const Tchar * m_p{nullptr} ;
+	const char * m_p{nullptr} ;
 	std::size_t m_n{0U} ;
 } ;
 
 namespace G
 {
-	template <typename Tchar> std::basic_string<Tchar> sv_to_string( basic_string_view<Tchar> sv )
+	inline std::string sv_to_string( string_view sv )
 	{
 		// (greppable name -- remove when using c++17 std::string_view)
-		return std::basic_string<Tchar>( sv.sv_to_string_imp() ) ;
+		return sv.sv_to_string_imp() ;
 	}
 	inline std::ostream & operator<<( std::ostream & stream , const string_view & sv )
 	{
@@ -216,13 +113,7 @@ namespace G
 			stream.write( sv.data() , sv.size() ) ; // NOLINT narrowing
 		return stream ;
 	}
-	inline std::wostream & operator<<( std::wostream & stream , const wstring_view & sv )
-	{
-		if( !sv.empty() )
-			stream.write( sv.data() , sv.size() ) ; // NOLINT narrowing
-		return stream ;
-	}
-	template <typename Tchar> void swap( basic_string_view<Tchar> & a , basic_string_view<Tchar> b ) noexcept
+	inline void swap( string_view & a , string_view b ) noexcept
 	{
 		a.swap( b ) ;
 	}
@@ -244,4 +135,17 @@ namespace G
 	}
 }
 
+namespace std /// NOLINT
+{
+	inline bool operator<( const string & s , G::string_view sv )
+	{
+		return s.compare( 0 , s.size() , sv.data() , sv.size() ) < 0 ;
+	}
+}
+
+constexpr G::string_view operator "" _sv( const char * p , std::size_t n ) noexcept
+{
+	return {p,n} ;
+}
+
 #endif
diff --git a/src/glib/gstringwrap.cpp b/src/glib/gstringwrap.cpp
index 23bc2c0..231ee2b 100644
--- a/src/glib/gstringwrap.cpp
+++ b/src/glib/gstringwrap.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -28,6 +28,10 @@
 #include <clocale>
 #include <locale>
 
+#ifdef emit
+#undef emit
+#endif
+
 struct G::StringWrap::Config /// Private implementation structure for G::StringWrap.
 {
 	string_view prefix_first ;
@@ -47,8 +51,8 @@ public:
 	~WordWrapper() = default ;
 	WordWrapper( const WordWrapper & ) = delete ;
 	WordWrapper( WordWrapper && ) = delete ;
-	void operator=( const WordWrapper & ) = delete ;
-	void operator=( WordWrapper && ) = delete ;
+	WordWrapper & operator=( const WordWrapper & ) = delete ;
+	WordWrapper & operator=( WordWrapper && ) = delete ;
 
 private:
 	string_view prefix() const ;
@@ -117,8 +121,8 @@ std::string G::StringWrap::wrap( const std::string & text_in ,
 	bool preserve_spaces , const std::locale & loc )
 {
 	StringWrap::Config config {
-		{ prefix_first.data() , prefix_first.size() } ,
-		{ prefix_other.data() , prefix_other.size() } ,
+		prefix_first ,
+		prefix_other ,
 		width_first , width_other?width_other:width_first ,
 		preserve_spaces
 	} ;
diff --git a/src/glib/gstringwrap.h b/src/glib/gstringwrap.h
index 52d49eb..fa313ef 100644
--- a/src/glib/gstringwrap.h
+++ b/src/glib/gstringwrap.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gstrmacros.h b/src/glib/gstrmacros.h
index 23e5928..646908e 100644
--- a/src/glib/gstrmacros.h
+++ b/src/glib/gstrmacros.h
@@ -1,5 +1,5 @@
 /*
-   Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+   Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gtest.cpp b/src/glib/gtest.cpp
index 69c5b51..579bebf 100644
--- a/src/glib/gtest.cpp
+++ b/src/glib/gtest.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gtest.h b/src/glib/gtest.h
index ef2a5b1..1f4b215 100644
--- a/src/glib/gtest.h
+++ b/src/glib/gtest.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gthread.cpp b/src/glib/gthread.cpp
index 0070c27..7321df0 100644
--- a/src/glib/gthread.cpp
+++ b/src/glib/gthread.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/glib/gtime.cpp b/src/glib/gtime.cpp
index eb9a24a..27b998f 100644
--- a/src/glib/gtime.cpp
+++ b/src/glib/gtime.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -32,9 +32,7 @@ G::Time::Time( int hh , int mm , int ss ) :
 }
 
 G::Time::Time( const BrokenDownTime & tm ) :
-	m_hh(tm.hour()) ,
-	m_mm(tm.min()) ,
-	m_ss(tm.sec())
+	Time(tm.hour(),tm.min(),tm.sec())
 {
 }
 
@@ -73,27 +71,26 @@ int G::Time::seconds() const
 	return m_ss ;
 }
 
+std::string G::Time::xx( int n )
+{
+	return std::string(1U,'0'+n/10).append(1U,'0'+n%10) ;
+}
+
 std::string G::Time::hhmmss( const char * sep ) const
 {
 	if( sep == nullptr ) sep = "" ;
-	std::ostringstream ss ;
-	ss << (m_hh/10) << (m_hh%10) << sep << (m_mm/10) << (m_mm%10) << sep << (m_ss/10) << (m_ss%10) ;
-	return ss.str() ;
+	return std::string(xx(m_hh)).append(sep).append(xx(m_mm)).append(sep).append(xx(m_ss)) ;
 }
 
 std::string G::Time::hhmm( const char * sep ) const
 {
 	if( sep == nullptr ) sep = "" ;
-	std::ostringstream ss ;
-	ss << (m_hh/10) << (m_hh%10) << sep << (m_mm/10) << (m_mm%10) ;
-	return ss.str() ;
+	return std::string(xx(m_hh)).append(sep).append(xx(m_mm)) ;
 }
 
 std::string G::Time::ss() const
 {
-	std::ostringstream ss ;
-	ss << (m_ss/10) << (m_ss%10) ;
-	return ss.str() ;
+	return xx( m_ss ) ;
 }
 
 unsigned int G::Time::value() const
diff --git a/src/glib/gtime.h b/src/glib/gtime.h
index 8b4608a..0274728 100644
--- a/src/glib/gtime.h
+++ b/src/glib/gtime.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -95,6 +95,9 @@ public:
 	bool operator!=( const Time & ) const ;
 		///< Comparison operator.
 
+private:
+	static std::string xx( int ) ;
+
 private:
 	int m_hh ;
 	int m_mm ;
diff --git a/src/glib/gxtext.cpp b/src/glib/gxtext.cpp
index cbe2f7c..5c81a62 100644
--- a/src/glib/gxtext.cpp
+++ b/src/glib/gxtext.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -29,7 +29,7 @@ namespace G
 	{
 		inline char hex( unsigned int n )
 		{
-			static const char * map = "0123456789ABCDEF" ;
+			static constexpr char map[17] = "0123456789ABCDEF" ;
 			return map[n] ;
 		}
 		inline bool ishex( char c , bool allow_lowercase )
@@ -72,7 +72,7 @@ namespace G
 	}
 }
 
-bool G::Xtext::valid( const std::string & s , bool strict )
+bool G::Xtext::valid( string_view s , bool strict )
 {
 	namespace imp = XtextImp ;
 	if( !Str::isPrintableAscii(s) || ( strict && s.find_first_of("= ") != std::string::npos ) )
@@ -92,7 +92,7 @@ bool G::Xtext::valid( const std::string & s , bool strict )
 	}
 }
 
-std::string G::Xtext::encode( const std::string & s )
+std::string G::Xtext::encode( string_view s )
 {
 	namespace imp = XtextImp ;
 	std::string result ;
@@ -114,11 +114,12 @@ std::string G::Xtext::encode( const std::string & s )
 	return result ;
 }
 
-std::string G::Xtext::decode( const std::string & s )
+std::string G::Xtext::decode( string_view s )
 {
 	namespace imp = XtextImp ;
 	std::string result ;
-	for( std::string::const_iterator p = s.begin() ; p != s.end() ; ++p )
+	result.reserve( s.size() ) ;
+	for( auto p = s.begin() ; p != s.end() ; ++p )
 	{
 		if( *p == '+' )
 		{
diff --git a/src/glib/gxtext.h b/src/glib/gxtext.h
index abcaa7e..cfedf01 100644
--- a/src/glib/gxtext.h
+++ b/src/glib/gxtext.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,6 +22,7 @@
 #define G_XTEXT_H
 
 #include "gdef.h"
+#include "gstringview.h"
 #include <string>
 
 namespace G
@@ -36,18 +37,18 @@ namespace G
 class G::Xtext
 {
 public:
-	static std::string encode( const std::string & ) ;
+	static std::string encode( string_view ) ;
 		///< Encodes the given string.
 
-	static std::string decode( const std::string & ) ;
+	static std::string decode( string_view ) ;
 		///< Decodes the given string. Input strings must be
 		///< un-strictly valid(), otherwise the result is
 		///< undefined.
 
-	static bool valid( const std::string & , bool strict = false ) ;
-		///< Returns true if a valid encoding. If strict
-		///< then 'equals' and 'space' are disallowed and
-		///< hex characters must be uppercase (eg. "+1A").
+	static bool valid( string_view , bool strict = false ) ;
+		///< Returns true if a valid encoding, or empty. If
+		///< strict then 'equals' and 'space' are disallowed
+		///< and hex characters must be uppercase (eg. "+1A").
 
 public:
 	Xtext() = delete ;
diff --git a/src/gnet/Makefile.am b/src/gnet/Makefile.am
index 2138c86..cfb8da2 100644
--- a/src/gnet/Makefile.am
+++ b/src/gnet/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -17,153 +17,57 @@
 
 noinst_LIBRARIES = libgnet.a
 
+# -- OS
+
 if GCONFIG_WINDOWS
 
 AM_CPPFLAGS = -I$(top_srcdir)/src/glib -I$(top_srcdir)/src/gssl -I$(top_srcdir)/src/win32
 
-EXTRA_DIST_COMMON=\
-	gaddresslocal_unix.cpp \
+OS_EXTRA_DIST = \
 	gdescriptor_unix.cpp \
-	geventloop_select.cpp \
-	geventloop_epoll.cpp \
 	gfutureevent_unix.cpp \
 	gsocket_unix.cpp
 
-if GCONFIG_INTERFACE_NAMES
-
-EXTRA_DIST = \
-	$(EXTRA_DIST_COMMON) \
-	ginterfaces_unix.cpp \
-	ginterfaces_none.cpp
-
-INTERFACES_SOURCES = \
-	ginterfaces_common.cpp \
-	ginterfaces_win32.cpp
-
-else
-
-EXTRA_DIST = \
-	$(EXTRA_DIST_COMMON) \
-	ginterfaces_unix.cpp \
-	ginterfaces_common.cpp \
-	ginterfaces_win32.cpp
-
-INTERFACES_SOURCES = \
-	ginterfaces_none.cpp
-
-endif
-
-libgnet_a_SOURCES = \
-	gaddresslocal_none.cpp \
-	gaddresslocal.h \
-	gaddress4.cpp \
-	gaddress4.h \
-	gaddress6.cpp \
-	gaddress6.h \
-	gaddress.cpp \
-	gaddress.h \
-	gclient.cpp \
-	gclient.h \
-	gclientptr.cpp \
-	gclientptr.h \
-	gconnection.cpp \
-	gconnection.h \
-	gdescriptor.h \
-	gdescriptor_win32.cpp \
-	gdnsblock.cpp \
-	gdnsblock.h \
-	gdnsmessage.cpp \
-	gdnsmessage.h \
-	gdnsmessage.cpp \
-	gdnsmessage.h \
-	gevent.h \
-	geventhandler.cpp \
-	geventhandler.h \
-	geventhandlerlist.cpp \
-	geventhandlerlist.h \
-	geventloggingcontext.cpp \
-	geventloggingcontext.h \
-	geventloop.cpp \
-	geventloop.h \
-	geventloop_win32.cpp \
-	gexceptionhandler.cpp \
-	gexceptionhandler.h \
-	gexceptionsink.cpp \
-	gexceptionsink.h \
-	gexceptionsource.cpp \
-	gexceptionsource.h \
-	gfutureevent.h \
-	gfutureevent_win32.cpp \
-	ginterfaces.h \
-	$(INTERFACES_SOURCES) \
-	glinebuffer.cpp \
-	glinebuffer.h \
-	glinestore.cpp \
-	glinestore.h \
-	glistener.h \
-	glocal.cpp \
-	glocal.h \
-	glocation.cpp \
-	glocation.h \
-	gmonitor.cpp \
-	gmonitor.h \
-	gmultiserver.cpp \
-	gmultiserver.h \
-	gnetdone.cpp \
-	gnetdone.h \
-	gresolver.cpp \
-	gresolver.h \
-	gresolverfuture.cpp \
-	gresolverfuture.h \
-	gserver.cpp \
-	gserver.h \
-	gserverpeer.cpp \
-	gserverpeer.h \
-	gsocket.cpp \
-	gsocket.h \
-	gsocketprotocol.cpp \
-	gsocketprotocol.h \
-	gsocket_win32.cpp \
-	gsocks.cpp \
-	gsocks.h \
-	gtask.cpp \
-	gtask.h \
-	gtimer.cpp \
-	gtimer.h \
-	gtimerlist.cpp \
-	gtimerlist.h
-
-else
-
-AM_CPPFLAGS = -I$(top_srcdir)/src/glib -I$(top_srcdir)/src/gssl
-
-EXTRA_DIST_COMMON=\
+OS_SOURCES = \
 	gdescriptor_win32.cpp \
 	geventloop_win32.cpp \
 	gfutureevent_win32.cpp \
 	gsocket_win32.cpp
 
-if GCONFIG_UDS
-
-UDS_SOURCES = \
-	gaddresslocal_unix.cpp
-
-EXTRA_DIST_UDS = \
-	gaddresslocal_none.cpp
-
 else
 
-UDS_SOURCES = \
-	gaddresslocal_none.cpp
+AM_CPPFLAGS = -I$(top_srcdir)/src/glib -I$(top_srcdir)/src/gssl
 
-EXTRA_DIST_UDS = \
-	gaddresslocal_unix.cpp
+OS_EXTRA_DIST = \
+	gdescriptor_win32.cpp \
+	geventloop_win32.cpp \
+	gfutureevent_win32.cpp \
+	gsocket_win32.cpp
+
+OS_SOURCES = \
+	gdescriptor_unix.cpp \
+	gfutureevent_unix.cpp \
+	gsocket_unix.cpp
 
 endif
 
+# -- INTERFACE_NAMES
+
 if GCONFIG_INTERFACE_NAMES
 
-EXTRA_DIST_INTERFACES = \
+if GCONFIG_WINDOWS
+
+INTERFACES_EXTRA_DIST = \
+	ginterfaces_unix.cpp \
+	ginterfaces_none.cpp
+
+INTERFACES_SOURCES = \
+	ginterfaces_common.cpp \
+	ginterfaces_win32.cpp
+
+else
+
+INTERFACES_EXTRA_DIST = \
 	ginterfaces_win32.cpp \
 	ginterfaces_none.cpp
 
@@ -171,11 +75,13 @@ INTERFACES_SOURCES = \
 	ginterfaces_unix.cpp \
 	ginterfaces_common.cpp
 
+endif
+
 else
 
-EXTRA_DIST_INTERFACES = \
-	ginterfaces_win32.cpp \
+INTERFACES_EXTRA_DIST = \
 	ginterfaces_unix.cpp \
+	ginterfaces_win32.cpp \
 	ginterfaces_common.cpp
 
 INTERFACES_SOURCES = \
@@ -183,9 +89,89 @@ INTERFACES_SOURCES = \
 
 endif
 
+# -- DNSBL
+
+if GCONFIG_DNSBL
+
+DNSBL_EXTRA_DIST = \
+	gdnsbl_disabled.cpp
+
+DNSBL_SOURCES = \
+	gdnsbl.h \
+	gdnsbl_enabled.cpp \
+	gdnsblock.h \
+	gdnsblock.cpp \
+	gdnsmessage.h \
+	gdnsmessage.cpp
+
+else
+
+DNSBL_EXTRA_DIST = \
+	gdnsbl_enabled.cpp \
+	gdnsblock.h \
+	gdnsblock.cpp \
+	gdnsmessage.h \
+	gdnsmessage.cpp
+
+DNSBL_SOURCES = \
+	gdnsbl.h \
+	gdnsbl_disabled.cpp
+
+endif
+
+# -- UDS
+
+if GCONFIG_UDS
+
+if GCONFIG_WINDOWS
+
+UDS_SOURCES = \
+	gaddresslocal_none.cpp
+
+UDS_EXTRA_DIST =
+	gaddresslocal_unix.cpp
+
+else
+
+UDS_SOURCES = \
+	gaddresslocal_unix.cpp
+
+UDS_EXTRA_DIST =
+	gaddresslocal_none.cpp
+
+endif
+
+else
+
+UDS_SOURCES = \
+	gaddresslocal_none.cpp
+
+UDS_EXTRA_DIST =
+	gaddresslocal_unix.cpp
+
+endif
+
+# -- EVENTLOOP
+
+if GCONFIG_WINDOWS
+
+EVENTLOOP_EXTRA_DIST = \
+	geventloop_epoll.cpp \
+	geventloop_select.cpp
+
+EVENTLOOP_SOURCES = \
+	geventloop_win32.cpp \
+	geventloophandles.h \
+	geventloophandles.cpp
+
+else
+
 if GCONFIG_EPOLL
 
-EXTRA_DIST_EVENTLOOP = \
+EVENTLOOP_EXTRA_DIST = \
+	geventloop_win32.cpp \
+	geventloophandles.h \
+	geventloophandles.cpp \
 	geventloop_select.cpp
 
 EVENTLOOP_SOURCES = \
@@ -193,29 +179,41 @@ EVENTLOOP_SOURCES = \
 
 else
 
-EXTRA_DIST_EVENTLOOP = \
-	geventloop_epoll.cpp
+EVENTLOOP_EXTRA_DIST = \
+	geventloop_win32.cpp \
+	geventloophandles.cpp \
+	geventloophandles.h \
+	geventloop_select.cpp
 
 EVENTLOOP_SOURCES = \
 	geventloop_select.cpp
 
 endif
 
+endif
+
+# ===
+
 EXTRA_DIST = \
-	$(EXTRA_DIST_COMMON) \
-	$(EXTRA_DIST_UDS) \
-	$(EXTRA_DIST_INTERFACES) \
-	$(EXTRA_DIST_EVENTLOOP)
+	$(DNSBL_EXTRA_DIST) \
+	$(EVENTLOOP_EXTRA_DIST) \
+	$(INTERFACES_EXTRA_DIST) \
+	$(OS_EXTRA_DIST) \
+	$(UDS_EXTRA_DIST)
 
 libgnet_a_SOURCES = \
+	$(DNSBL_SOURCES) \
+	$(EVENTLOOP_SOURCES) \
+	$(INTERFACES_SOURCES) \
+	$(OS_SOURCES) \
 	$(UDS_SOURCES) \
 	gaddress.cpp \
 	gaddress.h \
-	gaddresslocal.h \
 	gaddress4.h \
 	gaddress4.cpp \
 	gaddress6.h \
 	gaddress6.cpp \
+	gaddresslocal.h \
 	gclient.cpp \
 	gclient.h \
 	gclientptr.cpp \
@@ -223,21 +221,15 @@ libgnet_a_SOURCES = \
 	gconnection.cpp \
 	gconnection.h \
 	gdescriptor.h \
-	gdescriptor_unix.cpp \
-	gdnsblock.cpp \
-	gdnsblock.h \
-	gdnsmessage.cpp \
-	gdnsmessage.h \
 	gevent.h \
+	geventemitter.cpp \
+	geventemitter.h \
 	geventhandler.cpp \
 	geventhandler.h \
-	geventhandlerlist.cpp \
-	geventhandlerlist.h \
 	geventloggingcontext.cpp \
 	geventloggingcontext.h \
 	geventloop.cpp \
 	geventloop.h \
-	$(EVENTLOOP_SOURCES) \
 	gexceptionhandler.cpp \
 	gexceptionhandler.h \
 	gexceptionsink.cpp \
@@ -245,9 +237,7 @@ libgnet_a_SOURCES = \
 	gexceptionsource.cpp \
 	gexceptionsource.h \
 	gfutureevent.h \
-	gfutureevent_unix.cpp \
 	ginterfaces.h \
-	$(INTERFACES_SOURCES) \
 	glinebuffer.cpp \
 	glinebuffer.h \
 	glinestore.cpp \
@@ -273,7 +263,6 @@ libgnet_a_SOURCES = \
 	gserverpeer.h \
 	gsocket.h \
 	gsocket.cpp \
-	gsocket_unix.cpp \
 	gsocketprotocol.cpp \
 	gsocketprotocol.h \
 	gsocks.cpp \
@@ -285,4 +274,3 @@ libgnet_a_SOURCES = \
 	gtimerlist.cpp \
 	gtimerlist.h
 
-endif
diff --git a/src/gnet/Makefile.in b/src/gnet/Makefile.in
index d6212dd..173453e 100644
--- a/src/gnet/Makefile.in
+++ b/src/gnet/Makefile.in
@@ -110,100 +110,69 @@ am__v_AR_0 = @echo "  AR      " $@;
 am__v_AR_1 = 
 libgnet_a_AR = $(AR) $(ARFLAGS)
 libgnet_a_LIBADD =
-am__libgnet_a_SOURCES_DIST = gaddresslocal_none.cpp \
-	gaddresslocal_unix.cpp gaddress.cpp gaddress.h gaddresslocal.h \
-	gaddress4.h gaddress4.cpp gaddress6.h gaddress6.cpp \
-	gclient.cpp gclient.h gclientptr.cpp gclientptr.h \
-	gconnection.cpp gconnection.h gdescriptor.h \
-	gdescriptor_unix.cpp gdnsblock.cpp gdnsblock.h gdnsmessage.cpp \
-	gdnsmessage.h gevent.h geventhandler.cpp geventhandler.h \
-	geventhandlerlist.cpp geventhandlerlist.h \
-	geventloggingcontext.cpp geventloggingcontext.h geventloop.cpp \
-	geventloop.h geventloop_select.cpp geventloop_epoll.cpp \
+am__libgnet_a_SOURCES_DIST = gdnsbl.h gdnsbl_disabled.cpp \
+	gdnsbl_enabled.cpp gdnsblock.h gdnsblock.cpp gdnsmessage.h \
+	gdnsmessage.cpp geventloop_select.cpp geventloop_epoll.cpp \
+	geventloop_win32.cpp geventloophandles.h geventloophandles.cpp \
+	ginterfaces_none.cpp ginterfaces_unix.cpp \
+	ginterfaces_common.cpp ginterfaces_win32.cpp \
+	gdescriptor_unix.cpp gfutureevent_unix.cpp gsocket_unix.cpp \
+	gdescriptor_win32.cpp gfutureevent_win32.cpp gsocket_win32.cpp \
+	gaddresslocal_none.cpp gaddresslocal_unix.cpp gaddress.cpp \
+	gaddress.h gaddress4.h gaddress4.cpp gaddress6.h gaddress6.cpp \
+	gaddresslocal.h gclient.cpp gclient.h gclientptr.cpp \
+	gclientptr.h gconnection.cpp gconnection.h gdescriptor.h \
+	gevent.h geventemitter.cpp geventemitter.h geventhandler.cpp \
+	geventhandler.h geventloggingcontext.cpp \
+	geventloggingcontext.h geventloop.cpp geventloop.h \
 	gexceptionhandler.cpp gexceptionhandler.h gexceptionsink.cpp \
 	gexceptionsink.h gexceptionsource.cpp gexceptionsource.h \
-	gfutureevent.h gfutureevent_unix.cpp ginterfaces.h \
-	ginterfaces_none.cpp ginterfaces_unix.cpp \
-	ginterfaces_common.cpp ginterfaces_win32.cpp glinebuffer.cpp \
-	glinebuffer.h glinestore.cpp glinestore.h glistener.h \
-	glocal.cpp glocal.h glocation.cpp glocation.h gmonitor.cpp \
-	gmonitor.h gmultiserver.cpp gmultiserver.h gnetdone.cpp \
-	gnetdone.h gresolver.cpp gresolver.h gresolverfuture.cpp \
+	gfutureevent.h ginterfaces.h glinebuffer.cpp glinebuffer.h \
+	glinestore.cpp glinestore.h glistener.h glocal.cpp glocal.h \
+	glocation.cpp glocation.h gmonitor.cpp gmonitor.h \
+	gmultiserver.cpp gmultiserver.h gnetdone.cpp gnetdone.h \
+	gresolver.cpp gresolver.h gresolverfuture.cpp \
 	gresolverfuture.h gserver.cpp gserver.h gserverpeer.cpp \
-	gserverpeer.h gsocket.h gsocket.cpp gsocket_unix.cpp \
-	gsocketprotocol.cpp gsocketprotocol.h gsocks.cpp gsocks.h \
-	gtask.cpp gtask.h gtimer.cpp gtimer.h gtimerlist.cpp \
-	gtimerlist.h gdescriptor_win32.cpp geventloop_win32.cpp \
-	gfutureevent_win32.cpp gsocket_win32.cpp
-@GCONFIG_UDS_FALSE@@GCONFIG_WINDOWS_FALSE@am__objects_1 = gaddresslocal_none.$(OBJEXT)
-@GCONFIG_UDS_TRUE@@GCONFIG_WINDOWS_FALSE@am__objects_1 = gaddresslocal_unix.$(OBJEXT)
+	gserverpeer.h gsocket.h gsocket.cpp gsocketprotocol.cpp \
+	gsocketprotocol.h gsocks.cpp gsocks.h gtask.cpp gtask.h \
+	gtimer.cpp gtimer.h gtimerlist.cpp gtimerlist.h
+@GCONFIG_DNSBL_FALSE@am__objects_1 = gdnsbl_disabled.$(OBJEXT)
+@GCONFIG_DNSBL_TRUE@am__objects_1 = gdnsbl_enabled.$(OBJEXT) \
+@GCONFIG_DNSBL_TRUE@	gdnsblock.$(OBJEXT) gdnsmessage.$(OBJEXT)
 @GCONFIG_EPOLL_FALSE@@GCONFIG_WINDOWS_FALSE@am__objects_2 = geventloop_select.$(OBJEXT)
 @GCONFIG_EPOLL_TRUE@@GCONFIG_WINDOWS_FALSE@am__objects_2 = geventloop_epoll.$(OBJEXT)
-@GCONFIG_INTERFACE_NAMES_FALSE@@GCONFIG_WINDOWS_FALSE@am__objects_3 = ginterfaces_none.$(OBJEXT)
-@GCONFIG_INTERFACE_NAMES_FALSE@@GCONFIG_WINDOWS_TRUE@am__objects_3 = ginterfaces_none.$(OBJEXT)
+@GCONFIG_WINDOWS_TRUE@am__objects_2 = geventloop_win32.$(OBJEXT) \
+@GCONFIG_WINDOWS_TRUE@	geventloophandles.$(OBJEXT)
+@GCONFIG_INTERFACE_NAMES_FALSE@am__objects_3 =  \
+@GCONFIG_INTERFACE_NAMES_FALSE@	ginterfaces_none.$(OBJEXT)
 @GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_FALSE@am__objects_3 = ginterfaces_unix.$(OBJEXT) \
 @GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_FALSE@	ginterfaces_common.$(OBJEXT)
 @GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_TRUE@am__objects_3 = ginterfaces_common.$(OBJEXT) \
 @GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_TRUE@	ginterfaces_win32.$(OBJEXT)
-@GCONFIG_WINDOWS_FALSE@am_libgnet_a_OBJECTS = $(am__objects_1) \
-@GCONFIG_WINDOWS_FALSE@	gaddress.$(OBJEXT) gaddress4.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gaddress6.$(OBJEXT) gclient.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gclientptr.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gconnection.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gdescriptor_unix.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gdnsblock.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gdnsmessage.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	geventhandler.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	geventhandlerlist.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	geventloggingcontext.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	geventloop.$(OBJEXT) $(am__objects_2) \
-@GCONFIG_WINDOWS_FALSE@	gexceptionhandler.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gexceptionsink.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gexceptionsource.$(OBJEXT) \
+@GCONFIG_WINDOWS_FALSE@am__objects_4 = gdescriptor_unix.$(OBJEXT) \
 @GCONFIG_WINDOWS_FALSE@	gfutureevent_unix.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	$(am__objects_3) glinebuffer.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	glinestore.$(OBJEXT) glocal.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	glocation.$(OBJEXT) gmonitor.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gmultiserver.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gnetdone.$(OBJEXT) gresolver.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gresolverfuture.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gserver.$(OBJEXT) gserverpeer.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gsocket.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gsocket_unix.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gsocketprotocol.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gsocks.$(OBJEXT) gtask.$(OBJEXT) \
-@GCONFIG_WINDOWS_FALSE@	gtimer.$(OBJEXT) gtimerlist.$(OBJEXT)
-@GCONFIG_WINDOWS_TRUE@am_libgnet_a_OBJECTS =  \
-@GCONFIG_WINDOWS_TRUE@	gaddresslocal_none.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gaddress4.$(OBJEXT) gaddress6.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gaddress.$(OBJEXT) gclient.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gclientptr.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gconnection.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gdescriptor_win32.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gdnsblock.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gdnsmessage.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gdnsmessage.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	geventhandler.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	geventhandlerlist.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	geventloggingcontext.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	geventloop.$(OBJEXT) \
+@GCONFIG_WINDOWS_FALSE@	gsocket_unix.$(OBJEXT)
+@GCONFIG_WINDOWS_TRUE@am__objects_4 = gdescriptor_win32.$(OBJEXT) \
 @GCONFIG_WINDOWS_TRUE@	geventloop_win32.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gexceptionhandler.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gexceptionsink.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gexceptionsource.$(OBJEXT) \
 @GCONFIG_WINDOWS_TRUE@	gfutureevent_win32.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	$(am__objects_3) glinebuffer.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	glinestore.$(OBJEXT) glocal.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	glocation.$(OBJEXT) gmonitor.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gmultiserver.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gnetdone.$(OBJEXT) gresolver.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gresolverfuture.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gserver.$(OBJEXT) gserverpeer.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gsocket.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gsocketprotocol.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gsocket_win32.$(OBJEXT) gsocks.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gtask.$(OBJEXT) gtimer.$(OBJEXT) \
-@GCONFIG_WINDOWS_TRUE@	gtimerlist.$(OBJEXT)
+@GCONFIG_WINDOWS_TRUE@	gsocket_win32.$(OBJEXT)
+@GCONFIG_UDS_FALSE@am__objects_5 = gaddresslocal_none.$(OBJEXT)
+@GCONFIG_UDS_TRUE@@GCONFIG_WINDOWS_FALSE@am__objects_5 = gaddresslocal_unix.$(OBJEXT)
+@GCONFIG_UDS_TRUE@@GCONFIG_WINDOWS_TRUE@am__objects_5 = gaddresslocal_none.$(OBJEXT)
+am_libgnet_a_OBJECTS = $(am__objects_1) $(am__objects_2) \
+	$(am__objects_3) $(am__objects_4) $(am__objects_5) \
+	gaddress.$(OBJEXT) gaddress4.$(OBJEXT) gaddress6.$(OBJEXT) \
+	gclient.$(OBJEXT) gclientptr.$(OBJEXT) gconnection.$(OBJEXT) \
+	geventemitter.$(OBJEXT) geventhandler.$(OBJEXT) \
+	geventloggingcontext.$(OBJEXT) geventloop.$(OBJEXT) \
+	gexceptionhandler.$(OBJEXT) gexceptionsink.$(OBJEXT) \
+	gexceptionsource.$(OBJEXT) glinebuffer.$(OBJEXT) \
+	glinestore.$(OBJEXT) glocal.$(OBJEXT) glocation.$(OBJEXT) \
+	gmonitor.$(OBJEXT) gmultiserver.$(OBJEXT) gnetdone.$(OBJEXT) \
+	gresolver.$(OBJEXT) gresolverfuture.$(OBJEXT) \
+	gserver.$(OBJEXT) gserverpeer.$(OBJEXT) gsocket.$(OBJEXT) \
+	gsocketprotocol.$(OBJEXT) gsocks.$(OBJEXT) gtask.$(OBJEXT) \
+	gtimer.$(OBJEXT) gtimerlist.$(OBJEXT)
 libgnet_a_OBJECTS = $(am_libgnet_a_OBJECTS)
 AM_V_P = $(am__v_P_@AM_V@)
 am__v_P_ = $(am__v_P_@AM_DEFAULT_V@)
@@ -225,13 +194,15 @@ am__depfiles_remade = ./$(DEPDIR)/gaddress.Po ./$(DEPDIR)/gaddress4.Po \
 	./$(DEPDIR)/gaddresslocal_unix.Po ./$(DEPDIR)/gclient.Po \
 	./$(DEPDIR)/gclientptr.Po ./$(DEPDIR)/gconnection.Po \
 	./$(DEPDIR)/gdescriptor_unix.Po \
-	./$(DEPDIR)/gdescriptor_win32.Po ./$(DEPDIR)/gdnsblock.Po \
-	./$(DEPDIR)/gdnsmessage.Po ./$(DEPDIR)/geventhandler.Po \
-	./$(DEPDIR)/geventhandlerlist.Po \
+	./$(DEPDIR)/gdescriptor_win32.Po \
+	./$(DEPDIR)/gdnsbl_disabled.Po ./$(DEPDIR)/gdnsbl_enabled.Po \
+	./$(DEPDIR)/gdnsblock.Po ./$(DEPDIR)/gdnsmessage.Po \
+	./$(DEPDIR)/geventemitter.Po ./$(DEPDIR)/geventhandler.Po \
 	./$(DEPDIR)/geventloggingcontext.Po ./$(DEPDIR)/geventloop.Po \
 	./$(DEPDIR)/geventloop_epoll.Po \
 	./$(DEPDIR)/geventloop_select.Po \
 	./$(DEPDIR)/geventloop_win32.Po \
+	./$(DEPDIR)/geventloophandles.Po \
 	./$(DEPDIR)/gexceptionhandler.Po ./$(DEPDIR)/gexceptionsink.Po \
 	./$(DEPDIR)/gexceptionsource.Po \
 	./$(DEPDIR)/gfutureevent_unix.Po \
@@ -431,43 +402,48 @@ top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 noinst_LIBRARIES = libgnet.a
 @GCONFIG_WINDOWS_FALSE@AM_CPPFLAGS = -I$(top_srcdir)/src/glib -I$(top_srcdir)/src/gssl
+
+# -- OS
 @GCONFIG_WINDOWS_TRUE@AM_CPPFLAGS = -I$(top_srcdir)/src/glib -I$(top_srcdir)/src/gssl -I$(top_srcdir)/src/win32
-@GCONFIG_WINDOWS_FALSE@EXTRA_DIST_COMMON = \
+@GCONFIG_WINDOWS_FALSE@OS_EXTRA_DIST = \
 @GCONFIG_WINDOWS_FALSE@	gdescriptor_win32.cpp \
 @GCONFIG_WINDOWS_FALSE@	geventloop_win32.cpp \
 @GCONFIG_WINDOWS_FALSE@	gfutureevent_win32.cpp \
 @GCONFIG_WINDOWS_FALSE@	gsocket_win32.cpp
 
-@GCONFIG_WINDOWS_TRUE@EXTRA_DIST_COMMON = \
-@GCONFIG_WINDOWS_TRUE@	gaddresslocal_unix.cpp \
+@GCONFIG_WINDOWS_TRUE@OS_EXTRA_DIST = \
 @GCONFIG_WINDOWS_TRUE@	gdescriptor_unix.cpp \
-@GCONFIG_WINDOWS_TRUE@	geventloop_select.cpp \
-@GCONFIG_WINDOWS_TRUE@	geventloop_epoll.cpp \
 @GCONFIG_WINDOWS_TRUE@	gfutureevent_unix.cpp \
 @GCONFIG_WINDOWS_TRUE@	gsocket_unix.cpp
 
-@GCONFIG_INTERFACE_NAMES_FALSE@@GCONFIG_WINDOWS_TRUE@EXTRA_DIST = \
-@GCONFIG_INTERFACE_NAMES_FALSE@@GCONFIG_WINDOWS_TRUE@	$(EXTRA_DIST_COMMON) \
-@GCONFIG_INTERFACE_NAMES_FALSE@@GCONFIG_WINDOWS_TRUE@	ginterfaces_unix.cpp \
-@GCONFIG_INTERFACE_NAMES_FALSE@@GCONFIG_WINDOWS_TRUE@	ginterfaces_common.cpp \
-@GCONFIG_INTERFACE_NAMES_FALSE@@GCONFIG_WINDOWS_TRUE@	ginterfaces_win32.cpp
+@GCONFIG_WINDOWS_FALSE@OS_SOURCES = \
+@GCONFIG_WINDOWS_FALSE@	gdescriptor_unix.cpp \
+@GCONFIG_WINDOWS_FALSE@	gfutureevent_unix.cpp \
+@GCONFIG_WINDOWS_FALSE@	gsocket_unix.cpp
 
-@GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_TRUE@EXTRA_DIST = \
-@GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_TRUE@	$(EXTRA_DIST_COMMON) \
+@GCONFIG_WINDOWS_TRUE@OS_SOURCES = \
+@GCONFIG_WINDOWS_TRUE@	gdescriptor_win32.cpp \
+@GCONFIG_WINDOWS_TRUE@	geventloop_win32.cpp \
+@GCONFIG_WINDOWS_TRUE@	gfutureevent_win32.cpp \
+@GCONFIG_WINDOWS_TRUE@	gsocket_win32.cpp
+
+@GCONFIG_INTERFACE_NAMES_FALSE@INTERFACES_EXTRA_DIST = \
+@GCONFIG_INTERFACE_NAMES_FALSE@	ginterfaces_unix.cpp \
+@GCONFIG_INTERFACE_NAMES_FALSE@	ginterfaces_win32.cpp \
+@GCONFIG_INTERFACE_NAMES_FALSE@	ginterfaces_common.cpp
+
+@GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_FALSE@INTERFACES_EXTRA_DIST = \
+@GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_FALSE@	ginterfaces_win32.cpp \
+@GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_FALSE@	ginterfaces_none.cpp
+
+
+# -- INTERFACE_NAMES
+@GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_TRUE@INTERFACES_EXTRA_DIST = \
 @GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_TRUE@	ginterfaces_unix.cpp \
 @GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_TRUE@	ginterfaces_none.cpp
 
-@GCONFIG_WINDOWS_FALSE@EXTRA_DIST = \
-@GCONFIG_WINDOWS_FALSE@	$(EXTRA_DIST_COMMON) \
-@GCONFIG_WINDOWS_FALSE@	$(EXTRA_DIST_UDS) \
-@GCONFIG_WINDOWS_FALSE@	$(EXTRA_DIST_INTERFACES) \
-@GCONFIG_WINDOWS_FALSE@	$(EXTRA_DIST_EVENTLOOP)
-
-@GCONFIG_INTERFACE_NAMES_FALSE@@GCONFIG_WINDOWS_FALSE@INTERFACES_SOURCES = \
-@GCONFIG_INTERFACE_NAMES_FALSE@@GCONFIG_WINDOWS_FALSE@	ginterfaces_none.cpp
-
-@GCONFIG_INTERFACE_NAMES_FALSE@@GCONFIG_WINDOWS_TRUE@INTERFACES_SOURCES = \
-@GCONFIG_INTERFACE_NAMES_FALSE@@GCONFIG_WINDOWS_TRUE@	ginterfaces_none.cpp
+@GCONFIG_INTERFACE_NAMES_FALSE@INTERFACES_SOURCES = \
+@GCONFIG_INTERFACE_NAMES_FALSE@	ginterfaces_none.cpp
 
 @GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_FALSE@INTERFACES_SOURCES = \
 @GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_FALSE@	ginterfaces_unix.cpp \
@@ -477,197 +453,155 @@ noinst_LIBRARIES = libgnet.a
 @GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_TRUE@	ginterfaces_common.cpp \
 @GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_TRUE@	ginterfaces_win32.cpp
 
-@GCONFIG_WINDOWS_FALSE@libgnet_a_SOURCES = \
-@GCONFIG_WINDOWS_FALSE@	$(UDS_SOURCES) \
-@GCONFIG_WINDOWS_FALSE@	gaddress.cpp \
-@GCONFIG_WINDOWS_FALSE@	gaddress.h \
-@GCONFIG_WINDOWS_FALSE@	gaddresslocal.h \
-@GCONFIG_WINDOWS_FALSE@	gaddress4.h \
-@GCONFIG_WINDOWS_FALSE@	gaddress4.cpp \
-@GCONFIG_WINDOWS_FALSE@	gaddress6.h \
-@GCONFIG_WINDOWS_FALSE@	gaddress6.cpp \
-@GCONFIG_WINDOWS_FALSE@	gclient.cpp \
-@GCONFIG_WINDOWS_FALSE@	gclient.h \
-@GCONFIG_WINDOWS_FALSE@	gclientptr.cpp \
-@GCONFIG_WINDOWS_FALSE@	gclientptr.h \
-@GCONFIG_WINDOWS_FALSE@	gconnection.cpp \
-@GCONFIG_WINDOWS_FALSE@	gconnection.h \
-@GCONFIG_WINDOWS_FALSE@	gdescriptor.h \
-@GCONFIG_WINDOWS_FALSE@	gdescriptor_unix.cpp \
-@GCONFIG_WINDOWS_FALSE@	gdnsblock.cpp \
-@GCONFIG_WINDOWS_FALSE@	gdnsblock.h \
-@GCONFIG_WINDOWS_FALSE@	gdnsmessage.cpp \
-@GCONFIG_WINDOWS_FALSE@	gdnsmessage.h \
-@GCONFIG_WINDOWS_FALSE@	gevent.h \
-@GCONFIG_WINDOWS_FALSE@	geventhandler.cpp \
-@GCONFIG_WINDOWS_FALSE@	geventhandler.h \
-@GCONFIG_WINDOWS_FALSE@	geventhandlerlist.cpp \
-@GCONFIG_WINDOWS_FALSE@	geventhandlerlist.h \
-@GCONFIG_WINDOWS_FALSE@	geventloggingcontext.cpp \
-@GCONFIG_WINDOWS_FALSE@	geventloggingcontext.h \
-@GCONFIG_WINDOWS_FALSE@	geventloop.cpp \
-@GCONFIG_WINDOWS_FALSE@	geventloop.h \
-@GCONFIG_WINDOWS_FALSE@	$(EVENTLOOP_SOURCES) \
-@GCONFIG_WINDOWS_FALSE@	gexceptionhandler.cpp \
-@GCONFIG_WINDOWS_FALSE@	gexceptionhandler.h \
-@GCONFIG_WINDOWS_FALSE@	gexceptionsink.cpp \
-@GCONFIG_WINDOWS_FALSE@	gexceptionsink.h \
-@GCONFIG_WINDOWS_FALSE@	gexceptionsource.cpp \
-@GCONFIG_WINDOWS_FALSE@	gexceptionsource.h \
-@GCONFIG_WINDOWS_FALSE@	gfutureevent.h \
-@GCONFIG_WINDOWS_FALSE@	gfutureevent_unix.cpp \
-@GCONFIG_WINDOWS_FALSE@	ginterfaces.h \
-@GCONFIG_WINDOWS_FALSE@	$(INTERFACES_SOURCES) \
-@GCONFIG_WINDOWS_FALSE@	glinebuffer.cpp \
-@GCONFIG_WINDOWS_FALSE@	glinebuffer.h \
-@GCONFIG_WINDOWS_FALSE@	glinestore.cpp \
-@GCONFIG_WINDOWS_FALSE@	glinestore.h \
-@GCONFIG_WINDOWS_FALSE@	glistener.h \
-@GCONFIG_WINDOWS_FALSE@	glocal.cpp \
-@GCONFIG_WINDOWS_FALSE@	glocal.h \
-@GCONFIG_WINDOWS_FALSE@	glocation.cpp \
-@GCONFIG_WINDOWS_FALSE@	glocation.h \
-@GCONFIG_WINDOWS_FALSE@	gmonitor.cpp \
-@GCONFIG_WINDOWS_FALSE@	gmonitor.h \
-@GCONFIG_WINDOWS_FALSE@	gmultiserver.cpp \
-@GCONFIG_WINDOWS_FALSE@	gmultiserver.h \
-@GCONFIG_WINDOWS_FALSE@	gnetdone.cpp \
-@GCONFIG_WINDOWS_FALSE@	gnetdone.h \
-@GCONFIG_WINDOWS_FALSE@	gresolver.cpp \
-@GCONFIG_WINDOWS_FALSE@	gresolver.h \
-@GCONFIG_WINDOWS_FALSE@	gresolverfuture.cpp \
-@GCONFIG_WINDOWS_FALSE@	gresolverfuture.h \
-@GCONFIG_WINDOWS_FALSE@	gserver.cpp \
-@GCONFIG_WINDOWS_FALSE@	gserver.h \
-@GCONFIG_WINDOWS_FALSE@	gserverpeer.cpp \
-@GCONFIG_WINDOWS_FALSE@	gserverpeer.h \
-@GCONFIG_WINDOWS_FALSE@	gsocket.h \
-@GCONFIG_WINDOWS_FALSE@	gsocket.cpp \
-@GCONFIG_WINDOWS_FALSE@	gsocket_unix.cpp \
-@GCONFIG_WINDOWS_FALSE@	gsocketprotocol.cpp \
-@GCONFIG_WINDOWS_FALSE@	gsocketprotocol.h \
-@GCONFIG_WINDOWS_FALSE@	gsocks.cpp \
-@GCONFIG_WINDOWS_FALSE@	gsocks.h \
-@GCONFIG_WINDOWS_FALSE@	gtask.cpp \
-@GCONFIG_WINDOWS_FALSE@	gtask.h \
-@GCONFIG_WINDOWS_FALSE@	gtimer.cpp \
-@GCONFIG_WINDOWS_FALSE@	gtimer.h \
-@GCONFIG_WINDOWS_FALSE@	gtimerlist.cpp \
-@GCONFIG_WINDOWS_FALSE@	gtimerlist.h
+@GCONFIG_DNSBL_FALSE@DNSBL_EXTRA_DIST = \
+@GCONFIG_DNSBL_FALSE@	gdnsbl_enabled.cpp \
+@GCONFIG_DNSBL_FALSE@	gdnsblock.h \
+@GCONFIG_DNSBL_FALSE@	gdnsblock.cpp \
+@GCONFIG_DNSBL_FALSE@	gdnsmessage.h \
+@GCONFIG_DNSBL_FALSE@	gdnsmessage.cpp
 
-@GCONFIG_WINDOWS_TRUE@libgnet_a_SOURCES = \
-@GCONFIG_WINDOWS_TRUE@	gaddresslocal_none.cpp \
-@GCONFIG_WINDOWS_TRUE@	gaddresslocal.h \
-@GCONFIG_WINDOWS_TRUE@	gaddress4.cpp \
-@GCONFIG_WINDOWS_TRUE@	gaddress4.h \
-@GCONFIG_WINDOWS_TRUE@	gaddress6.cpp \
-@GCONFIG_WINDOWS_TRUE@	gaddress6.h \
-@GCONFIG_WINDOWS_TRUE@	gaddress.cpp \
-@GCONFIG_WINDOWS_TRUE@	gaddress.h \
-@GCONFIG_WINDOWS_TRUE@	gclient.cpp \
-@GCONFIG_WINDOWS_TRUE@	gclient.h \
-@GCONFIG_WINDOWS_TRUE@	gclientptr.cpp \
-@GCONFIG_WINDOWS_TRUE@	gclientptr.h \
-@GCONFIG_WINDOWS_TRUE@	gconnection.cpp \
-@GCONFIG_WINDOWS_TRUE@	gconnection.h \
-@GCONFIG_WINDOWS_TRUE@	gdescriptor.h \
-@GCONFIG_WINDOWS_TRUE@	gdescriptor_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	gdnsblock.cpp \
-@GCONFIG_WINDOWS_TRUE@	gdnsblock.h \
-@GCONFIG_WINDOWS_TRUE@	gdnsmessage.cpp \
-@GCONFIG_WINDOWS_TRUE@	gdnsmessage.h \
-@GCONFIG_WINDOWS_TRUE@	gdnsmessage.cpp \
-@GCONFIG_WINDOWS_TRUE@	gdnsmessage.h \
-@GCONFIG_WINDOWS_TRUE@	gevent.h \
-@GCONFIG_WINDOWS_TRUE@	geventhandler.cpp \
-@GCONFIG_WINDOWS_TRUE@	geventhandler.h \
-@GCONFIG_WINDOWS_TRUE@	geventhandlerlist.cpp \
-@GCONFIG_WINDOWS_TRUE@	geventhandlerlist.h \
-@GCONFIG_WINDOWS_TRUE@	geventloggingcontext.cpp \
-@GCONFIG_WINDOWS_TRUE@	geventloggingcontext.h \
-@GCONFIG_WINDOWS_TRUE@	geventloop.cpp \
-@GCONFIG_WINDOWS_TRUE@	geventloop.h \
-@GCONFIG_WINDOWS_TRUE@	geventloop_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	gexceptionhandler.cpp \
-@GCONFIG_WINDOWS_TRUE@	gexceptionhandler.h \
-@GCONFIG_WINDOWS_TRUE@	gexceptionsink.cpp \
-@GCONFIG_WINDOWS_TRUE@	gexceptionsink.h \
-@GCONFIG_WINDOWS_TRUE@	gexceptionsource.cpp \
-@GCONFIG_WINDOWS_TRUE@	gexceptionsource.h \
-@GCONFIG_WINDOWS_TRUE@	gfutureevent.h \
-@GCONFIG_WINDOWS_TRUE@	gfutureevent_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	ginterfaces.h \
-@GCONFIG_WINDOWS_TRUE@	$(INTERFACES_SOURCES) \
-@GCONFIG_WINDOWS_TRUE@	glinebuffer.cpp \
-@GCONFIG_WINDOWS_TRUE@	glinebuffer.h \
-@GCONFIG_WINDOWS_TRUE@	glinestore.cpp \
-@GCONFIG_WINDOWS_TRUE@	glinestore.h \
-@GCONFIG_WINDOWS_TRUE@	glistener.h \
-@GCONFIG_WINDOWS_TRUE@	glocal.cpp \
-@GCONFIG_WINDOWS_TRUE@	glocal.h \
-@GCONFIG_WINDOWS_TRUE@	glocation.cpp \
-@GCONFIG_WINDOWS_TRUE@	glocation.h \
-@GCONFIG_WINDOWS_TRUE@	gmonitor.cpp \
-@GCONFIG_WINDOWS_TRUE@	gmonitor.h \
-@GCONFIG_WINDOWS_TRUE@	gmultiserver.cpp \
-@GCONFIG_WINDOWS_TRUE@	gmultiserver.h \
-@GCONFIG_WINDOWS_TRUE@	gnetdone.cpp \
-@GCONFIG_WINDOWS_TRUE@	gnetdone.h \
-@GCONFIG_WINDOWS_TRUE@	gresolver.cpp \
-@GCONFIG_WINDOWS_TRUE@	gresolver.h \
-@GCONFIG_WINDOWS_TRUE@	gresolverfuture.cpp \
-@GCONFIG_WINDOWS_TRUE@	gresolverfuture.h \
-@GCONFIG_WINDOWS_TRUE@	gserver.cpp \
-@GCONFIG_WINDOWS_TRUE@	gserver.h \
-@GCONFIG_WINDOWS_TRUE@	gserverpeer.cpp \
-@GCONFIG_WINDOWS_TRUE@	gserverpeer.h \
-@GCONFIG_WINDOWS_TRUE@	gsocket.cpp \
-@GCONFIG_WINDOWS_TRUE@	gsocket.h \
-@GCONFIG_WINDOWS_TRUE@	gsocketprotocol.cpp \
-@GCONFIG_WINDOWS_TRUE@	gsocketprotocol.h \
-@GCONFIG_WINDOWS_TRUE@	gsocket_win32.cpp \
-@GCONFIG_WINDOWS_TRUE@	gsocks.cpp \
-@GCONFIG_WINDOWS_TRUE@	gsocks.h \
-@GCONFIG_WINDOWS_TRUE@	gtask.cpp \
-@GCONFIG_WINDOWS_TRUE@	gtask.h \
-@GCONFIG_WINDOWS_TRUE@	gtimer.cpp \
-@GCONFIG_WINDOWS_TRUE@	gtimer.h \
-@GCONFIG_WINDOWS_TRUE@	gtimerlist.cpp \
-@GCONFIG_WINDOWS_TRUE@	gtimerlist.h
 
-@GCONFIG_UDS_FALSE@@GCONFIG_WINDOWS_FALSE@UDS_SOURCES = \
-@GCONFIG_UDS_FALSE@@GCONFIG_WINDOWS_FALSE@	gaddresslocal_none.cpp
+# -- DNSBL
+@GCONFIG_DNSBL_TRUE@DNSBL_EXTRA_DIST = \
+@GCONFIG_DNSBL_TRUE@	gdnsbl_disabled.cpp
+
+@GCONFIG_DNSBL_FALSE@DNSBL_SOURCES = \
+@GCONFIG_DNSBL_FALSE@	gdnsbl.h \
+@GCONFIG_DNSBL_FALSE@	gdnsbl_disabled.cpp
+
+@GCONFIG_DNSBL_TRUE@DNSBL_SOURCES = \
+@GCONFIG_DNSBL_TRUE@	gdnsbl.h \
+@GCONFIG_DNSBL_TRUE@	gdnsbl_enabled.cpp \
+@GCONFIG_DNSBL_TRUE@	gdnsblock.h \
+@GCONFIG_DNSBL_TRUE@	gdnsblock.cpp \
+@GCONFIG_DNSBL_TRUE@	gdnsmessage.h \
+@GCONFIG_DNSBL_TRUE@	gdnsmessage.cpp
+
+@GCONFIG_UDS_FALSE@UDS_SOURCES = \
+@GCONFIG_UDS_FALSE@	gaddresslocal_none.cpp
 
 @GCONFIG_UDS_TRUE@@GCONFIG_WINDOWS_FALSE@UDS_SOURCES = \
 @GCONFIG_UDS_TRUE@@GCONFIG_WINDOWS_FALSE@	gaddresslocal_unix.cpp
 
-@GCONFIG_UDS_FALSE@@GCONFIG_WINDOWS_FALSE@EXTRA_DIST_UDS = \
-@GCONFIG_UDS_FALSE@@GCONFIG_WINDOWS_FALSE@	gaddresslocal_unix.cpp
 
-@GCONFIG_UDS_TRUE@@GCONFIG_WINDOWS_FALSE@EXTRA_DIST_UDS = \
-@GCONFIG_UDS_TRUE@@GCONFIG_WINDOWS_FALSE@	gaddresslocal_none.cpp
+# -- UDS
+@GCONFIG_UDS_TRUE@@GCONFIG_WINDOWS_TRUE@UDS_SOURCES = \
+@GCONFIG_UDS_TRUE@@GCONFIG_WINDOWS_TRUE@	gaddresslocal_none.cpp
 
-@GCONFIG_INTERFACE_NAMES_FALSE@@GCONFIG_WINDOWS_FALSE@EXTRA_DIST_INTERFACES = \
-@GCONFIG_INTERFACE_NAMES_FALSE@@GCONFIG_WINDOWS_FALSE@	ginterfaces_win32.cpp \
-@GCONFIG_INTERFACE_NAMES_FALSE@@GCONFIG_WINDOWS_FALSE@	ginterfaces_unix.cpp \
-@GCONFIG_INTERFACE_NAMES_FALSE@@GCONFIG_WINDOWS_FALSE@	ginterfaces_common.cpp
+@GCONFIG_UDS_FALSE@UDS_EXTRA_DIST = 
+@GCONFIG_UDS_TRUE@@GCONFIG_WINDOWS_FALSE@UDS_EXTRA_DIST = 
+@GCONFIG_UDS_TRUE@@GCONFIG_WINDOWS_TRUE@UDS_EXTRA_DIST = 
+@GCONFIG_EPOLL_FALSE@@GCONFIG_WINDOWS_FALSE@EVENTLOOP_EXTRA_DIST = \
+@GCONFIG_EPOLL_FALSE@@GCONFIG_WINDOWS_FALSE@	geventloop_win32.cpp \
+@GCONFIG_EPOLL_FALSE@@GCONFIG_WINDOWS_FALSE@	geventloophandles.cpp \
+@GCONFIG_EPOLL_FALSE@@GCONFIG_WINDOWS_FALSE@	geventloophandles.h \
+@GCONFIG_EPOLL_FALSE@@GCONFIG_WINDOWS_FALSE@	geventloop_select.cpp
 
-@GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_FALSE@EXTRA_DIST_INTERFACES = \
-@GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_FALSE@	ginterfaces_win32.cpp \
-@GCONFIG_INTERFACE_NAMES_TRUE@@GCONFIG_WINDOWS_FALSE@	ginterfaces_none.cpp
-
-@GCONFIG_EPOLL_FALSE@@GCONFIG_WINDOWS_FALSE@EXTRA_DIST_EVENTLOOP = \
-@GCONFIG_EPOLL_FALSE@@GCONFIG_WINDOWS_FALSE@	geventloop_epoll.cpp
-
-@GCONFIG_EPOLL_TRUE@@GCONFIG_WINDOWS_FALSE@EXTRA_DIST_EVENTLOOP = \
+@GCONFIG_EPOLL_TRUE@@GCONFIG_WINDOWS_FALSE@EVENTLOOP_EXTRA_DIST = \
+@GCONFIG_EPOLL_TRUE@@GCONFIG_WINDOWS_FALSE@	geventloop_win32.cpp \
+@GCONFIG_EPOLL_TRUE@@GCONFIG_WINDOWS_FALSE@	geventloophandles.h \
+@GCONFIG_EPOLL_TRUE@@GCONFIG_WINDOWS_FALSE@	geventloophandles.cpp \
 @GCONFIG_EPOLL_TRUE@@GCONFIG_WINDOWS_FALSE@	geventloop_select.cpp
 
+
+# -- EVENTLOOP
+@GCONFIG_WINDOWS_TRUE@EVENTLOOP_EXTRA_DIST = \
+@GCONFIG_WINDOWS_TRUE@	geventloop_epoll.cpp \
+@GCONFIG_WINDOWS_TRUE@	geventloop_select.cpp
+
 @GCONFIG_EPOLL_FALSE@@GCONFIG_WINDOWS_FALSE@EVENTLOOP_SOURCES = \
 @GCONFIG_EPOLL_FALSE@@GCONFIG_WINDOWS_FALSE@	geventloop_select.cpp
 
 @GCONFIG_EPOLL_TRUE@@GCONFIG_WINDOWS_FALSE@EVENTLOOP_SOURCES = \
 @GCONFIG_EPOLL_TRUE@@GCONFIG_WINDOWS_FALSE@	geventloop_epoll.cpp
 
+@GCONFIG_WINDOWS_TRUE@EVENTLOOP_SOURCES = \
+@GCONFIG_WINDOWS_TRUE@	geventloop_win32.cpp \
+@GCONFIG_WINDOWS_TRUE@	geventloophandles.h \
+@GCONFIG_WINDOWS_TRUE@	geventloophandles.cpp
+
+
+# ===
+EXTRA_DIST = \
+	$(DNSBL_EXTRA_DIST) \
+	$(EVENTLOOP_EXTRA_DIST) \
+	$(INTERFACES_EXTRA_DIST) \
+	$(OS_EXTRA_DIST) \
+	$(UDS_EXTRA_DIST)
+
+libgnet_a_SOURCES = \
+	$(DNSBL_SOURCES) \
+	$(EVENTLOOP_SOURCES) \
+	$(INTERFACES_SOURCES) \
+	$(OS_SOURCES) \
+	$(UDS_SOURCES) \
+	gaddress.cpp \
+	gaddress.h \
+	gaddress4.h \
+	gaddress4.cpp \
+	gaddress6.h \
+	gaddress6.cpp \
+	gaddresslocal.h \
+	gclient.cpp \
+	gclient.h \
+	gclientptr.cpp \
+	gclientptr.h \
+	gconnection.cpp \
+	gconnection.h \
+	gdescriptor.h \
+	gevent.h \
+	geventemitter.cpp \
+	geventemitter.h \
+	geventhandler.cpp \
+	geventhandler.h \
+	geventloggingcontext.cpp \
+	geventloggingcontext.h \
+	geventloop.cpp \
+	geventloop.h \
+	gexceptionhandler.cpp \
+	gexceptionhandler.h \
+	gexceptionsink.cpp \
+	gexceptionsink.h \
+	gexceptionsource.cpp \
+	gexceptionsource.h \
+	gfutureevent.h \
+	ginterfaces.h \
+	glinebuffer.cpp \
+	glinebuffer.h \
+	glinestore.cpp \
+	glinestore.h \
+	glistener.h \
+	glocal.cpp \
+	glocal.h \
+	glocation.cpp \
+	glocation.h \
+	gmonitor.cpp \
+	gmonitor.h \
+	gmultiserver.cpp \
+	gmultiserver.h \
+	gnetdone.cpp \
+	gnetdone.h \
+	gresolver.cpp \
+	gresolver.h \
+	gresolverfuture.cpp \
+	gresolverfuture.h \
+	gserver.cpp \
+	gserver.h \
+	gserverpeer.cpp \
+	gserverpeer.h \
+	gsocket.h \
+	gsocket.cpp \
+	gsocketprotocol.cpp \
+	gsocketprotocol.h \
+	gsocks.cpp \
+	gsocks.h \
+	gtask.cpp \
+	gtask.h \
+	gtimer.cpp \
+	gtimer.h \
+	gtimerlist.cpp \
+	gtimerlist.h
+
 all: all-am
 
 .SUFFIXES:
@@ -726,15 +660,18 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gconnection.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gdescriptor_unix.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gdescriptor_win32.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gdnsbl_disabled.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gdnsbl_enabled.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gdnsblock.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gdnsmessage.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/geventemitter.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/geventhandler.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/geventhandlerlist.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/geventloggingcontext.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/geventloop.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/geventloop_epoll.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/geventloop_select.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/geventloop_win32.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/geventloophandles.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gexceptionhandler.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gexceptionsink.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gexceptionsource.Po@am__quote@ # am--include-marker
@@ -918,15 +855,18 @@ distclean: distclean-am
 	-rm -f ./$(DEPDIR)/gconnection.Po
 	-rm -f ./$(DEPDIR)/gdescriptor_unix.Po
 	-rm -f ./$(DEPDIR)/gdescriptor_win32.Po
+	-rm -f ./$(DEPDIR)/gdnsbl_disabled.Po
+	-rm -f ./$(DEPDIR)/gdnsbl_enabled.Po
 	-rm -f ./$(DEPDIR)/gdnsblock.Po
 	-rm -f ./$(DEPDIR)/gdnsmessage.Po
+	-rm -f ./$(DEPDIR)/geventemitter.Po
 	-rm -f ./$(DEPDIR)/geventhandler.Po
-	-rm -f ./$(DEPDIR)/geventhandlerlist.Po
 	-rm -f ./$(DEPDIR)/geventloggingcontext.Po
 	-rm -f ./$(DEPDIR)/geventloop.Po
 	-rm -f ./$(DEPDIR)/geventloop_epoll.Po
 	-rm -f ./$(DEPDIR)/geventloop_select.Po
 	-rm -f ./$(DEPDIR)/geventloop_win32.Po
+	-rm -f ./$(DEPDIR)/geventloophandles.Po
 	-rm -f ./$(DEPDIR)/gexceptionhandler.Po
 	-rm -f ./$(DEPDIR)/gexceptionsink.Po
 	-rm -f ./$(DEPDIR)/gexceptionsource.Po
@@ -1010,15 +950,18 @@ maintainer-clean: maintainer-clean-am
 	-rm -f ./$(DEPDIR)/gconnection.Po
 	-rm -f ./$(DEPDIR)/gdescriptor_unix.Po
 	-rm -f ./$(DEPDIR)/gdescriptor_win32.Po
+	-rm -f ./$(DEPDIR)/gdnsbl_disabled.Po
+	-rm -f ./$(DEPDIR)/gdnsbl_enabled.Po
 	-rm -f ./$(DEPDIR)/gdnsblock.Po
 	-rm -f ./$(DEPDIR)/gdnsmessage.Po
+	-rm -f ./$(DEPDIR)/geventemitter.Po
 	-rm -f ./$(DEPDIR)/geventhandler.Po
-	-rm -f ./$(DEPDIR)/geventhandlerlist.Po
 	-rm -f ./$(DEPDIR)/geventloggingcontext.Po
 	-rm -f ./$(DEPDIR)/geventloop.Po
 	-rm -f ./$(DEPDIR)/geventloop_epoll.Po
 	-rm -f ./$(DEPDIR)/geventloop_select.Po
 	-rm -f ./$(DEPDIR)/geventloop_win32.Po
+	-rm -f ./$(DEPDIR)/geventloophandles.Po
 	-rm -f ./$(DEPDIR)/gexceptionhandler.Po
 	-rm -f ./$(DEPDIR)/gexceptionsink.Po
 	-rm -f ./$(DEPDIR)/gexceptionsource.Po
@@ -1081,6 +1024,9 @@ uninstall-am:
 
 .PRECIOUS: Makefile
 
+@GCONFIG_UDS_TRUE@@GCONFIG_WINDOWS_TRUE@	gaddresslocal_unix.cpp
+@GCONFIG_UDS_TRUE@@GCONFIG_WINDOWS_FALSE@	gaddresslocal_none.cpp
+@GCONFIG_UDS_FALSE@	gaddresslocal_unix.cpp
 
 # Tell versions [3.59,3.63) of GNU make to not export all variables.
 # Otherwise a system limit (for SysV at least) may be exceeded.
diff --git a/src/gnet/gaddress.cpp b/src/gnet/gaddress.cpp
index d1f9b2d..92d6932 100644
--- a/src/gnet/gaddress.cpp
+++ b/src/gnet/gaddress.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -30,20 +30,24 @@
 #include <sstream>
 #include <cstring>
 
-bool GNet::Address::supports( Family f )
+bool GNet::Address::supports( Family f ) noexcept
 {
-	if( f == Address::Family::local && AddressLocal::af() == 0 )
+	if( f == Address::Family::ipv4 && Address4::af() == 0 )
+		return false ; // fwiw
+	else if( f == Address::Family::ipv6 && Address6::af() == 0 )
+		return false ; // fwiw
+	else if( f == Address::Family::local && AddressLocal::af() == 0 )
 		return false ;
 	else
 		return true ;
 }
 
-bool GNet::Address::supports( int af , int )
+bool GNet::Address::supports( int af , int ) noexcept
 {
 	return af == Address4::af() || af == Address6::af() || af == AddressLocal::af() ;
 }
 
-bool GNet::Address::supports( const Address::Domain & , int domain )
+bool GNet::Address::supports( const Address::Domain & , int domain ) noexcept
 {
 	return domain == Address4::domain() || domain == Address6::domain() || domain == AddressLocal::domain() ;
 }
@@ -60,59 +64,40 @@ GNet::Address::Address( Family f , unsigned int port )
 		throw Address::BadFamily() ;
 }
 
-GNet::Address::Address( const AddressStorage & storage )
+GNet::Address::Address( const sockaddr * addr , socklen_t len , bool ipv6_scope_id_fixup )
 {
-	if( storage.p()->sa_family == 0 )
-		throw Address::BadFamily() ;
-	else if( Address4::af() && storage.p()->sa_family == Address4::af() )
-		m_ipv4 = std::make_unique<Address4>( storage.p() , storage.n() ) ;
-	else if( Address6::af() && storage.p()->sa_family == Address6::af() )
-		m_ipv6 = std::make_unique<Address6>( storage.p() , storage.n() ) ;
-	else if( AddressLocal::af() && storage.p()->sa_family == AddressLocal::af() )
-		m_local = std::make_unique<AddressLocal>( storage.p() , storage.n() ) ;
-	else
-		throw Address::BadFamily() ;
-}
-
-GNet::Address::Address( const sockaddr * addr , socklen_t len )
-{
-	if( addr == nullptr || len < sizeof(sockaddr::sa_family) )
+	if( addr == nullptr || len < static_cast<socklen_t>(sizeof(sockaddr::sa_family)) )
 		throw Address::Error() ;
 	else if( addr->sa_family == 0 )
 		throw Address::BadFamily() ;
 	else if( Address4::af() && addr->sa_family == Address4::af() )
 		m_ipv4 = std::make_unique<Address4>( addr , len ) ;
 	else if( Address6::af() && addr->sa_family == Address6::af() )
-		m_ipv6 = std::make_unique<Address6>( addr , len ) ;
+		m_ipv6 = std::make_unique<Address6>( addr , len , ipv6_scope_id_fixup ) ;
 	else if( AddressLocal::af() && addr->sa_family == AddressLocal::af() )
 		m_local = std::make_unique<AddressLocal>( addr , len ) ;
 	else
 		throw Address::BadFamily() ;
 }
 
-GNet::Address::Address( const sockaddr * addr , socklen_t len , bool ipv6_scope_id_fixup )
+GNet::Address::Address( const sockaddr * addr , socklen_t len ) :
+	Address(addr,len,false)
 {
-	if( addr == nullptr || len < sizeof(sockaddr::sa_family) )
-		throw Address::Error() ;
-	else if( addr->sa_family == 0 )
-		throw Address::BadFamily() ;
-	else if( Address4::af() && addr->sa_family == Address4::af() )
-		m_ipv4 = std::make_unique<Address4>( addr , len , ipv6_scope_id_fixup ) ;
-	else if( Address6::af() && addr->sa_family == Address6::af() )
-		m_ipv6 = std::make_unique<Address6>( addr , len , ipv6_scope_id_fixup ) ;
-	else if( AddressLocal::af() && addr->sa_family == AddressLocal::af() )
-		m_local = std::make_unique<AddressLocal>( addr , len , ipv6_scope_id_fixup ) ;
-	else
-		throw Address::BadFamily() ;
 }
 
-GNet::Address::Address( const std::string & s )
+GNet::Address::Address( const AddressStorage & storage ) :
+	Address(storage.p(),storage.n(),false)
+{
+}
+
+GNet::Address::Address( const std::string & s , bool with_local )
 {
-	std::string r1 ;
-	std::string r2 ;
 	if( s.empty() )
 		throw Address::Error( "empty string" ) ;
-	else if( AddressLocal::af() && isFamilyLocal(s) )
+
+	std::string r1 ;
+	std::string r2 ;
+	if( with_local && AddressLocal::af() && isFamilyLocal(s) )
 		m_local = std::make_unique<AddressLocal>( s ) ;
 	else if( Address4::af() && Address4::validString(s,&r1) )
 		m_ipv4 = std::make_unique<Address4>( s ) ;
@@ -122,50 +107,26 @@ GNet::Address::Address( const std::string & s )
 		throw Address::Error( r1 , r1==r2?std::string():r2 , G::Str::printable(s) ) ;
 }
 
-GNet::Address::Address( const std::string & s , NotLocal )
-{
-	std::string r1 ;
-	std::string r2 ;
-	if( s.empty() )
-		throw Address::Error( "empty string" ) ;
-	else if( Address4::af() && Address4::validString(s,&r1) )
-		m_ipv4 = std::make_unique<Address4>( s ) ;
-	else if( Address6::af() && Address6::validString(s,&r2) )
-		m_ipv6 = std::make_unique<Address6>( s ) ;
-	else
-		throw Address::Error( r1 , r1==r2?std::string():r2 , G::Str::printable(s) ) ;
-}
-
 GNet::Address::Address( const std::string & host_part , const std::string & port_part )
 {
-	std::string r1 ;
-	std::string r2 ;
 	if( host_part.empty() )
 		throw Address::Error( "empty string" ) ;
-	else if( AddressLocal::af() && isFamilyLocal( host_part ) )
-		m_local = std::make_unique<AddressLocal>( host_part , port_part ) ;
+
+	std::string r1 ;
+	std::string r2 ;
+	if( AddressLocal::af() && isFamilyLocal( host_part ) )
+		m_local = std::make_unique<AddressLocal>( host_part ) ;
 	else if( Address4::af() && Address4::validStrings(host_part,port_part,&r1) )
 		m_ipv4 = std::make_unique<Address4>( host_part , port_part ) ;
 	else if( Address6::af() && Address6::validStrings(host_part,port_part,&r2) )
 		m_ipv6 = std::make_unique<Address6>( host_part , port_part ) ;
 	else
-		throw Address::Error( r1 , r1==r2?std::string():r2 , G::Str::printable(host_part) + " " + G::Str::printable(port_part) ) ;
+		throw Address::Error( r1 , r1==r2?std::string():r2 , G::Str::printable(host_part) , G::Str::printable(port_part) ) ;
 }
 
-GNet::Address::Address( const std::string & host_part , unsigned int port )
+GNet::Address::Address( const std::string & host_part , unsigned int port ) :
+	Address(host_part,G::Str::fromUInt(port))
 {
-	std::string r1 ;
-	std::string r2 ;
-	if( host_part.empty() )
-		throw Address::Error( "empty string" ) ;
-	else if( AddressLocal::af() && isFamilyLocal( host_part ) )
-		m_local = std::make_unique<AddressLocal>( host_part , port ) ;
-	else if( Address4::af() && Address4::validStrings(host_part,"0",&r1) && Address4::validPort(port) )
-		m_ipv4 = std::make_unique<Address4>( host_part , port ) ;
-	else if( Address6::af() && Address6::validStrings(host_part,"0",&r2) && Address6::validPort(port) )
-		m_ipv6 = std::make_unique<Address6>( host_part , port ) ;
-	else
-		throw Address::Error( r1 , r1==r2?std::string():r2 , G::Str::printable(host_part) ) ;
 }
 
 GNet::Address::Address( Family f , unsigned int port , int loopback_overload )
@@ -216,12 +177,12 @@ GNet::Address & GNet::Address::operator=( Address && other ) noexcept
 
 GNet::Address GNet::Address::parse( const std::string & s )
 {
-	return Address( s ) ;
+	return { s , true } ;
 }
 
-GNet::Address GNet::Address::parse( const std::string & s , Address::NotLocal not_local )
+GNet::Address GNet::Address::parse( const std::string & s , Address::NotLocal )
 {
-	return { s , not_local } ;
+	return { s , false } ;
 }
 
 GNet::Address GNet::Address::parse( const std::string & host_part , unsigned int port )
@@ -234,7 +195,7 @@ GNet::Address GNet::Address::parse( const std::string & host_part , const std::s
 	return { host_part , port_part } ;
 }
 
-bool GNet::Address::isFamilyLocal( const std::string & s )
+bool GNet::Address::isFamilyLocal( const std::string & s ) noexcept
 {
 	return supports( Family::local ) && !s.empty() && s[0] == '/' ;
 }
@@ -312,6 +273,15 @@ bool GNet::Address::isLinkLocal() const
 		( m_local && m_local->isLinkLocal() ) ;
 }
 
+bool GNet::Address::isMulticast() const
+{
+	G_ASSERT( m_ipv4 || m_ipv6 || m_local ) ;
+	return
+		( m_ipv4 && m_ipv4->isMulticast() ) ||
+		( m_ipv6 && m_ipv6->isMulticast() ) ||
+		( m_local && m_local->isMulticast() ) ;
+}
+
 bool GNet::Address::isUniqueLocal() const
 {
 	G_ASSERT( m_ipv4 || m_ipv6 || m_local ) ;
@@ -330,12 +300,12 @@ bool GNet::Address::isAny() const
 		( m_local && m_local->isAny() ) ;
 }
 
-bool GNet::Address::is4() const
+bool GNet::Address::is4() const noexcept
 {
 	return !!m_ipv4 ;
 }
 
-bool GNet::Address::is6() const
+bool GNet::Address::is6() const noexcept
 {
 	return !!m_ipv6 ;
 }
@@ -381,12 +351,12 @@ std::string GNet::Address::displayString( bool ipv6_with_scope_id ) const
 	return {} ;
 }
 
-std::string GNet::Address::hostPartString( bool raw ) const
+std::string GNet::Address::hostPartString() const
 {
 	G_ASSERT( m_ipv4 || m_ipv6 || m_local ) ;
-	if( m_ipv4 ) return m_ipv4->hostPartString( raw ) ;
-	if( m_ipv6 ) return m_ipv6->hostPartString( raw ) ;
-	if( m_local ) return m_local->hostPartString( raw ) ;
+	if( m_ipv4 ) return m_ipv4->hostPartString() ;
+	if( m_ipv6 ) return m_ipv6->hostPartString() ;
+	if( m_local ) return m_local->hostPartString() ;
 	return {} ;
 }
 
@@ -480,7 +450,7 @@ bool GNet::Address::validData( const sockaddr * addr , socklen_t len )
 		AddressLocal::validData( addr , len ) ;
 }
 
-int GNet::Address::domain( Family family )
+int GNet::Address::domain( Family family ) noexcept
 {
 	if( family == Family::ipv4 ) return Address4::domain() ;
 	if( family == Family::ipv6 ) return Address6::domain() ;
@@ -488,18 +458,16 @@ int GNet::Address::domain( Family family )
 	return 0 ;
 }
 
-GNet::Address::Family GNet::Address::family() const
+GNet::Address::Family GNet::Address::family() const noexcept
 {
-	G_ASSERT( m_ipv4 || m_ipv6 || m_local ) ;
 	if( m_ipv4 ) return Family::ipv4 ;
 	if( m_ipv6 ) return Family::ipv6 ;
 	if( m_local ) return Family::local ;
 	return Family::ipv4 ;
 }
 
-int GNet::Address::af() const
+int GNet::Address::af() const noexcept
 {
-	G_ASSERT( m_ipv4 || m_ipv6 || m_local ) ;
 	if( m_ipv4 ) return Address4::af() ;
 	if( m_ipv6 ) return Address6::af() ;
 	if( m_local ) return AddressLocal::af() ;
@@ -628,8 +596,8 @@ const char * GNet::inet_ntop_imp( int f , void * ap , char * buffer , std::size_
 		const char * hexmap = "0123456789abcdef" ;
 		for( int i = 0 ; i < 16 ; i++ , sep = *sep ? "" : ":" ) // sep alternates
 		{
-			unsigned int n = static_cast<unsigned int>(a.s6_addr[i]) % 256U ;
-			ss << sep << hexmap[(n>>4U)%16U] << hexmap[(n&15U)%16U] ;
+			unsigned int nn = static_cast<unsigned int>(a.s6_addr[i]) % 256U ;
+			ss << sep << hexmap[(nn>>4U)%16U] << hexmap[(nn&15U)%16U] ;
 		}
 		ss << ":" ;
 		// eg. ":0001:0002:0000:0000:0005:0006:dead:beef:"
diff --git a/src/gnet/gaddress.h b/src/gnet/gaddress.h
index 8fd315f..a487257 100644
--- a/src/gnet/gaddress.h
+++ b/src/gnet/gaddress.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,7 +22,7 @@
 #define G_NET_ADDRESS_H
 
 #include "gdef.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gexception.h"
 #include <string>
 #include <memory>
@@ -47,6 +47,14 @@ namespace GNet
 /// the GNet::Address6 can be forward-declared but not defined, with all methods
 /// forwarded to the GNet::Address4 sub-object.
 ///
+/// Unix domain addresses are supported by the GNet::AddressLocal implementation
+/// class. Port numbers are not expected when parsing and port numbers are not
+/// included in the display string. Unix domain addresses are only allowed
+/// to be absolute filesystem paths starting with '/' and with no unprintable
+/// characters, or the well-defined zero-length address (for unbound sockets)
+/// which is given the display string of "/". Paths with funny characters or
+/// linux-specific abstract addresses (see man unix(7)) will throw.
+///
 /// \see GNet::Resolver
 ///
 class GNet::Address
@@ -61,19 +69,19 @@ public:
 	struct Domain /// Overload discriminator for Address::supports()
 		{} ;
 
-	G_EXCEPTION( Error , "address error" ) ;
-	G_EXCEPTION( BadString , "invalid address" ) ;
-	G_EXCEPTION_CLASS( BadFamily , "unsupported address family" ) ;
+	G_EXCEPTION( Error , tx("address error") ) ;
+	G_EXCEPTION( BadString , tx("invalid address") ) ;
+	G_EXCEPTION_CLASS( BadFamily , tx("unsupported address family") ) ;
 
-	static bool supports( Family ) ;
+	static bool supports( Family ) noexcept ;
 		///< Returns true if the implementation supports the given
 		///< address family.
 
-	static bool supports( int af , int dummy ) ;
+	static bool supports( int af , int dummy ) noexcept ;
 		///< Returns true if the implementation supports the given
 		///< address family given as AF_INET etc.
 
-	static bool supports( const Domain & , int domain ) ;
+	static bool supports( const Domain & , int domain ) noexcept ;
 		///< Returns true if the implementation supports the given
 		///< address domain given as PF_INET etc.
 
@@ -128,7 +136,7 @@ public:
 		///< Factory function for Family::ipv4 or Family::ipv6.
 		///< Throws if an invalid string. See also validStrings().
 
-	static bool isFamilyLocal( const std::string & display_string ) ;
+	static bool isFamilyLocal( const std::string & display_string ) noexcept ;
 		///< Returns true if the given address display string looks
 		///< will parse to Family::local and Family::local is
 		///< supported. The address may still fail to parse if
@@ -153,13 +161,12 @@ public:
 		///< Returns the size of the sockaddr address. See address().
 
 	std::string displayString( bool with_scope_id = false ) const ;
-		///< Returns a string which represents the transport address.
+		///< Returns a printable string that represents the transport
+		///< address.
 
-	std::string hostPartString( bool raw = false ) const ;
-		///< Returns a string which represents the network address.
-		///< For unix-domain sockets this returns the address path
-		///< and if the 'raw' parameter is set then any non-printing
-		///< characters are not escaped.
+	std::string hostPartString() const ;
+		///< Returns a printable string that represents the network
+		///< address.
 
 	std::string queryString() const ;
 		///< Returns a string that can be used as a prefix for rDNS or
@@ -168,14 +175,14 @@ public:
 	unsigned int port() const;
 		///< Returns port part of the address.
 
-	static int domain( Family ) ;
+	static int domain( Family ) noexcept ;
 		///< Returns the address 'domain' for the given family, eg. PF_INET
 		///< for Family::ipv4.
 
-	Family family() const ;
+	Family family() const noexcept ;
 		///< Returns the address family enumeration.
 
-	int af() const ;
+	int af() const noexcept ;
 		///< Returns the address family number such as AF_INET or AFINET6.
 
 	static bool validPort( unsigned int n ) ;
@@ -249,10 +256,13 @@ public:
 		///< address that is likely to be more trusted. Returns an
 		///< explanation by reference otherwise.
 
-	bool is4() const ;
+	bool isMulticast() const ;
+		///< Returns true if this is a multicast address.
+
+	bool is4() const noexcept ;
 		///< Returns true if family() is ipv4.
 
-	bool is6() const ;
+	bool is6() const noexcept ;
 		///< Returns true if family() is ipv6.
 
 	bool same( const Address & , bool ipv6_compare_with_scope ) const ;
@@ -269,8 +279,7 @@ public:
 
 private:
 	Address( Family , unsigned int , int ) ; // loopback()
-	explicit Address( const std::string & display_string ) ; // parse()
-	Address( const std::string & display_string , NotLocal ) ; // parse(NotLocal)
+	Address( const std::string & display_string , bool with_local ) ; // parse(), parse(NotLocal)
 	Address( const std::string & ip , const std::string & port ) ; // parse(ip,port)
 	Address( const std::string & ip , unsigned int port ) ; // parse(ip,port)
 
@@ -319,8 +328,8 @@ public:
 public:
 	AddressStorage( const AddressStorage & ) = delete ;
 	AddressStorage( AddressStorage && ) = delete ;
-	void operator=( const AddressStorage & ) = delete ;
-	void operator=( AddressStorage && ) = delete ;
+	AddressStorage & operator=( const AddressStorage & ) = delete ;
+	AddressStorage & operator=( AddressStorage && ) = delete ;
 
 private:
 	std::unique_ptr<AddressStorageImp> m_imp ;
diff --git a/src/gnet/gaddress4.cpp b/src/gnet/gaddress4.cpp
index 4c50b07..0ad23f7 100644
--- a/src/gnet/gaddress4.cpp
+++ b/src/gnet/gaddress4.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,6 +21,7 @@
 #include "gdef.h"
 #include "gaddress4.h"
 #include "gstr.h"
+#include "gstringfield.h"
 #include "gtest.h"
 #include "gassert.h"
 #include "glog.h"
@@ -73,7 +74,7 @@ GNet::Address4::Address4( unsigned int port , int /*loopback_overload*/ ) :
 	if( reason ) throw Address::Error(reason) ;
 }
 
-GNet::Address4::Address4( const sockaddr * addr , socklen_t len , bool ) :
+GNet::Address4::Address4( const sockaddr * addr , socklen_t len ) :
 	Address4(nullptr)
 {
 	if( addr == nullptr )
@@ -84,16 +85,6 @@ GNet::Address4::Address4( const sockaddr * addr , socklen_t len , bool ) :
 	m_inet = *(reinterpret_cast<const sockaddr_type*>(addr)) ;
 }
 
-GNet::Address4::Address4( const std::string & host_part , unsigned int port ) :
-	Address4(nullptr)
-{
-	const char * reason = setHostAddress( m_inet , host_part ) ;
-	if( !reason )
-		reason = setPort( m_inet , port ) ;
-	if( reason )
-		throw Address::BadString( std::string(reason) + ": " + host_part ) ;
-}
-
 GNet::Address4::Address4( const std::string & host_part , const std::string & port_part ) :
 	Address4(nullptr)
 {
@@ -101,7 +92,7 @@ GNet::Address4::Address4( const std::string & host_part , const std::string & po
 	if( !reason )
 		reason = setPort( m_inet , port_part ) ;
 	if( reason )
-		throw Address::BadString( std::string(reason) + ": [" + host_part + "][" + port_part + "]" ) ;
+		throw Address::BadString( std::string(reason).append(": [").append(host_part).append("][").append(port_part).append(1U,']') ) ;
 }
 
 GNet::Address4::Address4( const std::string & display_string ) :
@@ -109,17 +100,17 @@ GNet::Address4::Address4( const std::string & display_string ) :
 {
 	const char * reason = setAddress( m_inet , display_string ) ;
 	if( reason )
-		throw Address::BadString( std::string(reason) + ": " + display_string ) ;
+		throw Address::BadString( std::string(reason).append(": ").append(display_string) ) ;
 }
 
-const char * GNet::Address4::setAddress( sockaddr_type & inet , const std::string & display_string )
+const char * GNet::Address4::setAddress( sockaddr_type & inet , G::string_view display_string )
 {
 	const std::string::size_type pos = display_string.find_last_of( Address4Imp::port_separators ) ;
 	if( pos == std::string::npos )
 		return "no port separator" ;
 
-	std::string host_part = G::Str::head( display_string , pos ) ;
-	std::string port_part = G::Str::tail( display_string , pos ) ;
+	G::string_view host_part = G::Str::headView( display_string , pos ) ;
+	G::string_view port_part = G::Str::tailView( display_string , pos ) ;
 
 	const char * reason = setHostAddress( inet , host_part ) ;
 	if( !reason )
@@ -127,13 +118,13 @@ const char * GNet::Address4::setAddress( sockaddr_type & inet , const std::strin
 	return reason ;
 }
 
-const char * GNet::Address4::setHostAddress( sockaddr_type & inet , const std::string & host_part )
+const char * GNet::Address4::setHostAddress( sockaddr_type & inet , G::string_view host_part )
 {
 	// start with a stricter check than inet_pton(), inet_addr() etc. since they allow eg. "123.123"
 	if( !Address4::format(host_part) )
 		return "invalid network address" ;
 
-	int rc = inet_pton( af() , host_part.c_str() , &inet.sin_addr ) ;
+	int rc = inet_pton( af() , sv_to_string(host_part).c_str() , &inet.sin_addr ) ;
 	return rc == 1 ? nullptr : "invalid network address" ;
 }
 
@@ -144,9 +135,9 @@ void GNet::Address4::setPort( unsigned int port )
 		throw Address::Error( "invalid port number" ) ;
 }
 
-const char * GNet::Address4::setPort( sockaddr_type & inet , const std::string & port_part )
+const char * GNet::Address4::setPort( sockaddr_type & inet , G::string_view port_part )
 {
-	if( port_part.length() == 0U ) return "empty port string" ;
+	if( port_part.empty() ) return "empty port string" ;
 	if( !G::Str::isNumeric(port_part) || !G::Str::isUInt(port_part) ) return "non-numeric port string" ;
 	return setPort( inet , G::Str::toUInt(port_part) ) ;
 }
@@ -176,7 +167,7 @@ std::string GNet::Address4::displayString( bool /*ipv6_with_scope*/ ) const
 	return ss.str() ;
 }
 
-std::string GNet::Address4::hostPartString( bool /*raw*/ ) const
+std::string GNet::Address4::hostPartString() const
 {
 	std::array<char,INET_ADDRSTRLEN+1U> buffer {} ;
 	const void * vp = & m_inet.sin_addr ;
@@ -189,7 +180,7 @@ std::string GNet::Address4::hostPartString( bool /*raw*/ ) const
 
 std::string GNet::Address4::queryString() const
 {
-	G::StringArray parts = G::Str::splitIntoFields( hostPartString() , "." ) ;
+	G::StringArray parts = G::Str::splitIntoFields( hostPartString() , '.' ) ;
 	std::reverse( parts.begin() , parts.end() ) ;
 	return G::Str::join( "." , parts ) ;
 }
@@ -276,49 +267,44 @@ socklen_t GNet::Address4::length() noexcept
 
 G::StringArray GNet::Address4::wildcards() const
 {
-	std::string ip_string = hostPartString() ;
+	std::string ip_str = hostPartString() ;
 
 	G::StringArray result ;
 	result.reserve( 38U ) ;
-	result.push_back( ip_string ) ;
+	result.push_back( ip_str ) ;
 
-	G::StringArray part ;
-	part.reserve( 4U ) ;
-	G::Str::splitIntoFields( ip_string , part , "." ) ;
+	G::string_view ip_sv( ip_str.data() , ip_str.size() ) ;
+	G::StringFieldT<G::string_view> part( ip_sv , "." , 1U ) ;
+	G::string_view part0 = part() ;
+	G::string_view part1 = (++part)() ;
+	G::string_view part2 = (++part)() ;
+	G::string_view part3 = (++part)() ;
 
-	G_ASSERT( part.size() == 4U ) ;
-	if( part.size() != 4U )
+	G_ASSERT( part.valid() ) ;
+	if( !part.valid() )
 		return result ;
 
-	if( part[0].empty() || !G::Str::isUInt(part[0]) ||
-		part[1].empty() || !G::Str::isUInt(part[1]) ||
-		part[2].empty() || !G::Str::isUInt(part[2]) ||
-		part[3].empty() || !G::Str::isUInt(part[3]) )
+	G_ASSERT( !(++part).valid() ) ;
+
+	if( part0.empty() || !G::Str::isUInt(part0) ||
+		part1.empty() || !G::Str::isUInt(part1) ||
+		part2.empty() || !G::Str::isUInt(part2) ||
+		part3.empty() || !G::Str::isUInt(part3) )
 	{
 		return result ;
 	}
 
-	unsigned int n0 = G::Str::toUInt(part[0]) ;
-	unsigned int n1 = G::Str::toUInt(part[1]) ;
-	unsigned int n2 = G::Str::toUInt(part[2]) ;
-	unsigned int n3 = G::Str::toUInt(part[3]) ;
+	unsigned int n0 = G::Str::toUInt(part0) ;
+	unsigned int n1 = G::Str::toUInt(part1) ;
+	unsigned int n2 = G::Str::toUInt(part2) ;
+	unsigned int n3 = G::Str::toUInt(part3) ;
 
-	std::string part_0_1_2 = part[0] ;
-	part_0_1_2.append( 1U , '.' ) ;
-	part_0_1_2.append( part[1] ) ;
-	part_0_1_2.append( 1U , '.' ) ;
-	part_0_1_2.append( part[2] ) ;
-	part_0_1_2.append( 1U , '.' ) ;
-
-	std::string part_0_1 = part[0] ;
-	part_0_1.append( 1U , '.' ) ;
-	part_0_1.append( part[1] ) ;
-	part_0_1.append( 1U , '.' ) ;
-
-	std::string part_0 = part[0] ;
-	part_0.append( 1U , '.' ) ;
-
-	const std::string empty ;
+	std::string part_0_1_2 = std::string(part0.data(),part0.size()).append(1U,'.')
+		.append(part1.data(),part1.size()).append(1U,'.')
+		.append(part2.data(),part2.size()).append(1U,'.') ;
+	std::string part_0_1 = std::string(part0.data(),part0.size()).append(1U,'.')
+		.append(part1.data(),part1.size()).append(1U,'.') ;
+	std::string part_0 = std::string(part0.data(),part0.size()).append(1U,'.') ;
 
 	add( result , part_0_1_2 , n3 & 0xffU , "/32" ) ;
 	add( result , part_0_1_2 , n3 & 0xfeU , "/31" ) ;
@@ -348,39 +334,46 @@ G::StringArray GNet::Address4::wildcards() const
 	add( result , part_0 , n1 & 0x80U , ".0.0/9" ) ;
 	add( result , part_0 , 0 , ".0.0/8" ) ;
 	add( result , part_0 , "*.*.*" ) ;
-	add( result , empty , n0 & 0xfeU , ".0.0.0/7" ) ;
-	add( result , empty , n0 & 0xfcU , ".0.0.0/6" ) ;
-	add( result , empty , n0 & 0xf8U , ".0.0.0/5" ) ;
-	add( result , empty , n0 & 0xf0U , ".0.0.0/4" ) ;
-	add( result , empty , n0 & 0xe0U , ".0.0.0/3" ) ;
-	add( result , empty , n0 & 0xc0U , ".0.0.0/2" ) ;
-	add( result , empty , n0 & 0x80U , ".0.0.0/1" ) ;
-	add( result , empty , 0 , ".0.0.0/0" ) ;
-	add( result , empty , "*.*.*.*" ) ;
+	add( result , n0 & 0xfeU , ".0.0.0/7" ) ;
+	add( result , n0 & 0xfcU , ".0.0.0/6" ) ;
+	add( result , n0 & 0xf8U , ".0.0.0/5" ) ;
+	add( result , n0 & 0xf0U , ".0.0.0/4" ) ;
+	add( result , n0 & 0xe0U , ".0.0.0/3" ) ;
+	add( result , n0 & 0xc0U , ".0.0.0/2" ) ;
+	add( result , n0 & 0x80U , ".0.0.0/1" ) ;
+	add( result , 0 , ".0.0.0/0" ) ;
+	add( result , "*.*.*.*" ) ;
 
 	return result ;
 }
 
-void GNet::Address4::add( G::StringArray & result , const std::string & head , unsigned int n , const char * tail )
+void GNet::Address4::add( G::StringArray & result , G::string_view head , unsigned int n , const char * tail )
 {
-	std::string s = head ;
-	s.append( G::Str::fromUInt( n ) ) ;
-	s.append( tail ) ;
-	result.push_back( s ) ;
+	result.push_back( G::sv_to_string(head).append(G::Str::fromUInt(n)).append(tail) ) ;
 }
 
-void GNet::Address4::add( G::StringArray & result , const std::string & head , const char * tail )
+void GNet::Address4::add( G::StringArray & result , unsigned int n , const char * tail )
 {
-	result.push_back( head + tail ) ;
+	result.push_back( G::Str::fromUInt(n).append(tail) ) ;
 }
 
-bool GNet::Address4::format( std::string s )
+void GNet::Address4::add( G::StringArray & result , G::string_view head , const char * tail )
+{
+	result.push_back( G::sv_to_string(head).append(tail) ) ;
+}
+
+void GNet::Address4::add( G::StringArray & result , const char * tail )
+{
+	result.push_back( std::string(tail) ) ;
+}
+
+bool GNet::Address4::format( G::string_view s )
 {
 	// an independent check for the IPv4 dotted-quad format
 
 	if( s.empty() || s.find_first_not_of("0123456789.") != std::string::npos ||
 		std::count(s.begin(),s.end(),'.') != 3U || s.at(0U) == '.' ||
-		s.at(s.length()-1U) == '.' || s.find("..") != std::string::npos )
+		s.at(s.size()-1U) == '.' || s.find("..") != std::string::npos )
 			return false ;
 
 	unsigned int n = 0U ;
@@ -413,10 +406,8 @@ bool GNet::Address4::isLocal( std::string & reason ) const
 	}
 	else
 	{
-		std::ostringstream ss ;
-		ss << hostPartString() << " is not in "
-			"127.0.0.0/8, 169.254.0.0/16, 10.0.0.0/8, 172.16.0.0/12, or 192.168.0.0/16" ;
-		reason = ss.str() ;
+		reason = hostPartString().append( " is not in "
+			"127.0.0.0/8, 169.254.0.0/16, 10.0.0.0/8, 172.16.0.0/12, or 192.168.0.0/16" ) ;
 		return false ;
 	}
 }
@@ -442,6 +433,12 @@ bool GNet::Address4::isUniqueLocal() const
 		( ntohl(m_inet.sin_addr.s_addr) >> 16U ) == 0xC0A8U ; // 192.168.0.0/16
 }
 
+bool GNet::Address4::isMulticast() const
+{
+	// RFC-5771
+	return ( ntohl(m_inet.sin_addr.s_addr) >> 28U ) == 0x0EU ; // [224-239].x.x.x
+}
+
 bool GNet::Address4::isAny() const
 {
 	return m_inet.sin_addr.s_addr == htonl(INADDR_ANY) ;
diff --git a/src/gnet/gaddress4.h b/src/gnet/gaddress4.h
index 2a687db..0dc2c63 100644
--- a/src/gnet/gaddress4.h
+++ b/src/gnet/gaddress4.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -41,9 +41,8 @@ public:
 	explicit Address4( unsigned int ) ;
 	explicit Address4( const std::string & ) ;
 	Address4( const std::string & , const std::string & ) ;
-	Address4( const std::string & , unsigned int ) ;
 	Address4( unsigned int port , int /*loopback_overload*/ ) ; // canonical loopback address
-	Address4( const sockaddr * addr , socklen_t len , bool ipv6_scope_id_fixup = false ) ;
+	Address4( const sockaddr * addr , socklen_t len ) ;
 
 	static int domain() noexcept ;
 	static unsigned short af() noexcept ;
@@ -66,23 +65,26 @@ public:
 	bool isLocal( std::string & ) const ;
 	bool isLinkLocal() const ;
 	bool isUniqueLocal() const ;
+	bool isMulticast() const ;
 	bool isAny() const ;
 	unsigned int bits() const ;
 	std::string displayString( bool ipv6_with_scope = false ) const ;
-	std::string hostPartString( bool raw = false ) const ;
+	std::string hostPartString() const ;
 	std::string queryString() const ;
 	G::StringArray wildcards() const ;
-	static bool format( std::string ) ;
+	static bool format( G::string_view ) ;
 
 private:
 	explicit Address4( std::nullptr_t ) ;
-	static const char * setAddress( sockaddr_type & , const std::string & ) ;
-	static const char * setHostAddress( sockaddr_type & , const std::string & ) ;
+	static const char * setAddress( sockaddr_type & , G::string_view ) ;
+	static const char * setHostAddress( sockaddr_type & , G::string_view ) ;
 	static const char * setPort( sockaddr_type & , unsigned int ) ;
-	static const char * setPort( sockaddr_type & , const std::string & ) ;
+	static const char * setPort( sockaddr_type & , G::string_view ) ;
 	static bool sameAddr( const ::in_addr & a , const ::in_addr & b ) ;
-	static void add( G::StringArray & , const std::string & , unsigned int , const char * ) ;
-	static void add( G::StringArray & , const std::string & , const char * ) ;
+	static void add( G::StringArray & , G::string_view , unsigned int , const char * ) ;
+	static void add( G::StringArray & , unsigned int , const char * ) ;
+	static void add( G::StringArray & , G::string_view , const char * ) ;
+	static void add( G::StringArray & , const char * ) ;
 
 private:
 	sockaddr_type m_inet ;
diff --git a/src/gnet/gaddress6.cpp b/src/gnet/gaddress6.cpp
index 8fe65da..2034443 100644
--- a/src/gnet/gaddress6.cpp
+++ b/src/gnet/gaddress6.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -98,16 +98,6 @@ GNet::Address6::Address6( const sockaddr * addr , socklen_t len , bool ipv6_scop
 	}
 }
 
-GNet::Address6::Address6( const std::string & host_part , unsigned int port ) :
-	Address6(nullptr)
-{
-	const char * reason = setHostAddress( m_inet , host_part ) ;
-	if( !reason )
-		reason = setPort( m_inet , port ) ;
-	if( reason )
-		throw Address::BadString( std::string(reason) + ": " + host_part ) ;
-}
-
 GNet::Address6::Address6( const std::string & host_part , const std::string & port_part ) :
 	Address6(nullptr)
 {
@@ -227,7 +217,7 @@ std::string GNet::Address6::displayString( bool ipv6_with_scope_id ) const
 	return ss.str() ;
 }
 
-std::string GNet::Address6::hostPartString( bool /*raw*/ ) const
+std::string GNet::Address6::hostPartString() const
 {
 	std::array<char,INET6_ADDRSTRLEN+1U> buffer {} ;
 	const void * vp = & m_inet.sin6_addr ;
@@ -470,6 +460,11 @@ bool GNet::Address6::isLinkLocal() const
 	return sameAddr( _fe80 , addr_64 ) ;
 }
 
+bool GNet::Address6::isMulticast() const
+{
+	return false ; // TODO ipv6 multicast
+}
+
 bool GNet::Address6::isUniqueLocal() const
 {
 	// fc00::/7 (cf. 192.168.0.0/16 or 10.0.0.0/8)
diff --git a/src/gnet/gaddress6.h b/src/gnet/gaddress6.h
index 55ce89b..5e2abe1 100644
--- a/src/gnet/gaddress6.h
+++ b/src/gnet/gaddress6.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -41,7 +41,6 @@ public:
 	explicit Address6( unsigned int ) ;
 	explicit Address6( const std::string & ) ;
 	Address6( const std::string & , const std::string & ) ;
-	Address6( const std::string & , unsigned int ) ;
 	Address6( unsigned int port , int /*for overload resolution*/ ) ; // canonical loopback address
 	Address6( const sockaddr * addr , socklen_t len , bool ipv6_scope_id_fixup = false ) ;
 
@@ -66,10 +65,11 @@ public:
 	bool isLocal( std::string & ) const ;
 	bool isLinkLocal() const ;
 	bool isUniqueLocal() const ;
+	bool isMulticast() const ;
 	bool isAny() const ;
 	unsigned int bits() const ;
 	std::string displayString( bool ipv6_with_scope = false ) const ;
-	std::string hostPartString( bool raw = false ) const ;
+	std::string hostPartString() const ;
 	std::string queryString() const ;
 	G::StringArray wildcards() const ;
 
diff --git a/src/gnet/gaddresslocal.h b/src/gnet/gaddresslocal.h
index 9dcbcfa..7d5581a 100644
--- a/src/gnet/gaddresslocal.h
+++ b/src/gnet/gaddresslocal.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,7 +23,7 @@
 
 #include "gdef.h"
 #include "gaddress.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include <string>
 #if GCONFIG_HAVE_UDS
 #include <sys/types.h>
@@ -58,10 +58,8 @@ public:
 
 	explicit AddressLocal( unsigned int ) ;
 	explicit AddressLocal( const std::string & ) ;
-	AddressLocal( const std::string & , const std::string & ) ;
-	AddressLocal( const std::string & , unsigned int ) ;
 	AddressLocal( unsigned int port , int /*for overload resolution*/ ) ;
-	AddressLocal( const sockaddr * addr , socklen_t len , bool ipv6_scope_id_fixup = false ) ;
+	AddressLocal( const sockaddr * addr , socklen_t len ) ;
 
 	static int domain() noexcept ;
 	static unsigned short af() noexcept ;
@@ -84,10 +82,11 @@ public:
 	bool isLocal( std::string & ) const ;
 	bool isLinkLocal() const ;
 	bool isUniqueLocal() const ;
+	bool isMulticast() const ;
 	bool isAny() const ;
 	unsigned int bits() const ;
 	std::string displayString( bool ipv6_with_scope = false ) const ;
-	std::string hostPartString( bool raw = false ) const ;
+	std::string hostPartString() const ;
 	std::string queryString() const ;
 	G::StringArray wildcards() const ;
 	static bool format( const std::string & ) ;
diff --git a/src/gnet/gaddresslocal_none.cpp b/src/gnet/gaddresslocal_none.cpp
index 26115ca..74d7cb0 100644
--- a/src/gnet/gaddresslocal_none.cpp
+++ b/src/gnet/gaddresslocal_none.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -32,38 +32,30 @@ int GNet::AddressLocal::domain() noexcept
 }
 
 GNet::AddressLocal::AddressLocal( std::nullptr_t ) :
-	m_local{} ,
+	m_size(0U)
+{
+	// avoid clang 'unused field' warnings...
+	GDEF_IGNORE_VARIABLE( m_size ) ;
+	GDEF_IGNORE_VARIABLE( m_local ) ;
+}
+
+GNet::AddressLocal::AddressLocal( unsigned int /*port*/ ) :
 	m_size(0U)
 {
 }
 
-GNet::AddressLocal::AddressLocal( unsigned int /*port*/ ) :
-	AddressLocal(nullptr)
-{
-}
-
 GNet::AddressLocal::AddressLocal( unsigned int /*port*/ , int /*loopback_overload*/ ) :
-	AddressLocal(nullptr)
+	m_size(0U)
 {
 }
 
-GNet::AddressLocal::AddressLocal( const sockaddr * /*addr*/ , socklen_t /*len*/ , bool /*ipv6_scope_id_fixup*/ ) :
-	AddressLocal(nullptr)
+GNet::AddressLocal::AddressLocal( const sockaddr * /*addr*/ , socklen_t /*len*/ ) :
+	m_size(0U)
 {
 }
 
-GNet::AddressLocal::AddressLocal( const std::string & /*host_part*/ , unsigned int /*port*/ ) :
-	AddressLocal(nullptr)
-{
-}
-
-GNet::AddressLocal::AddressLocal( const std::string & /*host_part*/ , const std::string & /*port_part*/ ) :
-	AddressLocal(nullptr)
-{
-}
-
-GNet::AddressLocal::AddressLocal( const std::string & /*display_string*/ ) :
-	AddressLocal(nullptr)
+GNet::AddressLocal::AddressLocal( const std::string & /*host_part*/ ) :
+	m_size(0U)
 {
 }
 
@@ -90,7 +82,7 @@ std::string GNet::AddressLocal::displayString( bool /*ipv6_with_scope*/ ) const
 	return path() ;
 }
 
-std::string GNet::AddressLocal::hostPartString( bool /*raw*/ ) const
+std::string GNet::AddressLocal::hostPartString() const
 {
 	return displayString() ;
 }
@@ -188,6 +180,11 @@ bool GNet::AddressLocal::isUniqueLocal() const
 	return false ;
 }
 
+bool GNet::AddressLocal::isMulticast() const
+{
+	return false ;
+}
+
 bool GNet::AddressLocal::isAny() const
 {
 	return false ;
diff --git a/src/gnet/gaddresslocal_unix.cpp b/src/gnet/gaddresslocal_unix.cpp
index 9fe42aa..0b2fb1d 100644
--- a/src/gnet/gaddresslocal_unix.cpp
+++ b/src/gnet/gaddresslocal_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -33,24 +33,34 @@ namespace GNet
 	{
 		static constexpr std::size_t minsize()
 		{
+			#if GCONFIG_HAVE_UDS_LEN
+			return offsetof( sockaddr_un , sun_family ) + sizeof( sockaddr_un::sun_family ) ;
+			#else
 			return sizeof( sockaddr_un::sun_family ) ;
+			#endif
+		}
+		static void setsize( sockaddr_un & a ) noexcept
+		{
+			#if GCONFIG_HAVE_UDS_LEN
+			a.sun_len = SUN_LEN( &a ) ; // ie. poffset() + strlen(sun_path)
+			#else
+			GDEF_IGNORE_PARAM( a ) ;
+			#endif
 		}
 		static constexpr std::size_t psize()
 		{
 			return sizeof( sockaddr_un::sun_path ) ;
 		}
-		static std::size_t poffset() noexcept
+		static constexpr std::size_t poffset() noexcept
 		{
 			return offsetof( sockaddr_un , sun_path ) ;
 		}
-		std::string unescape( std::string path )
+		static std::size_t strnlen( const char * p , std::size_t limit ) noexcept
 		{
-			if( path.size() > 1U && path[0U] == '\\' && path[1U] == '0' )
-			{
-				path = path.substr( 1U ) ;
-				path[0] = '\0' ;
-			}
-			return path ;
+			std::size_t n = 0U ;
+			for( ; p && *p && n < limit ; ++p )
+				n++ ;
+			return n ;
 		}
 	}
 }
@@ -69,8 +79,10 @@ GNet::AddressLocal::AddressLocal( std::nullptr_t ) :
 	m_local{} ,
 	m_size(AddressLocalImp::minsize())
 {
+	namespace imp = AddressLocalImp ;
 	m_local.sun_family = af() ;
 	std::memset( m_local.sun_path , 0 , AddressLocalImp::psize() ) ;
+	imp::setsize( m_local ) ;
 }
 
 GNet::AddressLocal::AddressLocal( unsigned int /*port*/ ) :
@@ -83,37 +95,91 @@ GNet::AddressLocal::AddressLocal( unsigned int /*port*/ , int /*loopback_overloa
 {
 }
 
-GNet::AddressLocal::AddressLocal( const sockaddr * addr , socklen_t len , bool /*ipv6_scope_id_fixup*/ ) :
+GNet::AddressLocal::AddressLocal( const sockaddr * addr , socklen_t len ) :
 	AddressLocal(nullptr)
 {
+	namespace imp = AddressLocalImp ;
 	std::size_t size = static_cast<std::size_t>( len ) ;
 
-	if( addr == nullptr )
-		throw Address::Error() ;
-	if( addr->sa_family != af() || size > sizeof(sockaddr_type) )
+	if( addr == nullptr || size < imp::minsize() || size > sizeof(sockaddr_type) )
+		throw Address::Error( "invalid unix domain sockaddr" ) ;
+
+	if( addr->sa_family != af() )
 		throw Address::BadFamily() ;
 
-	m_local = *(reinterpret_cast<const sockaddr_type*>(addr)) ;
-	m_size = size ;
+	std::memcpy( &m_local , addr , size ) ;
+
+	if( size <= imp::poffset() )
+	{
+		// unnamed/unbound address
+		m_size = imp::minsize() ;
+	}
+	else if( G::is_linux() && m_local.sun_path[0] == '\0' )
+	{
+		// abstract address (linux)
+		m_size = size ;
+	}
+	else
+	{
+		// pathname address
+
+		// make sure that sun_path[] is terminated somewhere
+		if( size == sizeof(sockaddr_type) )
+		{
+			const char * p = &m_local.sun_path[0] ;
+			const char * end = p + imp::psize() ;
+			if( std::find( p , end , 0 ) == end )
+				throw Address::Error( "unix domain path too long" ) ;
+		}
+
+		// our additional constraints
+		if( !G::Str::isPrintable( std::string(&m_local.sun_path[0]) ) )
+			throw Address::BadString( "invalid unix domain socket path" ) ;
+
+		// the structure passed in might be sized to beyond the first
+		// NUL, so calculate our own size
+		m_size = imp::poffset() + std::strlen( &m_local.sun_path[0] ) + 1U ;
+		G_ASSERT( m_size <= size ) ;
+
+		imp::setsize( m_local ) ;
+	}
 }
 
-GNet::AddressLocal::AddressLocal( const std::string & host_part , unsigned int /*port*/ ) :
+GNet::AddressLocal::AddressLocal( const std::string & host_part ) :
 	AddressLocal(nullptr)
 {
-	if( host_part.size() >= AddressLocalImp::psize() )
-		throw Address::BadString( "local-domain address too long" ) ;
-	std::memcpy( m_local.sun_path , host_part.data() , host_part.size() ) ;
-	m_size = AddressLocalImp::poffset() + host_part.size() + 1U ; // include terminator
+	namespace imp = AddressLocalImp ;
+
+	if( host_part.empty() || host_part.at(0) != '/' )
+		throw Address::BadString() ;
+
+	if( host_part == "/" || !G::Str::isPrintable(host_part) )
+		throw Address::BadString() ;
+
+	if( host_part.size() >= imp::psize() )
+		throw Address::BadString( "unix domain address too long" ) ;
+
+	std::memcpy( &m_local.sun_path[0] , host_part.data() , host_part.size() ) ;
+	imp::setsize( m_local ) ;
+	m_size = imp::poffset() + host_part.size() + 1U ; // include terminator in m_size (see unix(7))
 }
 
-GNet::AddressLocal::AddressLocal( const std::string & host_part , const std::string & /*port_part*/ ) :
-	AddressLocal(host_part,0)
-{
-}
-
-GNet::AddressLocal::AddressLocal( const std::string & display_string ) :
-	AddressLocal(AddressLocalImp::unescape(display_string),0)
+std::string GNet::AddressLocal::path() const
 {
+	namespace imp = AddressLocalImp ;
+	if( m_size <= imp::poffset() )
+	{
+		return std::string( 1U , '/' ) ; // unbound address displayed as "/"
+	}
+	else if( G::is_linux() && m_local.sun_path[0] == '\0' )
+	{
+		return std::string( &m_local.sun_path[0] , m_size - imp::poffset() ) ;
+	}
+	else
+	{
+		std::string p = std::string( &m_local.sun_path[0] , imp::strnlen( &m_local.sun_path[0] , std::min(m_size-imp::poffset(),imp::psize()) ) ) ;
+		return p.empty() ? std::string(1U,'/') : p ;
+	}
 }
 
 void GNet::AddressLocal::setPort( unsigned int /*port*/ )
@@ -129,28 +195,14 @@ void GNet::AddressLocal::setScopeId( unsigned long /*ipv6_scope_id*/ )
 {
 }
 
-std::string GNet::AddressLocal::path() const
-{
-	namespace imp = AddressLocalImp ;
-	G_ASSERT( m_size >= imp::minsize() ) ;
-	if( m_size <= imp::poffset() )
-		return {} ;
-	else if( m_local.sun_path[0] == '\0' ) // if abstract
-		return { m_local.sun_path , std::min(m_size-imp::poffset(),imp::psize()) } ;
-	else
-		return { m_local.sun_path , std::min(std::strlen(m_local.sun_path),imp::psize()) } ;
-
-}
-
 std::string GNet::AddressLocal::displayString( bool /*ipv6_with_scope*/ ) const
 {
-	std::string p = path() ;
-	return p.empty() ? std::string(1U,'/') : G::Str::printable( p ) ;
+	return path() ;
 }
 
-std::string GNet::AddressLocal::hostPartString( bool raw ) const
+std::string GNet::AddressLocal::hostPartString() const
 {
-	return raw ? path() : G::Str::printable(path()) ;
+	return path() ;
 }
 
 std::string GNet::AddressLocal::queryString() const
@@ -170,8 +222,10 @@ bool GNet::AddressLocal::validString( const std::string & path , std::string * r
 		reason = "local-domain address too long" ;
 	if( path.empty() )
 		reason = "empty string" ;
-	if( path[0] != '\0' && path[0] != '/' )
+	if( path[0] != '/' )
 		reason = "not an absolute filesystem path" ;
+	if( !G::Str::isPrintable(path) )
+		reason = "invalid characters" ;
 	if( reason && reason_p )
 		*reason_p = std::string( reason ) ;
 	return reason == nullptr ;
@@ -257,6 +311,11 @@ bool GNet::AddressLocal::isUniqueLocal() const
 	return true ;
 }
 
+bool GNet::AddressLocal::isMulticast() const
+{
+	return false ;
+}
+
 bool GNet::AddressLocal::isAny() const
 {
 	return path().empty() ;
diff --git a/src/gnet/gclient.cpp b/src/gnet/gclient.cpp
index c758fef..59071fd 100644
--- a/src/gnet/gclient.cpp
+++ b/src/gnet/gclient.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -30,21 +30,15 @@
 #include "gassert.h"
 #include "gtest.h"
 #include "glog.h"
-#include <numeric> // std::accumulate
+#include <numeric>
 #include <sstream>
 #include <cstdlib>
 
 GNet::Client::Client( ExceptionSink es , const Location & remote , const Config & config ) :
 	m_es(es) ,
+	m_config(config) ,
 	m_line_buffer(config.line_buffer_config) ,
 	m_remote_location(remote) ,
-	m_bind_local_address(config.bind_local_address) ,
-	m_local_address(config.local_address) ,
-	m_sync_dns(config.sync_dns) ,
-	m_secure_connection_timeout(config.secure_connection_timeout) ,
-	m_connection_timeout(config.connection_timeout) ,
-	m_response_timeout(config.response_timeout) ,
-	m_idle_timeout(config.idle_timeout) ,
 	m_state(State::Idle) ,
 	m_finished(false) ,
 	m_has_connected(false) ,
@@ -55,7 +49,7 @@ GNet::Client::Client( ExceptionSink es , const Location & remote , const Config
 	m_idle_timer(*this,&GNet::Client::onIdleTimeout,es)
 {
 	G_DEBUG( "Client::ctor" ) ;
-	if( config.auto_start )
+	if( m_config.auto_start )
 		m_start_timer.startTimer( 0U ) ;
 	Monitor::addClient( *this ) ;
 }
@@ -127,8 +121,8 @@ void GNet::Client::connect()
 		throw ConnectError( "wrong state" ) ;
 
 	// (one timer covers dns resolution and socket connection)
-	if( m_connection_timeout )
-		m_connect_timer.startTimer( m_connection_timeout ) ;
+	if( m_config.connection_timeout )
+		m_connect_timer.startTimer( m_config.connection_timeout ) ;
 
 	m_remote_location.resolveTrivially() ; // if host:service is already address:port
 	if( m_remote_location.resolved() )
@@ -136,7 +130,7 @@ void GNet::Client::connect()
 		setState( State::Connecting ) ;
 		startConnecting() ;
 	}
-	else if( m_sync_dns || !Resolver::async() )
+	else if( m_config.sync_dns || !Resolver::async() )
 	{
 		std::string error = Resolver::resolve( m_remote_location ) ;
 		if( !error.empty() )
@@ -171,7 +165,7 @@ void GNet::Client::onResolved( std::string error , Location location )
 
 void GNet::Client::startConnecting()
 {
-	G_DEBUG( "GNet::Client::startConnecting: local: " << m_local_address.displayString() ) ;
+	G_DEBUG( "GNet::Client::startConnecting: local: " << m_config.local_address.displayString() ) ;
 	G_DEBUG( "GNet::Client::startConnecting: remote: " << m_remote_location.displayString() ) ;
 	if( G::Test::enabled("client-slow-connect") )
 		setState( State::Testing ) ;
@@ -179,25 +173,26 @@ void GNet::Client::startConnecting()
 	// create and open a socket
 	//
 	m_sp.reset() ;
-	m_socket = std::make_unique<StreamSocket>( m_remote_location.address().family() ) ;
+	m_socket = std::make_unique<StreamSocket>( m_remote_location.address().family() , m_config.stream_socket_config ) ;
 	socket().addWriteHandler( *this , m_es ) ;
+	socket().addOtherHandler( *this , m_es ) ;
 
 	// create a socket protocol object
 	//
 	EventHandler & eh = *this ;
 	SocketProtocolSink & sp_sink = *this ;
-	m_sp = std::make_unique<SocketProtocol>( eh , m_es , sp_sink , *m_socket , m_secure_connection_timeout ) ;
+	m_sp = std::make_unique<SocketProtocol>( eh , m_es , sp_sink , *m_socket , m_config.socket_protocol_config ) ;
 
 	// bind a local address to the socket (throws on failure)
 	//
-	if( m_bind_local_address )
-		bindLocalAddress( m_local_address ) ;
+	if( m_config.bind_local_address )
+		bindLocalAddress( m_config.local_address ) ;
 
 	// start connecting
 	//
 	bool immediate = false ;
 	if( !socket().connect( m_remote_location.address() , &immediate ) )
-		throw ConnectError( "cannot connect to " + m_remote_location.address().displayString() ) ;
+		throw ConnectError( "cannot connect to " + m_remote_location.address().displayString() + ": " + socket().reason() ) ;
 
 	// deal with immediate connection (typically if connecting locally)
 	//
@@ -212,15 +207,17 @@ void GNet::Client::startConnecting()
 	}
 }
 
-void GNet::Client::finish( bool with_socket_shutdown )
+void GNet::Client::finish()
 {
 	m_finished = true ;
-	if( with_socket_shutdown )
+	if( m_sp != nullptr )
 	{
-		if( m_sp != nullptr )
-			m_sp->shutdown() ;
-		else if( m_socket != nullptr )
-			m_socket->shutdown() ;
+		m_sp->shutdown() ;
+	}
+	else if( m_socket != nullptr )
+	{
+		m_socket->dropWriteHandler() ;
+		m_socket->shutdown() ;
 	}
 }
 
@@ -247,7 +244,7 @@ void GNet::Client::emit( const std::string & action )
 void GNet::Client::onConnectTimeout()
 {
 	std::ostringstream ss ;
-	ss << "cannot connect to " << m_remote_location << ": timed out out after " << m_connection_timeout << "s" ;
+	ss << "cannot connect to " << m_remote_location << ": timed out out after " << m_config.connection_timeout << "s" ;
 	G_DEBUG( "GNet::Client::onConnectTimeout: " << ss.str() ) ;
 	throw ConnectError( ss.str() ) ;
 }
@@ -255,7 +252,7 @@ void GNet::Client::onConnectTimeout()
 void GNet::Client::onResponseTimeout()
 {
 	std::ostringstream ss ;
-	ss << "no response after " << m_response_timeout << "s while connected to " << m_remote_location ;
+	ss << "no response after " << m_config.response_timeout << "s while connected to " << m_remote_location ;
 	G_DEBUG( "GNet::Client::onResponseTimeout: response timeout: " << ss.str() ) ;
 	throw ResponseTimeout( ss.str() ) ;
 }
@@ -263,7 +260,7 @@ void GNet::Client::onResponseTimeout()
 void GNet::Client::onIdleTimeout()
 {
 	std::ostringstream ss ;
-	ss << "no activity after " << m_idle_timeout << "s while connected to " << m_remote_location ;
+	ss << "no activity after " << m_config.idle_timeout << "s while connected to " << m_remote_location ;
 	throw IdleTimeout( ss.str() ) ;
 }
 
@@ -299,13 +296,11 @@ void GNet::Client::onWriteable()
 		m_socks = std::make_unique<Socks>( m_remote_location ) ;
 		if( m_socks->send( socket() ) )
 		{
-			socket().addOtherHandler( *this , m_es ) ;
 			socket().dropWriteHandler() ;
 			socket().addReadHandler( *this , m_es ) ; // wait for the socks response
 		}
 		else
 		{
-			socket().addOtherHandler( *this , m_es ) ;
 			socket().addWriteHandler( *this , m_es ) ;
 			socket().dropReadHandler() ;
 		}
@@ -314,7 +309,6 @@ void GNet::Client::onWriteable()
 	{
 		socket().dropWriteHandler() ;
 		socket().addReadHandler( *this , m_es ) ;
-		socket().addOtherHandler( *this , m_es ) ;
 
 		setState( State::Connected ) ;
 		doOnConnect() ;
@@ -353,14 +347,13 @@ void GNet::Client::doOnConnect()
 void GNet::Client::otherEvent( EventHandler::Reason reason )
 {
 	if( m_state == State::Socksing || m_sp == nullptr )
-		EventHandler::otherEvent( reason ) ; // default implementation
+		EventHandler::otherEvent( reason ) ; // default implementation throws
 	else
-		m_sp->otherEvent( reason ) ;
+		m_sp->otherEvent( reason , m_config.no_throw_on_peer_disconnect ) ;
 }
 
 void GNet::Client::readEvent()
 {
-	G_ASSERT( m_sp != nullptr ) ;
 	if( m_state == State::Socksing )
 	{
 		G_ASSERT( m_socks != nullptr ) ;
@@ -373,18 +366,19 @@ void GNet::Client::readEvent()
 	}
 	else
 	{
-		if( m_sp != nullptr )
-			m_sp->readEvent() ;
+		G_ASSERT( m_sp != nullptr ) ;
+		if( m_sp->readEvent( m_config.no_throw_on_peer_disconnect ) )
+			onSendComplete() ;
 	}
 }
 
 void GNet::Client::onData( const char * data , std::size_t size )
 {
-	if( m_response_timeout && m_line_buffer.transparent() ) // anything will do
+	if( m_config.response_timeout && m_line_buffer.transparent() ) // anything will do
 		m_response_timer.cancelTimer() ;
 
-	if( m_idle_timeout )
-		m_idle_timer.startTimer( m_idle_timeout ) ;
+	if( m_config.idle_timeout )
+		m_idle_timer.startTimer( m_config.idle_timeout ) ;
 
 	bool fragments = m_line_buffer.transparent() ;
 	m_line_buffer.apply( this , &Client::onDataImp , data , size , fragments ) ;
@@ -393,7 +387,7 @@ void GNet::Client::onData( const char * data , std::size_t size )
 bool GNet::Client::onDataImp( const char * data , std::size_t size , std::size_t eolsize ,
 	std::size_t linesize , char c0 )
 {
-	if( m_response_timeout && eolsize ) // end of a complete line
+	if( m_config.response_timeout && eolsize ) // end of a complete line
 		m_response_timer.cancelTimer() ;
 
 	return onReceive( data , size , eolsize , linesize , c0 ) ;
@@ -424,39 +418,35 @@ void GNet::Client::setState( State new_state )
 	if( new_state == State::Connected )
 		m_has_connected = true ;
 
-	if( new_state == State::Connected && m_idle_timeout )
-		m_idle_timer.startTimer( m_idle_timeout ) ;
+	if( new_state == State::Connected && m_config.idle_timeout )
+		m_idle_timer.startTimer( m_config.idle_timeout ) ;
 
 	m_state = new_state ;
 }
 
-std::pair<bool,GNet::Address> GNet::Client::localAddress() const
+GNet::Address GNet::Client::localAddress() const
 {
-	return
-		m_socket != nullptr ?
-			std::make_pair(true,socket().getLocalAddress()) :
-			std::make_pair(false,GNet::Address::defaultAddress()) ;
+	return socket().getLocalAddress() ;
 }
 
-std::pair<bool,GNet::Address> GNet::Client::peerAddress() const
+GNet::Address GNet::Client::peerAddress() const
 {
-	return
-		m_socket != nullptr ?
-			socket().getPeerAddress() :
-			std::make_pair(false,GNet::Address::defaultAddress()) ;
+	if( m_state != State::Connected )
+		throw NotConnected() ;
+
+	auto pair = socket().getPeerAddress() ;
+	if( !pair.first )
+		throw NotConnected() ;
+
+	return pair.second ;
 }
 
 std::string GNet::Client::connectionState() const
 {
-	std::pair<bool,Address> pair =
-		m_socket != nullptr ?
-			socket().getPeerAddress() :
-			std::make_pair(false,GNet::Address::defaultAddress()) ;
-
-	return
-		pair.first ?
-			pair.second.displayString() :
-			("("+m_remote_location.displayString()+")") ;
+	if( m_state == State::Connected )
+		return socket().getPeerAddress().second.displayString() ;
+	else
+		return "("+m_remote_location.displayString()+")" ;
 }
 
 std::string GNet::Client::peerCertificate() const
@@ -471,19 +461,26 @@ void GNet::Client::secureConnect()
 	m_sp->secureConnect() ;
 }
 
-bool GNet::Client::send( const std::string & data , std::size_t offset )
+bool GNet::Client::send( const std::string & data )
 {
-	if( m_response_timeout && data.size() > offset )
-		m_response_timer.startTimer( m_response_timeout ) ;
-	return m_sp->send( data , offset ) ;
+	if( m_config.response_timeout )
+		m_response_timer.startTimer( m_config.response_timeout ) ;
+	return m_sp->send( data , 0U ) ;
+}
+
+bool GNet::Client::send( G::string_view data )
+{
+	if( m_config.response_timeout )
+		m_response_timer.startTimer( m_config.response_timeout ) ;
+	return m_sp->send( data ) ;
 }
 
 bool GNet::Client::send( const std::vector<G::string_view> & data , std::size_t offset )
 {
-	std::size_t total_size = std::accumulate( data.begin() , data.end() , std::size_t(0U) ,
-		[](std::size_t n,G::string_view s){return n+s.size();} ) ;
-	if( m_response_timeout && offset < total_size )
-		m_response_timer.startTimer( m_response_timeout ) ;
+    std::size_t total_size = std::accumulate( data.begin() , data.end() , std::size_t(0) ,
+        [](std::size_t n,G::string_view s){return n+s.size();} ) ;
+	if( m_config.response_timeout && offset < total_size )
+		m_response_timer.startTimer( m_config.response_timeout ) ;
 	return m_sp->send( data , offset ) ;
 }
 
@@ -492,63 +489,16 @@ GNet::LineBufferState GNet::Client::lineBuffer() const
 	return m_line_buffer.state() ;
 }
 
+void GNet::Client::onPeerDisconnect()
+{
+}
+
 // ==
 
-namespace GNet
-{
-	namespace ClientImp
-	{
-		bool sync_default()
-		{
-			if( G::Test::enabled("client-dns-asynchronous") ) return false ;
-			if( G::Test::enabled("client-dns-synchronous") ) return true ;
-			return false ;
-		}
-	}
-}
-
-GNet::Client::Config::Config() :
-	local_address(Address::defaultAddress()) ,
-	line_buffer_config(LineBufferConfig::transparent()) ,
-	sync_dns(ClientImp::sync_default())
-{
-}
-
-GNet::Client::Config::Config( const LineBufferConfig & lbc ) :
-	local_address(Address::defaultAddress()) ,
-	line_buffer_config(lbc) ,
-	sync_dns(ClientImp::sync_default())
-{
-}
-
-GNet::Client::Config::Config( const LineBufferConfig & lbc , unsigned int connection_timeout_in ,
-	unsigned int secure_connection_timeout_in , unsigned int response_timeout_in ,
-	unsigned int idle_timeout_in ) :
-		local_address(Address::defaultAddress()) ,
-		line_buffer_config(lbc) ,
-		sync_dns(ClientImp::sync_default()) ,
-		connection_timeout(connection_timeout_in) ,
-		secure_connection_timeout(secure_connection_timeout_in) ,
-		response_timeout(response_timeout_in) ,
-		idle_timeout(idle_timeout_in)
-{
-}
-
-GNet::Client::Config::Config( const LineBufferConfig & lbc , unsigned int all_timeouts ) :
-	local_address(Address::defaultAddress()) ,
-	line_buffer_config(lbc) ,
-	sync_dns(ClientImp::sync_default()) ,
-	connection_timeout(all_timeouts) ,
-	secure_connection_timeout(all_timeouts) ,
-	response_timeout(all_timeouts) ,
-	idle_timeout(all_timeouts*2U)
-{
-}
-
 GNet::Client::Config & GNet::Client::Config::set_all_timeouts( unsigned int all_timeouts )
 {
+	socket_protocol_config.secure_connection_timeout = all_timeouts ;
 	connection_timeout = all_timeouts ;
-	secure_connection_timeout = all_timeouts ;
 	response_timeout = all_timeouts ;
 	idle_timeout = all_timeouts * 2U ;
 	return *this ;
diff --git a/src/gnet/gclient.h b/src/gnet/gclient.h
index c0bea58..4e0a02a 100644
--- a/src/gnet/gclient.h
+++ b/src/gnet/gclient.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -40,6 +40,7 @@
 #include "gslot.h"
 #include "gstr.h"
 #include <string>
+#include <memory>
 
 namespace GNet
 {
@@ -74,28 +75,29 @@ namespace GNet
 class GNet::Client : private EventHandler, public Connection, private SocketProtocolSink, private Resolver::Callback , public ExceptionSource
 {
 public:
-	G_EXCEPTION( DnsError , "dns error" ) ;
-	G_EXCEPTION( ConnectError , "connect failure" ) ;
-	G_EXCEPTION( NotConnected , "socket not connected" ) ;
-	G_EXCEPTION( ResponseTimeout , "response timeout" ) ;
-	G_EXCEPTION( IdleTimeout , "idle timeout" ) ;
+	G_EXCEPTION( DnsError , tx("dns error") ) ;
+	G_EXCEPTION( ConnectError , tx("connect failure") ) ;
+	G_EXCEPTION( NotConnected , tx("socket not connected") ) ;
+	G_EXCEPTION( ResponseTimeout , tx("response timeout") ) ;
+	G_EXCEPTION( IdleTimeout , tx("idle timeout") ) ;
 
 	struct Config /// A structure containing GNet::Client configuration parameters.
 	{
-		Config() ;
-		explicit Config( const LineBufferConfig & ) ;
-		Config( const LineBufferConfig & , unsigned int all_timeouts ) ;
-		Config( const LineBufferConfig & , unsigned int connection_timeout ,
-			unsigned int secure_connection_timeout , unsigned int response_timeout , unsigned int idle_timeout ) ;
-		Address local_address ;
-		LineBufferConfig line_buffer_config ;
-		bool sync_dns ;
-		bool auto_start{true} ;
-		bool bind_local_address{false} ;
-		unsigned int connection_timeout{0U} ;
-		unsigned int secure_connection_timeout{0U} ;
-		unsigned int response_timeout{0U} ;
-		unsigned int idle_timeout{0U} ;
+		StreamSocket::Config stream_socket_config ;
+		LineBufferConfig line_buffer_config {LineBufferConfig::transparent()} ;
+		SocketProtocol::Config socket_protocol_config ; // inc. secure_connection_timeout
+		Address local_address {Address::defaultAddress()} ;
+		bool sync_dns {false} ;
+		bool auto_start {true} ;
+		bool bind_local_address {false} ;
+		unsigned int connection_timeout {0U} ;
+		unsigned int response_timeout {0U} ;
+		unsigned int idle_timeout {0U} ;
+		bool no_throw_on_peer_disconnect {false} ; // see SocketProtocolSink::onPeerDisconnect()
+
+		Config & set_stream_socket_config( const StreamSocket::Config & ) ;
+		Config & set_line_buffer_config( const LineBufferConfig & ) ;
+		Config & set_socket_protocol_config( const SocketProtocol::Config & ) ;
 		Config & set_sync_dns( bool = true ) ;
 		Config & set_auto_start( bool = true ) ;
 		Config & set_bind_local_address( bool = true ) ;
@@ -105,6 +107,7 @@ public:
 		Config & set_response_timeout( unsigned int ) ;
 		Config & set_idle_timeout( unsigned int ) ;
 		Config & set_all_timeouts( unsigned int ) ;
+		Config & set_no_throw_on_peer_disconnect( bool = true ) ;
 	} ;
 
 	Client( ExceptionSink , const Location & remote_location , const Config & ) ;
@@ -131,14 +134,12 @@ public:
 		///< only calls to hasConnected(), finished() and the dtor
 		///< are allowed.
 
-	std::pair<bool,Address> localAddress() const override ;
-		///< Override from Connection. Returns the local
-		///< address. Pair.first is false on error.
+	Address localAddress() const override ;
+		///< Returns the local address.
 		///< Override from GNet::Connection.
 
-	std::pair<bool,Address> peerAddress() const override ;
-		///< Override from Connection. Returns the peer
-		///< address. Pair.first is false on error.
+	Address peerAddress() const override ;
+		///< Returns the peer address. Throws if not connected().
 		///< Override from GNet::Connection.
 
 	std::string connectionState() const override ;
@@ -153,13 +154,16 @@ public:
 		///< Returns a Location structure, including the result of
 		///< name lookup if available.
 
-	bool send( const std::string & data , std::size_t offset = 0 ) ;
+	bool send( const std::string & data ) ;
 		///< Sends data to the peer and starts the response
 		///< timer (if configured). Returns true if all sent.
 		///< Returns false if flow control was asserted, in which
 		///< case the unsent portion is copied internally and
 		///< onSendComplete() called when complete. Throws on error.
 
+	bool send( G::string_view data ) ;
+		///< Overload for string_view.
+
 	bool send( const std::vector<G::string_view> & data , std::size_t offset = 0 ) ;
 		///< Overload for scatter/gather segments.
 
@@ -170,11 +174,22 @@ public:
 		///< classes may inject the own events into this channel.
 
 	void doOnDelete( const std::string & reason , bool done ) ;
-		///< Called by ClientPtr (or equivalent) to call onDelete(),
-		///< just before this client object is deleted.
+		///< This should be called by the Client owner (typically
+		///< ClientPtr) just before this Client object is deleted.
+		///<
+		///< A Client onDelete() call only ever comes from
+		///< something external calling doOnDelete().
+		///<
+		///< The 'done' argument should be true if the current
+		///< exception is GNet::Done. The 'reason' string passed
+		///< to onDelete() will be the given 'reason' or the
+		///< empty string if 'done||finished()'.
+		///<
+		///< See also GNet::ExceptionHandler::onException(),
+		///< GNet::ServerPeer::onDelete().
 
 	bool finished() const ;
-		///< Returns true if finish()ed or disconnect()ed.
+		///< Returns true if finish() has been called.
 
 	LineBufferState lineBuffer() const ;
 		///< Returns information about the state of the internal
@@ -190,7 +205,7 @@ protected:
 	const StreamSocket & socket() const ;
 		///< Returns a const reference to the socket. Throws if not connected.
 
-	void finish( bool with_socket_shutdown ) ;
+	void finish() ;
 		///< Indicates that the last data has been sent and the client
 		///< is expecting a peer disconnect. Any subsequent onDelete()
 		///< callback from doOnDelete() will have an empty reason
@@ -224,7 +239,7 @@ protected:
 
 	void secureConnect() ;
 		///< Starts TLS/SSL client-side negotiation. Uses a profile
-		///< called "client"; see GSsl::Library::addProfile().
+		///< called "client" by default; see GSsl::Library::addProfile().
 		///< The callback GNet::SocketProtocolSink::onSecure() is
 		///< triggered when the secure session is established.
 
@@ -234,15 +249,28 @@ private: // overrides
 	void otherEvent( EventHandler::Reason ) override ; // Override from GNet::EventHandler.
 	void onResolved( std::string , Location ) override ; // Override from GNet::Resolver.
 	void onData( const char * , std::size_t ) override ; // Override from GNet::SocketProtocolSink.
+	void onPeerDisconnect() override ; // Override from GNet::SocketProtocolSink.
 
 public:
 	Client( const Client & ) = delete ;
 	Client( Client && ) = delete ;
-	void operator=( const Client & ) = delete ;
-	void operator=( Client && ) = delete ;
+	Client & operator=( const Client & ) = delete ;
+	Client & operator=( Client && ) = delete ;
+	bool send( const char * , std::size_t ) = delete ;
+	bool send( const char * ) = delete ;
+	bool send( const std::string & , std::size_t ) = delete ;
 
 private:
-	enum class State { Idle , Resolving , Connecting , Connected , Socksing , Disconnected , Testing } ;
+	enum class State
+	{
+		Idle ,
+		Resolving ,
+		Connecting ,
+		Connected ,
+		Socksing ,
+		Disconnected ,
+		Testing
+	} ;
 	bool onDataImp( const char * , std::size_t , std::size_t , std::size_t , char ) ;
 	void emit( const std::string & ) ;
 	void startConnecting() ;
@@ -258,6 +286,7 @@ private:
 
 private:
 	ExceptionSink m_es ;
+	const Config m_config ;
 	G::CallStack m_call_stack ;
 	std::unique_ptr<StreamSocket> m_socket ;
 	std::unique_ptr<SocketProtocol> m_sp ;
@@ -265,13 +294,6 @@ private:
 	LineBuffer m_line_buffer ;
 	std::unique_ptr<Resolver> m_resolver ;
 	Location m_remote_location ;
-	bool m_bind_local_address ;
-	Address m_local_address ;
-	bool m_sync_dns ;
-	unsigned int m_secure_connection_timeout ;
-	unsigned int m_connection_timeout ;
-	unsigned int m_response_timeout ;
-	unsigned int m_idle_timeout ;
 	State m_state ;
 	bool m_finished ;
 	bool m_has_connected ;
@@ -283,13 +305,17 @@ private:
 	G::Slot::Signal<const std::string&,const std::string&,const std::string&> m_event_signal ;
 } ;
 
+inline GNet::Client::Config & GNet::Client::Config::set_stream_socket_config( const StreamSocket::Config & cfg ) { stream_socket_config = cfg ; return *this ; }
+inline GNet::Client::Config & GNet::Client::Config::set_line_buffer_config( const LineBufferConfig & cfg ) { line_buffer_config = cfg ; return *this ; }
+inline GNet::Client::Config & GNet::Client::Config::set_socket_protocol_config( const SocketProtocol::Config & cfg ) { socket_protocol_config = cfg ; return *this ; }
 inline GNet::Client::Config & GNet::Client::Config::set_sync_dns( bool b ) { sync_dns = b ; return *this ; }
 inline GNet::Client::Config & GNet::Client::Config::set_auto_start( bool b ) { auto_start = b ; return *this ; }
 inline GNet::Client::Config & GNet::Client::Config::set_bind_local_address( bool b ) { bind_local_address = b ; return *this ; }
 inline GNet::Client::Config & GNet::Client::Config::set_local_address( const Address & a ) { local_address = a ; return *this ; }
 inline GNet::Client::Config & GNet::Client::Config::set_connection_timeout( unsigned int t ) { connection_timeout = t ; return *this ; }
-inline GNet::Client::Config & GNet::Client::Config::set_secure_connection_timeout( unsigned int t ) { secure_connection_timeout = t ; return *this ; }
+inline GNet::Client::Config & GNet::Client::Config::set_secure_connection_timeout( unsigned int t ) { socket_protocol_config.secure_connection_timeout = t ; return *this ; }
 inline GNet::Client::Config & GNet::Client::Config::set_response_timeout( unsigned int t ) { response_timeout = t ; return *this ; }
 inline GNet::Client::Config & GNet::Client::Config::set_idle_timeout( unsigned int t ) { idle_timeout = t ; return *this ; }
+inline GNet::Client::Config & GNet::Client::Config::set_no_throw_on_peer_disconnect( bool b ) { no_throw_on_peer_disconnect = b ; return *this ; }
 
 #endif
diff --git a/src/gnet/gclientptr.cpp b/src/gnet/gclientptr.cpp
index 531b7bb..603db88 100644
--- a/src/gnet/gclientptr.cpp
+++ b/src/gnet/gclientptr.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gnet/gclientptr.h b/src/gnet/gclientptr.h
index d2178cc..313f0f2 100644
--- a/src/gnet/gclientptr.h
+++ b/src/gnet/gclientptr.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -37,7 +37,7 @@ namespace GNet
 }
 
 //| \class GNet::ClientPtrBase
-/// The non-template part of GNet::ClientPtr. It is an ExcptionHandler
+/// The non-template part of GNet::ClientPtr. It is an ExceptionHandler
 /// so that exceptions thrown by the Client out to the event loop can
 /// be delivered back to reset the ClientPtr with the expected Client
 /// onDelete() semantics (like GNet::ServerPeer).
@@ -75,8 +75,8 @@ public:
 	~ClientPtrBase() override = default ;
 	ClientPtrBase( const ClientPtrBase & ) = delete ;
 	ClientPtrBase( ClientPtrBase && ) = delete ;
-	void operator=( const ClientPtrBase & ) = delete ;
-	void operator=( ClientPtrBase && ) = delete ;
+	ClientPtrBase & operator=( const ClientPtrBase & ) = delete ;
+	ClientPtrBase & operator=( ClientPtrBase && ) = delete ;
 
 private:
 	void eventSlot( const std::string & , const std::string & , const std::string & ) ;
@@ -128,13 +128,14 @@ private:
 ///
 /// Note that the ClientPtr exception handler ignores the ExceptionSource
 /// pointer, so it can be set to be the same as the higher-level object,
-/// for better event logging (as shown above).
+/// for better event logging (as shown above) (see
+/// GNet::ExceptionSource::exceptionSourceId()).
 ///
 template <typename T>
 class GNet::ClientPtr : public ClientPtrBase
 {
 public:
-	G_EXCEPTION( InvalidState , "invalid state of network client holder" ) ;
+	G_EXCEPTION( InvalidState , tx("invalid state of network client holder") ) ;
 
 	explicit ClientPtr( T * p = nullptr ) ;
 		///< Constructor. Takes ownership of the new-ed client.
@@ -145,11 +146,11 @@ public:
 	bool busy() const ;
 		///< Returns true if the pointer is not nullptr.
 
-	void reset( T * p ) noexcept ;
+	void reset( T * p ) ;
 		///< Resets the pointer. There is no call to onDelete()
 		///< and no emitted signals.
 
-	void reset( std::unique_ptr<T> p ) noexcept ;
+	void reset( std::unique_ptr<T> p ) ;
 		///< Resets the pointer. There is no call to onDelete()
 		///< and no emitted signals.
 
@@ -177,8 +178,8 @@ private: // overrides
 public:
 	ClientPtr( const ClientPtr & ) = delete ;
 	ClientPtr( ClientPtr && ) = delete ;
-	void operator=( const ClientPtr & ) = delete ;
-	void operator=( ClientPtr && ) = delete ;
+	ClientPtr & operator=( const ClientPtr & ) = delete ;
+	ClientPtr & operator=( ClientPtr && ) = delete ;
 
 private:
 	T * set( T * ) ;
@@ -198,10 +199,13 @@ GNet::ClientPtr<T>::ClientPtr( T * p ) :
 		connectSignals( *m_p ) ;
 }
 
-template <typename T>
-GNet::ClientPtr<T>::~ClientPtr()
+namespace GNet
 {
-	delete release() ;
+	template <typename T>
+	ClientPtr<T>::~ClientPtr()
+	{
+		delete release() ;
+	}
 }
 
 template <typename T>
@@ -261,13 +265,13 @@ T * GNet::ClientPtr<T>::release() noexcept
 }
 
 template <typename T>
-void GNet::ClientPtr<T>::reset( T * p ) noexcept
+void GNet::ClientPtr<T>::reset( T * p )
 {
 	delete set( p ) ;
 }
 
 template <typename T>
-void GNet::ClientPtr<T>::reset( std::unique_ptr<T> p ) noexcept
+void GNet::ClientPtr<T>::reset( std::unique_ptr<T> p )
 {
 	delete set( p.release() ) ;
 }
diff --git a/src/gnet/gconnection.cpp b/src/gnet/gconnection.cpp
index 42035b3..5557145 100644
--- a/src/gnet/gconnection.cpp
+++ b/src/gnet/gconnection.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gnet/gconnection.h b/src/gnet/gconnection.h
index c73201d..b961887 100644
--- a/src/gnet/gconnection.h
+++ b/src/gnet/gconnection.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -30,7 +30,7 @@ namespace GNet
 }
 
 //| \class GNet::Connection
-/// An abstract interface which provides address information for a network
+/// An abstract interface which provides information about a network
 /// connection.
 /// \see GNet::Client, GNet::ServerPeer
 ///
@@ -40,18 +40,17 @@ public:
 	virtual ~Connection() = default ;
 		///< Destructor.
 
-	virtual std::pair<bool,Address> localAddress() const = 0 ;
+	virtual Address localAddress() const = 0 ;
 		///< Returns the connection's local address.
-		///< Pair.first is false if none.
 
-	virtual std::pair<bool,Address> peerAddress() const = 0 ;
+	virtual Address peerAddress() const = 0 ;
 		///< Returns the connection's peer address.
-		///< Pair.first is false if none.
+		///< Throws if a client connection that has not yet connected.
 
 	virtual std::string connectionState() const = 0 ;
 		///< Returns the connection state as a display string.
-		///< This should normally return the peerAddress() string
-		///< when the connection is fully established.
+		///< This should be the peerAddress() display string, unless
+		///< a client connection that has not yet connected.
 
 	virtual std::string peerCertificate() const = 0 ;
 		///< Returns the peer's TLS certificate. Returns the
diff --git a/src/gnet/gdescriptor.h b/src/gnet/gdescriptor.h
index f7ac97e..3b63745 100644
--- a/src/gnet/gdescriptor.h
+++ b/src/gnet/gdescriptor.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gnet/gdescriptor_unix.cpp b/src/gnet/gdescriptor_unix.cpp
index 5eeec63..f2f8b0e 100644
--- a/src/gnet/gdescriptor_unix.cpp
+++ b/src/gnet/gdescriptor_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gnet/gdescriptor_win32.cpp b/src/gnet/gdescriptor_win32.cpp
index b40c4c2..43decc4 100644
--- a/src/gnet/gdescriptor_win32.cpp
+++ b/src/gnet/gdescriptor_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gnet/gdnsbl.h b/src/gnet/gdnsbl.h
new file mode 100644
index 0000000..b96738f
--- /dev/null
+++ b/src/gnet/gdnsbl.h
@@ -0,0 +1,69 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file gdnsbl.h
+///
+
+#ifndef G_NET_DNSBL_H
+#define G_NET_DNSBL_H
+
+#include "gdef.h"
+#include "gexceptionsink.h"
+#include "gaddress.h"
+#include "gstringview.h"
+#include <functional>
+
+namespace GNet
+{
+	class Dnsbl ;
+	class DnsblImp ;
+}
+
+//| \class GNet::Dnsbl
+/// A minimal bridge to GNet::DnsBlock
+///
+class GNet::Dnsbl
+{
+public:
+	Dnsbl( std::function<void(bool)> callback , ExceptionSink , G::string_view config = {} ) ;
+		///< Constructor. See DnsBlock::DnsBlock().
+
+	~Dnsbl() ;
+		///< Destructor.
+
+	void start( const Address & ) ;
+		///< Starts an asychronous check on the given address. The result
+		///< is delivered via the callback function passed to the ctor.
+
+	bool busy() const ;
+		///< Returns true after start() and before the completion callback.
+
+	static void checkConfig( const std::string & ) ;
+		///< See DnsBlock::checkConfig().
+
+public:
+	Dnsbl( const Dnsbl & ) = delete ;
+	Dnsbl( Dnsbl && ) = delete ;
+	Dnsbl & operator=( const Dnsbl & ) = delete ;
+	Dnsbl & operator=( Dnsbl && ) = delete ;
+
+private:
+	std::function<void(bool)> m_callback ; // see gdnsbl_disabled.cpp
+	std::unique_ptr<DnsblImp> m_imp ;
+} ;
+
+#endif
diff --git a/src/gnet/gdnsbl_disabled.cpp b/src/gnet/gdnsbl_disabled.cpp
new file mode 100644
index 0000000..5e3a75f
--- /dev/null
+++ b/src/gnet/gdnsbl_disabled.cpp
@@ -0,0 +1,51 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file gdnsbl_disabled.cpp
+///
+
+#include "gdef.h"
+#include "gdnsbl.h"
+#include "gexception.h"
+
+class GNet::DnsblImp
+{
+} ;
+
+GNet::Dnsbl::Dnsbl( std::function<void(bool)> callback , ExceptionSink , G::string_view ) :
+	m_callback(callback)
+{
+}
+
+GNet::Dnsbl::~Dnsbl()
+= default ;
+
+void GNet::Dnsbl::start( const Address & )
+{
+	m_callback( /*allow=*/true ) ;
+}
+
+bool GNet::Dnsbl::busy() const
+{
+	return false ;
+}
+
+void GNet::Dnsbl::checkConfig( const std::string & config )
+{
+	if( !config.empty() )
+		throw G::Exception( "dnsbl has been disabled in this build" ) ;
+}
diff --git a/src/gnet/gdnsbl_enabled.cpp b/src/gnet/gdnsbl_enabled.cpp
new file mode 100644
index 0000000..9265ac4
--- /dev/null
+++ b/src/gnet/gdnsbl_enabled.cpp
@@ -0,0 +1,66 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file gdnsbl_enabled.cpp
+///
+
+#include "gdef.h"
+#include "gdnsbl.h"
+#include "gdnsblock.h"
+#include <utility>
+
+class GNet::DnsblImp : private DnsBlockCallback
+{
+public:
+	DnsblImp( std::function<void(bool)> callback , ExceptionSink es , G::string_view config ) :
+		m_callback(std::move(callback)) ,
+		m_block(*this,es,config)
+	{
+	}
+	void onDnsBlockResult( const DnsBlockResult & result ) override
+	{
+		result.log() ;
+		result.warn() ;
+		m_callback( result.allow() ) ;
+	}
+	std::function<void(bool)> m_callback ;
+	DnsBlock m_block ;
+} ;
+
+GNet::Dnsbl::Dnsbl( std::function<void(bool)> callback , ExceptionSink es , G::string_view config ) :
+	m_imp(std::make_unique<DnsblImp>(callback,es,config))
+{
+}
+
+GNet::Dnsbl::~Dnsbl()
+= default ;
+
+void GNet::Dnsbl::start( const Address & address )
+{
+	m_imp->m_block.start( address ) ;
+}
+
+bool GNet::Dnsbl::busy() const
+{
+	return m_imp->m_block.busy() ;
+}
+
+void GNet::Dnsbl::checkConfig( const std::string & config )
+{
+	DnsBlock::checkConfig( config ) ;
+}
+
diff --git a/src/gnet/gdnsblock.cpp b/src/gnet/gdnsblock.cpp
index e6ac314..322d23c 100644
--- a/src/gnet/gdnsblock.cpp
+++ b/src/gnet/gdnsblock.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -84,7 +84,7 @@ namespace GNet
 	}
 }
 
-GNet::DnsBlock::DnsBlock( DnsBlockCallback & callback , ExceptionSink es , const std::string & config ) :
+GNet::DnsBlock::DnsBlock( DnsBlockCallback & callback , ExceptionSink es , G::string_view config ) :
 	m_callback(callback) ,
 	m_es(es) ,
 	m_timer(*this,&DnsBlock::onTimeout,es) ,
@@ -106,20 +106,20 @@ void GNet::DnsBlock::checkConfig( const std::string & config )
 	}
 	catch( std::exception & e )
 	{
-		throw Error( "invalid dnsbl configuration string" , e.what() ) ;
+		throw ConfigError( e.what() ) ;
 	}
 }
 
-void GNet::DnsBlock::configure( const std::string & config )
+void GNet::DnsBlock::configure( G::string_view config )
 {
 	configureImp( config , this ) ;
 }
 
-void GNet::DnsBlock::configureImp( const std::string & config , DnsBlock * p )
+void GNet::DnsBlock::configureImp( G::string_view config , DnsBlock * p )
 {
-	G::StringArray list = G::Str::splitIntoFields( config , "," ) ;
+	G::StringArray list = G::Str::splitIntoFields( config , ',' ) ;
 	if( list.size() < 4U )
-		throw std::runtime_error( "not enough comma-sparated fields" ) ;
+		throw BadFieldCount() ;
 
 	Address dns_server = Address::parse( list.at(0U) , Address::NotLocal() ) ;
 
@@ -167,7 +167,9 @@ void GNet::DnsBlock::start( const Address & address )
 		id_generator = 10 ;
 
 	// create a socket to receive responses
-	m_socket_ptr = std::make_unique<DatagramSocket>( m_dns_server.family() ) ;
+	int protocol = 0 ;
+	DatagramSocket::Config datagram_socket_config ;
+	m_socket_ptr = std::make_unique<DatagramSocket>( m_dns_server.family() , protocol , datagram_socket_config ) ;
 	m_socket_ptr->addReadHandler( *this , m_es ) ;
 
 	// send a DNS query to each configured server
@@ -187,7 +189,7 @@ void GNet::DnsBlock::start( const Address & address )
 
 		ssize_t rc = m_socket_ptr->writeto( message.p() , message.n() , m_dns_server ) ;
 		if( rc < 0 || static_cast<std::size_t>(rc) != message.n() )
-			throw Error( "socket send failed" , m_socket_ptr->reason() ) ;
+			throw SendError( m_socket_ptr->reason() ) ;
 	}
 	m_timer.startTimer( m_timeout ) ;
 }
@@ -203,7 +205,7 @@ void GNet::DnsBlock::readEvent()
 	buffer.resize( 4096U ) ; // 512 in RFC-1035 4.2.1
 	ssize_t rc = m_socket_ptr->read( &buffer[0] , buffer.size() ) ;
 	if( rc <= 0 || static_cast<std::size_t>(rc) >= buffer.size() )
-		throw Error( "invalid dns response size" ) ;
+		throw BadDnsResponse() ;
 	buffer.resize( static_cast<std::size_t>(rc) ) ;
 
 	DnsMessage message( buffer ) ;
@@ -219,9 +221,11 @@ void GNet::DnsBlock::readEvent()
 
 	std::size_t server_count = m_result.list().size() ;
 	std::size_t responder_count = countResponders( m_result.list() ) ;
-	std::size_t laggard_count = server_count - responder_count ; G_ASSERT( laggard_count < server_count ) ;
+	std::size_t laggard_count = server_count - responder_count ;
 	std::size_t deny_count = countDeniers( m_result.list() ) ;
 
+	G_ASSERT( laggard_count < server_count ) ;
+
 	G_DEBUG( "GNet::DnsBlock::readEvent: id=" << message.ID() << " rcode=" << message.RCODE()
 		<< (message.ANCOUNT()?" deny ":" allow ")
 		<< "got=" << responder_count << "/" << server_count << " deny-count=" << deny_count << "/" << m_threshold ) ;
diff --git a/src/gnet/gdnsblock.h b/src/gnet/gdnsblock.h
index a3be013..f8d3a4f 100644
--- a/src/gnet/gdnsblock.h
+++ b/src/gnet/gdnsblock.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -27,9 +27,10 @@
 #include "geventhandler.h"
 #include "gexceptionsink.h"
 #include "gexception.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gtimer.h"
 #include "gsocket.h"
+#include <memory>
 #include <vector>
 
 namespace GNet
@@ -144,10 +145,14 @@ private:
 class GNet::DnsBlock : private EventHandler
 {
 public:
-	G_EXCEPTION( Error , "dnsbl error" ) ;
+	G_EXCEPTION( Error , tx("dnsbl error") ) ;
+	G_EXCEPTION( ConfigError , tx("invalid dnsbl configuration") ) ;
+	G_EXCEPTION( BadFieldCount , tx("not enough comma-sparated fields") ) ;
+	G_EXCEPTION( SendError , tx("socket send failed") ) ;
+	G_EXCEPTION( BadDnsResponse , tx("invalid dns response") ) ;
 	using ResultList = std::vector<DnsBlockServerResult> ;
 
-	DnsBlock( DnsBlockCallback & , ExceptionSink , const std::string & config = std::string() ) ;
+	DnsBlock( DnsBlockCallback & , ExceptionSink , G::string_view config = {} ) ;
 		///< Constructor. Use configure() if necessary and then start(),
 		///< one time only.
 
@@ -155,7 +160,7 @@ public:
 		G::TimeInterval timeout , const G::StringArray & servers ) ;
 			///< Configures the object after construction.
 
-	void configure( const std::string & ) ;
+	void configure( G::string_view ) ;
 		///< Configuration overload taking a configuration string containing
 		///< comma-separated fields of: dns-server-address, timeout-ms,
 		///< threshold, dnsbl-server-list.
@@ -174,14 +179,14 @@ public:
 	~DnsBlock() override = default ;
 	DnsBlock( const DnsBlock & ) = delete ;
 	DnsBlock( DnsBlock && ) = delete ;
-	void operator=( const DnsBlock & ) = delete ;
-	void operator=( DnsBlock && ) = delete ;
+	DnsBlock & operator=( const DnsBlock & ) = delete ;
+	DnsBlock & operator=( DnsBlock && ) = delete ;
 
 private: // overrides
 	void readEvent() override ; // Override from GNet::EventHandler.
 
 private:
-	static void configureImp( const std::string & , DnsBlock * ) ;
+	static void configureImp( G::string_view , DnsBlock * ) ;
 	void onTimeout() ;
 	static std::string queryString( const Address & ) ;
 	static std::size_t countResponders( const ResultList & ) ;
@@ -208,7 +213,7 @@ class GNet::DnsBlockCallback
 {
 public:
 	virtual ~DnsBlockCallback() = default ;
-		///< Desstructor.
+		///< Destructor.
 
 	virtual void onDnsBlockResult( const DnsBlockResult & ) = 0 ;
 		///< Called with the results from DnsBlock::start().
diff --git a/src/gnet/gdnsmessage.cpp b/src/gnet/gdnsmessage.cpp
index 4d1979d..a7c7224 100644
--- a/src/gnet/gdnsmessage.cpp
+++ b/src/gnet/gdnsmessage.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,6 +23,7 @@
 #include "gassert.h"
 #include "gstr.h"
 #include "gstringview.h"
+#include "gstringfield.h"
 #include <array>
 #include <vector>
 #include <iomanip>
@@ -49,20 +50,20 @@ GNet::DnsMessageRequest::DnsMessageRequest( const std::string & type , const std
 
 void GNet::DnsMessageRequest::q( const std::string & domain , char sep )
 {
-	G::StringArray parts ;
-	G::Str::splitIntoFields( domain , parts , {&sep,1U} ) ;
-	for( const auto & part : parts )
+	G::string_view domain_sv( domain ) ;
+	for( G::StringFieldView part( domain_sv , sep ) ; part ; ++part )
 	{
-		q( part ) ;
+		q( part() ) ;
 	}
-	q( std::string() ) ;
+	q( G::string_view() ) ;
 }
 
-void GNet::DnsMessageRequest::q( const std::string & data )
+void GNet::DnsMessageRequest::q( G::string_view data )
 {
 	if( data.size() > 63U ) throw DnsMessage::Error("overflow") ;
 	q( static_cast<unsigned int>(data.size()) ) ;
-	m_data.append( data ) ;
+	if( !data.empty() )
+		m_data.append( data.data() , data.size() ) ;
 }
 
 void GNet::DnsMessageRequest::q( int n )
@@ -102,12 +103,12 @@ GNet::DnsMessage::DnsMessage( const char * p , std::size_t n ) :
 {
 }
 
-const char * GNet::DnsMessage::p() const
+const char * GNet::DnsMessage::p() const noexcept
 {
 	return &m_buffer[0] ;
 }
 
-std::size_t GNet::DnsMessage::n() const
+std::size_t GNet::DnsMessage::n() const noexcept
 {
 	return m_buffer.size() ;
 }
@@ -299,7 +300,7 @@ unsigned int GNet::DnsMessageNameParser::size( const DnsMessage & msg , unsigned
 		if( ( n & 0xC0 ) == 0xC0 ) // compression -- see RFC-1035 4.1.4
 			return offset - offset_in + 2U ;
 		else if( ( n & 0xC0 ) != 0 )
-			throw GNet::DnsMessage::Error( "unknown label type" ) ; // "reserved for future use"
+			throw DnsMessage::Error( "unknown label type" ) ; // "reserved for future use"
 		else if( n == 0U )
 			break ;
 		else
@@ -311,7 +312,7 @@ unsigned int GNet::DnsMessageNameParser::size( const DnsMessage & msg , unsigned
 std::string GNet::DnsMessageNameParser::read( const DnsMessage & msg , unsigned int offset_in )
 {
 	unsigned int offset = offset_in ;
-	std::vector<std::string> name ;
+	std::string result ;
 	for(;;)
 	{
 		unsigned int n = msg.byte( offset ) ;
@@ -322,7 +323,7 @@ std::string GNet::DnsMessageNameParser::read( const DnsMessage & msg , unsigned
 		}
 		else if( ( n & 0xC0 ) != 0 )
 		{
-			throw GNet::DnsMessage::Error( "unknown label type" ) ; // "reserved for future use"
+			throw DnsMessage::Error( "unknown label type" ) ; // "reserved for future use"
 		}
 		else if( n == 0U )
 		{
@@ -331,13 +332,14 @@ std::string GNet::DnsMessageNameParser::read( const DnsMessage & msg , unsigned
 		else
 		{
 			if( n > 63U )
-				throw GNet::DnsMessage::Error( "name overflow" ) ;
+				throw DnsMessage::Error( "name overflow" ) ;
 
-			name.push_back( msg.span(offset+1U,offset+n+1U) ) ;
+			result.append( result.empty()?0U:1U , '.' ) ;
+			result.append( msg.span(offset+1U,offset+n+1U) ) ;
 			offset += (n+1U) ;
 		}
 	}
-	return G::Str::join( "." , name ) ;
+	return result ;
 }
 
 // ==
@@ -371,9 +373,9 @@ unsigned int GNet::DnsMessageRR::type() const
 	return m_type ;
 }
 
-bool GNet::DnsMessageRR::isa( const std::string & type_name ) const
+bool GNet::DnsMessageRR::isa( G::string_view type_name ) const noexcept
 {
-	return m_type == DnsMessageRecordType::value(type_name) ;
+	return m_type == DnsMessageRecordType::value( type_name , std::nothrow ) ;
 }
 
 unsigned int GNet::DnsMessageRR::size() const
@@ -386,44 +388,44 @@ std::string GNet::DnsMessageRR::name() const
 	return m_name ;
 }
 
-std::string GNet::DnsMessageRR::rdata_dname( unsigned int rdata_offset ) const
+std::string GNet::DnsMessageRR::rdataDname( unsigned int rdata_offset ) const
 {
 	return DnsMessageNameParser::read( m_msg , m_rdata_offset + rdata_offset ) ;
 }
 
-std::string GNet::DnsMessageRR::rdata_dname( unsigned int * rdata_offset_p ) const
+std::string GNet::DnsMessageRR::rdataDname( unsigned int * rdata_offset_p ) const
 {
 	std::string dname = DnsMessageNameParser::read( m_msg , m_rdata_offset + *rdata_offset_p ) ;
 	*rdata_offset_p += DnsMessageNameParser::size( m_msg , m_rdata_offset + *rdata_offset_p ) ;
 	return dname ;
 }
 
-std::string GNet::DnsMessageRR::rdata_span( unsigned int rdata_begin ) const
+std::string GNet::DnsMessageRR::rdataSpan( unsigned int rdata_begin ) const
 {
-	return rdata_span( rdata_begin , rdata_size() ) ;
+	return rdataSpan( rdata_begin , rdataSize() ) ;
 }
 
-std::string GNet::DnsMessageRR::rdata_span( unsigned int rdata_begin , unsigned int rdata_end ) const
+std::string GNet::DnsMessageRR::rdataSpan( unsigned int rdata_begin , unsigned int rdata_end ) const
 {
 	return m_msg.span( m_rdata_offset + rdata_begin , m_rdata_offset + rdata_end ) ;
 }
 
-unsigned int GNet::DnsMessageRR::rdata_offset() const
+unsigned int GNet::DnsMessageRR::rdataOffset() const
 {
 	return m_rdata_offset ;
 }
 
-unsigned int GNet::DnsMessageRR::rdata_size() const
+unsigned int GNet::DnsMessageRR::rdataSize() const
 {
 	return m_rdata_size ;
 }
 
-unsigned int GNet::DnsMessageRR::rdata_byte( unsigned int i ) const
+unsigned int GNet::DnsMessageRR::rdataByte( unsigned int i ) const
 {
 	return m_msg.byte( m_rdata_offset + i ) ;
 }
 
-unsigned int GNet::DnsMessageRR::rdata_word( unsigned int i ) const
+unsigned int GNet::DnsMessageRR::rdataWord( unsigned int i ) const
 {
 	return m_msg.word( m_rdata_offset + i ) ;
 }
@@ -431,15 +433,15 @@ unsigned int GNet::DnsMessageRR::rdata_word( unsigned int i ) const
 GNet::Address GNet::DnsMessageRR::address() const
 {
 	std::ostringstream ss ;
-	if( isa("A") && rdata_size() == 4U )
+	if( isa("A") && rdataSize() == 4U )
 	{
-		ss << rdata_byte(0U) << "." << rdata_byte(1U) << "." << rdata_byte(2U) << "." << rdata_byte(3U) << ":0" ;
+		ss << rdataByte(0U) << "." << rdataByte(1U) << "." << rdataByte(2U) << "." << rdataByte(3U) << ":0" ;
 	}
-	else if( isa("AAAA") && rdata_size() == 16U )
+	else if( isa("AAAA") && rdataSize() == 16U )
 	{
 		const char * sep = "" ;
 		for( unsigned int i = 0 ; i < 8U ; i++ , sep = ":" )
-			ss << sep << std::hex << rdata_word(i*2U) ;
+			ss << sep << std::hex << rdataWord(i*2U) ;
 		ss << ".0" ;
 	}
 	else
@@ -490,15 +492,23 @@ namespace GNet
 	}
 }
 
-unsigned int GNet::DnsMessageRecordType::value( const std::string & type_name )
+unsigned int GNet::DnsMessageRecordType::value( G::string_view type_name , std::nothrow_t ) noexcept
 {
 	namespace imp = DnsMessageRecordTypeImp ;
 	for( const auto & item : imp::map )
 	{
-		if( type_name == item.second )
+		if( G::Str::match( type_name , item.second ) )
 			return item.first ;
 	}
-	throw DnsMessage::Error( "invalid rr type name" ) ;
+	return 0U ;
+}
+
+unsigned int GNet::DnsMessageRecordType::value( G::string_view type_name )
+{
+	unsigned int v = value( type_name , std::nothrow ) ;
+	if( v == 0U )
+		throw DnsMessage::Error( "invalid rr type name" ) ;
+	return v ;
 }
 
 std::string GNet::DnsMessageRecordType::name( unsigned int type_value )
diff --git a/src/gnet/gdnsmessage.h b/src/gnet/gdnsmessage.h
index adecb70..c4e8008 100644
--- a/src/gnet/gdnsmessage.h
+++ b/src/gnet/gdnsmessage.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,10 +24,12 @@
 #include "gdef.h"
 #include "gexception.h"
 #include "gaddress.h"
+#include "gstringview.h"
 #include <vector>
 #include <utility>
 #include <string>
 #include <map>
+#include <new>
 
 namespace GNet
 {
@@ -38,6 +40,7 @@ namespace GNet
 	class DnsMessageNameParser ;
 	class DnsMessageRequest ;
 	class DnsMessageDumper ;
+	class DnsMessageRRData ;
 }
 
 //| \class GNet::DnsMessage
@@ -51,7 +54,7 @@ namespace GNet
 class GNet::DnsMessage
 {
 public:
-	G_EXCEPTION( Error , "dns message error" ) ;
+	G_EXCEPTION( Error , tx("dns message error") ) ;
 	using Question = DnsMessageQuestion ;
 	using RR = DnsMessageRR ;
 
@@ -120,10 +123,10 @@ public:
 	Address rrAddress( unsigned int n ) const ;
 		///< Returns the address in the n'th record treated as a RR record.
 
-	const char * p() const ;
+	const char * p() const noexcept ;
 		///< Returns the raw data.
 
-	std::size_t n() const ;
+	std::size_t n() const noexcept ;
 		///< Returns the raw data size.
 
 	unsigned int byte( unsigned int byte_index ) const ;
@@ -164,8 +167,13 @@ private:
 class GNet::DnsMessageRecordType
 {
 public:
-	static unsigned int value( const std::string & type_name ) ;
+	static unsigned int value( G::string_view type_name ) ;
 		///< Returns the type value for the given type name.
+		///< Throws on error.
+
+	static unsigned int value( G::string_view type_name , std::nothrow_t ) noexcept ;
+		///< Returns the type value for the given type name,
+		///< or zero on error.
 
 	static std::string name( unsigned int type_value ) ;
 		///< Returns the type name for the given type value.
@@ -174,10 +182,37 @@ public:
 	DnsMessageRecordType() = delete ;
 } ;
 
+//| \class GNet::DnsMessageRR
+/// Provides access to raw DnsMessageRR data.
+///
+class GNet::DnsMessageRRData
+{
+public:
+	unsigned int byte( unsigned int offset ) const ;
+		///< Returns RDATA byte at the given offset.
+
+	unsigned int word( unsigned int offset ) const ;
+		///< Returns RDATA word at the given offset.
+
+	std::string span( unsigned int begin , unsigned int end ) const ;
+		///< Returns the data in the given half-open byte range.
+
+	std::string span( unsigned int begin ) const ;
+		///< Returns the data starting at the given offset.
+
+	std::string dname( unsigned int rdata_offset ) const ;
+	std::string dname( unsigned int * rdata_offset_inout_p ) const ;
+	unsigned int offset() const ;
+	unsigned int size() const ;
+
+protected:
+	DnsMessageRRData() = default ;
+} ;
+
 //| \class GNet::DnsMessageRR
 /// Represents DNS response record.
 ///
-class GNet::DnsMessageRR
+class GNet::DnsMessageRR : private DnsMessageRRData
 {
 public:
 	using RR = DnsMessageRR ;
@@ -187,31 +222,34 @@ public:
 		///< Constructor. Keeps the reference, which is then passed
 		///< to copies.
 
-	bool isa( const std::string & ) const ;
+	bool isa( G::string_view ) const noexcept ;
 		///< Returns true if the type() has the given name().
 
 	unsigned int type() const ;
-		///< Returns the type value().
+		///< Returns the RR TYPE value().
 
 	unsigned int size() const ;
-		///< Returns the size.
+		///< Returns the size of the RR.
 
 	std::string name() const ;
-		///< Returns the NAME.
+		///< Returns the RR NAME.
 
 	Address address() const ;
 		///< Returns the Address if isa(A) or isa(AAAA).
 
+	const DnsMessageRRData & rdata() const ;
+		///< Provides access to the message RDATA.
+
 private:
-	friend class DnsMessageDumper ;
-	std::string rdata_dname( unsigned int rdata_offset ) const ;
-	std::string rdata_dname( unsigned int * rdata_offset_p ) const ;
-	std::string rdata_span( unsigned int begin ) const ;
-	std::string rdata_span( unsigned int begin , unsigned int end ) const ;
-	unsigned int rdata_offset() const ;
-	unsigned int rdata_size() const ;
-	unsigned int rdata_byte( unsigned int offset ) const ;
-	unsigned int rdata_word( unsigned int offset ) const ;
+	friend class GNet::DnsMessageRRData ;
+	std::string rdataDname( unsigned int rdata_offset ) const ;
+	std::string rdataDname( unsigned int * rdata_offset_inout_p ) const ;
+	std::string rdataSpan( unsigned int begin ) const ;
+	std::string rdataSpan( unsigned int begin , unsigned int end ) const ;
+	unsigned int rdataOffset() const ;
+	unsigned int rdataSize() const ;
+	unsigned int rdataByte( unsigned int offset ) const ;
+	unsigned int rdataWord( unsigned int offset ) const ;
 
 private:
 	const DnsMessage & m_msg ;
@@ -281,7 +319,7 @@ public:
 
 private:
 	void q( const std::string & domain , char ) ;
-	void q( const std::string & ) ;
+	void q( G::string_view ) ;
 	void q( unsigned int ) ;
 	void q( int ) ;
 
@@ -289,4 +327,52 @@ private:
 	std::string m_data ;
 } ;
 
+inline
+const GNet::DnsMessageRRData & GNet::DnsMessageRR::rdata() const
+{
+	return *this ;
+}
+
+inline
+std::string GNet::DnsMessageRRData::dname( unsigned int offset ) const
+{
+	return static_cast<const DnsMessageRR *>(this)->rdataDname( offset ) ;
+}
+
+inline
+std::string GNet::DnsMessageRRData::dname( unsigned int * offset_inout_p ) const
+{
+	return static_cast<const DnsMessageRR *>(this)->rdataDname( offset_inout_p ) ;
+}
+
+inline
+std::string GNet::DnsMessageRRData::span( unsigned int begin ) const
+{
+	return static_cast<const DnsMessageRR *>(this)->rdataSpan( begin ) ;
+}
+
+inline
+std::string GNet::DnsMessageRRData::span( unsigned int begin , unsigned int end ) const
+{
+	return static_cast<const DnsMessageRR *>(this)->rdataSpan( begin , end ) ;
+}
+
+inline
+unsigned int GNet::DnsMessageRRData::size() const
+{
+	return static_cast<const DnsMessageRR *>(this)->rdataSize() ;
+}
+
+inline
+unsigned int GNet::DnsMessageRRData::byte( unsigned int offset ) const
+{
+	return static_cast<const DnsMessageRR *>(this)->rdataByte( offset ) ;
+}
+
+inline
+unsigned int GNet::DnsMessageRRData::word( unsigned int offset ) const
+{
+	return static_cast<const DnsMessageRR *>(this)->rdataWord( offset ) ;
+}
+
 #endif
diff --git a/src/gnet/gevent.h b/src/gnet/gevent.h
index 801bbce..2b9672b 100644
--- a/src/gnet/gevent.h
+++ b/src/gnet/gevent.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,10 +22,12 @@
 #define G_NET_EVENT_H
 
 #include "gdef.h"
-#include "gexceptionhandler.h"
 #include "geventloop.h"
 #include "geventhandler.h"
-#include "geventhandlerlist.h"
+#include "geventemitter.h"
+#include "gexceptionhandler.h"
+#include "gexceptionsink.h"
+#include "gexceptionsource.h"
 
 #endif
 
diff --git a/src/gnet/geventemitter.cpp b/src/gnet/geventemitter.cpp
new file mode 100644
index 0000000..026028e
--- /dev/null
+++ b/src/gnet/geventemitter.cpp
@@ -0,0 +1,123 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file geventemitter.cpp
+///
+
+#include "gdef.h"
+#include "geventemitter.h"
+#include "gnetdone.h"
+#include "geventloggingcontext.h"
+#include "glog.h"
+#include "gassert.h"
+
+GNet::EventEmitter::EventEmitter() noexcept
+= default ;
+
+GNet::EventEmitter::EventEmitter( EventHandler * handler , ExceptionSink es ) noexcept :
+	m_handler(handler) ,
+	m_es(es)
+{
+}
+
+void GNet::EventEmitter::update( EventHandler * handler , ExceptionSink es ) noexcept
+{
+	m_handler = handler ;
+	m_es = es ;
+}
+
+void GNet::EventEmitter::raiseReadEvent( Descriptor fd )
+{
+	raiseEvent( &EventHandler::readEvent , fd ) ;
+}
+
+void GNet::EventEmitter::raiseWriteEvent( Descriptor fd )
+{
+	raiseEvent( &EventHandler::writeEvent , fd ) ;
+}
+
+void GNet::EventEmitter::raiseOtherEvent( Descriptor fd , EventHandler::Reason reason )
+{
+	raiseEvent( &EventHandler::otherEvent , fd , reason ) ;
+}
+
+void GNet::EventEmitter::raiseEvent( void (EventHandler::*method)() , Descriptor )
+{
+	// see also: std::make_exception_ptr, std::rethrow_exception
+
+	EventLoggingContext set_logging_context( m_es.esrc() ) ;
+	m_es_saved = m_es ; // in case the fd gets closed and re-opened when calling the event handler
+	try
+	{
+		if( m_handler != nullptr )
+			(m_handler->*method)() ; // EventHandler::readEvent()/writeEvent()
+	}
+	catch( GNet::Done & e )
+	{
+		if( m_es_saved.set() )
+			m_es_saved.call( e , true ) ; // ExceptionHandler::onException()
+		else
+			throw ;
+	}
+	catch( std::exception & e )
+	{
+		if( m_es_saved.set() )
+			m_es_saved.call( e , false ) ; // ExceptionHandler::onException()
+		else
+			throw ;
+	}
+}
+
+void GNet::EventEmitter::raiseEvent( void (EventHandler::*method)(EventHandler::Reason) ,
+	Descriptor , EventHandler::Reason reason )
+{
+	EventLoggingContext set_logging_context( m_handler && m_es.set() ? m_es.esrc() : nullptr ) ;
+	m_es_saved = m_es ; // (fd might get closed and reopened with a different exception sink)
+	try
+	{
+		if( m_handler != nullptr )
+			(m_handler->*method)( reason ) ; // EventHandler::otherEvent()
+	}
+	catch( GNet::Done & e )
+	{
+		if( m_es_saved.set() )
+			m_es_saved.call( e , true ) ; // ExceptionHandler::onException()
+		else
+			throw ;
+	}
+	catch( std::exception & e )
+	{
+		if( m_es_saved.set() )
+			m_es_saved.call( e , false ) ; // ExceptionHandler::onException()
+		else
+			throw ;
+	}
+}
+
+void GNet::EventEmitter::reset() noexcept
+{
+	m_handler = nullptr ;
+}
+
+void GNet::EventEmitter::disarm( ExceptionHandler * eh ) noexcept
+{
+	if( m_es.eh() == eh )
+		m_es.reset() ;
+	if( m_es_saved.eh() == eh )
+		m_es_saved.reset() ;
+}
+
diff --git a/src/gnet/geventemitter.h b/src/gnet/geventemitter.h
new file mode 100644
index 0000000..cde02da
--- /dev/null
+++ b/src/gnet/geventemitter.h
@@ -0,0 +1,107 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file geventemitter.h
+///
+
+#ifndef G_NET_EVENT_EMITTER_H
+#define G_NET_EVENT_EMITTER_H
+
+#include "gdef.h"
+#include "geventhandler.h"
+#include "gexceptionsink.h"
+
+namespace GNet
+{
+	class EventEmitter ;
+}
+
+//| \class GNet::EventEmitter
+/// An EventHandler and ExceptionSink tuple, with methods to raise an
+/// event and handle any exceptions. Used in EventLoop implementations.
+/// Also sets an appropriate G::LogOutput context while events are
+/// being handled.
+///
+/// The event loop should normally instantiate a read emitter and
+/// a write emitter for each new file descriptor; any existing
+/// emitters should be update()d rather than destructed and
+/// constructed, with garbage collection once all the events
+/// have been handled.
+///
+class GNet::EventEmitter
+{
+public:
+	EventEmitter() noexcept ;
+		///< Default constructor. The raise methods do nothing and
+		///< consequently the exception sink is not used.
+		///< Postcondition: !handler()
+
+	EventEmitter( EventHandler * , ExceptionSink ) noexcept ;
+		///< Constructor.
+
+	void raiseReadEvent( Descriptor ) ;
+		///< Calls the EventHandler readEvent() method.
+
+	void raiseWriteEvent( Descriptor ) ;
+		///< Calls the EventHandler writeEvent() method.
+
+	void raiseOtherEvent( Descriptor , EventHandler::Reason ) ;
+		///< Calls the EventHandler otherEvent() method.
+
+	EventHandler * handler() const ;
+		///< Returns the handler, as passed to the ctor.
+
+	ExceptionSink es() const ;
+		///< Returns the exception sink, as passed to the ctor.
+
+	void update( EventHandler * , ExceptionSink ) noexcept ;
+		///< Sets the event handler and the exception sink.
+
+	void reset() noexcept ;
+		///< Resets the EventHandler so that the raise methods
+		///< do nothing.
+		///< Postcondition: !handler()
+
+	void disarm( ExceptionHandler * ) noexcept ;
+		///< If the exception handler matches then reset it
+		///< so that it is not called. Any exceptions will be
+		///< thrown out of of the event loop and back to
+		///< main().
+
+private:
+	void raiseEvent( void (EventHandler::*method)() , Descriptor ) ;
+	void raiseEvent( void (EventHandler::*method)(EventHandler::Reason) , Descriptor , EventHandler::Reason ) ;
+
+private:
+	EventHandler * m_handler {nullptr} ; // handler for the event
+	ExceptionSink m_es ; // handler for any thrown exception
+	ExceptionSink m_es_saved ; // in case disarm()ed but still needed
+} ;
+
+inline
+GNet::EventHandler * GNet::EventEmitter::handler() const
+{
+	return m_handler ;
+}
+
+inline
+GNet::ExceptionSink GNet::EventEmitter::es() const
+{
+	return m_es ;
+}
+
+#endif
diff --git a/src/gnet/geventhandler.cpp b/src/gnet/geventhandler.cpp
index 3ec1e70..5f7a3fd 100644
--- a/src/gnet/geventhandler.cpp
+++ b/src/gnet/geventhandler.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,8 +21,21 @@
 #include "gdef.h"
 #include "geventhandler.h"
 #include "gexception.h"
+#include "geventloop.h"
 #include "glog.h"
 
+GNet::EventHandler::EventHandler()
+= default ;
+
+GNet::EventHandler::~EventHandler()
+{
+	EventLoop * event_loop ;
+	if( (event_loop=EventLoop::ptr()) != nullptr && m_fd.valid() )
+	{
+		event_loop->drop( m_fd ) ;
+	}
+}
+
 void GNet::EventHandler::readEvent()
 {
 	G_DEBUG( "GNet::EventHandler::readEvent: no override" ) ;
@@ -35,20 +48,16 @@ void GNet::EventHandler::writeEvent()
 
 void GNet::EventHandler::otherEvent( EventHandler::Reason reason )
 {
-	// this event is mostly relevant to windows -- the default action
-	// is to throw an exception -- for 'reason_closed' (ie. a clean
-	// shutdown()) it would also be reasonable to read the socket
-	// until it returns an error or zero, and/or set a close timer
-
 	throw G::Exception( "socket disconnect event" , str(reason) ) ;
 }
 
 std::string GNet::EventHandler::str( EventHandler::Reason reason )
 {
+	if( reason == EventHandler::Reason::failed ) return "connection failed" ;
 	if( reason == EventHandler::Reason::closed ) return "closed" ;
 	if( reason == EventHandler::Reason::down ) return "network down" ;
 	if( reason == EventHandler::Reason::reset ) return "connection reset by peer" ;
 	if( reason == EventHandler::Reason::abort ) return "connection aborted" ;
-	return std::string() ;
+	return {} ;
 }
 
diff --git a/src/gnet/geventhandler.h b/src/gnet/geventhandler.h
index 20a13ed..9fb47ba 100644
--- a/src/gnet/geventhandler.h
+++ b/src/gnet/geventhandler.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -34,14 +34,14 @@ namespace GNet
 }
 
 //| \class GNet::EventHandler
-/// A base class for classes that handle asynchronous events from the
-/// event loop.
+/// A base class for classes that have a file descriptor and handle
+/// asynchronous events from the event loop.
 ///
-/// An event handler object has its virtual methods called when an
-/// event is detected on the relevant file descriptor.
+/// The event handler virtual methods are called when an event is
+/// detected on the associated file descriptor.
 ///
-/// The EventHandlerList class ensures that if an exception is thrown
-/// out of an event handler it is caught and delivered to an associated
+/// The EventEmitter class ensures that if an exception is thrown out
+/// of an event handler it is caught and delivered to an associated
 /// ExceptionHandler interface (if any).
 ///
 class GNet::EventHandler
@@ -49,6 +49,7 @@ class GNet::EventHandler
 public:
 	enum class Reason
 	{
+		failed , // connection failed
 		closed , // fin packet, clean shutdown
 		down , // network down
 		reset , // rst packet
@@ -56,12 +57,16 @@ public:
 		other // eg. oob data
 	} ;
 
-	virtual ~EventHandler() = default ;
+	EventHandler() ;
+		///< Constructor.
+
+	virtual ~EventHandler() ;
 		///< Destructor.
 
 	virtual void readEvent() ;
 		///< Called for a read event. Overridable. The default
-		///< implementation does nothing.
+		///< implementation does nothing. The descriptor might
+		///< not be valid() if a non-socket event on windows.
 
 	virtual void writeEvent() ;
 		///< Called for a write event. Overrideable. The default
@@ -75,6 +80,33 @@ public:
 	static std::string str( Reason ) ;
 		///< Returns a printable description of the other-event
 		///< reason.
+
+	void setDescriptor( Descriptor ) noexcept ;
+		///< File descriptor setter. Used by the event loop.
+
+	Descriptor descriptor() const noexcept ;
+		///< File descriptor getter. Used by the event loop.
+
+public:
+	EventHandler( const EventHandler & ) = delete ;
+	EventHandler( EventHandler && ) = delete ;
+	EventHandler & operator=( const EventHandler & ) = delete ;
+	EventHandler & operator=( EventHandler && ) = delete ;
+
+private:
+	Descriptor m_fd ;
 } ;
 
+inline
+void GNet::EventHandler::setDescriptor( Descriptor fd ) noexcept
+{
+	m_fd = fd ;
+}
+
+inline
+GNet::Descriptor GNet::EventHandler::descriptor() const noexcept
+{
+	return m_fd ;
+}
+
 #endif
diff --git a/src/gnet/geventhandlerlist.cpp b/src/gnet/geventhandlerlist.cpp
deleted file mode 100644
index 93d792f..0000000
--- a/src/gnet/geventhandlerlist.cpp
+++ /dev/null
@@ -1,282 +0,0 @@
-//
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-// ===
-///
-/// \file geventhandlerlist.cpp
-///
-
-#include "gdef.h"
-#include "gnetdone.h"
-#include "geventhandlerlist.h"
-#include "geventloggingcontext.h"
-#include "glog.h"
-#include "gassert.h"
-#include <algorithm>
-
-namespace GNet
-{
-	namespace EventHandlerListImp /// An implementation namespace for GNet::EventHandlerList.
-	{
-		struct fdless /// A functor that compares two file descriptors.
-		{
-			using Value = GNet::EventHandlerList::Value ;
-			bool operator()( const Value & p1 , const Value & p2 ) noexcept
-			{
-				return p1.m_fd < p2.m_fd ;
-			}
-		} ;
-	}
-}
-
-GNet::EventHandlerList::EventHandlerList( const std::string & type ) :
-	m_type(type) ,
-	m_lock(0U) ,
-	m_has_garbage(false)
-{
-}
-
-void GNet::EventHandlerList::add( Descriptor fd , EventHandler * handler , ExceptionSink es )
-{
-	G_ASSERT( handler != nullptr ) ; if( handler == nullptr ) return ;
-	G_ASSERT( es.eh() != nullptr ) ; if( es.eh() == nullptr ) return ;
-
-	G_DEBUG( "GNet::EventHandlerList::add: " << m_type << "-list: " << "adding " << fd << (m_lock?" (pending)":"") ) ;
-	addImp( m_lock?m_pending_list:m_list , fd , handler , es ) ;
-}
-
-void GNet::EventHandlerList::addImp( List & list , Descriptor fd , EventHandler * handler , ExceptionSink es )
-{
-	namespace imp = EventHandlerListImp ;
-	using Range = std::pair<List::iterator,List::iterator> ;
-	Range range = std::equal_range( list.begin() , list.end() , List::value_type(fd) , imp::fdless() ) ;
-	if( range.first == range.second )
-		list.insert( range.first , List::value_type(fd,handler,es) ) ;
-	else
-		*range.first = List::value_type(fd,handler,es) ;
-}
-
-void GNet::EventHandlerList::remove( Descriptor fd ) noexcept
-{
-	G_DEBUG( "GNet::EventHandlerList::remove: " << m_type << "-list: " << "removing " << fd ) ;
-	if( m_lock )
-	{
-		if( disable(m_list,fd) ) m_has_garbage = true ;
-		disable( m_pending_list , fd ) ;
-	}
-	else
-	{
-		remove( m_list , fd ) ;
-	}
-}
-
-bool GNet::EventHandlerList::disable( List & list , Descriptor fd ) noexcept
-{
-	namespace imp = EventHandlerListImp ;
-	using Range = std::pair<List::iterator,List::iterator> ;
-	Range range = std::equal_range( list.begin() , list.end() , List::value_type(fd) , imp::fdless() ) ;
-	const bool found = range.first != range.second ;
-	if( found )
-	{
-		(*range.first).m_event_handler = nullptr ;
-	}
-	return found ;
-}
-
-bool GNet::EventHandlerList::remove( List & list , Descriptor fd ) noexcept
-{
-	namespace imp = EventHandlerListImp ;
-	using Range = std::pair<List::iterator,List::iterator> ;
-	Range range = std::equal_range( list.begin() , list.end() , List::value_type(fd) , imp::fdless() ) ;
-	const bool found = range.first != range.second ;
-	if( found )
-		list.erase( range.first ) ; // noexcept since Value::op=() does not throw
-	return found ;
-}
-
-void GNet::EventHandlerList::disarm( ExceptionHandler * eh ) noexcept
-{
-	disarm( m_list , eh ) ;
-	disarm( m_pending_list , eh ) ;
-}
-
-void GNet::EventHandlerList::disarm( List & list , ExceptionHandler * eh ) noexcept
-{
-	for( auto & value : list )
-	{
-		if( value.m_es.eh() == eh )
-			value.m_es.reset() ;
-	}
-}
-
-GNet::EventHandlerList::Iterator GNet::EventHandlerList::find( Descriptor fd ) const
-{
-	namespace imp = EventHandlerListImp ;
-	using Range = std::pair<List::const_iterator,List::const_iterator> ;
-	Range range = std::equal_range( m_list.begin() , m_list.end() , List::value_type(fd) , imp::fdless() ) ;
-	return range.first == range.second ? Iterator(m_list.end(),m_list.end()) : Iterator(range.first,m_list.end()) ;
-}
-
-bool GNet::EventHandlerList::contains( Descriptor fd ) const noexcept
-{
-	namespace imp = EventHandlerListImp ;
-	using Range = std::pair<List::const_iterator,List::const_iterator> ;
-	Range range = std::equal_range( m_pending_list.begin() , m_pending_list.end() ,
-		List::value_type(fd) , imp::fdless() ) ;
-	if( range.first == range.second )
-		range = std::equal_range( m_list.begin() , m_list.end() , List::value_type(fd) , imp::fdless() ) ;
-	return range.first != range.second && (*range.first).m_event_handler != nullptr ;
-}
-
-std::size_t GNet::EventHandlerList::size() const noexcept
-{
-	return m_list.size() ;
-}
-
-void GNet::EventHandlerList::getHandles( std::vector<HANDLE> & out ) const
-{
-	getHandles( m_list , out ) ;
-	getHandles( m_pending_list , out ) ;
-}
-
-void GNet::EventHandlerList::getHandles( const List & list , std::vector<HANDLE> & out )
-{
-	using iterator = std::vector<HANDLE>::iterator ;
-	using Range = std::pair<iterator,iterator> ;
-	for( const auto & value : list )
-	{
-		HANDLE h = value.m_fd.h() ;
-		if( !h || value.m_event_handler == nullptr ) continue ;
-		Range range = std::equal_range( out.begin() , out.end() , h ) ;
-		if( range.first == range.second )
-			out.insert( range.first , h ) ;
-	}
-}
-
-void GNet::EventHandlerList::lock()
-{
-	m_lock++ ;
-}
-
-bool GNet::EventHandlerList::unlock()
-{
-	G_ASSERT( m_lock != 0U ) ;
-	m_lock-- ;
-	bool updated = false ;
-	if( m_lock == 0U )
-	{
-		updated = !m_pending_list.empty() || m_has_garbage ;
-		commitPending() ;
-		collectGarbage() ;
-	}
-	return updated ;
-}
-
-void GNet::EventHandlerList::commitPending()
-{
-	const List::iterator end = m_pending_list.end() ;
-	for( auto p = m_pending_list.begin() ; p != end ; ++p )
-	{
-		if( (*p).m_event_handler != nullptr )
-		{
-			G_DEBUG( "GNet::EventHandlerList::commitPending: " << m_type << "-list: " << "commiting " << (*p).m_fd ) ;
-			addImp( m_list , (*p).m_fd , (*p).m_event_handler , (*p).m_es ) ;
-		}
-	}
-	m_pending_list.clear() ;
-}
-
-void GNet::EventHandlerList::collectGarbage()
-{
-	if( m_has_garbage )
-	{
-		m_has_garbage = false ;
-		for( auto p = m_list.begin() ; p != m_list.end() ; )
-		{
-			if( (*p).m_event_handler == nullptr )
-				p = m_list.erase( p ) ;
-			else
-				++p ;
-		}
-	}
-}
-
-// ==
-
-void GNet::EventHandlerList::Iterator::raiseEvent( void (EventHandler::*method)() )
-{
-	// TODO use std::make_exception_ptr and std::rethrow_exception
-	EventLoggingContext set_logging_context( (m_p!=m_end&&handler()&&es().set()) ? es().esrc() : nullptr ) ;
-	try
-	{
-		if( m_p != m_end && handler() != nullptr )
-			(handler()->*method)() ;
-	}
-	catch( GNet::Done & e ) // (caught separately to avoid requiring rtti)
-	{
-		if( m_p != m_end && es().set() )
-			es().call( e , true ) ; // call onException()
-		else
-			throw ;
-	}
-	catch( std::exception & e )
-	{
-		if( m_p != m_end && es().set() )
-			es().call( e , false ) ; // call onException()
-		else
-			throw ;
-	}
-}
-
-void GNet::EventHandlerList::Iterator::raiseEvent( void (EventHandler::*method)(EventHandler::Reason) ,
-	EventHandler::Reason reason )
-{
-	EventLoggingContext set_logging_context( (m_p!=m_end&&handler()&&es().set()) ? es().esrc() : nullptr ) ;
-	try
-	{
-		if( m_p != m_end && handler() != nullptr )
-			(handler()->*method)( reason ) ;
-	}
-	catch( GNet::Done & e ) // (caught separately to avoid requiring rtti)
-	{
-		if( m_p != m_end && es().set() )
-			es().call( e , true ) ; // call onException()
-		else
-			throw ;
-	}
-	catch( std::exception & e )
-	{
-		if( m_p != m_end && es().set() )
-			es().call( e , false ) ; // call onException()
-		else
-			throw ;
-	}
-}
-
-// ==
-
-GNet::EventHandlerList::Lock::Lock( EventHandlerList & list , bool * invalid_p ) :
-	m_list(list) ,
-	m_invalid_p(invalid_p)
-{
-	m_list.lock() ;
-}
-
-GNet::EventHandlerList::Lock::~Lock()
-{
-	if( m_list.unlock() && m_invalid_p != nullptr )
-		*m_invalid_p = true ;
-}
-
diff --git a/src/gnet/geventhandlerlist.h b/src/gnet/geventhandlerlist.h
deleted file mode 100644
index d1ad117..0000000
--- a/src/gnet/geventhandlerlist.h
+++ /dev/null
@@ -1,283 +0,0 @@
-//
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-// ===
-///
-/// \file geventhandlerlist.h
-///
-
-#ifndef G_NET_EVENT_HANDLER_LIST_H
-#define G_NET_EVENT_HANDLER_LIST_H
-
-#include "gdef.h"
-#include "geventhandler.h"
-#include "gexceptionsink.h"
-#include "gdescriptor.h"
-#include <vector>
-#include <string>
-
-namespace GNet
-{
-	class EventHandlerList ;
-}
-
-//| \class GNet::EventHandlerList
-/// A class that maps from a file descriptor to an event handler and
-/// exception handler, used in the implemention of classes derived
-/// from GNet::EventLoop.
-///
-/// If an event handler is removed from the list while the list is
-/// being iterated over then the relevant pointer is reset without
-/// affecting the iteration. The unlock() method does garbage collection
-/// once the iteration is complete.
-///
-/// If an event handler is added to the list while the list is being
-/// iterated over then it is added to a pending-list. The pending
-/// list is added to the main list by unlock() once the iteration
-/// is complete.
-///
-/// Each event handler has an associated exception handler, typically a
-/// more long-lived object that has the event handler as a sub-object.
-/// If the event hander throws an exception then the event
-/// handler list catches it and invokes the exception handler -- and
-/// if that throws then the exception escapes the event loop. This is
-/// safe even if the exception handler object is destroyed by the
-/// original exception because the exception handler base-class
-/// destructor uses the list's disarm() mechanism. This is the same
-/// behaviour as in the TimerList.
-///
-/// Exception handlers are combined with an additional 'source' pointer
-/// in an ExceptionSink tuple. The exception source pointer can be used
-/// to provide additional information to the exception handler, typically
-/// as a pointer to the event handler object. (The EventHandler class
-/// is not used as the exception source type because timers also refer
-/// to exception sources and because of possible multiple inheritance of
-/// the EventHandler base.)
-///
-/// Note that the Descriptor class is actually in two parts for Windows:
-/// a socket handle (file descriptor) and an event-object handle. The
-/// event handler list is keyed by the full Descriptor object rather than
-/// just the socket handle and this allows it to contain event-handling
-/// objects that are not sockets. See GNet::FutureEvent.
-///
-class GNet::EventHandlerList
-{
-public:
-	struct Value /// A tuple for GNet::EventHandlerList.
-	{
-		Descriptor m_fd ;
-		EventHandler * m_event_handler ; // handler for the event
-		ExceptionSink m_es ; // handler for any thrown exception
-		explicit Value( Descriptor fd ) noexcept ;
-		Value( Descriptor fd , EventHandler * , ExceptionSink ) noexcept ;
-	} ;
-	struct Iterator /// An iterator for GNet::EventHandlerList.
-	{
-		using Value = EventHandlerList::Value ;
-		Iterator( const std::vector<Value> & , bool ) noexcept ;
-		Iterator( std::vector<Value>::const_iterator , std::vector<Value>::const_iterator ) noexcept ;
-		Iterator & operator++() noexcept ;
-		const Value & operator*() const noexcept ;
-		bool operator==( const Iterator & ) const noexcept ;
-		bool operator!=( const Iterator & ) const noexcept ;
-		Descriptor fd() const noexcept ;
-		EventHandler * handler() noexcept ;
-		ExceptionSink es() noexcept ;
-		void raiseEvent( void (EventHandler::*method)() ) ;
-		void raiseEvent( void (EventHandler::*method)(EventHandler::Reason) , EventHandler::Reason ) ;
-		std::vector<Value>::const_iterator m_p ;
-		std::vector<Value>::const_iterator m_end ;
-	} ;
-	struct Lock /// A RAII class to lock and unlock GNet::EventHandlerList.
-	{
-		explicit Lock( EventHandlerList & , bool * invalid_p = nullptr ) ;
-		~Lock() ;
-		Lock( const Lock & ) = delete ;
-		Lock( Lock && ) = delete ;
-		void operator=( const Lock & ) = delete ;
-		void operator=( Lock && ) = delete ;
-		EventHandlerList & m_list ;
-		bool * m_invalid_p ;
-	} ;
-
-public:
-	explicit EventHandlerList( const std::string & type ) ;
-		///< Constructor. The type parameter (eg. "read") is used only in
-		///< debugging messages.
-
-	void add( Descriptor fd , EventHandler * handler , ExceptionSink ) ;
-		///< Adds a file-descriptor/handler tuple to the list.
-
-	void remove( Descriptor fd ) noexcept ;
-		///< Removes a file-descriptor from the list. Does nothing if the
-		///< file-descriptor is not in the list.
-
-	Iterator find( Descriptor fd ) const ;
-		///< Finds an entry in the list. Returns end() if not found.
-		///< This ignores any pending changes, ie. descriptors add()ed
-		///< or remove()d while lock()ed.
-
-	bool contains( Descriptor fd ) const noexcept ;
-		///< Returns true if the list, taking account of any pending
-		///< changes, contains the given descriptor.
-
-	void lock() ;
-		///< To be called at the start of an begin()/end() iteration if the
-		///< list might change during the iteration. Must be paired with
-		///< unlock().
-
-	bool unlock() ;
-		///< Called at the end of a begin()/end() iteration to match a call
-		///< to lock(). Does garbage collection. Returns true if anything
-		///< might have changed.
-
-	Iterator begin() const noexcept ;
-		///< Returns a forward iterator. If the list is lock()ed then the
-		///< iterator will skip over descriptors that have been remove()d
-		///< or add()ed while locked.
-
-	Iterator end() const noexcept ;
-		///< Returns an end iterator.
-
-	void disarm( ExceptionHandler * ) noexcept ;
-		///< Resets any matching ExceptionHandler pointers, so exceptions
-		///< thrown out of the relevant file descriptors' event handlers
-		///< are rethrown by this class rather than being delivered to
-		///< the exception handler interface.
-
-	void getHandles( std::vector<HANDLE> & ) const ;
-		///< Adds unique, non-zero Descriptor handles to the given
-		///< sorted list, including any add()ed while lock()ed.
-
-	std::size_t size() const noexcept ;
-		///< Returns the size of the list, ignoring any changes while
-		///< lock()ed.
-
-public:
-	~EventHandlerList() = default ;
-	EventHandlerList( const EventHandlerList & ) = delete ;
-	EventHandlerList( EventHandlerList && ) = delete ;
-	void operator=( const EventHandlerList & ) = delete ;
-	void operator=( EventHandlerList && ) = delete ;
-
-private:
-	using List = std::vector<Value> ;
-	static void addImp( List & list , Descriptor fd , EventHandler * , ExceptionSink ) ;
-	static bool disable( List & list , Descriptor fd ) noexcept ;
-	static bool remove( List & list , Descriptor fd ) noexcept ;
-	static void getHandles( const List & , std::vector<HANDLE> & ) ;
-	void disarm( List & , ExceptionHandler * ) noexcept ;
-	void commitPending() ;
-	void collectGarbage() ;
-
-private:
-	std::string m_type ;
-	List m_list ;
-	List m_pending_list ;
-	unsigned int m_lock ;
-	bool m_has_garbage ;
-} ;
-
-inline
-GNet::EventHandlerList::Value::Value( Descriptor fd , EventHandler * event_handler , ExceptionSink es ) noexcept :
-	m_fd(fd),
-	m_event_handler(event_handler),
-	m_es(es)
-{
-}
-
-inline
-GNet::EventHandlerList::Value::Value( Descriptor fd ) noexcept :
-	m_fd(fd),
-	m_event_handler(nullptr),
-	m_es(ExceptionSink(ExceptionSink::Type::Null))
-{
-}
-
-inline
-GNet::EventHandlerList::Iterator GNet::EventHandlerList::begin() const noexcept
-{
-	return Iterator( m_list , false ) ;
-}
-
-inline
-GNet::EventHandlerList::Iterator GNet::EventHandlerList::end() const noexcept
-{
-	return Iterator( m_list , true ) ;
-}
-
-inline
-GNet::EventHandlerList::Iterator::Iterator( std::vector<Value>::const_iterator p ,
-	std::vector<Value>::const_iterator end ) noexcept :
-		m_p(p) ,
-		m_end(end)
-{
-}
-
-inline
-GNet::EventHandlerList::Iterator::Iterator( const std::vector<Value> & v , bool end ) noexcept :
-	m_p(end?v.end():v.begin()) ,
-	m_end(v.end())
-{
-	while( m_p != m_end && (*m_p).m_event_handler == nullptr )
-		++m_p ;
-}
-
-inline
-GNet::EventHandlerList::Iterator & GNet::EventHandlerList::Iterator::operator++() noexcept
-{
-	++m_p ;
-	while( m_p != m_end && (*m_p).m_event_handler == nullptr )
-		++m_p ;
-	return *this ;
-}
-
-inline
-const GNet::EventHandlerList::Value & GNet::EventHandlerList::Iterator::operator*() const noexcept
-{
-	return *m_p ;
-}
-
-inline
-GNet::Descriptor GNet::EventHandlerList::Iterator::fd() const noexcept
-{
-	return (*m_p).m_fd ;
-}
-
-inline
-GNet::EventHandler * GNet::EventHandlerList::Iterator::handler() noexcept
-{
-	return (*m_p).m_event_handler ;
-}
-
-inline
-GNet::ExceptionSink GNet::EventHandlerList::Iterator::es() noexcept
-{
-	return (*m_p).m_es ;
-}
-
-inline
-bool GNet::EventHandlerList::Iterator::operator==( const Iterator & other ) const noexcept
-{
-	return m_p == other.m_p ;
-}
-
-inline
-bool GNet::EventHandlerList::Iterator::operator!=( const Iterator & other ) const noexcept
-{
-	return !(*this == other) ;
-}
-
-#endif
diff --git a/src/gnet/geventloggingcontext.cpp b/src/gnet/geventloggingcontext.cpp
index 7e92665..8781d6e 100644
--- a/src/gnet/geventloggingcontext.cpp
+++ b/src/gnet/geventloggingcontext.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gnet/geventloggingcontext.h b/src/gnet/geventloggingcontext.h
index 05a3753..987dd0a 100644
--- a/src/gnet/geventloggingcontext.h
+++ b/src/gnet/geventloggingcontext.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -50,8 +50,8 @@ public:
 public:
 	EventLoggingContext( const EventLoggingContext & ) = delete ;
 	EventLoggingContext( EventLoggingContext && ) = delete ;
-	void operator=( const EventLoggingContext & ) = delete ;
-	void operator=( EventLoggingContext && ) = delete ;
+	EventLoggingContext & operator=( const EventLoggingContext & ) = delete ;
+	EventLoggingContext & operator=( EventLoggingContext && ) = delete ;
 
 private:
 	static std::string fn( void * ) ;
diff --git a/src/gnet/geventloop.cpp b/src/gnet/geventloop.cpp
index 0ae3dfa..7d5f002 100644
--- a/src/gnet/geventloop.cpp
+++ b/src/gnet/geventloop.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gnet/geventloop.h b/src/gnet/geventloop.h
index c590190..b5984fc 100644
--- a/src/gnet/geventloop.h
+++ b/src/gnet/geventloop.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -49,12 +49,22 @@ namespace GNet
 /// The class has a static member for finding an instance, but instances
 /// are not created automatically.
 ///
+/// \code
+/// int main()
+/// {
+///    auto event_loop = GNet::EventLoop::create() ;
+///    App app ; // EventLoop::instance().addRead() etc.
+///    event_loop->run() ;
+///    return 0 ;
+/// }
+/// \endcode
+///
 class GNet::EventLoop
 {
 public:
-	G_EXCEPTION( Error , "failed to initialise the event loop" ) ;
-	G_EXCEPTION( NoInstance , "no event loop instance" ) ;
-	G_EXCEPTION( Overflow , "event loop overflow" ) ;
+	G_EXCEPTION( Error , tx("event loop error") ) ;
+	G_EXCEPTION( NoInstance , tx("no event loop instance") ) ;
+	G_EXCEPTION( Overflow , tx("event loop overflow") ) ;
 
 protected:
 	EventLoop() ;
@@ -114,20 +124,25 @@ public:
 		///< See also Socket::addOtherHandler().
 
 	virtual void dropRead( Descriptor fd ) noexcept = 0 ;
-		///< Removes the given event source descriptor from the
+		///< Removes the given event descriptor from the
 		///< list of read sources.
 		///< See also Socket::dropReadHandler().
 
 	virtual void dropWrite( Descriptor fd ) noexcept = 0 ;
-		///< Removes the given event source descriptor from the
+		///< Removes the given event descriptor from the
 		///< list of write sources.
 		///< See also Socket::dropWriteHandler().
 
 	virtual void dropOther( Descriptor fd ) noexcept = 0 ;
-		///< Removes the given event source descriptor from the
-		///< list of exception sources.
+		///< Removes the given event descriptor from the
+		///< list of other-event sources.
 		///< See also Socket::dropOtherHandler().
 
+	virtual void drop( Descriptor fd ) noexcept = 0 ;
+		///< Removes the given event descriptor from the
+		///< event loop as the EventHandler is being
+		///< destructed.
+
 	virtual void disarm( ExceptionHandler * ) noexcept = 0 ;
 		///< Used to prevent the given interface from being used,
 		///< typically called from the ExceptionHandler
@@ -136,8 +151,8 @@ public:
 public:
 	EventLoop( const EventLoop & ) = delete ;
 	EventLoop( EventLoop && ) = delete ;
-	void operator=( const EventLoop & ) = delete ;
-	void operator=( EventLoop && ) = delete ;
+	EventLoop & operator=( const EventLoop & ) = delete ;
+	EventLoop & operator=( EventLoop && ) = delete ;
 
 private:
 	static EventLoop * m_this ;
diff --git a/src/gnet/geventloop_epoll.cpp b/src/gnet/geventloop_epoll.cpp
index 3c09f6c..1e38c49 100644
--- a/src/gnet/geventloop_epoll.cpp
+++ b/src/gnet/geventloop_epoll.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,13 +22,12 @@
 #include "gevent.h"
 #include "gscope.h"
 #include "gexception.h"
-#include "geventhandlerlist.h"
 #include "gtimerlist.h"
 #include "gprocess.h"
-#include "gtest.h"
-#include "gfile.h"
-#include "gstr.h"
 #include "glog.h"
+#include "gassert.h"
+#include <algorithm>
+#include <vector>
 #include <sys/epoll.h>
 
 namespace GNet
@@ -36,14 +35,10 @@ namespace GNet
 	class EventLoopImp ;
 }
 
-//| \class GNet::EventLoopImp
-/// A concrete implementation of GNet::EventLoop using epoll() in its
-/// implementation.
-///
 class GNet::EventLoopImp : public EventLoop
 {
 public:
-	G_EXCEPTION( Error , "epoll error" ) ;
+	G_EXCEPTION( Error , tx("epoll error") ) ;
 	EventLoopImp() ;
 	~EventLoopImp() override ;
 
@@ -58,32 +53,45 @@ private: // overrides
 	void dropRead( Descriptor fd ) noexcept override ;
 	void dropWrite( Descriptor fd ) noexcept override ;
 	void dropOther( Descriptor fd ) noexcept override ;
+	void drop( Descriptor fd ) noexcept override ;
 	void disarm( ExceptionHandler * ) noexcept override ;
 
 public:
 	EventLoopImp( const EventLoopImp & ) = delete ;
 	EventLoopImp( EventLoopImp && ) = delete ;
-	void operator=( const EventLoopImp & ) = delete ;
-	void operator=( EventLoopImp && ) = delete ;
+	EventLoopImp & operator=( const EventLoopImp & ) = delete ;
+	EventLoopImp & operator=( EventLoopImp && ) = delete ;
+
+private:
+	struct ListItem
+	{
+		unsigned int m_events {0U} ;
+		EventEmitter m_read_emitter ;
+		EventEmitter m_write_emitter ;
+	} ;
+	using List = std::vector<ListItem> ;
 
 private:
 	void runOnce() ;
-	bool add( int fd , int events ) ;
-	bool modify( int fd , int events ) ;
-	void remove( int fd ) noexcept ;
-	void clear( int fd ) noexcept ;
+	ListItem * find( Descriptor fd ) noexcept ;
+	ListItem & findOrCreate( Descriptor fd ) ;
 	int ms() const ;
 	static int ms( unsigned int , unsigned int ) ;
+	void fdupdate( int fd , unsigned int old_events , unsigned int new_events ) ;
+	void fdupdate( int fd , unsigned int old_events , unsigned int new_events , std::nothrow_t ) noexcept ;
+	void fdadd( int fd , unsigned int events ) ;
+	void fdmodify( int fd , unsigned int events ) ;
+	int fdmodify( int fd , unsigned int events , std::nothrow_t ) noexcept ;
+	void fdremove( int fd ) noexcept ;
 
 private:
 	std::vector<struct epoll_event> m_wait_events ;
-	int m_wait_rc{0} ;
-	bool m_quit{false} ;
+	int m_wait_rc {0} ;
+	bool m_quit {false} ;
 	std::string m_quit_reason ;
-	bool m_running{false} ;
-	int m_fd{-1} ;
-	EventHandlerList m_read_list ;
-	EventHandlerList m_write_list ;
+	bool m_running {false} ;
+	int m_fd {-1} ;
+	List m_list ;
 } ;
 
 // ===
@@ -93,11 +101,11 @@ std::unique_ptr<GNet::EventLoop> GNet::EventLoop::create()
 	return std::make_unique<EventLoopImp>() ;
 }
 
+// ===
+
 GNet::EventLoopImp::EventLoopImp() :
-	m_read_list("read") ,
-	m_write_list("write")
+	m_fd(epoll_create1(EPOLL_CLOEXEC))
 {
-	m_fd = epoll_create1( EPOLL_CLOEXEC ) ;
 	if( m_fd == -1 )
 		throw Error( "epoll_create" ) ;
 }
@@ -107,9 +115,24 @@ GNet::EventLoopImp::~EventLoopImp()
 	close( m_fd ) ;
 }
 
+void GNet::EventLoopImp::disarm( ExceptionHandler * p ) noexcept
+{
+	for( auto & item : m_list )
+	{
+		item.m_read_emitter.disarm( p ) ;
+		item.m_write_emitter.disarm( p ) ;
+	}
+}
+
+bool GNet::EventLoopImp::running() const
+{
+	return m_running ;
+}
+
 std::string GNet::EventLoopImp::run()
 {
-	G::ScopeExitSetFalse _( m_running = true ) ;
+	G::ScopeExitSetFalse running( m_running = true ) ;
+	m_quit = false ;
 	while( !m_quit )
 	{
 		runOnce() ;
@@ -122,13 +145,14 @@ std::string GNet::EventLoopImp::run()
 
 void GNet::EventLoopImp::runOnce()
 {
-	// resize the output array -- a small fixed-size array works but might lead to starvation
-	m_wait_events.resize( std::max(std::size_t(1U),m_read_list.size()+m_write_list.size()) ) ;
+	// make the output array big enough for the largest file descriptor --
+	// probably better than trying to count non-negative fds
+	m_wait_events.resize( std::max(std::size_t(1U),m_list.size()) ) ;
 
 	// extract the pending events
 	int timeout_ms = ms() ;
 	m_wait_rc = epoll_wait( m_fd , &m_wait_events[0] , m_wait_events.size() , timeout_ms ) ;
-	if( m_wait_rc == -1 )
+	if( m_wait_rc < 0 )
 	{
 		int e = G::Process::errno_() ;
 		if( e != EINTR )
@@ -136,68 +160,58 @@ void GNet::EventLoopImp::runOnce()
 	}
 
 	// handle timer events
-	if( m_wait_rc <= 0 || timeout_ms == 0 )
+	if( m_wait_rc == 0 || timeout_ms == 0 )
 	{
 		TimerList::instance().doTimeouts() ;
 	}
 
-	// handle read events
+	// handle i/o events
 	for( int i = 0 ; m_wait_rc > 0 && i < m_wait_rc ; i++ )
 	{
-		int fd = m_wait_events[i].data.fd ;
-		int e = m_wait_events[i].events ;
-		if( fd >= 0 && (e & EPOLLIN) ) // see clear()
+		unsigned int e = m_wait_events[i].events ;
+		Descriptor fd( m_wait_events[i].data.fd ) ;
+		if( e & EPOLLIN )
 		{
-			auto p = m_read_list.find( Descriptor(fd) ) ;
-			if( p != m_read_list.end() )
-				p.raiseEvent( &EventHandler::readEvent ) ;
+			ListItem * item = find( fd ) ;
+			if( item )
+				item->m_read_emitter.raiseReadEvent( fd ) ;
 		}
-	}
-
-	// handle write events
-	for( int i = 0 ; m_wait_rc > 0 && i < m_wait_rc ; i++ )
-	{
-		int fd = m_wait_events[i].data.fd ;
-		int e = m_wait_events[i].events ;
-		if( fd >= 0 && (e & EPOLLOUT) ) // see clear()
+		if( e & EPOLLOUT )
 		{
-			auto p = m_write_list.find( Descriptor(fd) ) ;
-			if( p != m_write_list.end() )
-				p.raiseEvent( &EventHandler::writeEvent ) ;
+			ListItem * item = find( fd ) ; // again
+			if( item )
+				item->m_write_emitter.raiseWriteEvent( fd ) ;
 		}
 	}
 }
 
 int GNet::EventLoopImp::ms() const
 {
+	constexpr int infinite = -1 ;
 	if( TimerList::ptr() )
 	{
 		auto pair = TimerList::instance().interval() ;
 		if( pair.second )
-			return -1 ;
+			return infinite ;
 		else if( pair.first.s() == 0 && pair.first.us() == 0U )
 			return 0 ;
 		else
-			return ms( pair.first.s() , pair.first.us() ) ;
+			return std::max( 1 , ms(pair.first.s(),pair.first.us()) ) ;
 	}
 	else
 	{
-		return -1 ;
+		return infinite ;
 	}
 }
 
 int GNet::EventLoopImp::ms( unsigned int s , unsigned int us )
 {
 	constexpr unsigned int s_max = static_cast<unsigned int>( std::numeric_limits<int>::max()/1000 - 1 ) ;
+	static_assert( s_max > 600 , "" ) ; // sanity check that clipping at more than ten mins
 	return
 		s >= s_max ?
 			std::numeric_limits<int>::max() :
-			static_cast<int>( s * 1000U + ( us >> 10 ) ) ;
-}
-
-bool GNet::EventLoopImp::running() const
-{
-	return m_running ;
+			static_cast<int>( (s*1000U) + ((us+999U)/1000U) ) ;
 }
 
 void GNet::EventLoopImp::quit( const std::string & reason )
@@ -211,100 +225,45 @@ void GNet::EventLoopImp::quit( const G::SignalSafe & )
 	m_quit = true ;
 }
 
-bool GNet::EventLoopImp::add( int fd , int events )
+GNet::EventLoopImp::ListItem * GNet::EventLoopImp::find( Descriptor fd ) noexcept
 {
-	epoll_event event {} ;
-	event.events = events ;
-	event.data.fd = fd ;
-	int rc = epoll_ctl( m_fd , EPOLL_CTL_ADD , fd , &event ) ;
-	if( rc == -1 )
+	std::size_t ufd = static_cast<unsigned int>(fd.fd()) ;
+	return fd.valid() && ufd < m_list.size() ? &m_list[ufd] : nullptr ;
+}
+
+GNet::EventLoopImp::ListItem & GNet::EventLoopImp::findOrCreate( Descriptor fd )
+{
+	ListItem * p = find( fd ) ;
+	if( p == nullptr )
 	{
-		int e = G::Process::errno_() ;
-		if( e != EEXIST )
-			throw Error( "epoll_ctl(add)" ) ;
-	}
-	return rc != -1 ;
-}
-
-bool GNet::EventLoopImp::modify( int fd , int events )
-{
-	epoll_event event {} ;
-	event.events = events ;
-	event.data.fd = fd ;
-	int rc = epoll_ctl( m_fd , EPOLL_CTL_MOD , fd , &event ) ;
-	if( rc == -1 )
-		throw Error( "epoll_ctl(mod)" ) ;
-	return true ;
-}
-
-void GNet::EventLoopImp::remove( int fd ) noexcept
-{
-	epoll_event event {} ;
-	epoll_ctl( m_fd , EPOLL_CTL_DEL , fd , &event ) ;
-}
-
-void GNet::EventLoopImp::clear( int fd ) noexcept
-{
-	for( int i = 0 ; m_wait_rc > 0 && i < m_wait_rc ; i++ )
-	{
-		if( m_wait_events[i].data.fd == fd )
-		{
-			m_wait_events[i].data.fd = -1 ;
-			break ;
-		}
+		std::size_t ufd = static_cast<unsigned int>(fd.fd()) ;
+		m_list.resize( std::max(m_list.size(),ufd+1U) ) ; // grow, not shrink
+		p = &m_list[ufd] ;
+		*p = ListItem() ;
 	}
+	return *p ;
 }
 
 void GNet::EventLoopImp::addRead( Descriptor fd , EventHandler & handler , ExceptionSink es )
 {
-	if( !m_read_list.contains(fd) )
-	{
-		if( m_write_list.contains(fd) )
-			modify( fd.fd() , EPOLLIN|EPOLLOUT ) ;
-		else
-			add( fd.fd() , EPOLLIN ) ;
-		m_read_list.add( fd , &handler , es ) ;
-	}
+	G_ASSERT( fd.valid() ) ;
+	handler.setDescriptor( fd ) ; // see EventHandler::dtor
+	unsigned int new_events = EPOLLIN ;
+	ListItem & item = findOrCreate( Descriptor(fd) ) ;
+	fdupdate( fd.fd() , item.m_events , item.m_events | new_events ) ;
+	item.m_events |= new_events ;
+	item.m_read_emitter.update( &handler , es ) ;
 }
 
 void GNet::EventLoopImp::addWrite( Descriptor fd , EventHandler & handler , ExceptionSink es )
 {
-	if( !m_write_list.contains(fd) )
-	{
-		if( m_read_list.contains(fd) )
-			modify( fd.fd() , EPOLLIN|EPOLLOUT ) ;
-		else
-			add( fd.fd() , EPOLLOUT ) ;
-		m_write_list.add( fd , &handler , es ) ;
-	}
-}
-
-void GNet::EventLoopImp::dropRead( Descriptor fd ) noexcept
-{
-	m_read_list.remove( fd ) ;
-	if( m_write_list.contains(fd) )
-	{
-		modify( fd.fd() , EPOLLOUT ) ;
-	}
-	else
-	{
-		remove( fd.fd() ) ;
-		clear( fd.fd() ) ;
-	}
-}
-
-void GNet::EventLoopImp::dropWrite( Descriptor fd ) noexcept
-{
-	m_write_list.remove( fd ) ;
-	if( m_read_list.contains(fd) )
-	{
-		modify( fd.fd() , EPOLLIN ) ;
-	}
-	else
-	{
-		remove( fd.fd() ) ;
-		clear( fd.fd() ) ;
-	}
+	G_ASSERT( fd.valid() ) ;
+	handler.setDescriptor( fd ) ; // see EventHandler::dtor
+	unsigned int new_events = EPOLLOUT ;
+	ListItem & item = findOrCreate( Descriptor(fd) ) ;
+	fdupdate( fd.fd() , item.m_events , item.m_events | new_events ) ;
+	item.m_events |= new_events ;
+	item.m_write_emitter.update( &handler , es ) ;
 }
 
 void GNet::EventLoopImp::addOther( Descriptor , EventHandler & , ExceptionSink )
@@ -312,14 +271,103 @@ void GNet::EventLoopImp::addOther( Descriptor , EventHandler & , ExceptionSink )
 	// no-op
 }
 
+void GNet::EventLoopImp::dropRead( Descriptor fd ) noexcept
+{
+	ListItem * item = find( Descriptor(fd) ) ;
+	if( item && ( item->m_events & EPOLLIN ) )
+	{
+		unsigned int new_events = item->m_events & ~EPOLLIN ;
+		fdupdate( fd.fd() , item->m_events , new_events , std::nothrow ) ;
+		item->m_events = new_events ;
+	}
+}
+
+void GNet::EventLoopImp::dropWrite( Descriptor fd ) noexcept
+{
+	ListItem * item = find( Descriptor(fd) ) ;
+	if( item && ( item->m_events & EPOLLOUT ) )
+	{
+		unsigned int new_events = item->m_events & ~EPOLLOUT ;
+		fdupdate( fd.fd() , item->m_events , new_events , std::nothrow ) ;
+		item->m_events = new_events ;
+	}
+}
+
 void GNet::EventLoopImp::dropOther( Descriptor ) noexcept
 {
 	// no-op
 }
 
-void GNet::EventLoopImp::disarm( ExceptionHandler * p ) noexcept
+void GNet::EventLoopImp::drop( Descriptor fd ) noexcept
 {
-	m_read_list.disarm( p ) ;
-	m_write_list.disarm( p ) ;
+	ListItem * item = find( fd ) ;
+	if( item )
+	{
+		if( item->m_events )
+			fdremove( fd.fd() ) ;
+		item->m_events = 0U ;
+		item->m_read_emitter.reset() ;
+		item->m_write_emitter.reset() ;
+	}
+}
+
+void GNet::EventLoopImp::fdupdate( int fd , unsigned int old_events , unsigned int new_events )
+{
+	if( new_events == 0U )
+		fdremove( fd ) ;
+	else if( old_events == 0U )
+		fdadd( fd , new_events ) ;
+	else
+		fdmodify( fd , new_events ) ;
+}
+
+void GNet::EventLoopImp::fdupdate( int fd , unsigned int /*old_events*/ , unsigned int new_events , std::nothrow_t ) noexcept
+{
+	if( new_events == 0U )
+		fdremove( fd ) ;
+	else
+		fdmodify( fd , new_events , std::nothrow ) ;
+}
+
+void GNet::EventLoopImp::fdadd( int fd , unsigned int events )
+{
+	epoll_event event {} ;
+	event.data.fd = fd ;
+	event.events = events ;
+	int rc = epoll_ctl( m_fd , EPOLL_CTL_ADD , fd , &event ) ;
+	if( rc == -1 )
+	{
+		int e = G::Process::errno_() ;
+		throw Error( "epoll_ctl" , "add" , G::Process::strerror(e) ) ;
+	}
+}
+
+void GNet::EventLoopImp::fdmodify( int fd , unsigned int events )
+{
+	epoll_event event {} ;
+	event.data.fd = fd ;
+	event.events = events ;
+	int rc = epoll_ctl( m_fd , EPOLL_CTL_MOD , fd , &event ) ;
+	if( rc == -1 )
+	{
+		int e = G::Process::errno_() ;
+		throw Error( "epoll_ctl" , "modify" , G::Process::strerror(e) ) ;
+	}
+}
+
+int GNet::EventLoopImp::fdmodify( int fd , unsigned int events , std::nothrow_t ) noexcept
+{
+	epoll_event event {} ;
+	event.data.fd = fd ;
+	event.events = events ;
+	int rc = epoll_ctl( m_fd , EPOLL_CTL_MOD , fd , &event ) ;
+	int e = G::Process::errno_() ;
+	return rc == -1 ? e : 0 ;
+}
+
+void GNet::EventLoopImp::fdremove( int fd ) noexcept
+{
+	epoll_event event {} ;
+	epoll_ctl( m_fd , EPOLL_CTL_DEL , fd , &event ) ;
 }
 
diff --git a/src/gnet/geventloop_select.cpp b/src/gnet/geventloop_select.cpp
index cdff476..2f4ea2d 100644
--- a/src/gnet/geventloop_select.cpp
+++ b/src/gnet/geventloop_select.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,7 +21,7 @@
 #include "gdef.h"
 #include "gscope.h"
 #include "gevent.h"
-#include "geventhandlerlist.h"
+#include "geventemitter.h"
 #include "gprocess.h"
 #include "gexception.h"
 #include "gstr.h"
@@ -31,6 +31,8 @@
 #include "gtest.h"
 #include "glog.h"
 #include "gassert.h"
+#include <memory>
+#include <tuple>
 #include <sstream>
 #include <sys/types.h>
 #include <sys/time.h>
@@ -38,41 +40,13 @@
 namespace GNet
 {
 	class EventLoopImp ;
-	class FdSet ;
 }
 
-//| \class GNet::FdSet
-/// An "fd_set" wrapper class used by GNet::EventLoopImp.
-///
-class GNet::FdSet
-{
-public:
-	FdSet() ;
-	void init( const EventHandlerList & ) ;
-	void raiseEvents( EventHandlerList & , void (EventHandler::*method)() ) ;
-	void raiseEvents( EventHandlerList & , void (EventHandler::*method)(EventHandler::Reason) ,
-		EventHandler::Reason ) ;
-	void invalidate() noexcept ;
-	int fdmax( int = 0 ) const ;
-	fd_set * operator()() ;
-
-private:
-	bool m_valid{false} ;
-	int m_fdmax{0} ;
-	fd_set m_set_internal ; // set from EventHandlerList
-	fd_set m_set_external ; // passed to select() and modified by it
-} ;
-
-//| \class GNet::EventLoopImp
-/// A concrete implementation of GNet::EventLoop using select() in its
-/// implementation.
-///
 class GNet::EventLoopImp : public EventLoop
 {
 public:
-	G_EXCEPTION( Error , "select error" ) ;
+	G_EXCEPTION( Error , tx("select error") ) ;
 	EventLoopImp() ;
-	~EventLoopImp() override ;
 
 private: // overrides
 	std::string run() override ;
@@ -85,110 +59,42 @@ private: // overrides
 	void dropRead( Descriptor fd ) noexcept override ;
 	void dropWrite( Descriptor fd ) noexcept override ;
 	void dropOther( Descriptor fd ) noexcept override ;
+	void drop( Descriptor fd ) noexcept override ;
 	void disarm( ExceptionHandler * ) noexcept override ;
 
 public:
+	~EventLoopImp() override = default ;
 	EventLoopImp( const EventLoopImp & ) = delete ;
 	EventLoopImp( EventLoopImp && ) = delete ;
-	void operator=( const EventLoopImp & ) = delete ;
-	void operator=( EventLoopImp && ) = delete ;
+	EventLoopImp & operator=( const EventLoopImp & ) = delete ;
+	EventLoopImp & operator=( EventLoopImp && ) = delete ;
 
 private:
+	using Emitters = std::vector<EventEmitter> ;
 	void runOnce() ;
-	static void check( int ) ;
+	void addImp( int fd , Emitters & , EventHandler & , ExceptionSink ) ;
+	void dropImp( int fd , Emitters & ) noexcept ;
+	void disarmImp( Emitters & , ExceptionHandler * ) noexcept ;
+	static int events( int nfds , fd_set * ) ;
 
 private:
-	bool m_quit{false} ;
+	bool m_quit {false} ;
 	std::string m_quit_reason ;
-	bool m_running{false} ;
-	EventHandlerList m_read_list ;
-	FdSet m_read_set ;
-	EventHandlerList m_write_list ;
-	FdSet m_write_set ;
-	EventHandlerList m_other_list ;
-	FdSet m_other_set ;
+	bool m_running {false} ;
+	int m_nfds {0} ;
+	fd_set m_read_set ; // NOLINT cppcoreguidelines-pro-type-member-init
+	fd_set m_write_set ; // NOLINT cppcoreguidelines-pro-type-member-init
+	fd_set m_other_set ; // NOLINT cppcoreguidelines-pro-type-member-init
+	Emitters m_read_emitters ;
+	Emitters m_write_emitters ;
+	Emitters m_other_emitters ;
+	fd_set m_read_set_copy ;
+	fd_set m_write_set_copy ;
+	fd_set m_other_set_copy ;
 } ;
 
 // ===
 
-GNet::FdSet::FdSet() // NOLINT cppcoreguidelines-pro-type-member-init
-= default;
-
-fd_set * GNet::FdSet::operator()()
-{
-	return &m_set_external ;
-}
-
-void GNet::FdSet::invalidate() noexcept
-{
-	m_valid = false ;
-}
-
-void GNet::FdSet::init( const EventHandlerList & list )
-{
-	// if the internal set has been inivalidate()d then re-initialise
-	// it from the event-handler-list -- then copy the internal list
-	// to the external list -- the external list is passed to select()
-	// and modified by it -- this might look klunky but it is well
-	// optimised on the high frequency code paths and it keeps the
-	// choice of select()/fd_set hidden from client code
-	//
-	if( !m_valid )
-	{
-		// copy the event-handler-list into the internal fd-set
-		m_fdmax = 0 ;
-		FD_ZERO( &m_set_internal ) ; // NOLINT readability-isolate-declaration
-		const EventHandlerList::Iterator end = list.end() ;
-		for( EventHandlerList::Iterator p = list.begin() ; p != end ; ++p )
-		{
-			G_ASSERT( p.fd().valid() && p.fd().fd() >= 0 ) ;
-			Descriptor fd = p.fd() ;
-			if( fd.fd() < 0 ) continue ;
-			FD_SET( fd.fd() , &m_set_internal ) ;
-			if( (fd.fd()+1) > m_fdmax )
-				m_fdmax = (fd.fd()+1) ;
-		}
-		m_valid = true ;
-	}
-	m_set_external = m_set_internal ; // fast structure copy
-}
-
-int GNet::FdSet::fdmax( int n ) const
-{
-	return n > m_fdmax ? n : m_fdmax ;
-}
-
-void GNet::FdSet::raiseEvents( EventHandlerList & list , void (EventHandler::*method)() )
-{
-	EventHandlerList::Lock lock( list ) ; // since event handlers may change the list while we iterate
-	const EventHandlerList::Iterator end = list.end() ;
-	for( EventHandlerList::Iterator p = list.begin() ; p != end ; ++p )
-	{
-		Descriptor fd = p.fd() ;
-		if( fd.fd() >= 0 && FD_ISSET( fd.fd() , &m_set_external ) )
-		{
-			p.raiseEvent( method ) ;
-		}
-	}
-}
-
-void GNet::FdSet::raiseEvents( EventHandlerList & list , void (EventHandler::*method)(EventHandler::Reason) ,
-	EventHandler::Reason reason )
-{
-	EventHandlerList::Lock lock( list ) ; // since event handlers may change the list while we iterate
-	const EventHandlerList::Iterator end = list.end() ;
-	for( EventHandlerList::Iterator p = list.begin() ; p != end ; ++p )
-	{
-		Descriptor fd = p.fd() ;
-		if( fd.fd() >= 0 && FD_ISSET( fd.fd() , &m_set_external ) )
-		{
-			p.raiseEvent( method , reason ) ;
-		}
-	}
-}
-
-// ===
-
 std::unique_ptr<GNet::EventLoop> GNet::EventLoop::create()
 {
 	return std::make_unique<EventLoopImp>() ;
@@ -196,16 +102,16 @@ std::unique_ptr<GNet::EventLoop> GNet::EventLoop::create()
 
 // ===
 
-GNet::EventLoopImp::EventLoopImp() :
-	m_read_list("read") ,
-	m_write_list("write") ,
-	m_other_list("other")
+GNet::EventLoopImp::EventLoopImp() // NOLINT cppcoreguidelines-pro-type-member-init
 {
+	FD_ZERO( &m_read_set ) ;
+	FD_ZERO( &m_write_set ) ;
+	FD_ZERO( &m_other_set ) ;
+	FD_ZERO( &m_read_set_copy ) ;
+	FD_ZERO( &m_write_set_copy ) ;
+	FD_ZERO( &m_other_set_copy ) ;
 }
 
-GNet::EventLoopImp::~EventLoopImp()
-= default;
-
 std::string GNet::EventLoopImp::run()
 {
 	G::ScopeExitSetFalse running( m_running = true ) ;
@@ -237,28 +143,21 @@ void GNet::EventLoopImp::quit( const G::SignalSafe & )
 
 void GNet::EventLoopImp::runOnce()
 {
-	// build fd-sets from handler lists
-	//
-	m_read_set.init( m_read_list ) ;
-	m_write_set.init( m_write_list ) ;
-	m_other_set.init( m_other_list ) ;
-	int n = m_read_set.fdmax( m_write_set.fdmax(m_other_set.fdmax()) ) ;
-
 	// get a timeout interval() from TimerList
 	//
 	using Timeval = struct timeval ;
 	Timeval timeout ;
 	Timeval * timeout_p = nullptr ;
-	bool timeout_immediate = false ;
+	bool immediate = false ;
 	if( TimerList::ptr() != nullptr )
 	{
-		std::pair<G::TimeInterval,bool> interval_pair = TimerList::instance().interval() ;
-		G::TimeInterval interval = interval_pair.first ;
-		bool timeout_infinite = interval_pair.second ;
-		timeout_immediate = !timeout_infinite && interval.s() == 0 && interval.us() == 0U ;
+		G::TimeInterval interval = G::TimeInterval::zero() ;
+		bool infinite ;
+		std::tie( interval , infinite ) = TimerList::instance().interval() ;
 		timeout.tv_sec = interval.s() ;
 		timeout.tv_usec = interval.us() ;
-		timeout_p = timeout_infinite ? nullptr : &timeout ;
+		timeout_p = infinite ? nullptr : &timeout ;
+		immediate = !infinite && interval.s() == 0 && interval.us() == 0U ;
 	}
 
 	if( G::Test::enabled("event-loop-quitfile") ) // esp. for profiling
@@ -275,32 +174,71 @@ void GNet::EventLoopImp::runOnce()
 
 	// do the select()
 	//
-	int rc = ::select( n , m_read_set() , m_write_set() , m_other_set() , timeout_p ) ;
+	int nfds = m_nfds ; // make copies since modified via event handling
+	m_read_set_copy = m_read_set ;
+	m_write_set_copy = m_write_set ;
+	m_other_set_copy = m_other_set ;
+	int rc = ::select( nfds , &m_read_set_copy , &m_write_set_copy , &m_other_set_copy , timeout_p ) ;
 	if( rc < 0 )
 	{
 		int e = G::Process::errno_() ;
 		if( e != EINTR ) // eg. when profiling
 			throw Error( G::Str::fromInt(e) ) ;
 	}
+	G_ASSERT( rc < 0 ||
+		rc == (events(nfds,&m_read_set_copy)+events(nfds,&m_write_set_copy)+events(nfds,&m_other_set_copy)) ) ;
 
 	// call the timeout handlers
 	//
-	if( rc == 0 || timeout_immediate )
+	if( rc == 0 || immediate )
 	{
-		//G_DEBUG( "GNet::EventLoopImp::runOnce: select() timeout" ) ;
 		TimerList::instance().doTimeouts() ;
 	}
 
-	// call the fd event handlers
+	// call the fd event handlers -- note that event handlers can
+	// remove fds from the 'copy' sets but not add them -- that means
+	// that ecount might be smaller that expected, but it still
+	// serves as a valid optimisation
 	//
-	if( rc > 0 )
+	int ecount = 0 ; // optimisation to stop when all events accounted for
+	for( int fd = 0 ; ecount < rc && fd < nfds ; fd++ )
 	{
-		//G_DEBUG( "GNet::EventLoopImp::runOnce: detected event(s) on " << rc << " fd(s)" ) ;
-		m_read_set.raiseEvents( m_read_list , &EventHandler::readEvent ) ;
-		m_write_set.raiseEvents( m_write_list , &EventHandler::writeEvent ) ;
-		m_other_set.raiseEvents( m_other_list , &EventHandler::otherEvent , EventHandler::Reason::other ) ;
+		if( FD_ISSET(fd,&m_read_set_copy) )
+		{
+			ecount++ ;
+			G_ASSERT( static_cast<unsigned int>(fd) < m_read_emitters.size() ) ;
+			m_read_emitters[fd].raiseReadEvent( Descriptor(fd) ) ;
+		}
+		if( FD_ISSET(fd,&m_write_set_copy) )
+		{
+			ecount++ ;
+			G_ASSERT( static_cast<unsigned int>(fd) < m_write_emitters.size() ) ;
+			m_write_emitters[fd].raiseWriteEvent( Descriptor(fd) ) ;
+		}
+		if( FD_ISSET(fd,&m_other_set_copy) )
+		{
+			ecount++ ;
+			G_ASSERT( static_cast<unsigned int>(fd) < m_other_emitters.size() ) ;
+			m_other_emitters[fd].raiseOtherEvent( Descriptor(fd) , EventHandler::Reason::other ) ;
+		}
 	}
 
+	// collect garbage
+	int fd_max = 0 ;
+	for( int fd = 0 ; fd < m_nfds ; fd++ )
+	{
+		if( FD_ISSET(fd,&m_read_set) ||
+			FD_ISSET(fd,&m_write_set) ||
+			FD_ISSET(fd,&m_other_set) )
+		{
+			fd_max = fd ;
+		}
+	}
+	m_nfds = fd_max + 1 ;
+	m_read_emitters.resize( m_nfds ) ;
+	m_write_emitters.resize( m_nfds ) ;
+	m_other_emitters.resize( m_nfds ) ;
+
 	if( G::Test::enabled("event-loop-slow") )
 	{
 		Timeval timeout_slow ;
@@ -310,55 +248,110 @@ void GNet::EventLoopImp::runOnce()
 	}
 }
 
+int GNet::EventLoopImp::events( int nfds , fd_set * sp )
+{
+	int n = 0 ;
+	for( int fd = 0 ; fd < nfds ; fd++ )
+	{
+		if( FD_ISSET(fd,sp) )
+			n++ ;
+	}
+	return n ;
+}
+
 void GNet::EventLoopImp::addRead( Descriptor fd , EventHandler & handler , ExceptionSink es )
 {
-	check( fd.fd() ) ;
-	m_read_list.add( fd , &handler , es ) ;
-	m_read_set.invalidate() ;
+	if( fd.valid() )
+	{
+		handler.setDescriptor( fd ) ; // see EventHandler::dtor
+		addImp( fd.fd() , m_read_emitters , handler , es ) ;
+		FD_SET( fd.fd() , &m_read_set ) ;
+	}
 }
 
 void GNet::EventLoopImp::addWrite( Descriptor fd , EventHandler & handler , ExceptionSink es )
 {
-	check( fd.fd() ) ;
-	m_write_list.add( fd , &handler , es ) ;
-	m_write_set.invalidate() ;
+	if( fd.valid() )
+	{
+		handler.setDescriptor( fd ) ; // see EventHandler::dtor
+		addImp( fd.fd() , m_write_emitters , handler , es ) ;
+		FD_SET( fd.fd() , &m_write_set ) ;
+	}
 }
 
 void GNet::EventLoopImp::addOther( Descriptor fd , EventHandler & handler , ExceptionSink es )
 {
-	check( fd.fd() ) ;
-	m_other_list.add( fd , &handler , es ) ;
-	m_other_set.invalidate() ;
+	if( fd.valid() )
+	{
+		handler.setDescriptor( fd ) ; // see EventHandler::dtor
+		addImp( fd.fd() , m_other_emitters , handler , es ) ;
+		FD_SET( fd.fd() , &m_other_set ) ;
+	}
 }
 
-void GNet::EventLoopImp::check( int fd )
+void GNet::EventLoopImp::addImp( int fd , Emitters & emitters , EventHandler & handler , ExceptionSink es )
 {
 	if( fd >= FD_SETSIZE )
 		throw EventLoop::Overflow( "too many open file descriptors for select()" ) ;
+
+	m_nfds = std::max( m_nfds , fd+1 ) ;
+	emitters.resize( m_nfds ) ;
+	emitters[fd].update( &handler , es ) ;
 }
 
 void GNet::EventLoopImp::dropRead( Descriptor fd ) noexcept
 {
-	m_read_list.remove( fd ) ;
-	m_read_set.invalidate() ;
+	if( fd.valid() )
+	{
+		FD_CLR( fd.fd() , &m_read_set ) ;
+		FD_CLR( fd.fd() , &m_read_set_copy ) ;
+	}
 }
 
 void GNet::EventLoopImp::dropWrite( Descriptor fd ) noexcept
 {
-	m_write_list.remove( fd ) ;
-	m_write_set.invalidate() ;
+	if( fd.valid() )
+	{
+		FD_CLR( fd.fd() , &m_write_set ) ;
+		FD_CLR( fd.fd() , &m_write_set_copy ) ;
+	}
 }
 
 void GNet::EventLoopImp::dropOther( Descriptor fd ) noexcept
 {
-	m_other_list.remove( fd ) ;
-	m_other_set.invalidate() ;
+	if( fd.valid() )
+	{
+		FD_CLR( fd.fd() , &m_other_set ) ;
+		FD_CLR( fd.fd() , &m_other_set_copy ) ;
+	}
+}
+
+void GNet::EventLoopImp::drop( Descriptor fd ) noexcept
+{
+	dropRead( fd ) ;
+	dropWrite( fd ) ;
+	dropOther( fd ) ;
+	std::size_t ufd = static_cast<unsigned int>(fd.fd()) ;
+	if( ufd < m_read_emitters.size() )
+		m_read_emitters[ufd].reset() ;
+	if( ufd < m_write_emitters.size() )
+		m_write_emitters[ufd].reset() ;
+	if( ufd < m_other_emitters.size() )
+		m_other_emitters[ufd].reset() ;
 }
 
 void GNet::EventLoopImp::disarm( ExceptionHandler * p ) noexcept
 {
-	m_read_list.disarm( p ) ;
-	m_write_list.disarm( p ) ;
-	m_other_list.disarm( p ) ;
+	disarmImp( m_read_emitters , p ) ;
+	disarmImp( m_write_emitters , p ) ;
+	disarmImp( m_other_emitters , p ) ;
+}
+
+void GNet::EventLoopImp::disarmImp( Emitters & emitters , ExceptionHandler * p ) noexcept
+{
+	for( auto & emitter : emitters )
+	{
+		emitter.disarm( p ) ;
+	}
 }
 
diff --git a/src/gnet/geventloop_win32.cpp b/src/gnet/geventloop_win32.cpp
index 0fdd66c..ac1f37b 100644
--- a/src/gnet/geventloop_win32.cpp
+++ b/src/gnet/geventloop_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -19,104 +19,131 @@
 ///
 
 #include "gdef.h"
-#include "gscope.h"
-#include "gstr.h"
+#include "geventloop.h"
+#include "geventloophandles.h"
 #include "gevent.h"
-#include "gappinst.h"
 #include "gpump.h"
 #include "gexception.h"
 #include "gtimer.h"
 #include "gtimerlist.h"
+#include "gscope.h"
+#include "gstr.h"
 #include "gtest.h"
 #include "gassert.h"
 #include "glog.h"
+#include <algorithm>
 #include <stdexcept>
 #include <vector>
-#include <algorithm>
+#include <memory>
 #include <new>
 
-#if ! GCONFIG_HAVE_WINDOWS_CREATE_WAITABLE_TIMER_EX
-HANDLE CreateWaitableTimerEx( LPSECURITY_ATTRIBUTES sec , LPCTSTR name , DWORD flags , DWORD )
-{
-	BOOL manual_reset = ( flags & 1 ) ? TRUE : FALSE ;
-	return CreateWaitableTimer( sec , manual_reset , name ) ;
-}
-#endif
-
 namespace GNet
 {
 	class EventLoopImp ;
-	const long READ_EVENTS = (FD_READ | FD_ACCEPT | FD_OOB) ;
-	const long WRITE_EVENTS = (FD_WRITE) ; // no need for "FD_CONNECT"
-	const long EXCEPTION_EVENTS = (FD_CLOSE) ;
+	class EventLoopHandles ;
 }
 
 class GNet::EventLoopImp : public EventLoop
 {
-public:
-	struct Library
-	{
-		Library() ;
-		~Library() ;
-		Library( const Library & ) = delete ;
-		Library( Library && ) = delete ;
-		void operator=( const Library & ) = delete ;
-		void operator=( Library && ) = delete ;
-	} ;
-
 public:
 	EventLoopImp() ;
+		// Default constructor.
+
 	virtual ~EventLoopImp() ;
+		// Destructor.
+
+private: // overrides
 	std::string run() override ;
 	bool running() const override ;
 	void quit( const std::string & ) override ;
 	void quit( const G::SignalSafe & ) override ;
 	void disarm( ExceptionHandler * ) noexcept override ;
-
-private:
 	void addRead( Descriptor , EventHandler & , ExceptionSink ) override ;
 	void addWrite( Descriptor , EventHandler & , ExceptionSink ) override ;
 	void addOther( Descriptor , EventHandler & , ExceptionSink ) override ;
 	void dropRead( Descriptor ) noexcept override ;
 	void dropWrite( Descriptor ) noexcept override ;
 	void dropOther( Descriptor ) noexcept override ;
+	void drop( Descriptor ) noexcept override ;
 
 public:
 	EventLoopImp( const EventLoopImp & ) = delete ;
 	EventLoopImp( EventLoopImp && ) = delete ;
-	void operator=( const EventLoopImp & ) = delete ;
-	void operator=( EventLoopImp && ) = delete ;
+	EventLoopImp & operator=( const EventLoopImp & ) = delete ;
+	EventLoopImp & operator=( EventLoopImp && ) = delete ;
 
 private:
-	using Handles = std::vector<HANDLE> ;
-	using Sockets = std::vector<SOCKET> ;
-	DWORD interval() ;
-	void updateSocket( Descriptor ) ;
-	bool updateSocket( Descriptor , std::nothrow_t ) noexcept ;
-	void updateHandles() ;
-	void loadHandles( Handles & , Sockets & ) ;
-	static void getHandles( EventHandlerList & , Handles & , Sockets & ) ;
-	long desiredEvents( Descriptor ) noexcept ;
-	void onEventHandleEvent( std::size_t ) ;
-	void checkOnAdd( Descriptor ) ;
-	static void checkForOverflow( std::size_t ) ;
-	static int isActive( HANDLE h ) ;
+	void runOnce() ;
+
+private:
+	using Rc = EventLoopHandles::Rc ;
+	using RcType = EventLoopHandles::RcType ;
+	static constexpr long READ_EVENTS = (FD_READ | FD_ACCEPT | FD_OOB) ;
+	static constexpr long WRITE_EVENTS = (FD_WRITE) ;
+	static constexpr long EXCEPTION_EVENTS = (FD_CLOSE | FD_CONNECT) ;
+	using s_type = G::TimeInterval::s_type ;
+	using us_type = G::TimeInterval::us_type ;
+	struct Library
+	{
+		Library() ;
+		~Library() ;
+		Library( const Library & ) = delete ;
+		Library( Library && ) = delete ;
+		Library & operator=( const Library & ) = delete ;
+		Library & operator=( Library && ) = delete ;
+	} ;
+
+public:
+	enum class ListItemType // A type enumeration for the list of event sources.
+	{
+		socket ,
+		simple
+	} ;
+	struct ListItem /// A structure holding an event handle and its event handlers.
+	{
+		explicit ListItem( Descriptor fdd ) :
+			m_type(fdd.fd()==INVALID_SOCKET?ListItemType::simple:ListItemType::socket) ,
+			m_socket(fdd.fd()) ,
+			m_handle(fdd.h())
+		{
+		}
+		Descriptor fd() const
+		{
+			return Descriptor( m_socket , m_handle ) ;
+		}
+		ListItemType m_type{ListItemType::socket} ;
+		SOCKET m_socket {INVALID_SOCKET} ;
+		HANDLE m_handle {HNULL} ;
+		long m_events {0L} ; // 0 => new or garbage
+		EventEmitter m_read_emitter ;
+		EventEmitter m_write_emitter ;
+		EventEmitter m_other_emitter ;
+	} ;
+	using List = std::vector<ListItem> ;
+
+private:
+	ListItem * find( Descriptor ) ;
+	ListItem & findOrCreate( Descriptor ) ;
+	void fdupdate( Descriptor , long ) ;
+	bool fdupdate( Descriptor , long , std::nothrow_t ) noexcept ;
+	void handleSimpleEvent( ListItem & ) ;
+	void handleSocketEvent( std::size_t ) ;
+	void checkForOverflow( const ListItem & ) ;
+	DWORD ms() ;
+	static DWORD ms( s_type , us_type ) noexcept ;
+	static bool isValid( const ListItem & ) ;
+	static bool isInvalid( const ListItem & ) ;
 
 private:
-	bool m_running ;
 	Library m_library ;
-	std::string m_reason ;
-	EventHandlerList m_read_list ;
-	EventHandlerList m_write_list ;
-	EventHandlerList m_other_list ;
-	std::vector<int> m_active ;
-	Handles m_handles ;
-	Sockets m_sockets ;
-	Handles m_count_handles ;
+	List m_list ;
+	std::unique_ptr<EventLoopHandles> m_handles ;
+	bool m_running ;
+	bool m_dirty ;
+	bool m_quit ;
+	std::string m_quit_reason ;
 } ;
 
-// ===
-
 std::unique_ptr<GNet::EventLoop> GNet::EventLoop::create()
 {
 	return std::make_unique<EventLoopImp>() ;
@@ -126,273 +153,23 @@ std::unique_ptr<GNet::EventLoop> GNet::EventLoop::create()
 
 GNet::EventLoopImp::EventLoopImp() :
 	m_running(false) ,
-	m_read_list("read") ,
-	m_write_list("write") ,
-	m_other_list("other")
+	m_dirty(true) ,
+	m_quit(false)
 {
+	m_handles = std::make_unique<EventLoopHandles>() ;
 }
 
 GNet::EventLoopImp::~EventLoopImp()
 {
 }
 
-int GNet::EventLoopImp::isActive( HANDLE h )
-{
-	return WAIT_OBJECT_0 == WaitForSingleObject( h , /*timeout-ms*/0 ) ? 1 : 0 ;
-}
-
-std::string GNet::EventLoopImp::run()
-{
-	G::ScopeExitSetFalse running( m_running = true ) ;
-	updateHandles() ;
-	std::string quit_reason ;
-	for(;;)
-	{
-		DWORD handles_n = static_cast<DWORD>(m_handles.size()) ;
-		HANDLE * handles_p = handles_n ? &m_handles[0] : nullptr ;
-
-		checkForOverflow( handles_n ) ;
-
-		DWORD rc = MsgWaitForMultipleObjectsEx( handles_n , handles_p , interval() , QS_ALLINPUT , 0 ) ;
-		bool updated = false ;
-		{
-			EventHandlerList::Lock lock_read( m_read_list , &updated ) ;
-			EventHandlerList::Lock lock_write( m_write_list , &updated ) ;
-			EventHandlerList::Lock lock_other( m_other_list , &updated ) ;
-
-			if( rc == WAIT_TIMEOUT )
-			{
-				TimerList::instance().doTimeouts() ;
-			}
-			else if( rc >= WAIT_OBJECT_0 && rc < (WAIT_OBJECT_0+handles_n) ) // socket etc event
-			{
-				// rc indicates left-most event, but we want to process all events in the
-				// current iteration since leaving events for the next iteration leads
-				// to starvation, so check forwards from the left-most using isActive()
-				std::size_t index = static_cast<std::size_t>(rc-WAIT_OBJECT_0) ;
-				std::transform( m_handles.begin()+index , m_handles.end() , m_active.begin()+index , isActive ) ;
-				for( ; index < handles_n ; index++ )
-				{
-					if( m_active[index] )
-						onEventHandleEvent( index ) ;
-				}
-			}
-			else if( rc == (WAIT_OBJECT_0+handles_n) ) // window message
-			{
-				std::pair<bool,std::string> quit = GGui::Pump::runToEmpty() ;
-				if( quit.first )
-				{
-					G_DEBUG( "GNet::EventLoopImp::run: quit" ) ;
-					quit_reason = quit.second ;
-					break ;
-				}
-			}
-			else
-			{
-				DWORD e = GetLastError() ;
-				throw Error( "msg-wait-for-multiple-objects failed" ,
-					G::Str::fromUInt(static_cast<unsigned int>(handles_n)) ,
-					G::Str::fromUInt(static_cast<unsigned int>(e)) ) ;
-			}
-		}
-		if( updated )
-			updateHandles() ;
-	}
-	return quit_reason ;
-}
-
-void GNet::EventLoopImp::onEventHandleEvent( std::size_t handle_index )
-{
-	Descriptor fdd( m_sockets.at(handle_index) , m_handles.at(handle_index) ) ;
-	if( fdd.fd() == INVALID_SOCKET ) // future event
-	{
-		GNet::EventHandlerList::Iterator p = m_read_list.find( fdd ) ;
-		if( p != m_read_list.end() ) // the FutureEvent may have disappeared and invalidated the handle
-		{
-			::ResetEvent( fdd.h() ) ; // manual-reset event-object, similar to a socket handle
-			p.raiseEvent( &EventHandler::readEvent ) ;
-		}
-	}
-	else
-	{
-		WSANETWORKEVENTS events_info ;
-		int rc = WSAEnumNetworkEvents( fdd.fd() , fdd.h() , &events_info ) ;
-		if( rc != 0 )
-			throw Error( "wsa-enum-network-events failed" ) ;
-
-		long event = events_info.lNetworkEvents ;
-		if( event & WRITE_EVENTS )
-		{
-			m_write_list.find(fdd).raiseEvent( &EventHandler::writeEvent ) ;
-		}
-		if( event & READ_EVENTS )
-		{
-			m_read_list.find(fdd).raiseEvent( &EventHandler::readEvent ) ;
-		}
-		if( event & EXCEPTION_EVENTS )
-		{
-			int e = events_info.iErrorCode[FD_CLOSE_BIT] ; G_ASSERT( EXCEPTION_EVENTS == FD_CLOSE ) ;
-			EventHandler::Reason reason = EventHandler::Reason::other ;
-			if( e == 0 ) reason = EventHandler::Reason::closed ;
-			if( e == WSAENETDOWN ) reason = EventHandler::Reason::down ;
-			if( e == WSAECONNRESET ) reason = EventHandler::Reason::reset ;
-			if( e == WSAECONNABORTED ) reason = EventHandler::Reason::abort ;
-			m_other_list.find(fdd).raiseEvent( &EventHandler::otherEvent , reason ) ;
-		}
-	}
-}
-
-void GNet::EventLoopImp::addRead( Descriptor fdd , EventHandler & handler , ExceptionSink es )
-{
-	checkOnAdd( fdd ) ;
-	m_read_list.add( fdd , &handler , es ) ;
-	updateSocket( fdd ) ;
-}
-
-void GNet::EventLoopImp::addWrite( Descriptor fdd , EventHandler & handler , ExceptionSink es )
-{
-	checkOnAdd( fdd ) ;
-	m_write_list.add( fdd , &handler , es ) ;
-	updateSocket( fdd ) ;
-}
-
-void GNet::EventLoopImp::addOther( Descriptor fdd , EventHandler & handler , ExceptionSink es )
-{
-	checkOnAdd( fdd ) ;
-	m_other_list.add( fdd , &handler , es ) ;
-	updateSocket( fdd ) ;
-}
-
-void GNet::EventLoopImp::dropRead( Descriptor fdd ) noexcept
-{
-	m_read_list.remove( fdd ) ;
-	updateSocket( fdd , std::nothrow ) ;
-}
-
-void GNet::EventLoopImp::dropWrite( Descriptor fdd ) noexcept
-{
-	m_write_list.remove( fdd ) ;
-	updateSocket( fdd , std::nothrow ) ;
-}
-
-void GNet::EventLoopImp::dropOther( Descriptor fdd ) noexcept
-{
-	m_other_list.remove( fdd ) ;
-	updateSocket( fdd , std::nothrow ) ;
-}
-
-void GNet::EventLoopImp::updateSocket( Descriptor fdd )
-{
-	G_ASSERT( fdd.h() != 0 ) ;
-	if( fdd.fd() != INVALID_SOCKET ) // see GNet::FutureEvent
-	{
-		int rc = WSAEventSelect( fdd.fd() , fdd.h() , desiredEvents(fdd) ) ;
-		if( rc != 0 )
-			throw Error( "wsa-event-select failed" ) ;
-	}
-}
-
-bool GNet::EventLoopImp::updateSocket( Descriptor fdd , std::nothrow_t ) noexcept
-{
-	int rc = 0 ;
-	if( fdd.fd() != INVALID_SOCKET )
-		rc = WSAEventSelect( fdd.fd() , fdd.h() , desiredEvents(fdd) ) ;
-	return rc == 0 ;
-}
-
-void GNet::EventLoopImp::updateHandles()
-{
-	loadHandles( m_handles , m_sockets ) ;
-	m_active.resize( m_handles.size() ) ;
-}
-
-void GNet::EventLoopImp::loadHandles( Handles & handles , Sockets & sockets )
-{
-	handles.clear() ;
-	sockets.clear() ;
-	getHandles( m_read_list , handles , sockets ) ;
-	getHandles( m_write_list , handles , sockets ) ;
-	getHandles( m_other_list , handles , sockets ) ;
-}
-
-void GNet::EventLoopImp::getHandles( EventHandlerList & list , Handles & handles , Sockets & sockets )
-{
-	G_ASSERT( handles.size() == sockets.size() ) ;
-	using Range = std::pair<Handles::iterator,Handles::iterator> ;
-	for( EventHandlerList::Iterator p = list.begin() ; p != list.end() ; ++p )
-	{
-		// we need to avoid duplicate handles so populate as a sorted list
-		HANDLE h = p.fd().h() ;
-		SOCKET s = p.fd().fd() ;
-		Range range = std::equal_range( handles.begin() , handles.end() , h ) ;
-		if( range.first == range.second )
-		{
-			Handles::iterator h_pos = handles.insert( range.first , h ) ;
-			Sockets::iterator s_pos = sockets.begin() + std::distance(handles.begin(),h_pos) ;
-			sockets.insert( s_pos , s ) ;
-		}
-	}
-}
-
-void GNet::EventLoopImp::checkOnAdd( Descriptor new_fdd )
-{
-	// check the number of handles that will be waited for in the next
-	// event-loop iteration assuming no other adds or removes happen
-	// before we get there
-
-	if( !new_fdd.h() ) return ;
-	m_count_handles.clear() ;
-	m_read_list.getHandles( m_count_handles ) ;
-	m_write_list.getHandles( m_count_handles ) ;
-	m_other_list.getHandles( m_count_handles ) ;
-	bool is_new = std::binary_search( m_count_handles.begin() , m_count_handles.end() , new_fdd.h() ) ;
-	std::size_t n = m_count_handles.size() + (is_new?1U:0U) ;
-	checkForOverflow( n ) ;
-}
-
-void GNet::EventLoopImp::checkForOverflow( std::size_t n )
-{
-	std::size_t limit = MAXIMUM_WAIT_OBJECTS ;
-	if( n >= limit )
-		throw EventLoop::Overflow( "too many open handles" ) ;
-}
-
-long GNet::EventLoopImp::desiredEvents( Descriptor fdd ) noexcept
-{
-	long mask = 0 ;
-	const bool read = m_read_list.contains( fdd ) ;
-	const bool write = m_write_list.contains( fdd ) ;
-	const bool other = m_other_list.contains( fdd ) ;
-	if( read ) mask |= READ_EVENTS ;
-	if( write ) mask |= WRITE_EVENTS ;
-	if( other ) mask |= EXCEPTION_EVENTS ;
-	return mask ;
-}
-
 void GNet::EventLoopImp::disarm( ExceptionHandler * p ) noexcept
 {
-	m_read_list.disarm( p ) ;
-	m_write_list.disarm( p ) ;
-	m_other_list.disarm( p ) ;
-}
-
-DWORD GNet::EventLoopImp::interval()
-{
-	std::pair<G::TimeInterval,bool> interval_pair = TimerList::instance().interval() ;
-	if( interval_pair.second )
+	for( auto & item : m_list )
 	{
-		return INFINITE ; // 0xffffffff
-	}
-	else
-	{
-		ULARGE_INTEGER u ; // (64-bit ULONGLONG Quad and 32-bit DWORD HighPart/LowPart)
-		u.QuadPart = static_cast<ULONGLONG>( interval_pair.first.s() ) ;
-		if( u.HighPart ) u.HighPart = 0 , u.LowPart = 0xffffffff ;
-		u.QuadPart = UInt32x32To64( u.LowPart , 1000U ) ; // s->ms
-		u.QuadPart += ( interval_pair.first.us() / 1000U ) ; // us->ms
-		DWORD ms = u.HighPart ? 0xffffffff : u.LowPart ;
-		if( ms == INFINITE ) --ms ;
-		return ms ;
+		item.m_read_emitter.disarm( p ) ;
+		item.m_write_emitter.disarm( p ) ;
+		item.m_other_emitter.disarm( p ) ;
 	}
 }
 
@@ -401,6 +178,106 @@ bool GNet::EventLoopImp::running() const
 	return m_running ;
 }
 
+std::string GNet::EventLoopImp::run()
+{
+	m_handles->init( m_list ) ;
+
+	G::ScopeExitSetFalse running( m_running = true ) ;
+	m_dirty = false ;
+	m_quit = false ;
+	while( !m_quit )
+	{
+		runOnce() ;
+	}
+	std::string quit_reason = m_quit_reason ;
+	m_quit_reason.clear() ;
+	m_quit = false ;
+	return quit_reason ;
+}
+
+void GNet::EventLoopImp::runOnce()
+{
+	EventLoopHandles & handles = *m_handles ;
+
+	if( handles.overflow( m_list.size() ) )
+		throw Overflow( handles.help(m_list,false) ) ;
+
+	auto rc = handles.waitForMultipleObjects( ms() ) ;
+
+	if( rc == RcType::timeout )
+	{
+		TimerList::instance().doTimeouts() ;
+	}
+	else if( rc == RcType::event )
+	{
+		// let the handles object shuffle our list
+		std::size_t list_index = handles.shuffle( m_list , rc ) ;
+
+		ListItem & list_item = m_list[list_index] ;
+		if( list_item.m_type == ListItemType::socket )
+			handleSocketEvent( list_index ) ;
+		else
+			handleSimpleEvent( list_item ) ;
+	}
+	else if( rc == RcType::message )
+	{
+		std::pair<bool,std::string> quit = GGui::Pump::runToEmpty() ;
+		if( quit.first )
+		{
+			G_DEBUG( "GNet::EventLoopImp::run: quit" ) ;
+			m_quit_reason = quit.second ;
+			m_quit = true ;
+		}
+	}
+	else if( rc == RcType::failed )
+	{
+		DWORD e = GetLastError() ;
+		throw Error( "wait-for-multiple-objects failed" ,
+			G::Str::fromUInt(static_cast<unsigned int>(e)) ) ;
+	}
+
+	// garbage collection
+	bool updated = m_dirty ; // m_list updated as a result of event handling
+	if( m_dirty )
+	{
+		m_list.erase( std::remove_if(m_list.begin(),m_list.end(),&EventLoopImp::isInvalid) , m_list.end() ) ;
+		m_dirty = false ;
+	}
+
+	// let the handles object see the new, garbage-collected list
+	handles.update( m_list , updated , rc ) ;
+}
+
+DWORD GNet::EventLoopImp::ms()
+{
+	if( TimerList::ptr() )
+	{
+		auto pair = TimerList::instance().interval() ;
+		if( pair.second )
+			return INFINITE ;
+		else if( pair.first.s() == 0 && pair.first.us() == 0U )
+			return 0 ;
+		else
+			return std::max( DWORD(1) , ms(pair.first.s(),pair.first.us()) ) ;
+	}
+	else
+	{
+		return INFINITE ;
+	}
+}
+
+DWORD GNet::EventLoopImp::ms( s_type s , us_type us ) noexcept
+{
+	constexpr DWORD dword_max = 0xffffffff ;
+	constexpr DWORD dword_max_1 = dword_max - 1 ;
+	static_assert( INFINITE == dword_max , "" ) ;
+	constexpr auto s_max = static_cast<s_type>( dword_max/1000U - 1U ) ;
+	return
+		s >= s_max ?
+			dword_max_1 :
+			static_cast<DWORD>( (s*1000U) + ((us+999U)/1000U) ) ;
+}
+
 void GNet::EventLoopImp::quit( const std::string & reason )
 {
 	GGui::Pump::quit( reason ) ;
@@ -408,7 +285,209 @@ void GNet::EventLoopImp::quit( const std::string & reason )
 
 void GNet::EventLoopImp::quit( const G::SignalSafe & )
 {
-	// not implemented
+	// (quit without processing window messages)
+	m_quit = true ;
+}
+
+GNet::EventLoopImp::ListItem * GNet::EventLoopImp::find( Descriptor fd )
+{
+	const HANDLE h = fd.h() ;
+	auto p = std::find_if( m_list.begin() , m_list.end() , [h](const ListItem & i){return i.m_handle==h;} ) ;
+	return p == m_list.end() ? nullptr : &(*p) ;
+}
+
+GNet::EventLoopImp::ListItem & GNet::EventLoopImp::findOrCreate( Descriptor fd )
+{
+	G_ASSERT( fd.h() != HNULL ) ;
+	const HANDLE h = fd.h() ;
+	auto p = std::find_if( m_list.begin() , m_list.end() , [h](const ListItem & i){return i.m_handle==h;} ) ;
+	if( p == m_list.end() )
+	{
+		m_list.emplace_back( fd ) ;
+		p = m_list.begin() + m_list.size() - 1U ;
+		(*p).m_events = 0 ; // => newly created
+	}
+	return *p ;
+}
+
+void GNet::EventLoopImp::addRead( Descriptor fd , EventHandler & handler , ExceptionSink es )
+{
+	handler.setDescriptor( fd ) ; // see EventHandler::dtor
+	ListItem & item = findOrCreate( fd ) ;
+	checkForOverflow( item ) ;
+	m_dirty |= ( item.m_events == 0L ) ; // dirty if new Item created
+	item.m_events |= READ_EVENTS ;
+	item.m_read_emitter = EventEmitter( &handler , es ) ;
+	fdupdate( fd , item.m_events ) ;
+}
+
+void GNet::EventLoopImp::addWrite( Descriptor fd , EventHandler & handler , ExceptionSink es )
+{
+	handler.setDescriptor( fd ) ; // see EventHandler::dtor
+	ListItem & item = findOrCreate( fd ) ;
+	checkForOverflow( item ) ;
+	m_dirty |= ( item.m_events == 0L ) ;
+	item.m_events |= WRITE_EVENTS ;
+	item.m_write_emitter = EventEmitter( &handler , es ) ;
+	fdupdate( fd , item.m_events ) ;
+}
+
+void GNet::EventLoopImp::addOther( Descriptor fd , EventHandler & handler , ExceptionSink es )
+{
+	handler.setDescriptor( fd ) ; // see EventHandler::dtor
+	ListItem & item = findOrCreate( fd ) ;
+	checkForOverflow( item ) ;
+	m_dirty |= ( item.m_events == 0L ) ;
+	item.m_events |= EXCEPTION_EVENTS ;
+	item.m_other_emitter = EventEmitter( &handler , es ) ;
+	fdupdate( fd , item.m_events ) ;
+}
+
+void GNet::EventLoopImp::dropRead( Descriptor fd ) noexcept
+{
+	ListItem * item = find( fd ) ;
+	if( item )
+	{
+		item->m_events &= ~READ_EVENTS ;
+		fdupdate( fd , item->m_events , std::nothrow ) ;
+		m_dirty |= ( item->m_events == 0L ) ; // dirty if Item now logically deleted
+	}
+}
+
+void GNet::EventLoopImp::dropWrite( Descriptor fd ) noexcept
+{
+	ListItem * item = find( fd ) ;
+	if( item )
+	{
+		item->m_events &= ~WRITE_EVENTS ;
+		fdupdate( fd , item->m_events , std::nothrow ) ;
+		m_dirty |= ( item->m_events == 0L ) ;
+	}
+}
+
+void GNet::EventLoopImp::dropOther( Descriptor fd ) noexcept
+{
+	ListItem * item = find( fd ) ;
+	if( item )
+	{
+		item->m_events &= ~EXCEPTION_EVENTS ;
+		fdupdate( fd , item->m_events , std::nothrow ) ;
+		m_dirty |= ( item->m_events == 0L ) ;
+	}
+}
+
+void GNet::EventLoopImp::drop( Descriptor fd ) noexcept
+{
+	ListItem * item = find( fd ) ;
+	if( item )
+	{
+		item->m_events = 0U ;
+		fdupdate( fd , item->m_events , std::nothrow ) ;
+		item->m_read_emitter.reset() ;
+		item->m_write_emitter.reset() ;
+		item->m_other_emitter.reset() ;
+		m_dirty = true ;
+	}
+}
+
+bool GNet::EventLoopImp::isInvalid( const ListItem & item )
+{
+	return item.m_events == 0L ;
+}
+
+bool GNet::EventLoopImp::isValid( const ListItem & item )
+{
+	return item.m_events != 0L ;
+}
+
+void GNet::EventLoopImp::handleSimpleEvent( ListItem & item )
+{
+	ResetEvent( item.m_handle ) ; // manual-reset event-object -- see GNet::FutureEvent
+	item.m_read_emitter.raiseReadEvent( Descriptor(INVALID_SOCKET,item.m_handle) ) ;
+}
+
+void GNet::EventLoopImp::handleSocketEvent( std::size_t index )
+{
+	ListItem * item = &m_list[index] ;
+
+	WSANETWORKEVENTS events_info ;
+	int rc = WSAEnumNetworkEvents( item->m_socket , item->m_handle , &events_info ) ;
+	bool e_not_sock = false ;
+	if( rc != 0 && !(e_not_sock = (WSAGetLastError()==WSAENOTSOCK)) )
+		throw Error( "enum-network-events failed" ) ;
+
+	G_ASSERT( !e_not_sock ) ;
+	if( e_not_sock )
+		throw Error( "enum-network-events failed: not a socket" ) ;
+
+	// we might do more than one raiseEvent() here and m_list can change
+	// between each call, potentially invalidating our ListItem pointer --
+	// however we use garbage collection and no inserts on m_list so we
+	// can recover a valid pointer from the index
+
+	long events = events_info.lNetworkEvents ;
+	if( events & READ_EVENTS )
+	{
+		item->m_read_emitter.raiseReadEvent( item->fd() ) ;
+		item = nullptr ;
+	}
+	if( events & WRITE_EVENTS )
+	{
+		item = item ? item : &m_list[index] ;
+		item->m_write_emitter.raiseWriteEvent( item->fd() ) ;
+		item = nullptr ;
+	}
+	if( events & EXCEPTION_EVENTS )
+	{
+		static_assert( EXCEPTION_EVENTS == (FD_CLOSE|FD_CONNECT) , "" ) ;
+		item = item ? item : &m_list[index] ;
+		if( events_info.lNetworkEvents & FD_CONNECT )
+		{
+			int e = events_info.iErrorCode[FD_CONNECT_BIT] ;
+			if( e )
+				item->m_other_emitter.raiseOtherEvent( item->fd() , EventHandler::Reason::failed ) ;
+		}
+		else
+		{
+			int e = events_info.iErrorCode[FD_CLOSE_BIT] ;
+			EventHandler::Reason reason = EventHandler::Reason::other ;
+			if( e == 0 ) reason = EventHandler::Reason::closed ;
+			if( e == WSAENETDOWN ) reason = EventHandler::Reason::down ;
+			if( e == WSAECONNRESET ) reason = EventHandler::Reason::reset ;
+			if( e == WSAECONNABORTED ) reason = EventHandler::Reason::abort ;
+			item->m_other_emitter.raiseOtherEvent( item->fd() , reason ) ;
+		}
+	}
+}
+
+void GNet::EventLoopImp::checkForOverflow( const ListItem & item )
+{
+	G_ASSERT( m_handles != nullptr ) ;
+	const bool is_new = item.m_events == 0L ;
+	if( is_new && m_handles->overflow( m_list , &EventLoopImp::isValid ) )
+	{
+		m_list.pop_back() ;
+		throw Overflow( m_handles->help(m_list,true) ) ;
+	}
+}
+
+void GNet::EventLoopImp::fdupdate( Descriptor fdd , long events )
+{
+	G_ASSERT( fdd.h() != 0 ) ;
+	if( fdd.fd() != INVALID_SOCKET ) // see GNet::FutureEvent
+	{
+		int rc = WSAEventSelect( fdd.fd() , fdd.h() , events ) ;
+		if( rc != 0 )
+			throw Error( "wsa-event-select failed" ) ;
+	}
+}
+
+bool GNet::EventLoopImp::fdupdate( Descriptor fdd , long events , std::nothrow_t ) noexcept
+{
+	int rc = 0 ;
+	if( fdd.fd() != INVALID_SOCKET )
+		rc = WSAEventSelect( fdd.fd() , fdd.h() , events ) ;
+	return rc == 0 ;
 }
 
 // ==
diff --git a/src/gnet/geventloophandles.cpp b/src/gnet/geventloophandles.cpp
new file mode 100644
index 0000000..ae067c8
--- /dev/null
+++ b/src/gnet/geventloophandles.cpp
@@ -0,0 +1,29 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file geventloophandles.cpp
+///
+
+#include "gdef.h"
+#include "geventloophandles.h"
+
+GNet::EventLoopHandles::EventLoopHandles()
+= default ;
+
+GNet::EventLoopHandles::~EventLoopHandles()
+= default ;
+
diff --git a/src/gnet/geventloophandles.h b/src/gnet/geventloophandles.h
new file mode 100644
index 0000000..521e91e
--- /dev/null
+++ b/src/gnet/geventloophandles.h
@@ -0,0 +1,370 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file geventloophandles.h
+///
+
+#ifndef G_NET_EVENTLOOPHANDLES_H
+#define G_NET_EVENTLOOPHANDLES_H
+
+#include "gdef.h"
+#include "geventloop.h"
+#include "glog.h"
+#include "gassert.h"
+#include <memory>
+#include <vector>
+#include <array>
+#include <algorithm>
+#include <sstream>
+
+namespace GNet
+{
+	class EventLoopHandles ;
+	class EventLoopHandlesMT ;
+	static constexpr std::size_t LIMIT = (MAXIMUM_WAIT_OBJECTS-1) ; // sic
+}
+
+//| \class GNet::EventLoopHandles
+/// Wraps WaitForMultipleObjects(), holding an array of Windows handles.
+/// The handles are obtained from a list of event-emitting items
+/// maintained by the Windows event-loop implementation.
+///
+/// \code
+/// List m_list ;
+/// void run()
+/// {
+///   Handles handles ;
+///   handles.init( m_list ) ;
+///   for(;;)
+///   {
+///     if( handles.overflow( m_list.size() ) ) throw ;
+///     auto rc = handles.waitForMultipleObjects( timeout() ) ;
+///     if( rc == RcType::event )
+///     {
+///       auto i = handles.shuffle( m_list , rc ) ;
+///       handleEvent( m_list[i] ) ;
+///     }
+///     if( m_list.isDirty() )
+///       m_list.collectGarbage() ;
+///     handles.update( m_list , m_list.wasDirty() , rc ) ;
+///   }
+/// }
+/// void add( HANDLE h )
+/// {
+///   m_list.push_back( {h,...} ) ;
+///   if( handles.overflow( m_list , ... ) ) throw ... ;
+/// }
+/// \endcode
+///
+class GNet::EventLoopHandles
+{
+public:
+	enum class RcType // A type enumeration for GNet::EventLoopImp::Rc.
+	{
+		timeout ,
+		event ,
+		message ,
+		failed ,
+		other
+	}  ;
+	struct Rc /// A structure for the return code from WaitForMultipleObjects().
+	{
+		Rc( RcType type , std::size_t index = 0U ) noexcept ;
+		RcType type() const noexcept ;
+		operator RcType () const noexcept { return m_type ; } // (inline definition for msvc)
+		std::size_t index() const noexcept ;
+		//
+		RcType m_type ;
+		std::size_t m_index ; // ListItem index
+	} ;
+
+public:
+	EventLoopHandles() ;
+		///< Constructor. The implementation immediately after construction
+		///< is single-threaded.
+
+	~EventLoopHandles() ;
+		///< Destructor.
+
+	Rc waitForMultipleObjects( DWORD ms ) ;
+		///< Waits for an event on any of the handles, up to some time
+		///< limit. Returns an enumerated result together with the index
+		///< of the first handle with an event.
+
+	template <typename TList> void init( TList & ) ;
+		///< Initialises the handles from the event-loop list.
+
+	template <typename TList> void update( TList & , bool full_update , Rc rc ) ;
+		///< Copies in a fresh set of handles from the event-loop list.
+		///< The list must be freshly garbage-collected so that all
+		///< the handles are valid. This is called after every
+		///< waitForMultipleObjects() once any returned event has
+		///< been fully handled. If the list has changed as a result
+		///< of handling the event then 'full-update' should be set
+		///< to true, along with the index of the event that has just
+		///< been handled in 'rc'.
+
+	template <typename TList> std::size_t shuffle( TList & , Rc rc ) ;
+		///< Shuffles the external event-loop list and the internal
+		///< handles as necessary to prevent starvation. Returns
+		///< the new list index of the current event after shuffling
+		///< (see Rc::index()).
+
+	template <typename TList> bool overflow( TList & list , bool (*valid_fn)(const typename TList::value_type&) ) ;
+		///< Returns true if the number of valid entries in the event-loop
+		///< list would cause an overflow, using the given function to
+		///< ignore list items that are going to be garbage collected.
+		///< The last item on the list is considered to be valid,
+		///< regardless of what the tester function says.
+		///<
+		///< The event loop should use this immediately after adding
+		///< an item to the list and not just wait for the next go-round.
+		///< This allows the error condition to be handled cleanly
+		///< without terminating the event-loop and exiting main().
+		///<
+		///< This overload allows the implementation to switch over
+		///< automatically on first overflow to an implementation
+		///< that supports more handles.
+
+	bool overflow( std::size_t ) const ;
+		///< An overload taking the number of valid entries in the
+		///< event-loop list. This overload does not allow the
+		///< implementation to switch over.
+
+	template <typename TList> std::string help( const TList & , bool on_add ) const ;
+		///< Returns a helpful explanation for overflow().
+
+private:
+	Rc waitForMultipleObjects_MT( DWORD ms ) ;
+	template <typename TList> void update_MT( TList & , bool (*fn)(const typename TList::value_type&) ) ;
+	template <typename TList> std::size_t shuffle_MT( TList & , Rc ) ;
+	template <typename TList> bool overflow_MT( TList & , bool (*fn)(const typename TList::value_type&) ) ;
+	bool overflow_MT( std::size_t ) const ;
+	template <typename TList> std::string help_MT( const TList & , bool ) const ;
+
+private:
+	std::vector<HANDLE> m_handles ;
+	std::unique_ptr<EventLoopHandlesMT> m_mt ;
+} ;
+
+class GNet::EventLoopHandlesMT
+{
+	///< no multi-threaded implemention
+} ;
+
+// ===
+
+inline
+GNet::EventLoopHandles::Rc::Rc( RcType type , std::size_t index ) noexcept :
+	m_type(type) ,
+	m_index(index)
+{
+}
+
+inline
+GNet::EventLoopHandles::RcType GNet::EventLoopHandles::Rc::type() const noexcept
+{
+	return m_type ;
+}
+
+inline
+std::size_t GNet::EventLoopHandles::Rc::index() const noexcept
+{
+	return m_index ;
+}
+
+// ==
+
+template <typename TList>
+void GNet::EventLoopHandles::init( TList & list )
+{
+	G_ASSERT( m_mt.get() == nullptr ) ;
+	{
+		m_handles.resize( list.size() ) ;
+		std::size_t i = 0U ;
+		for( const auto & list_item : list )
+			m_handles[i++] = list_item.m_handle ;
+	}
+}
+
+inline
+GNet::EventLoopHandles::Rc GNet::EventLoopHandles::waitForMultipleObjects( DWORD ms )
+{
+	if( m_mt )
+	{
+		return waitForMultipleObjects_MT( ms ) ;
+	}
+	else
+	{
+		DWORD handles_n = static_cast<DWORD>( m_handles.size() ) ;
+		HANDLE * handles_p = m_handles.empty() ? nullptr : &m_handles[0] ;
+		DWORD rc = MsgWaitForMultipleObjectsEx( handles_n , handles_p , ms , QS_ALLINPUT , 0 ) ;
+
+		if( rc == WAIT_TIMEOUT )
+		{
+			return { RcType::timeout } ;
+		}
+		else if( rc >= WAIT_OBJECT_0 && rc < (WAIT_OBJECT_0+handles_n) )
+		{
+			return { RcType::event , static_cast<std::size_t>(rc-WAIT_OBJECT_0) } ;
+		}
+		else if( rc == (WAIT_OBJECT_0+handles_n) )
+		{
+			return { RcType::message } ;
+		}
+		else if( rc == WAIT_FAILED )
+		{
+			return { RcType::failed } ;
+		}
+		else
+		{
+			return { RcType::other } ;
+		}
+	}
+}
+
+template <typename TList>
+std::size_t GNet::EventLoopHandles::shuffle( TList & list , Rc rc )
+{
+	if( m_mt )
+	{
+		return shuffle_MT( list , rc ) ;
+	}
+	else
+	{
+		G_ASSERT( !m_handles.empty() ) ;
+		G_ASSERT( list.size() == m_handles.size() ) ;
+		G_ASSERT( rc.index() < m_handles.size() ) ;
+		std::size_t index = rc.index() ;
+		std::vector<HANDLE> & handles = m_handles ;
+		if( (index+1U) < handles.size() ) // if not already rightmost
+		{
+			std::size_t index_1 = index + 1U ;
+			std::rotate( handles.begin()+index , handles.begin()+index_1 , handles.end() ) ;
+			std::rotate( list.begin()+index , list.begin()+index_1 , list.end() ) ;
+			index = handles.size() - 1U ;
+		}
+		return index ;
+	}
+}
+
+template <typename TList>
+void GNet::EventLoopHandles::update( TList & list , bool updated , Rc rc )
+{
+	if( !updated ) return ;
+	if( m_mt )
+	{
+		update_MT( list , nullptr ) ;
+	}
+	else
+	{
+		m_handles.resize( list.size() ) ;
+		std::size_t i = 0U ;
+		for( const auto & list_item : list )
+			m_handles[i++] = list_item.m_handle ;
+	}
+}
+
+inline
+bool GNet::EventLoopHandles::overflow( std::size_t n ) const
+{
+	if( m_mt )
+	{
+		return overflow_MT( n ) ;
+	}
+	else
+	{
+		return n > LIMIT ;
+	}
+}
+
+template <typename TList>
+bool GNet::EventLoopHandles::overflow( TList & list , bool (*fn)(const typename TList::value_type&) )
+{
+	if( m_mt )
+	{
+		return overflow_MT( list , fn ) ;
+	}
+	else
+	{
+		bool is_overflow =
+			list.size() > LIMIT &&
+			static_cast<std::size_t>(1+std::count_if(list.cbegin(),list.cbegin()+list.size()-1U,fn)) > LIMIT ;
+		// if( is_overflow ) { m_mt = std::make_unique<EventLoopHandlesMT>() ; m_mt->update_MT(list) ; return false ; }
+		return is_overflow ;
+	}
+}
+
+template <typename TList>
+std::string GNet::EventLoopHandles::help( const TList & list , bool on_add ) const
+{
+	if( m_mt )
+	{
+		return help_MT( list , on_add ) ;
+	}
+	else
+	{
+		return "too many open handles" ;
+	}
+}
+
+// ==
+
+template <typename TList>
+void GNet::EventLoopHandles::update_MT( TList & , bool (*)(const typename TList::value_type&) )
+{
+	///< auto x = m_mt->updateStart() ;
+	///< for( item : list ) if(fn(item)) x.add( item.m_handle ) ;
+	///< m_mt->updateEnd() ;
+}
+
+template <typename TList>
+bool GNet::EventLoopHandles::overflow_MT( TList & , bool (*)(const typename TList::value_type&) )
+{
+	// return m_mt->overflow( std::count_if(list,fn) ) ;
+	return false ;
+}
+
+inline
+bool GNet::EventLoopHandles::overflow_MT( std::size_t ) const
+{
+	// return m_mt->overflow( n ) ;
+	return false ;
+}
+
+template <typename TList>
+std::string GNet::EventLoopHandles::help_MT( const TList & , bool ) const
+{
+	// return m_mt->help() ;
+	return {} ;
+}
+
+template <typename TList>
+std::size_t GNet::EventLoopHandles::shuffle_MT( TList & , Rc rc )
+{
+	// return m_mt->shuffle( rc ) ;
+	return 0U ;
+}
+
+inline
+GNet::EventLoopHandles::Rc GNet::EventLoopHandles::waitForMultipleObjects_MT( DWORD ms )
+{
+	// return m_mt->wait( ms ) ;
+	return Rc( RcType::other ) ;
+}
+
+#endif
diff --git a/src/gnet/gexceptionhandler.cpp b/src/gnet/gexceptionhandler.cpp
index bc2b72c..c59b99a 100644
--- a/src/gnet/gexceptionhandler.cpp
+++ b/src/gnet/gexceptionhandler.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gnet/gexceptionhandler.h b/src/gnet/gexceptionhandler.h
index b3b9734..3ca2876 100644
--- a/src/gnet/gexceptionhandler.h
+++ b/src/gnet/gexceptionhandler.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -50,7 +50,8 @@ public:
 	virtual void onException( ExceptionSource * source , std::exception & e , bool done ) = 0 ;
 		///< Called by the event loop when an exception is thrown out
 		///< of an event loop callback. The exception is still active
-		///< so it can be rethrown with "throw".
+		///< so it can be rethrown with "throw" or captured with
+		///< std::current_exception().
 		///<
 		///< The source parameter can be used to point to the object
 		///< that received the original event loop callback. This
@@ -67,9 +68,9 @@ public:
 public:
 	ExceptionHandler() = default ;
 	ExceptionHandler( const ExceptionHandler & ) = delete ;
-	ExceptionHandler( ExceptionHandler && ) = delete ;
-	void operator=( const ExceptionHandler & ) = delete ;
-	void operator=( ExceptionHandler && ) = delete ;
+	ExceptionHandler( ExceptionHandler && ) = default ;
+	ExceptionHandler & operator=( const ExceptionHandler & ) = delete ;
+	ExceptionHandler & operator=( ExceptionHandler && ) = default ;
 } ;
 
 #endif
diff --git a/src/gnet/gexceptionsink.cpp b/src/gnet/gexceptionsink.cpp
index 9c31eac..f14451e 100644
--- a/src/gnet/gexceptionsink.cpp
+++ b/src/gnet/gexceptionsink.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,26 +22,27 @@
 #include "gnetdone.h"
 #include "gexceptionsink.h"
 #include "geventloop.h"
+#include "glog.h"
 #include "gassert.h"
+#include <exception>
 
 namespace GNet
 {
 	namespace ExceptionSinkImp /// An implementation namespace for GNet::ExceptionSink.
 	{
-		struct RethrowExceptionHandler : public GNet::ExceptionHandler /// An GNet::ExceptionHandler that rethrows.
+		struct LogExceptionHandler : ExceptionHandler /// A GNet::ExceptionHandler that just logs.
 		{
-			void onException( GNet::ExceptionSource * , std::exception & , bool ) override
+			void onException( ExceptionSource * , std::exception & e , bool net_done ) override
 			{
-				throw ;
+				if( !net_done )
+					G_LOG( "GNet::ExceptionSink: exception: " << e.what() ) ;
 			}
-		} rethrow_exception_handler ;
+		} ;
 	}
 }
 
-GNet::ExceptionSink::ExceptionSink( Type type , ExceptionSource * ) noexcept :
-	m_eh(type==Type::Null?nullptr:&ExceptionSinkImp::rethrow_exception_handler)
-{
-}
+GNet::ExceptionSink::ExceptionSink() noexcept
+= default ;
 
 GNet::ExceptionSink::ExceptionSink( ExceptionHandler & eh , ExceptionSource * esrc ) noexcept :
 	m_eh(&eh) ,
@@ -55,6 +56,12 @@ GNet::ExceptionSink::ExceptionSink( ExceptionHandler * eh , ExceptionSource * es
 {
 }
 
+GNet::ExceptionSink GNet::ExceptionSink::logOnly()
+{
+	static ExceptionSinkImp::LogExceptionHandler log_only_exception_handler ;
+	return { log_only_exception_handler , nullptr } ;
+}
+
 GNet::ExceptionHandler * GNet::ExceptionSink::eh() const noexcept
 {
 	return m_eh ;
@@ -67,10 +74,8 @@ GNet::ExceptionSource * GNet::ExceptionSink::esrc() const noexcept
 
 void GNet::ExceptionSink::call( std::exception & e , bool done )
 {
-	if( m_eh != nullptr )
-	{
-		m_eh->onException( m_esrc , e , done ) ;
-	}
+	G_ASSERT( m_eh != nullptr ) ; // precondition -- see EventEmitter and TimerList
+	m_eh->onException( m_esrc , e , done ) ;
 }
 
 void GNet::ExceptionSink::reset() noexcept
@@ -99,6 +104,6 @@ GNet::ExceptionSinkUnbound::ExceptionSinkUnbound( ExceptionHandler * eh ) :
 
 GNet::ExceptionSink GNet::ExceptionSinkUnbound::bind( ExceptionSource * source ) const
 {
-	return ExceptionSink{ m_eh , source } ;
+	return { m_eh , source } ;
 }
 
diff --git a/src/gnet/gexceptionsink.h b/src/gnet/gexceptionsink.h
index ef74867..e8180cf 100644
--- a/src/gnet/gexceptionsink.h
+++ b/src/gnet/gexceptionsink.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -37,7 +37,7 @@ namespace GNet
 /// A tuple containing an ExceptionHandler interface pointer and
 /// a bound 'exception source' pointer.
 ///
-/// The EventHandlerList and TimerList classes associate an
+/// The EventEmitter and TimerList classes associate an
 /// event handler and ExceptionSink with each event source
 /// (file descriptor or timer). If the event handler throws
 /// an exception then the associated ExceptionHandler's
@@ -65,9 +65,10 @@ namespace GNet
 /// } ;
 /// \endcode
 ///
-/// The ExceptionSinkUnbound class is used as syntactic sugar
-/// to force factory methods to supply an ExceptionSource
-/// pointer that points to the most-derived ServerPeer class.
+/// The ExceptionSinkUnbound class is used as a device to force
+/// factory methods to plumb-in an ExceptionSource pointer to
+/// the newly-created object as soon as its address is available
+/// (ie. before the constructor body runs).
 ///
 /// \code
 /// class FooServerPeer : public ServerPeer
@@ -86,40 +87,44 @@ namespace GNet
 /// \endcode
 ///
 /// So then the ServerPeer constructor has a bound ExceptionSink that
-/// it can pass to its timers etc. and to the event-handler list:
+/// it can pass to its timers and other event-handling objects:
 ///
 /// \code
 /// ServerPeer::ServerPeer( ExceptionSink es , ... ) :
-///    m_timer(..., es)
+///    m_timer(*this,...,es) ,
+///    m_other(es,...)
 /// {
-///   EventHandlerList::instance().add( es , ... ) ;
 /// }
 /// \endcode
 ///
 class GNet::ExceptionSink
 {
 public:
-	enum class Type
-	{
-		Null , // eh() is nullptr, call() does nothing
-		Rethrow , // rethrows
-		Log // logs an error with G_ERROR
-	} ;
-
-	explicit ExceptionSink( Type = Type::Rethrow , ExceptionSource * source = nullptr ) noexcept ;
-		///< Constructor.
+	ExceptionSink() noexcept ;
+		///< Default constructor for an exception handler that rethrows.
+		///< Postcondition: !set()
 
 	ExceptionSink( ExceptionHandler & eh , ExceptionSource * source ) noexcept ;
 		///< Constructor. The ExceptionHandler reference must
 		///< remain valid as the ExceptionSink is copied around.
+		///< Postcondition: set()
 
 	ExceptionSink( ExceptionHandler * eh , ExceptionSource * source ) noexcept ;
 		///< Constructor. The ExceptionHandler pointer must
 		///< remain valid as the ExceptionSink is copied around.
+		///< Precondition: eh != nullptr
+		///< Postcondition: set()
 
 	ExceptionSink( std::nullptr_t , ExceptionSource * ) = delete ;
 		///< Deleted override to prohibit a null ExceptionHandler.
 
+	static ExceptionSink logOnly() ;
+		///< A factory function for an exception handler that logs the
+		///< exception as an error but does not re-throw. This can
+		///< be a convenient alternative to a try/catch block for
+		///< code that might throw but should not terminate a
+		///< long-running server process.
+
 	ExceptionHandler * eh() const noexcept ;
 		///< Returns the exception handler pointer.
 
@@ -128,19 +133,20 @@ public:
 
 	void call( std::exception & e , bool done ) ;
 		///< Calls the exception handler's onException() method.
-		///< Used by EventHandlerList and TimerList. Exceptions
-		///< thrown out of the onException() implementation are
-		///< allowed to propagate.
+		///< Used by EventEmitter and TimerList when handling
+		///< an exception thrown from an event handler.
+		///< Precondition: set()
 
 	void reset() noexcept ;
-		///< Resets the pointers.
+		///< Resets the object as if default constructed.
+		///< Postcondition: !set()
 
 	bool set() const noexcept ;
 		///< Returns true if eh() is not null.
 
 private:
-	ExceptionHandler * m_eh ;
-	ExceptionSource * m_esrc{nullptr} ;
+	ExceptionHandler * m_eh {nullptr} ;
+	ExceptionSource * m_esrc {nullptr} ;
 } ;
 
 //| \class GNet::ExceptionSinkUnbound
@@ -163,7 +169,7 @@ public:
 		///< Returns a sink object with the source pointer set.
 
 private:
-	ExceptionHandler * m_eh ;
+	ExceptionHandler * m_eh {nullptr} ;
 } ;
 
 #endif
diff --git a/src/gnet/gexceptionsource.cpp b/src/gnet/gexceptionsource.cpp
index 156efe2..13a512c 100644
--- a/src/gnet/gexceptionsource.cpp
+++ b/src/gnet/gexceptionsource.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,7 +24,7 @@
 
 std::string GNet::ExceptionSource::exceptionSourceId() const
 {
-	return std::string() ;
+	return {} ;
 }
 
 GNet::ExceptionSource::~ExceptionSource()
diff --git a/src/gnet/gexceptionsource.h b/src/gnet/gexceptionsource.h
index f6fa28e..0ccd2d1 100644
--- a/src/gnet/gexceptionsource.h
+++ b/src/gnet/gexceptionsource.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -42,7 +42,8 @@ public:
 	virtual std::string exceptionSourceId() const ;
 		///< Returns an identifying string for logging purposes,
 		///< or the empty string. This typically provides the
-		///< remote peer's network address.
+		///< remote peer's network address. The default
+		///< implementation returns the empty string.
 
 	virtual ~ExceptionSource() ;
 		///< Destructor.
@@ -50,9 +51,9 @@ public:
 public:
 	ExceptionSource() = default ;
 	ExceptionSource( const ExceptionSource & ) = delete ;
-	ExceptionSource( ExceptionSource && ) = delete ;
-	void operator=( const ExceptionSource & ) = delete ;
-	void operator=( ExceptionSource && ) = delete ;
+	ExceptionSource( ExceptionSource && ) = default ;
+	ExceptionSource & operator=( const ExceptionSource & ) = delete ;
+	ExceptionSource & operator=( ExceptionSource && ) = default ;
 } ;
 
 #endif
diff --git a/src/gnet/gfutureevent.h b/src/gnet/gfutureevent.h
index 1cc5ef7..3aa67b8 100644
--- a/src/gnet/gfutureevent.h
+++ b/src/gnet/gfutureevent.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,6 +24,8 @@
 #include "gdef.h"
 #include "gexceptionsink.h"
 #include "geventhandler.h"
+#include "gexception.h"
+#include <memory>
 
 namespace GNet
 {
@@ -33,12 +35,13 @@ namespace GNet
 }
 
 //| \class GNet::FutureEvent
-/// A FutureEvent object can be used to send a one-shot event via the
-/// event loop to the relevant event handler. Used in the implementation
-/// of 'future' classes.
+/// A FutureEvent object can be used to send a one-shot event between
+/// threads via the event loop, resulting in a call to the relevant
+/// event handler. This is used in the implementation of multi-threaded
+/// asynchronous task classes such as GNet::Task and GNet::Resolver.
 ///
 /// The thread-safe trigger function send() is typically called from
-/// a 'future' worker thread just before it finishes.
+/// a worker thread just before it finishes.
 ///
 /// Eg:
 /// \code
@@ -46,7 +49,7 @@ namespace GNet
 /// {
 ///  Foo() ;
 ///  void onFutureEvent() ;
-///  void run( FutureEvent::handle_type ) ;
+///  void run( HANDLE ) ;
 ///  FutureEvent m_future_event ;
 ///  std::thread m_thread ;
 ///  int m_result ;
@@ -56,7 +59,7 @@ namespace GNet
 ///    m_thread(&Foo::run,this,m_future_event.handle())
 /// {
 /// }
-/// void Foo::run( FutureEvent::handle_type h )
+/// void Foo::run( HANDLE h )
 /// {
 ///   m_result = ... ; // do blocking work in worker thread
 ///   FutureEvent::send( h ) ; // raise 'work complete' event
@@ -71,8 +74,7 @@ namespace GNet
 class GNet::FutureEvent
 {
 public:
-	G_EXCEPTION( Error , "FutureEvent error" ) ;
-	using handle_type = HANDLE ;
+	G_EXCEPTION( Error , tx("FutureEvent error") ) ;
 
 	FutureEvent( FutureEventHandler & , ExceptionSink ) ;
 		///< Constructor. Installs itself in the event loop.
@@ -80,12 +82,12 @@ public:
 	~FutureEvent() ;
 		///< Destructor.
 
-	handle_type handle() noexcept ;
+	HANDLE handle() noexcept ;
 		///< Extracts a handle that can be passed between threads
 		///< and used in send(). This should be called once,
 		///< typically as the worker thread is created.
 
-	static bool send( handle_type handle , bool close = true ) noexcept ;
+	static bool send( HANDLE handle , bool close = true ) noexcept ;
 		///< Pokes an event into the main event loop so that the
 		///< FutureEventHandler callback is called asynchronously.
 		///<
@@ -96,11 +98,15 @@ public:
 		///< This is safe even if the FutureEvent object has been
 		///< deleted. Returns true on success.
 
+	static HANDLE createHandle() ;
+		///< Used by some event loop implementations to create the
+		///< underlying synchronisation object.
+
 public:
 	FutureEvent( const FutureEvent & ) = delete ;
 	FutureEvent( FutureEvent && ) = delete ;
-	void operator=( const FutureEvent & ) = delete ;
-	void operator=( FutureEvent && ) = delete ;
+	FutureEvent & operator=( const FutureEvent & ) = delete ;
+	FutureEvent & operator=( FutureEvent && ) = delete ;
 
 private:
 	std::unique_ptr<FutureEventImp> m_imp ;
diff --git a/src/gnet/gfutureevent_unix.cpp b/src/gnet/gfutureevent_unix.cpp
index a7703ca..98dc3cf 100644
--- a/src/gnet/gfutureevent_unix.cpp
+++ b/src/gnet/gfutureevent_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -20,6 +20,7 @@
 
 #include "gdef.h"
 #include "gfutureevent.h"
+#include "gprocess.h"
 #include "gmsg.h"
 #include "geventloop.h"
 #include <array>
@@ -33,28 +34,26 @@
 class GNet::FutureEventImp : public EventHandler
 {
 public:
-	using handle_type = FutureEvent::handle_type ;
-
 	FutureEventImp( FutureEventHandler & , ExceptionSink ) ;
 		// Constructor.
 
 	~FutureEventImp() override ;
 		// Destructor.
 
-	static bool send( handle_type , bool ) noexcept ;
+	static bool send( HANDLE , bool ) noexcept ;
 		// Writes to the write socket.
 
 	void receive() ;
 		// Reads from the socket to clear the event.
 
-	handle_type handle() noexcept ;
+	HANDLE handle() noexcept ;
 		// Extracts the socket fd as a handle.
 
 public:
 	FutureEventImp( const FutureEventImp & ) = delete ;
 	FutureEventImp( FutureEventImp && ) = delete ;
-	void operator=( const FutureEventImp & ) = delete ;
-	void operator=( FutureEventImp && ) = delete ;
+	FutureEventImp & operator=( const FutureEventImp & ) = delete ;
+	FutureEventImp & operator=( FutureEventImp && ) = delete ;
 
 private: // overrides
 	void readEvent() override ; // Override from GNet::EventHandler.
@@ -71,8 +70,8 @@ private:
 		int fd{-1} ;
 		Fd( const Fd & ) = delete ;
 		Fd( Fd && ) = delete ;
-		void operator=( const Fd & ) = delete ;
-		void operator=( Fd && ) = delete ;
+		Fd & operator=( const Fd & ) = delete ;
+		Fd & operator=( Fd && ) = delete ;
 	} ;
 
 private:
@@ -89,7 +88,10 @@ GNet::FutureEventImp::FutureEventImp( FutureEventHandler & handler , ExceptionSi
 	std::array<int,2U> fds {{ -1 , -1 }} ;
 	int rc = ::socketpair( AF_UNIX , SOCK_DGRAM , 0 , &fds[0] ) ;
 	if( rc != 0 )
-		throw FutureEvent::Error( "socketpair" ) ;
+	{
+		int e = G::Process::errno_() ;
+		throw FutureEvent::Error( "socketpair" , G::Process::strerror(e) ) ;
+	}
 	m_read = init( fds[0] ) ;
 	m_write = init( fds[1] ) ;
 	EventLoop::instance().addRead( Descriptor(m_read.fd) , *this , es ) ;
@@ -97,7 +99,7 @@ GNet::FutureEventImp::FutureEventImp( FutureEventHandler & handler , ExceptionSi
 
 int GNet::FutureEventImp::init( int fd )
 {
-	GDEF_IGNORE_RETURN ::fcntl( fd , F_SETFL , ::fcntl(fd,F_GETFL) | O_NONBLOCK ) ;
+	GDEF_IGNORE_RETURN ::fcntl( fd , F_SETFL , ::fcntl(fd,F_GETFL) | O_NONBLOCK ) ; // NOLINT
 	return fd ;
 }
 
@@ -110,11 +112,11 @@ GNet::FutureEventImp::~FutureEventImp()
 	}
 }
 
-GNet::FutureEventImp::handle_type GNet::FutureEventImp::handle() noexcept
+HANDLE GNet::FutureEventImp::handle() noexcept
 {
 	int fd = -1 ;
 	std::swap( m_write.fd , fd ) ;
-	return static_cast<handle_type>(fd) ;
+	return static_cast<HANDLE>(fd) ;
 }
 
 void GNet::FutureEventImp::receive()
@@ -123,7 +125,7 @@ void GNet::FutureEventImp::receive()
 	GDEF_IGNORE_RETURN ::recv( m_read.fd , &c , 1 , 0 ) ;
 }
 
-bool GNet::FutureEventImp::send( handle_type handle , bool close ) noexcept
+bool GNet::FutureEventImp::send( HANDLE handle , bool close ) noexcept
 {
 	int fd = static_cast<int>(handle) ;
 	char c = '\0' ;
@@ -154,12 +156,12 @@ GNet::FutureEvent::FutureEvent( FutureEventHandler & handler , ExceptionSink es
 GNet::FutureEvent::~FutureEvent()
 = default ;
 
-bool GNet::FutureEvent::send( handle_type handle , bool close ) noexcept
+bool GNet::FutureEvent::send( HANDLE handle , bool close ) noexcept
 {
 	return FutureEventImp::send( handle , close ) ;
 }
 
-GNet::FutureEvent::handle_type GNet::FutureEvent::handle() noexcept
+HANDLE GNet::FutureEvent::handle() noexcept
 {
 	return m_imp->handle() ;
 }
diff --git a/src/gnet/gfutureevent_win32.cpp b/src/gnet/gfutureevent_win32.cpp
index 384f4db..9d2dbcd 100644
--- a/src/gnet/gfutureevent_win32.cpp
+++ b/src/gnet/gfutureevent_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -40,18 +40,16 @@ HANDLE CreateEventEx( LPSECURITY_ATTRIBUTES sec , LPCTSTR name , DWORD flags , D
 class GNet::FutureEventImp : public EventHandler
 {
 public:
-	using handle_type = FutureEvent::handle_type ;
-
 	FutureEventImp( FutureEventHandler & handler , ExceptionSink es ) ;
 		// Constructor.
 
 	~FutureEventImp() override ;
 		// Destructor.
 
-	static bool send( handle_type , bool ) noexcept ;
+	static bool send( HANDLE , bool ) noexcept ;
 		// Raises an event.
 
-	handle_type handle() noexcept ;
+	HANDLE handle() noexcept ;
 		// Extracts the event-object handle.
 
 private: // overrides
@@ -60,8 +58,8 @@ private: // overrides
 public:
 	FutureEventImp( const FutureEventImp & ) = delete ;
 	FutureEventImp( FutureEventImp && ) = delete ;
-	void operator=( const FutureEventImp & ) = delete ;
-	void operator=( FutureEventImp && ) = delete ;
+	FutureEventImp & operator=( const FutureEventImp & ) = delete ;
+	FutureEventImp & operator=( FutureEventImp && ) = delete ;
 
 private:
 	HANDLE dup() ;
@@ -70,13 +68,13 @@ private:
 	struct Handle
 	{
 		Handle() = default ;
-		~Handle() { if(h) ::CloseHandle(h) ; }
-		void operator=( HANDLE h_ ) { h = h_ ; }
+		~Handle() { if(h) CloseHandle(h) ; }
+		Handle & operator=( HANDLE h_ ) { h = h_ ; return *this ; }
 		bool operator==( HANDLE h_ ) const { return h == h_ ; }
 		Handle( const Handle & ) = delete ;
 		Handle( Handle && ) = delete ;
-		void operator=( const Handle & ) = delete ;
-		void operator=( Handle && ) = delete ;
+		Handle & operator=( const Handle & ) = delete ;
+		Handle & operator=( Handle && ) = delete ;
 		HANDLE h{0} ;
 	} ;
 
@@ -91,14 +89,11 @@ GNet::FutureEventImp::FutureEventImp( FutureEventHandler & handler , ExceptionSi
 	m_handler(handler) ,
 	m_es(es)
 {
-	// (the event loop requires manual-reset because it re-tests the handle state after WFMO has been released)
-	const DWORD access = DELETE | SYNCHRONIZE | EVENT_MODIFY_STATE | PROCESS_DUP_HANDLE ;
-	m_h = CreateEventEx( nullptr , nullptr , CREATE_EVENT_MANUAL_RESET , access ) ;
+	m_h = FutureEvent::createHandle() ;
 	if( m_h == 0 )
 		throw FutureEvent::Error( "CreateEventEx" ) ;
 
 	m_h2 = dup() ;
-	G_DEBUG( "GNet::FutureEventImp::ctor: h=" << m_h.h << " h2=" << m_h2.h ) ;
 
 	EventLoop::instance().addRead( Descriptor(INVALID_SOCKET,m_h.h) , *this , es ) ;
 }
@@ -115,30 +110,30 @@ HANDLE GNet::FutureEventImp::dup()
 	// once both handles are closed -- we need the main thread and the
 	// worker thread to both keep the kernel event-object alive
 	HANDLE h = 0 ;
-	BOOL ok = ::DuplicateHandle(
-		::GetCurrentProcess() , m_h.h ,
-		::GetCurrentProcess() , &h ,
+	BOOL ok = DuplicateHandle(
+		GetCurrentProcess() , m_h.h ,
+		GetCurrentProcess() , &h ,
 		0 , FALSE , DUPLICATE_SAME_ACCESS ) ;
 	if( !ok )
 	{
-		DWORD e = ::GetLastError() ;
+		DWORD e = GetLastError() ;
 		throw FutureEvent::Error( "DuplicateHandle" , G::Str::fromUInt(static_cast<unsigned int>(e)) ) ;
 	}
 	return h ;
 }
 
-GNet::FutureEventImp::handle_type GNet::FutureEventImp::handle() noexcept
+HANDLE GNet::FutureEventImp::handle() noexcept
 {
 	HANDLE h2 = 0 ;
 	std::swap( h2 , m_h2.h ) ;
 	return h2 ;
 }
 
-bool GNet::FutureEventImp::send( handle_type handle , bool close ) noexcept
+bool GNet::FutureEventImp::send( HANDLE handle , bool close ) noexcept
 {
-	bool ok = ::SetEvent( handle ) != 0 ;
+	bool ok = SetEvent( handle ) != 0 ;
 	if( close )
-		::CloseHandle( handle ) ; // kernel event-object still open
+		CloseHandle( handle ) ; // kernel event-object still open
 	return ok ;
 }
 
@@ -158,13 +153,19 @@ GNet::FutureEvent::FutureEvent( FutureEventHandler & handler , ExceptionSink es
 GNet::FutureEvent::~FutureEvent()
 = default ;
 
-bool GNet::FutureEvent::send( handle_type handle , bool close ) noexcept
+bool GNet::FutureEvent::send( HANDLE handle , bool close ) noexcept
 {
 	return FutureEventImp::send( handle , close ) ;
 }
 
-GNet::FutureEvent::handle_type GNet::FutureEvent::handle() noexcept
+HANDLE GNet::FutureEvent::handle() noexcept
 {
 	return m_imp->handle() ;
 }
 
+HANDLE GNet::FutureEvent::createHandle()
+{
+	const DWORD access = DELETE | SYNCHRONIZE | EVENT_MODIFY_STATE | PROCESS_DUP_HANDLE ;
+	return CreateEventEx( nullptr , nullptr , CREATE_EVENT_MANUAL_RESET , access ) ;
+}
+
diff --git a/src/gnet/ginterfaces.h b/src/gnet/ginterfaces.h
index 5e7d9ff..f886054 100644
--- a/src/gnet/ginterfaces.h
+++ b/src/gnet/ginterfaces.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,12 +23,13 @@
 
 #include "gdef.h"
 #include "gaddress.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gexceptionsink.h"
 #include "geventhandler.h"
 #include "gfutureevent.h"
 #include "gsocket.h"
 #include <string>
+#include <memory>
 #include <vector>
 
 namespace GNet
@@ -46,8 +47,9 @@ class GNet::Interfaces : public EventHandler , public FutureEventHandler
 public:
 	struct Item /// Used by GNet::Interfaces to describe an interface address binding.
 	{
-		std::string name ;
+		std::string name ; // interface name
 		std::string altname ; // windows friendly name, utf8
+		int ifindex{0} ; // interface 1-based index, 0 on error, family-specific on windows
 		unsigned int address_family{0} ;
 		bool valid_address{false} ;
 		Address address ;
@@ -105,8 +107,9 @@ public:
 			///< found or if found but not up. Does lazy load()ing.
 
 	std::vector<Address> addresses( const G::StringArray & names , unsigned int port ,
-		G::StringArray & used_names , G::StringArray & empty_names ,
-		G::StringArray & bad_names ) const ;
+		G::StringArray * used_names_out = nullptr ,
+		G::StringArray * empty_names_out = nullptr ,
+		G::StringArray * bad_names_out = nullptr ) const ;
 			///< Treats each name given as an address or interface name and
 			///< returns the total set of addresses. Returns by reference
 			///< (1) names that are, or have, addresses, (2) names that might
@@ -114,6 +117,13 @@ public:
 			///< ie. names that are not addresses and cannot be a valid
 			///< interface name.
 
+	void addresses( const std::string & name , unsigned int port ,
+		std::vector<GNet::Address> & address_out ,
+		G::StringArray * used_names_out = nullptr ,
+		G::StringArray * empty_names_out = nullptr ,
+		G::StringArray * bad_names_out = nullptr ) const ;
+			///< An overload for a single name.
+
 private: // overrides
 	void readEvent() override ; // GNet::EventHandler
 	void onFutureEvent() override ; // GNet::FutureEventHandler
@@ -121,12 +131,13 @@ private: // overrides
 public:
 	Interfaces( const Interfaces & ) = delete ;
 	Interfaces( Interfaces && ) = delete ;
-	void operator=( const Interfaces & ) = delete ;
-	void operator=( Interfaces && ) = delete ;
+	Interfaces operator=( const Interfaces & ) = delete ;
+	Interfaces operator=( Interfaces && ) = delete ;
 
 private:
 	using AddressList = std::vector<Address> ;
 	void loadImp( ExceptionSink , std::vector<Item> & list ) ;
+	static int index( const std::string & ) ;
 
 private:
 	ExceptionSink m_es ;
diff --git a/src/gnet/ginterfaces_common.cpp b/src/gnet/ginterfaces_common.cpp
index b85b717..3143d2c 100644
--- a/src/gnet/ginterfaces_common.cpp
+++ b/src/gnet/ginterfaces_common.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -98,37 +98,44 @@ std::vector<GNet::Address> GNet::Interfaces::find( const std::string & name_in ,
 }
 
 std::vector<GNet::Address> GNet::Interfaces::addresses( const G::StringArray & names , unsigned int port ,
-	G::StringArray & used_names , G::StringArray & empty_names , G::StringArray & bad_names ) const
+	G::StringArray * used_names , G::StringArray * empty_names , G::StringArray * bad_names ) const
 {
 	AddressList result ;
 	for( const auto & name : names )
 	{
-		if( Address::validStrings( name , G::Str::fromUInt(port) ) )
+		addresses( name , port , result , used_names , empty_names , bad_names ) ;
+	}
+	return result ;
+}
+
+void GNet::Interfaces::addresses( const std::string & name , unsigned int port ,
+	std::vector<GNet::Address> & result ,
+	G::StringArray * used_names , G::StringArray * empty_names , G::StringArray * bad_names ) const
+{
+	if( Address::validStrings( name , G::Str::fromUInt(port) ) )
+	{
+		result.push_back( Address::parse(name,port) ) ;
+	}
+	else
+	{
+		// 'name' is not an address so treat it as an interface name having
+		// bound addresses -- reject file system paths as 'bad' unless
+		// they are under "/dev" (bsd)
+		AddressList list = find( name , port , true ) ;
+		if( list.empty() && ( name.empty() || ( name.find('/') != std::string::npos && name.find("/dev/") != 0U ) ) )
 		{
-			result.push_back( Address::parse(name,port) ) ;
+			if( bad_names ) bad_names->push_back( name ) ;
+		}
+		else if( list.empty() )
+		{
+			if( empty_names ) empty_names->push_back( name ) ;
 		}
 		else
 		{
-			// 'name' is not an address so treat it as an interface name having
-			// bound addresses -- reject file system paths as 'bad' unless
-			// they are under "/dev" (bsd)
-			AddressList list = find( name , port , true ) ;
-			if( list.empty() && ( name.empty() || ( name.find('/') != std::string::npos && name.find("/dev/") != 0U ) ) )
-			{
-				bad_names.push_back( name ) ;
-			}
-			else if( list.empty() )
-			{
-				empty_names.push_back( name ) ;
-			}
-			else
-			{
-				used_names.push_back( name ) ;
-			}
-			result.insert( result.end() , list.begin() , list.end() ) ;
+			if( used_names ) used_names->push_back( name ) ;
 		}
+		result.insert( result.end() , list.begin() , list.end() ) ;
 	}
-	return result ;
 }
 
 G::StringArray GNet::Interfaces::names( bool all ) const
diff --git a/src/gnet/ginterfaces_none.cpp b/src/gnet/ginterfaces_none.cpp
index 4785025..e701a4f 100644
--- a/src/gnet/ginterfaces_none.cpp
+++ b/src/gnet/ginterfaces_none.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -57,24 +57,31 @@ std::vector<GNet::Address> GNet::Interfaces::find( const std::string & , unsigne
 }
 
 std::vector<GNet::Address> GNet::Interfaces::addresses( const G::StringArray & names , unsigned int port ,
-	G::StringArray & used_names , G::StringArray & , G::StringArray & bad_names ) const
+	G::StringArray * used_names , G::StringArray * empty_names , G::StringArray * bad_names ) const
 {
 	AddressList result ;
 	for( const auto & name : names )
 	{
-		if( !Address::validStrings( name , G::Str::fromUInt(port) ) )
-		{
-			bad_names.push_back( name ) ;
-		}
-		else
-		{
-			used_names.push_back( name ) ;
-			result.push_back( Address::parse(name,port) ) ;
-		}
+		addresses( name , port , result , used_names , empty_names , bad_names ) ;
 	}
 	return result ;
 }
 
+void GNet::Interfaces::addresses( const std::string & name , unsigned int port ,
+	std::vector<GNet::Address> & result ,
+	G::StringArray * used_names , G::StringArray * /*empty_names*/ , G::StringArray * bad_names ) const
+{
+	if( !Address::validStrings( name , G::Str::fromUInt(port) ) )
+	{
+		if( bad_names ) bad_names->push_back( name ) ;
+	}
+	else
+	{
+		if( used_names ) used_names->push_back( name ) ;
+		result.push_back( Address::parse(name,port) ) ;
+	}
+}
+
 G::StringArray GNet::Interfaces::names( bool ) const
 {
 	return G::StringArray() ;
diff --git a/src/gnet/ginterfaces_unix.cpp b/src/gnet/ginterfaces_unix.cpp
index b1ce9b0..9cfa484 100644
--- a/src/gnet/ginterfaces_unix.cpp
+++ b/src/gnet/ginterfaces_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -58,9 +58,11 @@ class GNet::InterfacesNotifierImp : public InterfacesNotifier
 public:
 	static bool active() ;
 	InterfacesNotifierImp( Interfaces * , ExceptionSink es ) ;
+	template <typename T> std::pair<T*,std::size_t> readSocket() ;
+
+public: // overrides
 	std::string readEvent() override ; // unix
 	std::string onFutureEvent() override ; // windows
-	template <typename T> std::pair<T*,std::size_t> readSocket() ;
 
 public:
 	G::Buffer<char> m_buffer ;
@@ -99,7 +101,6 @@ void GNet::Interfaces::loadImp( ExceptionSink es , std::vector<Item> & list )
 		if( info_p->ifa_name == nullptr )
 			continue ;
 
-		G_ASSERT( info_p->ifa_addr ) ;
 		if( info_p->ifa_addr == nullptr )
 			continue ;
 
@@ -108,6 +109,7 @@ void GNet::Interfaces::loadImp( ExceptionSink es , std::vector<Item> & list )
 
 		Item item ;
 		item.name = std::string( info_p->ifa_name ) ;
+		item.ifindex = index( item.name ) ;
 		item.address_family = info_p->ifa_addr->sa_family ;
 		item.address = Address( info_p->ifa_addr , nmax , scope_id_fixup ) ;
 		item.valid_address = !item.address.isAny() ; // just in case
@@ -128,6 +130,26 @@ void GNet::Interfaces::loadImp( ExceptionSink es , std::vector<Item> & list )
 	}
 }
 
+#if GCONFIG_HAVE_IFINDEX
+#include <sys/ioctl.h>
+#include <net/if.h>
+int GNet::Interfaces::index( const std::string & name )
+{
+	struct ifreq req {} ;
+	G::Str::strncpy_s( req.ifr_name , sizeof(req.ifr_name) , name.c_str() , G::Str::truncate ) ;
+	int fd = socket( AF_INET , SOCK_DGRAM , 0 ) ; // man netdevice(7): "any socket.. regardless of.. family or type"
+	if( fd < 0 ) return 0 ;
+	int rc = ioctl( fd , SIOCGIFINDEX , &req , sizeof(req) ) ;
+	close( fd ) ;
+	return rc ? 0 : req.ifr_ifindex ;
+}
+#else
+int GNet::Interfaces::index( const std::string & )
+{
+	return 0 ;
+}
+#endif
+
 // ==
 
 template <typename T>
diff --git a/src/gnet/ginterfaces_win32.cpp b/src/gnet/ginterfaces_win32.cpp
index a5904d9..a8f03ba 100644
--- a/src/gnet/ginterfaces_win32.cpp
+++ b/src/gnet/ginterfaces_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -125,6 +125,7 @@ void GNet::Interfaces::loadImp( ExceptionSink es , std::vector<Item> & list )
 					item.netmask_bits = prefix_length ;
 				}
 #endif
+				item.ifindex = p->IfIndex ? p->IfIndex : p->Ipv6IfIndex ;
 				list.push_back( item ) ;
 			}
 		}
diff --git a/src/gnet/glinebuffer.cpp b/src/gnet/glinebuffer.cpp
index f74689b..160bf35 100644
--- a/src/gnet/glinebuffer.cpp
+++ b/src/gnet/glinebuffer.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -139,6 +139,11 @@ bool GNet::LineBuffer::more( bool fragments )
 	}
 }
 
+bool GNet::LineBuffer::peekmore() const
+{
+	return !m_in.empty() && !m_eol.empty() && m_in.find(m_eol,m_pos) != std::string::npos ;
+}
+
 bool GNet::LineBuffer::trivial( std::size_t pos ) const
 {
 	pos = pos == std::string::npos ? m_in.size() : pos ;
@@ -154,9 +159,9 @@ bool GNet::LineBuffer::detect()
 		if( pos != npos )
 		{
 			if( pos > 0U && m_in.at(pos-1U) == '\r' )
-				m_eol = std::string( "\r\n" , 2U ) ;
+				m_eol.assign( "\r\n" , 2U ) ;
 			else
-				m_eol = std::string( 1U , '\n' ) ;
+				m_eol.assign( 1U , '\n' ) ;
 			m_auto = false ;
 		}
 	}
@@ -181,17 +186,15 @@ std::string GNet::LineBuffer::eol() const
 void GNet::LineBuffer::output( std::size_t size , std::size_t eolsize , bool force_next_is_start_of_line )
 {
 	G_ASSERT( (size+eolsize) != 0U ) ;
+
 	m_pos += m_out.set( m_in , m_pos , size , eolsize ) ;
+
 	if( force_next_is_start_of_line )
 		m_out.m_first = true ;
-	check( m_out ) ;
-}
 
-void GNet::LineBuffer::check( const Output & out )
-{
-	if( !m_warned && m_warn_limit != 0U && out.m_size > m_warn_limit )
+	if( m_out.m_eolsize && m_out.m_size > m_warn_limit && !m_warned && m_warn_limit != 0U )
 	{
-		G_WARNING( "GNet::LineBuffer::check: very long line detected: " << out.m_size << " > " << m_warn_limit ) ;
+		G_WARNING( "GNet::LineBuffer::output: very long line detected: " << m_out.m_size << " > " << m_warn_limit ) ;
 		m_warned = true ;
 	}
 }
@@ -237,6 +240,15 @@ GNet::LineBufferConfig::LineBufferConfig( const std::string & eol , std::size_t
 {
 }
 
+bool GNet::LineBufferConfig::operator==( const LineBufferConfig & other ) const
+{
+	return
+		m_eol == other.m_eol &&
+		m_warn == other.m_warn &&
+		m_fmin == other.m_fmin &&
+		m_expect == other.m_expect ;
+}
+
 GNet::LineBufferConfig GNet::LineBufferConfig::transparent()
 {
 	static constexpr std::size_t inf = ~(std::size_t(0)) ;
diff --git a/src/gnet/glinebuffer.h b/src/gnet/glinebuffer.h
index 0b6db59..13722b8 100644
--- a/src/gnet/glinebuffer.h
+++ b/src/gnet/glinebuffer.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,7 +24,9 @@
 #include "gdef.h"
 #include "gexception.h"
 #include "glinestore.h"
+#include "gstringview.h"
 #include "gcall.h"
+#include <functional>
 #include <string>
 
 namespace GNet
@@ -49,9 +51,8 @@ namespace GNet
 ///   buffer.add("def\nABC\nDE") ;
 ///   buffer.add("F\n") ;
 ///
-///   GNet::LineBufferIterator iter( buffer ) ;
-///   while( iter.more() )
-///     cout << iter.line() << endl ;
+///   while( buffer.more() )
+///     cout << std::string_view(buffer.data(),buffer.size()) << endl ;
 /// }
 /// \endcode
 ///
@@ -82,7 +83,10 @@ namespace GNet
 class GNet::LineBuffer
 {
 public:
-	G_EXCEPTION( ErrorOverflow , "line buffer overflow" ) ;
+	G_EXCEPTION( ErrorOverflow , tx("line buffer overflow") ) ;
+	using SinkArgs = std::tuple<const char*,std::size_t,std::size_t,std::size_t,char,bool> ;
+	using SinkFn = std::function<bool(const SinkArgs&)> ;
+	using FragmentsFn = std::function<bool()> ;
 
 	explicit LineBuffer( const LineBufferConfig & ) ;
 		///< Constructor.
@@ -98,10 +102,10 @@ public:
 		///< See also apply().
 
 	void expect( std::size_t n ) ;
-		///< Requests that the next 'n' bytes extracted be extracted
-		///< in one contiguous block, without regard to line endings.
-		///< Once the expected number of bytes have been extracted
-		///< the line buffering returns to normal.
+		///< Requests that the next 'n' bytes are extracted in one
+		///< contiguous block, without regard to line endings. Once
+		///< the expected number of bytes have been extracted the
+		///< line buffering returns to normal.
 		///<
 		///< This method can be used during a data-transfer phase to
 		///< obtain a chunk of data of known size, as in http with a
@@ -112,8 +116,8 @@ public:
 		///<
 		///< A parameter value of std::size_t(-1) can be used to represent
 		///< an infinite expectation that is never fully satisfied.
-		///< This is only sensible when extracting fragments and
-		///< results in full transparency.
+		///< This is only sensible when extracting fragments with
+		///< apply(), and it results in full transparency.
 
 	std::string eol() const ;
 		///< Returns the end-of-line string as passed in to the
@@ -143,25 +147,37 @@ public:
 		///< \endcode
 
 	template <typename Tsink, typename Tmemfun>
-	void apply( Tsink sink_p , Tmemfun sink_memfun , const char * data , std::size_t data_size , bool fragments = false ) ;
-		///< Overload that calls out to a member function.
-		///<
-		///< \code
-		///< void Foo::onData( const char * data , std::size_t size )
-		///< {
-		///<   apply( this , &Foo::onLine , data , size , false ) ;
-		///< }
-		///< bool Foo::onLine( const char * data , std::size_t size , std::size_t , std::size_t , char )
-		///< {
-		///<   process( std::string(data,size) ) ;
-		///< }
-		///< \endcode
+	void apply( Tsink sink_p , Tmemfun sink_memfun , const char * data , std::size_t data_size ,
+		bool fragments = false ) ;
+			///< Overload that calls out to a member function.
+			///<
+			///< \code
+			///< void Foo::onData( const char * data , std::size_t size )
+			///< {
+			///<   apply( this , &Foo::onLine , data , size , false ) ;
+			///< }
+			///< bool Foo::onLine( const char * data , std::size_t size , std::size_t , std::size_t , char )
+			///< {
+			///<   process( std::string(data,size) ) ;
+			///< }
+			///< \endcode
 
 	template <typename Tsink, typename Tmemfun, typename Tmemfun2>
-	void apply( Tsink sink_p , Tmemfun sink_memfun , const char * data , std::size_t data_size , Tmemfun2 fragments_memfun ) ;
-		///< Overload where the 'fragments' flag comes from calling a member
-		///< function on the sink object, allowing the flag to change
-		///< dynamically as each line is delivered.
+	void apply( Tsink sink_p , Tmemfun sink_memfun , const char * data , std::size_t data_size ,
+		Tmemfun2 fragments_memfun ) ;
+			///< Overload where the 'fragments' flag comes from calling a member
+			///< function on the sink object, allowing the flag to change
+			///< dynamically as each line is delivered.
+
+	bool apply( SinkFn sink_fn , G::string_view data , FragmentsFn fragments_fn ) ;
+		///< Overload for std::function.
+		///<
+		///< This overload provides extra parameter 'more' to the
+		///< sink function that is true if there is another complete
+		///< line buffered-up after the current one (and eolsize is
+		///< non-zero).
+		///<
+		///< Returns false iff the sink function returned false.
 
 	template <typename Tfn>
 	void apply( const std::string & , Tfn sink_fn , bool fragments = false ) ;
@@ -218,6 +234,14 @@ public:
 		///< Returns information about the current state of the
 		///< line-buffer.
 
+	std::size_t buffersize() const ;
+		///< Returns the total number of bytes buffered up.
+
+	bool peekmore() const ;
+		///< Returns true if there is a line available after the
+		///< current line or expect()ation.
+		///< Precondition: more()
+
 public:
 	void extensionStart( const char * , std::size_t ) ;
 		///< A pseudo-private method used by the implementation
@@ -245,8 +269,8 @@ private:
 		~Extension() ;
 		Extension( const Extension & ) = delete ;
 		Extension( Extension && ) = delete ;
-		void operator=( const Extension & ) = delete ;
-		void operator=( Extension && ) = delete ;
+		Extension & operator=( const Extension & ) = delete ;
+		Extension & operator=( Extension && ) = delete ;
 		bool valid() const ;
 		LineBuffer * m_line_buffer ;
 		G::CallFrame m_call_frame ;
@@ -256,17 +280,15 @@ public:
 	~LineBuffer() = default ;
 	LineBuffer( const LineBuffer & ) = delete ;
 	LineBuffer( LineBuffer && ) = delete ;
-	void operator=( const LineBuffer & ) = delete ;
-	void operator=( LineBuffer && ) = delete ;
+	LineBuffer & operator=( const LineBuffer & ) = delete ;
+	LineBuffer & operator=( LineBuffer && ) = delete ;
 
 private:
 	friend class LineBufferState ;
-	void check( const Output & ) ;
 	void output( std::size_t size , std::size_t eolsize , bool = false ) ;
 	bool detect() ;
 	bool trivial( std::size_t pos ) const ;
 	bool finite() const ;
-	std::size_t insize() const ; // for LineBufferState
 	std::string head() const ; // for LineBufferState
 
 private:
@@ -283,41 +305,6 @@ private:
 	std::size_t m_pos ;
 } ;
 
-//| \class GNet::LineBufferIterator
-/// Syntactic sugar for calling GNet::LineBuffer iteration methods.
-///
-class GNet::LineBufferIterator
-{
-public:
-	explicit LineBufferIterator( LineBuffer & buffer ) ;
-		///< Constructor.
-
-	bool more() ;
-		///< See LineBuffer::more().
-
-	const char * data() const ;
-		///< See LineBuffer::data().
-
-	std::size_t size() const ;
-		///< See LineBuffer::size().
-
-	std::size_t eolsize() const ;
-		///< See LineBuffer::eolsize().
-
-	std::string line() const ;
-		///< Returns the current line (of length size()).
-
-public:
-	~LineBufferIterator() = default ;
-	LineBufferIterator( const LineBufferIterator & ) = delete ;
-	LineBufferIterator( LineBufferIterator && ) = delete ;
-	void operator=( const LineBufferIterator & ) = delete ;
-	void operator=( LineBufferIterator && ) = delete ;
-
-private:
-	LineBuffer & m_line_buffer ;
-} ;
-
 //| \class GNet::LineBufferConfig
 /// A configuration structure for GNet::LineBuffer.
 ///
@@ -348,6 +335,9 @@ public:
 	std::size_t expect() const ;
 		///< Returns the initial expect value, as passed to the constructor.
 
+	bool operator==( const LineBufferConfig & ) const ;
+		///< Equality operator.
+
 	static LineBufferConfig transparent() ;
 		///< Convenience factory function.
 
@@ -401,8 +391,13 @@ public:
 		///< Returns the first bytes of buffered data up to a limit
 		///< of sixteen bytes.
 
+	bool peekmore() const ;
+		///< Returns true if another complete line is available
+		///< after the current line or current expect() block.
+
 private:
 	bool m_transparent ;
+	bool m_peekmore ;
 	std::string m_eol ;
 	std::size_t m_size ;
 	std::string m_head ;
@@ -440,7 +435,7 @@ std::size_t GNet::LineBuffer::size() const
 }
 
 inline
-std::size_t GNet::LineBuffer::insize() const
+std::size_t GNet::LineBuffer::buffersize() const
 {
 	return m_in.size() ;
 }
@@ -502,6 +497,18 @@ void GNet::LineBuffer::apply( Tsink sink_p , Tmemfun memfun , const char * data_
 	}
 }
 
+inline
+bool GNet::LineBuffer::apply( SinkFn sink_fn , G::string_view data_in , FragmentsFn fragments_fn ) // NOLINT performance-unnecessary-value-param
+{
+	Extension e( this , data_in.data() , data_in.size() ) ;
+	while( e.valid() && more( fragments_fn() ) )
+	{
+		if( !sink_fn( SinkArgs(data(),size(),eolsize(),linesize(),c0(),peekmore()) ) )
+			return false ;
+	}
+	return true ;
+}
+
 template <typename T>
 inline
 void GNet::LineBuffer::apply( const std::string & data , T sink , bool with_fragments )
@@ -537,49 +544,12 @@ std::size_t GNet::LineBufferConfig::expect() const
 
 // ==
 
-inline
-GNet::LineBufferIterator::LineBufferIterator( LineBuffer & line_buffer ) :
-	m_line_buffer(line_buffer)
-{
-}
-
-inline
-bool GNet::LineBufferIterator::more()
-{
-	return m_line_buffer.more() ;
-}
-
-inline
-std::string GNet::LineBufferIterator::line() const
-{
-	return std::string( m_line_buffer.data() , m_line_buffer.size() ) ;
-}
-
-inline
-const char * GNet::LineBufferIterator::data() const
-{
-	return m_line_buffer.data() ;
-}
-
-inline
-std::size_t GNet::LineBufferIterator::size() const
-{
-	return m_line_buffer.size() ;
-}
-
-inline
-std::size_t GNet::LineBufferIterator::eolsize() const
-{
-	return m_line_buffer.eolsize() ;
-}
-
-// ==
-
 inline
 GNet::LineBufferState::LineBufferState( const LineBuffer & line_buffer ) :
 	m_transparent(line_buffer.transparent()) ,
+	m_peekmore(line_buffer.peekmore()) ,
 	m_eol(line_buffer.eol()) ,
-	m_size(line_buffer.insize()) ,
+	m_size(line_buffer.buffersize()) ,
 	m_head(line_buffer.head())
 {
 }
@@ -614,4 +584,10 @@ std::string GNet::LineBufferState::head() const
 	return m_head ;
 }
 
+inline
+bool GNet::LineBufferState::peekmore() const
+{
+	return m_peekmore ;
+}
+
 #endif
diff --git a/src/gnet/glinestore.cpp b/src/gnet/glinestore.cpp
index d4309ff..91a7443 100644
--- a/src/gnet/glinestore.cpp
+++ b/src/gnet/glinestore.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -36,7 +36,7 @@ namespace GNet
 class GNet::LineStoreIterator : public std::iterator<std::bidirectional_iterator_tag,char,ptrdiff_t>
 {
 public:
-	G_EXCEPTION( Error , "line buffer internal error" ) ;
+	G_EXCEPTION( Error , tx("line buffer internal error") ) ;
 	LineStoreIterator() = default;
 	~LineStoreIterator() = default;
 	explicit LineStoreIterator( const LineStore & line_store , bool end = false ) :
@@ -106,16 +106,12 @@ public:
 	char operator*() const
 	{
 		G_ASSERT( m_p != nullptr ) ;
-		if( m_p == nullptr )
-			throw Error() ;
-		return m_p->at( m_pos ) ;
+		return m_p ? m_p->at( m_pos ) : '\0' ;
 	}
 	char operator[]( std::size_t n ) const
 	{
 		G_ASSERT( m_p != nullptr ) ;
-		if( m_p == nullptr )
-			throw Error() ;
-		return m_p->at( m_pos + n ) ;
+		return m_p ? m_p->at( m_pos + n ) : '\0' ;
 	}
 	void operator+=( ptrdiff_t n )
 	{
diff --git a/src/gnet/glinestore.h b/src/gnet/glinestore.h
index 1c9fdd1..6740e9d 100644
--- a/src/gnet/glinestore.h
+++ b/src/gnet/glinestore.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -79,12 +79,13 @@ public:
 		///< not found.
 
 	std::size_t find( const std::string & s , std::size_t startpos = 0U ) const ;
-		///< Finds the given sub-string. Returns npos if not
+		///< Finds the given string. Returns npos if not
 		///< found.
 
 	std::size_t findSubStringAtEnd( const std::string & s , std::size_t startpos = 0U ) const ;
-		///< Finds a non-empty leading substring 's' that
-		///< appears at the end of the data. Returns npos
+		///< Tries to find some leading sub-string of 's' that
+		///< appears right at the end of the data, starting
+		///< with the longest sub-string. Returns npos
 		///< if not found.
 
 	const char * data( std::size_t pos , std::size_t size ) const ;
@@ -107,8 +108,8 @@ public:
 	~LineStore() = default ;
 	LineStore( const LineStore & ) = delete ;
 	LineStore( LineStore && ) = delete ;
-	void operator=( const LineStore & ) = delete ;
-	void operator=( LineStore && ) = delete ;
+	LineStore & operator=( const LineStore & ) = delete ;
+	LineStore & operator=( LineStore && ) = delete ;
 
 private:
 	const char * dataimp( std::size_t pos , std::size_t size ) ;
diff --git a/src/gnet/glistener.h b/src/gnet/glistener.h
index 6365dcf..d79dedb 100644
--- a/src/gnet/glistener.h
+++ b/src/gnet/glistener.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gnet/glocal.cpp b/src/gnet/glocal.cpp
index b7b1a60..f9e5613 100644
--- a/src/gnet/glocal.cpp
+++ b/src/gnet/glocal.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gnet/glocal.h b/src/gnet/glocal.h
index a2bd608..7d777db 100644
--- a/src/gnet/glocal.h
+++ b/src/gnet/glocal.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gnet/glocation.cpp b/src/gnet/glocation.cpp
index 100caee..fee18af 100644
--- a/src/gnet/glocation.cpp
+++ b/src/gnet/glocation.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -35,7 +35,7 @@ GNet::Location::Location( const std::string & spec , int family ) :
 {
 	m_using_socks = socksified( spec , m_socks_far_host , m_socks_far_port ) ;
 	if( m_host.empty() )
-		throw InvalidFormat( spec ) ;
+		throw InvalidFormat( spec ) ; // eg. ":25"
 	G_DEBUG( "GNet::Location::ctor: unresolved location [" << displayString() << "]" << (m_using_socks?" (using socks)":"") ) ;
 }
 
@@ -49,6 +49,8 @@ GNet::Location::Location( const std::string & spec , int family , int ) : // nos
 	m_using_socks(false)
 {
 	G_DEBUG( "GNet::Location::ctor: unresolved location [" << displayString() << "]" ) ;
+	if( m_host.empty() )
+		throw InvalidFormat( spec ) ;
 }
 
 GNet::Location::Location( const std::string & socks_server , const std::string & far_server , int family ) : // socks() overload
@@ -66,6 +68,8 @@ GNet::Location::Location( const std::string & socks_server , const std::string &
 		throw InvalidFormat() ;
 	if( !G::Str::isUInt(m_socks_far_port) )
 		throw InvalidFormat( "invalid port number: [" + m_socks_far_port + "]" ) ;
+	if( m_host.empty() )
+		throw InvalidFormat( socks_server ) ;
 	G_DEBUG( "GNet::Location::ctor: unresolved location [" << displayString() << "]" << " (using socks)" ) ;
 }
 
@@ -101,8 +105,8 @@ bool GNet::Location::socksified( const std::string & s , std::string & far_host_
 std::string GNet::Location::head( const std::string & s )
 {
 	std::size_t pos = s.rfind( ':' ) ;
-	std::string h = ( pos == std::string::npos && !s.empty() && s[0] == '/' ) ? s : G::Str::head( s , pos ) ;
-	if( h.size() > 1U && h.at(0U) == '[' && h.at(h.size()-1U) == ']' )
+	std::string h = ( pos == std::string::npos && !s.empty() && s[0] == '/' ) ? s : G::Str::head( s , pos ) ; // eg. "/tmp/socket"
+	if( h.size() > 1U && h.at(0U) == '[' && h.at(h.size()-1U) == ']' ) // eg. "[::1]:25"
 		h = h.substr( 1U , h.size()-2U ) ;
 	return h ;
 }
diff --git a/src/gnet/glocation.h b/src/gnet/glocation.h
index c7fdde0..78d3b80 100644
--- a/src/gnet/glocation.h
+++ b/src/gnet/glocation.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -70,8 +70,8 @@ namespace GNet
 class GNet::Location
 {
 public:
-	G_EXCEPTION( InvalidFormat , "invalid host:service format" ) ;
-	G_EXCEPTION( InvalidFamily , "invalid address family" ) ;
+	G_EXCEPTION( InvalidFormat , tx("invalid host:service format") ) ;
+	G_EXCEPTION( InvalidFamily , tx("invalid address family") ) ;
 
 	explicit Location( const std::string & spec , int family = AF_UNSPEC ) ;
 		///< Constructor taking a formatted "host:service" string.
diff --git a/src/gnet/gmonitor.cpp b/src/gnet/gmonitor.cpp
index b56bd92..da581b3 100644
--- a/src/gnet/gmonitor.cpp
+++ b/src/gnet/gmonitor.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -20,6 +20,7 @@
 
 #include "gdef.h"
 #include "gmonitor.h"
+#include "ggettext.h"
 #include "gstr.h"
 #include "gassert.h"
 #include <map>
@@ -47,7 +48,6 @@ private:
 	struct ConnectionInfo
 	{
 		bool is_client ;
-		explicit ConnectionInfo( bool is_client_ ) noexcept : is_client(is_client_) {}
 	} ;
 	using ConnectionMap = std::map<const Connection*,ConnectionInfo> ;
 	using ServerMap = std::map<const Listener*,Address> ;
@@ -56,8 +56,8 @@ public:
 	~MonitorImp() = default ;
 	MonitorImp( const MonitorImp & ) = delete ;
 	MonitorImp( MonitorImp && ) = delete ;
-	void operator=( const MonitorImp & ) = delete ;
-	void operator=( MonitorImp && ) = delete ;
+	MonitorImp & operator=( const MonitorImp & ) = delete ;
+	MonitorImp & operator=( MonitorImp && ) = delete ;
 
 private:
 	static std::string join( const std::string & , const std::string & ) ;
@@ -182,7 +182,7 @@ GNet::MonitorImp::MonitorImp( Monitor & ) :
 
 void GNet::MonitorImp::add( const Connection & connection , bool is_client )
 {
-	bool inserted = m_connections.insert(ConnectionMap::value_type(&connection,ConnectionInfo(is_client))).second ;
+	bool inserted = m_connections.insert(ConnectionMap::value_type(&connection,ConnectionInfo{is_client})).second ;
 	if( inserted )
 	{
 		if( is_client )
@@ -227,37 +227,38 @@ void GNet::MonitorImp::remove( const Listener & server ) noexcept
 
 void GNet::MonitorImp::report( std::ostream & s , const std::string & px , const std::string & eol ) const
 {
+	using G::txt ;
 	for( const auto & server : m_servers )
 	{
-		s << px << "LISTEN: " << server.second.displayString(true) << eol ;
+		s << px << txt("LISTEN: ") << server.second.displayString(true) << eol ;
 	}
 
-	s << px << "OUT started: " << m_client_adds << eol ;
-	s << px << "OUT finished: " << m_client_removes << eol ;
+	s << px << txt("OUT started: ") << m_client_adds << eol ;
+	s << px << txt("OUT finished: ") << m_client_removes << eol ;
 	{
 		for( const auto & connection : m_connections )
 		{
 			if( connection.second.is_client )
 			{
 				s << px
-					<< "OUT: "
-					<< connection.first->localAddress().second.displayString() << " -> "
+					<< txt("OUT: ")
+					<< connection.first->localAddress().displayString() << " -> "
 					<< connection.first->connectionState() << eol ;
 			}
 		}
 	}
 
-	s << px << "IN started: " << m_server_peer_adds << eol ;
-	s << px << "IN finished: " << m_server_peer_removes << eol ;
+	s << px << txt("IN started: ") << m_server_peer_adds << eol ;
+	s << px << txt("IN finished: ") << m_server_peer_removes << eol ;
 	{
 		for( const auto & connection : m_connections )
 		{
 			if( !connection.second.is_client )
 			{
 				s << px
-					<< "IN: "
-					<< connection.first->localAddress().second.displayString() << " <- "
-					<< connection.first->peerAddress().second.displayString() << eol ;
+					<< txt("IN: ")
+					<< connection.first->localAddress().displayString() << " <- "
+					<< connection.first->peerAddress().displayString() << eol ;
 			}
 		}
 	}
@@ -268,21 +269,22 @@ void GNet::MonitorImp::report( G::StringArray & out ) const
 	for( const auto & server : m_servers )
 		add( out , "Listening address" , server.second.displayString() ) ;
 
-	add( out , "Outgoing connections" , m_client_adds , "started" , m_client_removes , "finished" ) ;
-	add( out , "Incoming connections" , m_server_peer_adds , "started" , m_server_peer_removes , "finished" ) ;
+	using G::txt ;
+	add( out , txt("Outgoing connections") , m_client_adds , txt("started") , m_client_removes , txt("finished") ) ;
+	add( out , txt("Incoming connections") , m_server_peer_adds , txt("started") , m_server_peer_removes , txt("finished") ) ;
 	for( const auto & connection : m_connections )
 	{
 		if( connection.second.is_client )
 		{
-			add( out , "Outgoing connection" , connection.first->localAddress().second.displayString() , "-->" ,
+			add( out , txt("Outgoing connection") , connection.first->localAddress().displayString() , "-->" ,
 				connection.first->connectionState() , "" ) ;
 		}
 	}
 	for( const auto & connection : m_connections )
 	{
 		if( !connection.second.is_client )
-			add( out , "Incoming connection" , connection.first->localAddress().second.displayString() , "<--" ,
-				connection.first->peerAddress().second.displayString() , "" ) ;
+			add( out , txt("Incoming connection") , connection.first->localAddress().displayString() , "<--" ,
+				connection.first->peerAddress().displayString() , "" ) ;
 	}
 }
 
diff --git a/src/gnet/gmonitor.h b/src/gnet/gmonitor.h
index d298494..fc37ebb 100644
--- a/src/gnet/gmonitor.h
+++ b/src/gnet/gmonitor.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -25,8 +25,9 @@
 #include "gslot.h"
 #include "gconnection.h"
 #include "glistener.h"
-#include <iostream>
+#include <memory>
 #include <utility>
+#include <iostream>
 
 namespace GNet
 {
@@ -70,7 +71,7 @@ public:
 		///< Removes a server.
 
 	void report( std::ostream & stream ,
-		const std::string & line_prefix = std::string() ,
+		const std::string & line_prefix = {} ,
 		const std::string & eol = std::string("\n") ) const ;
 			///< Reports itself onto a stream.
 
@@ -89,8 +90,8 @@ public:
 public:
 	Monitor( const Monitor & ) = delete ;
 	Monitor( Monitor && ) = delete ;
-	void operator=( const Monitor & ) = delete ;
-	void operator=( Monitor && ) = delete ;
+	Monitor & operator=( const Monitor & ) = delete ;
+	Monitor & operator=( Monitor && ) = delete ;
 
 private:
 	static Monitor * & pthis() noexcept ;
diff --git a/src/gnet/gmultiserver.cpp b/src/gnet/gmultiserver.cpp
index 7e0f356..92ea187 100644
--- a/src/gnet/gmultiserver.cpp
+++ b/src/gnet/gmultiserver.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -28,10 +28,9 @@
 #include <list>
 #include <algorithm>
 
-GNet::MultiServer::MultiServer( ExceptionSink es , const G::StringArray & interfaces , unsigned int port ,
-	const std::string & server_type , ServerPeerConfig server_peer_config , ServerConfig server_config ) :
+GNet::MultiServer::MultiServer( ExceptionSink es , const G::StringArray & listener_list , unsigned int port ,
+	const std::string & server_type , ServerPeer::Config server_peer_config , Server::Config server_config ) :
 		m_es(es) ,
-		m_interfaces(interfaces) ,
 		m_port(port) ,
 		m_server_type(server_type) ,
 		m_server_peer_config(server_peer_config) ,
@@ -39,43 +38,73 @@ GNet::MultiServer::MultiServer( ExceptionSink es , const G::StringArray & interf
 		m_if(es,*this) ,
 		m_interface_event_timer(*this,&MultiServer::onInterfaceEventTimeout,es)
 {
-	// tidy the interface list
-	std::sort( m_interfaces.begin() , m_interfaces.end() ) ;
-	m_interfaces.erase( std::unique(m_interfaces.begin(),m_interfaces.end()) , m_interfaces.end() ) ;
-
-	// build a listening address list from explicit addresses and/or interface names
-	G::StringArray used_names ; // interface names having one or more addresses
+	// parse the listener list
+	G::StringArray used_names ; // addresses, or interface names having one or more addresses
 	G::StringArray empty_names ; // interface names having no addresses
 	G::StringArray bad_names ; // non-address non-interface names
-	AddressList address_list = addresses( port , used_names , empty_names , bad_names ) ;
+	std::vector<int> fds ;
+	AddressList address_list ;
+	parse( listener_list , port , address_list , fds , used_names , empty_names , bad_names ) ;
 
 	// fail if any bad names
 	if( !bad_names.empty() )
 		throw InvalidName( bad_names.at(0) ) ;
 
-	// fail if no addresses and no prospect of getting any
-	if( address_list.empty() && ( empty_names.empty() || !Interfaces::active() ) )
-		throw NoListeningAddresses() ;
-
-	// warn if no addresses from one or more interface names
-	if( !empty_names.empty() )
+	// apply a default set of two wildcard addresses
+	if( fds.empty() && address_list.empty() && empty_names.empty() )
 	{
-		if( !address_list.empty() )
-			G_WARNING( "GNet::MultiServer::ctor: no addresses bound to named network interface"
-				<< (empty_names.size()==1U?"":"s")
-				<< " \"" << G::Str::join("\", \"",empty_names) << "\"" ) ;
-		else if( Interfaces::active() )
-			G_WARNING( "GNet::MultiServer::ctor: no listening addresses: waiting for interface"
-				<< (empty_names.size()>1U?"s ":" ")
-				<< "[" << G::Str::join("] [",empty_names) << "]" ) ;
+		if( Address::supports(Address::Family::ipv4) )
+			address_list.push_back( Address(Address::Family::ipv4,port) ) ;
+		if( Address::supports(Address::Family::ipv6) && StreamSocket::supports(Address::Family::ipv6) )
+			address_list.push_back( Address(Address::Family::ipv6,port) ) ;
+		if( address_list.empty() )
+			throw NoListeningAddresses() ;
 	}
 
-	// bind the listening addresses, etc
-	init( address_list ) ;
+	// fail if no addresses and no prospect of getting any
+	if( fds.empty() && address_list.empty() && !Interfaces::active() )
+		throw NoListeningAddresses() ;
+
+	// save used and empty names to query G::Interfaces later on
+	m_if_names.insert( m_if_names.end() , used_names.begin() , used_names.end() ) ;
+	m_if_names.insert( m_if_names.end() , empty_names.begin() , empty_names.end() ) ;
+	std::sort( m_if_names.begin() , m_if_names.end() ) ;
+	m_if_names.erase( std::unique(m_if_names.begin(),m_if_names.end()) , m_if_names.end() ) ;
+
+	// warn if no addresses from one or more interface names
+	if( !empty_names.empty() && !address_list.empty() )
+	{
+		G_WARNING( "GNet::MultiServer::ctor: no addresses bound to named network interface"
+			<< (empty_names.size()==1U?"":"s")
+			<< " \"" << G::Str::join("\", \"",empty_names) << "\"" ) ;
+	}
+
+	// warn if doing nothing until an interface come up
+	if( address_list.empty() && fds.empty() && !empty_names.empty() )
+	{
+		G_WARNING( "GNet::MultiServer::ctor: " << m_server_type << " server: nothing to do: "
+			<< "waiting for interface" << (empty_names.size()>1U?"s ":" ")
+			<< "[" << G::Str::join("] [",empty_names) << "]" ) ;
+	}
 
 	// warn if we got addresses from an interface name but won't get dynamic updates
 	if( !used_names.empty() && !Interfaces::active() )
-		G_WARNING_ONCE( "GNet::MultiServer::ctor: named network interfaces are not monitored for updates" ) ;
+	{
+		G_WARNING_ONCE( "GNet::MultiServer::ctor: named network interfaces "
+			"are not being monitored for address updates" ) ;
+	}
+
+	// instantiate the servers
+	for( const auto & fd : fds )
+	{
+		m_server_list.emplace_back( std::make_unique<MultiServerImp>( *this , m_es ,
+			Descriptor(fd) , m_server_peer_config , m_server_config ) ) ;
+	}
+	for( const auto & address : address_list )
+	{
+		m_server_list.emplace_back( std::make_unique<MultiServerImp>( *this , m_es ,
+			address , m_server_peer_config , m_server_config ) ) ;
+	}
 }
 
 GNet::MultiServer::~MultiServer()
@@ -83,6 +112,32 @@ GNet::MultiServer::~MultiServer()
 	serverCleanup() ;
 }
 
+void GNet::MultiServer::parse( const G::StringArray & listener_list , unsigned int port ,
+	AddressList & addresses_out , std::vector<int> & fds_out ,
+	G::StringArray & used_names_out , G::StringArray & empty_names_out , G::StringArray & bad_names_out )
+{
+	for( const auto & listener : listener_list )
+	{
+		if( listener.empty() ) continue ;
+		int fd = G::is_windows() ? -1 : parseFd( listener ) ;
+		if( fd >= 0 )
+			fds_out.push_back( fd ) ;
+		else
+			m_if.addresses( listener , port , addresses_out , &used_names_out , &empty_names_out , &bad_names_out ) ;
+	}
+}
+
+int GNet::MultiServer::parseFd( const std::string & listener )
+{
+	if( listener.size() > 3U && listener.find("fd#") == 0U && G::Str::isUInt(listener.substr(3U)) )
+	{
+		int fd = G::Str::toInt( listener.substr(3U) ) ;
+		if( fd < 0 ) throw InvalidFd( listener ) ;
+		return fd ;
+	}
+	return -1 ;
+}
+
 void GNet::MultiServer::serverCleanup()
 {
 	for( auto & server : m_server_list )
@@ -91,46 +146,10 @@ void GNet::MultiServer::serverCleanup()
 	}
 }
 
-std::vector<GNet::Address> GNet::MultiServer::addresses( unsigned int port ) const
-{
-	AddressList result ;
-	G::StringArray empty_names ;
-	G::StringArray used_names ;
-	G::StringArray bad_names ;
-	return addresses( port , used_names , empty_names , bad_names ) ;
-}
-
-std::vector<GNet::Address> GNet::MultiServer::addresses( unsigned int port , G::StringArray & used_names ,
-	G::StringArray & empty_names , G::StringArray & bad_names ) const
-{
-	AddressList result ;
-	if( m_interfaces.empty() )
-	{
-		if( Address::supports(Address::Family::ipv4) )
-			result.push_back( Address(Address::Family::ipv4,port) ) ;
-		if( Address::supports(Address::Family::ipv6) && StreamSocket::supports(Address::Family::ipv6) )
-			result.push_back( Address(Address::Family::ipv6,port) ) ;
-	}
-	else
-	{
-		result = m_if.addresses( m_interfaces , port , used_names , empty_names , bad_names ) ;
-	}
-	return result ;
-}
-
-void GNet::MultiServer::init( const AddressList & address_list )
-{
-	for( const auto & address : address_list )
-	{
-		m_server_list.emplace_back( std::make_unique<MultiServerImp>( *this , m_es , address , m_server_peer_config , m_server_config ) ) ;
-	}
-}
-
 void GNet::MultiServer::onInterfaceEvent( const std::string & /*description*/ )
 {
 	// notifications can be periodic and/or bursty, so minimal logging here
 	G_DEBUG( "GNet::MultiServer::onInterfaceEvent: network configuration change event" ) ;
-
 	m_if.load() ;
 	m_interface_event_timer.startTimer( 1U , 500000U ) ; // maybe increase for fewer bind warnings
 }
@@ -146,7 +165,8 @@ bool GNet::MultiServer::match( const Address & interface_address , const Address
 
 void GNet::MultiServer::onInterfaceEventTimeout()
 {
-	AddressList address_list = addresses( m_port ) ;
+	// get a fresh address list
+	AddressList address_list = m_if.addresses( m_if_names , m_port ) ;
 
 	// delete old
 	for( auto server_ptr_p = m_server_list.begin() ; server_ptr_p != m_server_list.end() ; )
@@ -187,7 +207,7 @@ void GNet::MultiServer::onInterfaceEventTimeout()
 				// (can fail here if notified too soon, but succeeds later)
 				G_LOG( "GNet::MultiServer::onInterfaceEvent: failed to bind " << displayString(address)
 					<< " for new " << m_server_type << " server:"
-					<< G::Str::tail(e.what(),std::string(e.what()).rfind(':')) ) ;
+					<< G::Str::tail(e.what(),G::string_view(e.what()).rfind(':')) ) ;
 			}
 		}
 	}
@@ -199,12 +219,6 @@ bool GNet::MultiServer::gotServerFor( const Address & interface_address ) const
 		[&interface_address](const ServerPtr &ptr){return match(interface_address,ptr->address());} ) ;
 }
 
-bool GNet::MultiServer::canBind( const AddressList & address_list , bool do_throw )
-{
-	return std::all_of( address_list.begin() , address_list.end() ,
-		[do_throw](const Address & a){return Server::canBind(a,do_throw);} ) ;
-}
-
 std::string GNet::MultiServer::displayString( const Address & address )
 {
 	return address.displayString( true ) ;
@@ -219,9 +233,9 @@ void GNet::MultiServer::serverReport() const
 }
 
 std::unique_ptr<GNet::ServerPeer> GNet::MultiServer::doNewPeer( ExceptionSinkUnbound esu ,
-	const ServerPeerInfo & pi , const ServerInfo & si )
+	ServerPeerInfo && pi , const ServerInfo & si )
 {
-	return newPeer( esu , pi , si ) ;
+	return newPeer( esu , std::move(pi) , si ) ;
 }
 
 bool GNet::MultiServer::hasPeers() const
@@ -234,7 +248,7 @@ bool GNet::MultiServer::hasPeers() const
 	return false ;
 }
 
-std::vector<std::weak_ptr<GNet::ServerPeer> > GNet::MultiServer::peers()
+std::vector<std::weak_ptr<GNet::ServerPeer>> GNet::MultiServer::peers()
 {
 	using List = std::vector<std::weak_ptr<ServerPeer>> ;
 	List result ;
@@ -249,10 +263,16 @@ std::vector<std::weak_ptr<GNet::ServerPeer> > GNet::MultiServer::peers()
 // ==
 
 GNet::MultiServerImp::MultiServerImp( MultiServer & ms , ExceptionSink es , const Address & address ,
-	ServerPeerConfig server_peer_config , ServerConfig server_config ) :
+	ServerPeer::Config server_peer_config , Server::Config server_config ) :
 		GNet::Server(es,address,server_peer_config,server_config) ,
-		m_ms(ms) ,
-		m_address(address)
+		m_ms(ms)
+{
+}
+
+GNet::MultiServerImp::MultiServerImp( MultiServer & ms , ExceptionSink es , Descriptor fd ,
+	ServerPeer::Config server_peer_config , Server::Config server_config ) :
+		GNet::Server(es,fd,server_peer_config,server_config) ,
+		m_ms(ms)
 {
 }
 
@@ -264,11 +284,11 @@ void GNet::MultiServerImp::cleanup()
 	serverCleanup() ;
 }
 
-std::unique_ptr<GNet::ServerPeer> GNet::MultiServerImp::newPeer( ExceptionSinkUnbound esu , ServerPeerInfo peer_info )
+std::unique_ptr<GNet::ServerPeer> GNet::MultiServerImp::newPeer( ExceptionSinkUnbound esu , ServerPeerInfo && peer_info )
 {
 	MultiServer::ServerInfo server_info ;
 	server_info.m_address = address() ; // GNet::Server::address()
-	return m_ms.doNewPeer( esu , peer_info , server_info ) ;
+	return m_ms.doNewPeer( esu , std::move(peer_info) , server_info ) ;
 }
 
 // ==
diff --git a/src/gnet/gmultiserver.h b/src/gnet/gmultiserver.h
index f602df7..2a327cf 100644
--- a/src/gnet/gmultiserver.h
+++ b/src/gnet/gmultiserver.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -26,8 +26,10 @@
 #include "gserver.h"
 #include "gtimer.h"
 #include "ginterfaces.h"
-#include <vector>
+#include "gexception.h"
+#include <memory>
 #include <utility> // std::pair<>
+#include <vector>
 
 namespace GNet
 {
@@ -44,9 +46,10 @@ namespace GNet
 class GNet::MultiServer : private InterfacesHandler
 {
 public:
+	G_EXCEPTION( NoListeningAddresses , tx("no listening addresses") ) ;
+	G_EXCEPTION( InvalidName , tx("invalid address or interface name") ) ;
+	G_EXCEPTION( InvalidFd , tx("invalid listening file descriptor number") ) ;
 	using AddressList = std::vector<Address> ;
-	G_EXCEPTION( NoListeningAddresses , "no listening addresses" ) ;
-	G_EXCEPTION( InvalidName , "invalid address or interface name" ) ;
 
 	struct ServerInfo /// A structure used in GNet::MultiServer::newPeer().
 	{
@@ -54,15 +57,18 @@ public:
 		Address m_address ; ///< The server address that the peer connected to.
 	} ;
 
-	MultiServer( ExceptionSink listener_exception_sink , const G::StringArray & addresses ,
-		unsigned int port , const std::string & server_type , ServerPeerConfig server_peer_config ,
-		ServerConfig server_config ) ;
-			///< Constructor. The server listens on on the specific local
-			///< addresses, given as either interface names (eg. "eth0")
-			///< or IP network addresses (eg. "::1") together with a
-			///< fixed port number. Throws if there are no addresses in the
-			///< list and the GNet::Interfaces implementation is not active().
-			///< Listens on "0.0.0.0" and "::" if the list is empty.
+	MultiServer( ExceptionSink listener_exception_sink , const G::StringArray & listen_list ,
+		unsigned int port , const std::string & server_type ,
+		ServerPeer::Config server_peer_config , Server::Config server_config ) ;
+			///< Constructor. The server listens on inherited file descriptors
+			///< formatted like "#3", specific local addresses (eg. "127.0.0.1")
+			///< and addresses from named interfaces ("eth0").
+			///<
+			///< Listens on "0.0.0.0" and "::" if the listen list is
+			///< empty.
+			///<
+			///< Throws if there are no addresses in the list and the
+			///< GNet::Interfaces implementation is not active().
 
 	~MultiServer() override ;
 		///< Destructor.
@@ -70,19 +76,14 @@ public:
 	bool hasPeers() const ;
 		///< Returns true if peers() is not empty.
 
-	std::vector<std::weak_ptr<ServerPeer> > peers() ;
+	std::vector<std::weak_ptr<ServerPeer>> peers() ;
 		///< Returns the list of ServerPeer-derived objects.
 
-	static bool canBind( const AddressList & listening_address_list , bool do_throw ) ;
-		///< Checks that all the specified addresses can be
-		///< bound. Throws CannotBind if any of those addresses
-		///< cannot be bound and 'do_throw' is true.
-
-	std::unique_ptr<ServerPeer> doNewPeer( ExceptionSinkUnbound , const ServerPeerInfo & , const ServerInfo & ) ;
+	std::unique_ptr<ServerPeer> doNewPeer( ExceptionSinkUnbound , ServerPeerInfo && , const ServerInfo & ) ;
 		///< Pseudo-private method used by the pimple class.
 
 protected:
-	virtual std::unique_ptr<ServerPeer> newPeer( ExceptionSinkUnbound , ServerPeerInfo , ServerInfo ) = 0 ;
+	virtual std::unique_ptr<ServerPeer> newPeer( ExceptionSinkUnbound , ServerPeerInfo && , ServerInfo ) = 0 ;
 		///< A factory method which new()s a ServerPeer-derived
 		///< object. See GNet::Server for the details.
 
@@ -101,14 +102,15 @@ private: // overrides
 public:
 	MultiServer( const MultiServer & ) = delete ;
 	MultiServer( MultiServer && ) = delete ;
-	void operator=( const MultiServer & ) = delete ;
-	void operator=( MultiServer && ) = delete ;
+	MultiServer & operator=( const MultiServer & ) = delete ;
+	MultiServer & operator=( MultiServer && ) = delete ;
 
 private:
 	friend class GNet::MultiServerImp ;
-	AddressList addresses( unsigned int ) const ;
-	AddressList addresses( unsigned int , G::StringArray & , G::StringArray & , G::StringArray & ) const ;
-	void init( const AddressList & address_list ) ;
+	void parse( const G::StringArray & , unsigned int port ,
+		AddressList & , std::vector<int> & ,
+		G::StringArray & , G::StringArray & , G::StringArray & ) ;
+	static int parseFd( const std::string & ) ;
 	bool gotServerFor( const Address & ) const ;
 	void onInterfaceEventTimeout() ;
 	static bool match( const Address & , const Address & ) ;
@@ -118,12 +120,12 @@ private:
 	using ServerPtr = std::unique_ptr<MultiServerImp> ;
 	using ServerList = std::vector<ServerPtr> ;
 	ExceptionSink m_es ;
-	G::StringArray m_interfaces ;
 	unsigned int m_port ;
 	std::string m_server_type ;
-	ServerPeerConfig m_server_peer_config ;
-	ServerConfig m_server_config ;
+	ServerPeer::Config m_server_peer_config ;
+	Server::Config m_server_config ;
 	Interfaces m_if ;
+	G::StringArray m_if_names ;
 	ServerList m_server_list ;
 	Timer<MultiServer> m_interface_event_timer ;
 } ;
@@ -134,13 +136,16 @@ private:
 class GNet::MultiServerImp : public GNet::Server
 {
 public:
-	MultiServerImp( MultiServer & , ExceptionSink , const Address & , ServerPeerConfig , ServerConfig ) ;
+	MultiServerImp( MultiServer & , ExceptionSink , const Address & , ServerPeer::Config , Server::Config ) ;
+		///< Constructor.
+
+	MultiServerImp( MultiServer & , ExceptionSink , Descriptor , ServerPeer::Config , Server::Config ) ;
 		///< Constructor.
 
 	~MultiServerImp() override ;
 		///< Destructor.
 
-	std::unique_ptr<ServerPeer> newPeer( ExceptionSinkUnbound , ServerPeerInfo ) final ;
+	std::unique_ptr<ServerPeer> newPeer( ExceptionSinkUnbound , ServerPeerInfo&& ) final ;
 		///< Called by the base class to create a new ServerPeer.
 
 	void cleanup() ;
@@ -149,12 +154,11 @@ public:
 public:
 	MultiServerImp( const MultiServerImp & ) = delete ;
 	MultiServerImp( MultiServerImp && ) = delete ;
-	void operator=( const MultiServerImp & ) = delete ;
-	void operator=( MultiServerImp && ) = delete ;
+	MultiServerImp & operator=( const MultiServerImp & ) = delete ;
+	MultiServerImp & operator=( MultiServerImp && ) = delete ;
 
 private:
 	MultiServer & m_ms ;
-	Address m_address ;
 } ;
 
 #endif
diff --git a/src/gnet/gnetdone.cpp b/src/gnet/gnetdone.cpp
index cb0f18c..ce4a87a 100644
--- a/src/gnet/gnetdone.cpp
+++ b/src/gnet/gnetdone.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gnet/gnetdone.h b/src/gnet/gnetdone.h
index f841525..4d734c2 100644
--- a/src/gnet/gnetdone.h
+++ b/src/gnet/gnetdone.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gnet/gresolver.cpp b/src/gnet/gresolver.cpp
index 91cf605..a8d239f 100644
--- a/src/gnet/gresolver.cpp
+++ b/src/gnet/gresolver.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -52,7 +52,7 @@ public:
 		// Disarms the callback and schedules a 'delete this' for when
 		// the workder thread has finished.
 
-	static void start( ResolverImp * , FutureEvent::handle_type ) noexcept ;
+	static void start( ResolverImp * , HANDLE ) noexcept ;
 		// Static worker-thread function to do name resolution. Calls
 		// ResolverFuture::run() to do the work and then FutureEvent::send()
 		// to signal the main thread. The event plumbing then results in a
@@ -67,8 +67,8 @@ private: // overrides
 public:
 	ResolverImp( const ResolverImp & ) = delete ;
 	ResolverImp( ResolverImp && ) = delete ;
-	void operator=( const ResolverImp & ) = delete ;
-	void operator=( ResolverImp && ) = delete ;
+	ResolverImp & operator=( const ResolverImp & ) = delete ;
+	ResolverImp & operator=( ResolverImp && ) = delete ;
 
 private:
 	void onTimeout() ;
@@ -116,7 +116,7 @@ std::size_t GNet::ResolverImp::zcount() noexcept
 	return m_zcount ;
 }
 
-void GNet::ResolverImp::start( ResolverImp * This , FutureEvent::handle_type handle ) noexcept
+void GNet::ResolverImp::start( ResolverImp * This , HANDLE handle ) noexcept
 {
 	// thread function, spawned from ctor and join()ed from dtor
 	try
@@ -210,7 +210,7 @@ std::string GNet::Resolver::resolve( Location & location )
 		G_DEBUG( "GNet::Resolver::resolve: resolve result [" << result.first.displayString() << "]"
 			<< "[" << result.second << "]" ) ;
 		location.update( result.first , result.second ) ;
-		return std::string() ;
+		return {} ;
 	}
 }
 
diff --git a/src/gnet/gresolver.h b/src/gnet/gresolver.h
index 2c5b07e..18739e0 100644
--- a/src/gnet/gresolver.h
+++ b/src/gnet/gresolver.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -25,8 +25,10 @@
 #include "glocation.h"
 #include "geventhandler.h"
 #include "gexceptionsink.h"
+#include "gexception.h"
 #include "gaddress.h"
 #include <vector>
+#include <memory>
 
 namespace GNet
 {
@@ -43,9 +45,9 @@ namespace GNet
 class GNet::Resolver
 {
 public:
+	G_EXCEPTION( Error , tx("asynchronous resolver error") ) ;
+	G_EXCEPTION( BusyError , tx("asynchronous resolver still busy") ) ;
 	using AddressList = std::vector<Address> ;
-	G_EXCEPTION( Error , "asynchronous resolver error" ) ;
-	G_EXCEPTION( BusyError , "asynchronous resolver still busy" ) ;
 	struct Callback /// An interface used for GNet::Resolver callbacks.
 	{
 		virtual ~Callback() = default ;
@@ -89,8 +91,8 @@ public:
 public:
 	Resolver( const Resolver & ) = delete ;
 	Resolver( Resolver && ) = delete ;
-	void operator=( const Resolver & ) = delete ;
-	void operator=( Resolver && ) = delete ;
+	Resolver & operator=( const Resolver & ) = delete ;
+	Resolver & operator=( Resolver && ) = delete ;
 
 private:
 	friend class GNet::ResolverImp ;
diff --git a/src/gnet/gresolverfuture.cpp b/src/gnet/gresolverfuture.cpp
index 98c7a84..c26827c 100644
--- a/src/gnet/gresolverfuture.cpp
+++ b/src/gnet/gresolverfuture.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -77,7 +77,7 @@ std::string GNet::ResolverFuture::failure() const
 
 std::string GNet::ResolverFuture::ipvx() const
 {
-	if( m_family == AF_UNSPEC ) return std::string() ;
+	if( m_family == AF_UNSPEC ) return {} ;
 	if( m_family == AF_INET ) return "ipv4 " ;
 	return "ipv6 " ; // AF_INET6 possibly undefined
 }
diff --git a/src/gnet/gresolverfuture.h b/src/gnet/gresolverfuture.h
index 52b5294..e31ddca 100644
--- a/src/gnet/gresolverfuture.h
+++ b/src/gnet/gresolverfuture.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -89,8 +89,8 @@ public:
 public:
 	ResolverFuture( const ResolverFuture & ) = delete ;
 	ResolverFuture( ResolverFuture && ) = delete ;
-	void operator=( const ResolverFuture & ) = delete ;
-	void operator=( ResolverFuture && ) = delete ;
+	ResolverFuture & operator=( const ResolverFuture & ) = delete ;
+	ResolverFuture & operator=( ResolverFuture && ) = delete ;
 
 private:
 	std::string failure() const ;
diff --git a/src/gnet/gserver.cpp b/src/gnet/gserver.cpp
index b997878..34c76f7 100644
--- a/src/gnet/gserver.cpp
+++ b/src/gnet/gserver.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,18 +24,32 @@
 #include "gmonitor.h"
 #include "geventloggingcontext.h"
 #include "gcleanup.h"
-#include "gprocess.h"
 #include "glimits.h"
 #include "groot.h"
 #include "glog.h"
 #include "gassert.h"
 #include <algorithm>
 
-GNet::Server::Server( ExceptionSink es , const Address & listening_address ,
-	ServerPeerConfig server_peer_config , ServerConfig server_config ) :
+GNet::Server::Server( ExceptionSink es , Descriptor fd ,
+	const ServerPeer::Config & server_peer_config , const Config & server_config ) :
 		m_es(es) ,
+		m_config(server_config) ,
 		m_server_peer_config(server_peer_config) ,
-		m_socket(listening_address.family(),StreamSocket::Listener())
+		m_socket(StreamSocket::Listener(),fd,m_config.stream_socket_config)
+{
+	G_DEBUG( "GNet::Server::ctor: listening on socket " << m_socket.asString()
+		<< " with address " << m_socket.getLocalAddress().displayString() ) ;
+	m_socket.listen() ;
+	m_socket.addReadHandler( *this , m_es ) ;
+	Monitor::addServer( *this ) ;
+}
+
+GNet::Server::Server( ExceptionSink es , const Address & listening_address ,
+	const ServerPeer::Config & server_peer_config , const Config & server_config ) :
+		m_es(es) ,
+		m_config(server_config) ,
+		m_server_peer_config(server_peer_config) ,
+		m_socket(listening_address.family(),StreamSocket::Listener(),m_config.stream_socket_config)
 {
 	G_DEBUG( "GNet::Server::ctor: listening on socket " << m_socket.asString()
 		<< " with address " << listening_address.displayString() ) ;
@@ -43,7 +57,7 @@ GNet::Server::Server( ExceptionSink es , const Address & listening_address ,
 	bool uds = listening_address.family() == Address::Family::local ;
 	if( uds )
 	{
-		bool open = server_config.uds_open_permissions ;
+		bool open = m_config.uds_open_permissions ;
 		using Mode = G::Process::Umask::Mode ;
 		G::Root claim_root( false ) ; // group ownership from the effective group-id
 		G::Process::Umask set_umask( open ? Mode::Open : Mode::Tighter ) ;
@@ -55,14 +69,14 @@ GNet::Server::Server( ExceptionSink es , const Address & listening_address ,
 		m_socket.bind( listening_address ) ;
 	}
 
-	m_socket.listen( std::max(1,server_config.listen_queue) ) ;
+	m_socket.listen() ;
 	m_socket.addReadHandler( *this , m_es ) ;
 	Monitor::addServer( *this ) ;
 
 	if( uds )
 	{
-		std::string path = listening_address.hostPartString( true ) ;
-		if( path.size() > 1U && path.at(0U) == '/' ) // (just in case)
+		std::string path = listening_address.hostPartString() ;
+		if( path.size() > 1U && path.at(0U) == '/' )
 		{
 			G::Cleanup::add( &Server::unlink , G::Cleanup::strdup(path) ) ;
 		}
@@ -74,18 +88,6 @@ GNet::Server::~Server()
 	Monitor::removeServer( *this ) ;
 }
 
-bool GNet::Server::canBind( const Address & address , bool do_throw )
-{
-	std::string reason ;
-	{
-		G::Root claim_root ;
-		reason = Socket::canBindHint( address ) ;
-	}
-	if( !reason.empty() && do_throw )
-		throw CannotBind( address.displayString() , reason ) ;
-	return reason.empty() ;
-}
-
 GNet::Address GNet::Server::address() const
 {
 	bool with_scope = true ; // was false
@@ -104,14 +106,15 @@ void GNet::Server::readEvent()
 	//
 	ServerPeerInfo peer_info( this , m_server_peer_config ) ;
 	accept( peer_info ) ;
+	Address peer_address = peer_info.m_address ;
 
 	// do an early set of the logging context so that it applies
 	// during the newPeer() construction process -- it is then set
-	// more normally by the event hander list when handing out events
+	// more normally by the event emitter when handing out events
 	// with a well-defined ExceptionSource
 	//
-	EventLoggingContext event_logging_context( peer_info.m_address.hostPartString() ) ;
-	G_DEBUG( "GNet::Server::readEvent: new connection from " << peer_info.m_address.displayString()
+	EventLoggingContext event_logging_context( peer_address.hostPartString() ) ;
+	G_DEBUG( "GNet::Server::readEvent: new connection from " << peer_address.displayString()
 		<< " on " << peer_info.m_socket->asString() ) ;
 
 	// create the peer object -- newPeer() implementations will normally catch
@@ -121,12 +124,12 @@ void GNet::Server::readEvent()
 	// 'unbound' to force the peer object to set themselves as the exception
 	// source
 	//
-	std::unique_ptr<ServerPeer> peer = newPeer( ExceptionSinkUnbound(this) , peer_info ) ;
+	std::unique_ptr<ServerPeer> peer = newPeer( ExceptionSinkUnbound(this) , std::move(peer_info) ) ;
 
 	// commit or roll back
 	if( peer == nullptr )
 	{
-		G_WARNING( "GNet::Server::readEvent: connection rejected from " << peer_info.m_address.displayString() ) ;
+		G_WARNING( "GNet::Server::readEvent: connection rejected from " << peer_address.displayString() ) ;
 	}
 	else
 	{
@@ -137,13 +140,13 @@ void GNet::Server::readEvent()
 
 void GNet::Server::accept( ServerPeerInfo & peer_info )
 {
-	AcceptPair accept_pair ;
+	AcceptInfo accept_info ;
 	{
 		G::Root claim_root ;
-		accept_pair = m_socket.accept() ;
+		accept_info = m_socket.accept() ;
 	}
-	peer_info.m_socket = accept_pair.socket_ptr ;
-	peer_info.m_address = accept_pair.address ;
+	peer_info.m_address = accept_info.address ;
+	peer_info.m_socket = std::move( accept_info.socket_ptr ) ;
 }
 
 void GNet::Server::onException( ExceptionSource * esrc , std::exception & e , bool done )
@@ -181,9 +184,9 @@ bool GNet::Server::hasPeers() const
 	return !m_peer_list.empty() ;
 }
 
-std::vector<std::weak_ptr<GNet::ServerPeer> > GNet::Server::peers()
+std::vector<std::weak_ptr<GNet::ServerPeer>> GNet::Server::peers()
 {
-	using Peers = std::vector<std::weak_ptr<ServerPeer> > ;
+	using Peers = std::vector<std::weak_ptr<ServerPeer>> ;
 	Peers result ;
 	result.reserve( m_peer_list.size() ) ;
 	for( auto & peer : m_peer_list )
@@ -203,9 +206,9 @@ bool GNet::Server::unlink( G::SignalSafe , const char * path ) noexcept
 
 // ===
 
-GNet::ServerPeerInfo::ServerPeerInfo( Server * server , ServerPeerConfig config ) :
+GNet::ServerPeerInfo::ServerPeerInfo( Server * server , ServerPeer::Config server_peer_config ) :
 	m_address(Address::defaultAddress()) ,
-	m_config(config) ,
+	m_server_peer_config(server_peer_config) ,
 	m_server(server)
 {
 }
diff --git a/src/gnet/gserver.h b/src/gnet/gserver.h
index e039bfd..b3e6890 100644
--- a/src/gnet/gserver.h
+++ b/src/gnet/gserver.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -29,6 +29,7 @@
 #include "gsocket.h"
 #include "glistener.h"
 #include "glimits.h"
+#include "gprocess.h"
 #include "gevent.h"
 #include <utility>
 #include <memory>
@@ -36,23 +37,11 @@
 
 namespace GNet
 {
-	struct ServerConfig ;
 	class Server ;
 	class ServerPeer ;
-	class ServerPeerConfig ;
 	class ServerPeerInfo ;
 }
 
-//| \class GNet::ServerConfig
-/// A configuration structure for GNet::Server.
-///
-struct GNet::ServerConfig
-{
-	int listen_queue { G::limits::net_listen_queue } ; // Socket::listen() 'backlog'
-	bool uds_open_permissions { true } ;
-	ServerConfig & set_uds_open_permissions( bool b = true ) ;
-} ;
-
 //| \class GNet::Server
 /// A network server class which listens on a specific port and spins off
 /// ServerPeer objects for each incoming connection.
@@ -61,14 +50,26 @@ struct GNet::ServerConfig
 class GNet::Server : public Listener, private EventHandler, private ExceptionHandler
 {
 public:
-	G_EXCEPTION( CannotBind , G::gettext_noop("cannot bind the listening port") ) ;
+	G_EXCEPTION( CannotBind , tx("cannot bind the listening port") ) ;
 
-	Server( ExceptionSink , const Address & listening_address , ServerPeerConfig , ServerConfig ) ;
+	struct Config /// A configuration structure for GNet::Server.
+	{
+		StreamSocket::Config stream_socket_config ;
+		bool uds_open_permissions {false} ;
+		Config & set_stream_socket_config( const StreamSocket::Config & ) ;
+		Config & set_uds_open_permissions( bool b = true ) ;
+	} ;
+
+	Server( ExceptionSink , const Address & listening_address , const ServerPeer::Config & , const Config & ) ;
 		///< Constructor. The server listens on the given address,
 		///< which can be the 'any' address. The ExceptionSink
 		///< is used for exceptions relating to the listening
 		///< socket, not the server peers.
 
+	Server( ExceptionSink , Descriptor listening_fd , const ServerPeer::Config & , const Config & ) ;
+		///< Constructor overload for adopting an externally-managed
+		///< listening file descriptor.
+
 	~Server() override ;
 		///< Destructor.
 
@@ -76,26 +77,21 @@ public:
 		///< Returns the listening address.
 		///< Override from GNet::Listener.
 
-	static bool canBind( const Address & listening_address , bool do_throw ) ;
-		///< Checks that the specified address can be
-		///< bound. Throws CannotBind if the address cannot
-		///< be bound and 'do_throw' is true.
-
-	std::vector<std::weak_ptr<GNet::ServerPeer> > peers() ;
+	std::vector<std::weak_ptr<GNet::ServerPeer>> peers() ;
 		///< Returns the list of ServerPeer objects.
 
 	bool hasPeers() const ;
 		///< Returns true if peers() is not empty.
 
 protected:
-	virtual std::unique_ptr<ServerPeer> newPeer( ExceptionSinkUnbound , ServerPeerInfo ) = 0 ;
+	virtual std::unique_ptr<ServerPeer> newPeer( ExceptionSinkUnbound , ServerPeerInfo && ) = 0 ;
 		///< A factory method which new()s a ServerPeer-derived
 		///< object. This method is called when a new connection
 		///< comes in to this server. The new ServerPeer object
 		///< is used to represent the state of the client/server
 		///< connection.
 		///<
-		///< The implementation should pass the 'ServerPeerInfo'
+		///< The implementation should std::move the 'ServerPeerInfo'
 		///< parameter through to the ServerPeer base-class
 		///< constructor.
 		///<
@@ -120,34 +116,37 @@ private: // overrides
 public:
 	Server( const Server & ) = delete ;
 	Server( Server && ) = delete ;
-	void operator=( const Server & ) = delete ;
-	void operator=( Server && ) = delete ;
+	Server & operator=( const Server & ) = delete ;
+	Server & operator=( Server && ) = delete ;
 
 private:
 	void accept( ServerPeerInfo & ) ;
 	static bool unlink( G::SignalSafe , const char * ) noexcept ;
 
 private:
-	using PeerList = std::vector<std::shared_ptr<ServerPeer> > ;
+	using PeerList = std::vector<std::shared_ptr<ServerPeer>> ;
 	ExceptionSink m_es ;
-	ServerPeerConfig m_server_peer_config ;
+	Config m_config ;
+	ServerPeer::Config m_server_peer_config ;
 	StreamSocket m_socket ; // listening socket
 	PeerList m_peer_list ;
 } ;
 
 //| \class GNet::ServerPeerInfo
-/// A structure used in GNet::Server::newPeer().
+/// A move-only structure used in GNet::Server::newPeer() and
+/// containing the new socket.
 ///
 class GNet::ServerPeerInfo
 {
 public:
-	std::shared_ptr<StreamSocket> m_socket ;
+	std::unique_ptr<StreamSocket> m_socket ;
 	Address m_address ;
-	ServerPeerConfig m_config ;
+	ServerPeer::Config m_server_peer_config ;
 	Server * m_server ;
-	ServerPeerInfo( Server * , ServerPeerConfig ) ;
+	ServerPeerInfo( Server * , ServerPeer::Config ) ;
 } ;
 
-inline GNet::ServerConfig & GNet::ServerConfig::set_uds_open_permissions( bool b ) { uds_open_permissions = b ; return *this ; }
+inline GNet::Server::Config & GNet::Server::Config::set_stream_socket_config( const StreamSocket::Config & c ) { stream_socket_config = c ; return *this ; }
+inline GNet::Server::Config & GNet::Server::Config::set_uds_open_permissions( bool b ) { uds_open_permissions = b ; return *this ; }
 
 #endif
diff --git a/src/gnet/gserverpeer.cpp b/src/gnet/gserverpeer.cpp
index f9638a6..469f410 100644
--- a/src/gnet/gserverpeer.cpp
+++ b/src/gnet/gserverpeer.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,18 +21,20 @@
 #include "gdef.h"
 #include "gserver.h"
 #include "gmonitor.h"
+#include "gtest.h"
 #include "glog.h"
 #include "gassert.h"
 #include <sstream>
+#include <utility>
 
-GNet::ServerPeer::ServerPeer( ExceptionSink es , const ServerPeerInfo & peer_info ,
-	const LineBufferConfig & line_buffer_config ) :
-		m_address(peer_info.m_address) ,
-		m_socket(peer_info.m_socket) ,
-		m_sp(*this,es,*this,*m_socket,0U) ,
-		m_line_buffer(line_buffer_config) ,
-		m_config(peer_info.m_config) ,
-		m_idle_timer(*this,&ServerPeer::onIdleTimeout,es)
+GNet::ServerPeer::ServerPeer( ExceptionSink es , ServerPeerInfo && peer_info , const LineBufferConfig & line_buffer_config ) :
+	m_es(es) ,
+	m_address(peer_info.m_address) ,
+	m_socket(std::move(peer_info.m_socket)) ,
+	m_sp(*this,es,*this,*m_socket,peer_info.m_server_peer_config.socket_protocol_config) ,
+	m_line_buffer(line_buffer_config) ,
+	m_config(peer_info.m_server_peer_config) ,
+	m_idle_timer(*this,&ServerPeer::onIdleTimeout,es)
 {
 	G_ASSERT( peer_info.m_server != nullptr ) ;
 	G_ASSERT( m_socket.get() ) ;
@@ -58,6 +60,11 @@ void GNet::ServerPeer::secureAccept()
 	m_sp.secureAccept() ;
 }
 
+bool GNet::ServerPeer::secureAcceptCapable() const
+{
+	return m_sp.secureAcceptCapable() ;
+}
+
 void GNet::ServerPeer::expect( std::size_t n )
 {
 	m_line_buffer.expect( n ) ;
@@ -69,25 +76,36 @@ GNet::StreamSocket & GNet::ServerPeer::socket()
 	return *m_socket ;
 }
 
+void GNet::ServerPeer::dropReadHandler()
+{
+	socket().dropReadHandler() ;
+}
+
+void GNet::ServerPeer::addReadHandler()
+{
+	socket().addReadHandler( *this , m_es ) ;
+}
+
 void GNet::ServerPeer::otherEvent( EventHandler::Reason reason )
 {
-	m_sp.otherEvent( reason ) ;
+	m_sp.otherEvent( reason , m_config.no_throw_on_peer_disconnect ) ;
 }
 
 void GNet::ServerPeer::readEvent()
 {
-	m_sp.readEvent() ;
+	if( m_sp.readEvent( m_config.no_throw_on_peer_disconnect ) )
+		onSendComplete() ;
 }
 
-std::pair<bool,GNet::Address> GNet::ServerPeer::localAddress() const
+GNet::Address GNet::ServerPeer::localAddress() const
 {
 	G_ASSERT( m_socket != nullptr ) ;
-	return std::make_pair( true , m_socket->getLocalAddress() ) ;
+	return m_socket->getLocalAddress() ;
 }
 
-std::pair<bool,GNet::Address> GNet::ServerPeer::peerAddress() const
+GNet::Address GNet::ServerPeer::peerAddress() const
 {
-	return std::pair<bool,Address>( true , m_address ) ;
+	return m_address ;
 }
 
 std::string GNet::ServerPeer::connectionState() const
@@ -100,14 +118,19 @@ std::string GNet::ServerPeer::peerCertificate() const
 	return m_sp.peerCertificate() ;
 }
 
-bool GNet::ServerPeer::send( const std::string & data , std::string::size_type offset )
+bool GNet::ServerPeer::send( const std::string & data )
 {
-	return m_sp.send( data , offset ) ;
+	return m_sp.send( data , 0U ) ;
 }
 
-bool GNet::ServerPeer::send( const std::vector<G::string_view> & segments )
+bool GNet::ServerPeer::send( G::string_view data )
 {
-	return m_sp.send( segments ) ;
+	return m_sp.send( data ) ;
+}
+
+bool GNet::ServerPeer::send( const std::vector<G::string_view> & segments , std::size_t offset )
+{
+	return m_sp.send( segments , offset ) ;
 }
 
 void GNet::ServerPeer::writeEvent()
@@ -153,26 +176,27 @@ std::string GNet::ServerPeer::exceptionSourceId() const
 {
 	if( m_exception_source_id.empty() )
 	{
-		std::pair<bool,Address> pair = peerAddress() ; // GNet::Connection
-		if( pair.first )
-			m_exception_source_id = pair.second.hostPartString() ;
+		m_exception_source_id = peerAddress().hostPartString() ; // GNet::Connection
+		if( G::Test::enabled("log-full-address") )
+			m_exception_source_id = peerAddress().displayString() ;
 	}
 	return m_exception_source_id ;
 }
 
-// ==
+void GNet::ServerPeer::setIdleTimeout( unsigned int s )
+{
+	m_config.idle_timeout = s ;
+	m_idle_timer.cancelTimer() ;
+	if( m_config.idle_timeout )
+		m_idle_timer.startTimer( m_config.idle_timeout ) ;
+}
 
-GNet::ServerPeerConfig::ServerPeerConfig()
-= default;
+void GNet::ServerPeer::finish()
+{
+	m_sp.shutdown() ;
+}
 
-GNet::ServerPeerConfig::ServerPeerConfig( unsigned int idle_timeout_in ) :
-	idle_timeout(idle_timeout_in)
+void GNet::ServerPeer::onPeerDisconnect()
 {
 }
 
-GNet::ServerPeerConfig & GNet::ServerPeerConfig::set_idle_timeout( unsigned int t )
-{
-	idle_timeout = t ;
-	return *this ;
-}
-
diff --git a/src/gnet/gserverpeer.h b/src/gnet/gserverpeer.h
index c58f594..73b115f 100644
--- a/src/gnet/gserverpeer.h
+++ b/src/gnet/gserverpeer.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -40,36 +40,37 @@ namespace GNet
 {
 	class Server ;
 	class ServerPeer ;
-	class ServerPeerConfig ;
 	class ServerPeerInfo ;
 }
 
-//| \class GNet::ServerPeerConfig
-/// A structure that GNet::Server uses to configure its ServerPeer objects.
-///
-class GNet::ServerPeerConfig
-{
-public:
-	unsigned int idle_timeout{0U} ;
-	ServerPeerConfig() ;
-	explicit ServerPeerConfig( unsigned int idle_timeout ) ;
-	ServerPeerConfig & set_idle_timeout( unsigned int ) ;
-} ;
-
 //| \class GNet::ServerPeer
 /// An abstract base class for the GNet::Server's connection to a remote
 /// client. Instances are created on the heap by the Server::newPeer()
-/// override. Exceptions are delivered to the owning Server and result
-/// in a call to the relevant ServerPeer's onDelete() method followed
-/// by its deletion.
+/// override. Exceptions thrown from event handlers are delivered to
+/// the owning Server and result in a call to the relevant ServerPeer's
+/// onDelete() method followed by its deletion. Every ServerPeer can
+/// do line buffering, but line-buffering can be effectively disabled
+/// by configuring the line buffer as transparent.
+///
 /// \see GNet::Server, GNet::EventHandler
 ///
 class GNet::ServerPeer : private EventHandler , public Connection , private SocketProtocolSink , public ExceptionSource
 {
 public:
-	G_EXCEPTION( IdleTimeout , "idle timeout" ) ;
+	G_EXCEPTION( IdleTimeout , tx("idle timeout") ) ;
 
-	ServerPeer( ExceptionSink , const ServerPeerInfo & , const LineBufferConfig & ) ;
+	struct Config /// A configuration structure for GNet::ServerPeer.
+	{
+		SocketProtocol::Config socket_protocol_config ;
+		unsigned int idle_timeout {0U} ;
+		bool no_throw_on_peer_disconnect {false} ; // see SocketProtocolSink::onPeerDisconnect()
+		Config & set_socket_protocol_config( const SocketProtocol::Config & ) ;
+		Config & set_idle_timeout( unsigned int ) ;
+		Config & set_no_throw_on_peer_disconnect( bool = true ) ;
+		Config & set_all_timeouts( unsigned int ) ;
+	} ;
+
+	ServerPeer( ExceptionSink , ServerPeerInfo && , const LineBufferConfig & ) ;
 		///< Constructor. This constructor is only used from within the
 		///< override of GNet::Server::newPeer(). The ExceptionSink refers
 		///< to the owning Server.
@@ -77,24 +78,27 @@ public:
 	~ServerPeer() override ;
 		///< Destructor.
 
-	bool send( const std::string & data , std::size_t offset = 0U ) ;
+	bool send( const std::string & data ) ;
 		///< Sends data down the socket to the peer. Returns true if completely
 		///< sent; returns false if flow control asserted (see onSendComplete()).
 		///< If flow control is asserted then there should be no new calls to
 		///< send() until onSendComplete() is triggered.
 		///< Throws on error.
 
-	bool send( const std::vector<G::string_view> & data ) ;
+	bool send( G::string_view data ) ;
+		///< Overload for string_view.
+
+	bool send( const std::vector<G::string_view> & data , std::size_t offset = 0U ) ;
 		///< Overload to send data using scatter-gather segments. If false is
 		///< returned then segment data pointers must stay valid until
 		///< onSendComplete() is triggered.
 
-	std::pair<bool,Address> localAddress() const override ;
-		///< Returns the local address. Pair.first is false on error.
+	Address localAddress() const override ;
+		///< Returns the local address. Throws on error.
 		///< Override from GNet::Connection.
 
-	std::pair<bool,Address> peerAddress() const override ;
-		///< Returns the peer address.
+	Address peerAddress() const override ;
+		///< Returns the peer address. Throws on error.
 		///< Override from GNet::Connection.
 
 	std::string connectionState() const override ;
@@ -112,6 +116,9 @@ public:
 		///< Returns information about the state of the internal
 		///< line-buffer.
 
+	void setIdleTimeout( unsigned int seconds ) ;
+		///< Sets the idle timeout.
+
 protected:
 	virtual void onSendComplete() = 0 ;
 		///< Called after flow-control has been released and all
@@ -130,22 +137,35 @@ protected:
 
 	void secureAccept() ;
 		///< Waits for the peer to start a secure session. Uses a
-		///< profile called "server"; see GSsl::Library::addProfile().
+		///< profile called "server" by default; see GSsl::Library::addProfile().
 		///< The callback GNet::SocketProtocolSink::onSecure() is
 		///< triggered when the secure session is established.
 
+	bool secureAcceptCapable() const ;
+		///< Returns true if secureAccept() is usable.
+
 	StreamSocket & socket() ;
 		///< Returns a reference to the client-server connection
 		///< socket.
 
+	void dropReadHandler() ;
+		///< Drops the socket() read handler.
+
+	void addReadHandler() ;
+		///< Re-adds the socket() read handler.
+
 	void expect( std::size_t ) ;
 		///< Modifies the line buffer state so that it delivers
 		///< a chunk of non-line-delimited data.
 
+	void finish() ;
+		///< Does a socket shutdown(). See also GNet::Client::finish().
+
 private: // overrides
 	void readEvent() override ; // Override from GNet::EventHandler.
 	void writeEvent() override ; // Override from GNet::EventHandler.
 	void otherEvent( EventHandler::Reason ) override ; // Override from GNet::EventHandler.
+	void onPeerDisconnect() override ; // Override from GNet::SocketProtocolSink.
 	std::string exceptionSourceId() const override ; // Override from GNet::ExceptionSource.
 
 protected:
@@ -157,21 +177,30 @@ protected:
 public:
 	ServerPeer( const ServerPeer & ) = delete ;
 	ServerPeer( ServerPeer && ) = delete ;
-	void operator=( const ServerPeer & ) = delete ;
-	void operator=( ServerPeer && ) = delete ;
+	ServerPeer & operator=( const ServerPeer & ) = delete ;
+	ServerPeer & operator=( ServerPeer && ) = delete ;
+	bool send( const char * , std::size_t offset ) = delete ;
+	bool send( const char * ) = delete ;
+	bool send( const std::string & , std::size_t offset ) = delete ;
 
 private:
 	void onIdleTimeout() ;
 	bool onDataImp( const char * , std::size_t , std::size_t , std::size_t , char ) ;
 
 private:
+	ExceptionSink m_es ;
 	Address m_address ;
-	std::shared_ptr<StreamSocket> m_socket ; // order dependency -- first
+	std::unique_ptr<StreamSocket> m_socket ; // order dependency -- first
 	SocketProtocol m_sp ; // order dependency -- second
 	LineBuffer m_line_buffer ;
-	ServerPeerConfig m_config ;
+	Config m_config ;
 	Timer<ServerPeer> m_idle_timer ;
 	mutable std::string m_exception_source_id ;
 } ;
 
+inline GNet::ServerPeer::Config & GNet::ServerPeer::Config::set_idle_timeout( unsigned int t ) { idle_timeout = t ; return *this ; }
+inline GNet::ServerPeer::Config & GNet::ServerPeer::Config::set_all_timeouts( unsigned int t ) { idle_timeout = t ; socket_protocol_config.secure_connection_timeout = t ; return *this ; }
+inline GNet::ServerPeer::Config & GNet::ServerPeer::Config::set_socket_protocol_config( const SocketProtocol::Config & config ) { socket_protocol_config = config ; return *this ; }
+inline GNet::ServerPeer::Config & GNet::ServerPeer::Config::set_no_throw_on_peer_disconnect( bool b ) { no_throw_on_peer_disconnect = b ; return *this ; }
+
 #endif
diff --git a/src/gnet/gsocket.cpp b/src/gnet/gsocket.cpp
index 4825145..c09c76e 100644
--- a/src/gnet/gsocket.cpp
+++ b/src/gnet/gsocket.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,43 +22,19 @@
 #include "gsocket.h"
 #include "gtest.h"
 #include "gsleep.h"
+#include "glimits.h"
 #include "gmsg.h"
 #include "gstr.h"
 #include "gassert.h"
 #include "glog.h"
 
-namespace GNet
-{
-	namespace StreamSocketImp /// An implementation namespace for G::StreamSocket.
-	{
-		struct Options /// StreamSocket options.
-		{
-			enum class Linger { default_ , zero , nolinger } ;
-			Linger create_linger {Linger::nolinger} ;
-			bool create_keepalive { G::Test::enabled("socket-keepalive") } ;
-			Linger accept_linger {Linger::nolinger} ;
-			bool accept_keepalive { G::Test::enabled("socket-keepalive") } ;
-		} ;
-	}
-	namespace SocketImp /// An implementation namespace for G::Socket.
-	{
-		struct Options /// Socket options.
-		{
-			bool connect_pureipv6 {true} ;
-			bool bind_pureipv6 {true} ;
-			bool bind_reuse {true} ;
-			bool bind_exclusive { G::Test::enabled("socket-exclusive") } ;
-		} ;
-	}
-}
-
-// ==
-
 GNet::SocketBase::SocketBase( Address::Family family , int type , int protocol ) :
 	m_reason(0) ,
 	m_domain(Address::domain(family)) ,
 	m_family(family) ,
-	m_added(false) ,
+	m_read_added(false) ,
+	m_write_added(false) ,
+	m_other_added(false) ,
 	m_accepted(false)
 {
 	if( !create(m_domain,type,protocol) )
@@ -75,7 +51,9 @@ GNet::SocketBase::SocketBase( const SocketBase::Raw & , int domain , int type ,
 	m_reason(0) ,
 	m_domain(domain) ,
 	m_family(Address::Family::local) , // bogus value, see isFamily()
-	m_added(false) ,
+	m_read_added(false) ,
+	m_write_added(false) ,
+	m_other_added(false) ,
 	m_accepted(false)
 {
 	G_ASSERT( !Address::supports( Address::Domain() , domain ) ) ;
@@ -95,7 +73,9 @@ GNet::SocketBase::SocketBase( Address::Family family , Descriptor fd ) :
 	m_domain(Address::domain(family)) ,
 	m_family(family) ,
 	m_fd(fd) ,
-	m_added(false) ,
+	m_read_added(false) ,
+	m_write_added(false) ,
+	m_other_added(false) ,
 	m_accepted(false)
 {
 	if( !prepare(false) )
@@ -110,7 +90,9 @@ GNet::SocketBase::SocketBase( Address::Family family , Descriptor fd , const Acc
 	m_domain(Address::domain(family)) ,
 	m_family(family) ,
 	m_fd(fd) ,
-	m_added(false) ,
+	m_read_added(false) ,
+	m_write_added(false) ,
+	m_other_added(false) ,
 	m_accepted(true)
 {
 	if( !prepare(true) )
@@ -172,40 +154,46 @@ GNet::SocketBase::ssize_type GNet::SocketBase::writeImp( const char * buffer , s
 void GNet::SocketBase::addReadHandler( EventHandler & handler , ExceptionSink es )
 {
 	G_DEBUG( "GNet::SocketBase::addReadHandler: fd " << m_fd ) ;
-	EventLoop::instance().addRead( m_fd , handler , es ) ;
-	m_added = true ;
+	if( !m_read_added )
+		EventLoop::instance().addRead( m_fd , handler , es ) ;
+	m_read_added = true ;
 }
 
 void GNet::SocketBase::addWriteHandler( EventHandler & handler , ExceptionSink es )
 {
 	G_DEBUG( "GNet::SocketBase::addWriteHandler: fd " << m_fd ) ;
-	EventLoop::instance().addWrite( m_fd , handler , es ) ;
-	m_added = true ;
+	if( !m_write_added )
+		EventLoop::instance().addWrite( m_fd , handler , es ) ;
+	m_write_added = true ;
 }
 
 void GNet::SocketBase::addOtherHandler( EventHandler & handler , ExceptionSink es )
 {
 	G_DEBUG( "GNet::SocketBase::addOtherHandler: fd " << m_fd ) ;
-	EventLoop::instance().addOther( m_fd , handler , es ) ;
-	m_added = true ;
+	if( !m_other_added )
+		EventLoop::instance().addOther( m_fd , handler , es ) ;
+	m_other_added = true ;
 }
 
 void GNet::SocketBase::dropReadHandler() noexcept
 {
-	if( m_added && EventLoop::ptr() )
+	if( m_read_added && EventLoop::ptr() )
 		EventLoop::ptr()->dropRead( m_fd ) ;
+	m_read_added = false ;
 }
 
 void GNet::SocketBase::dropWriteHandler() noexcept
 {
-	if( m_added && EventLoop::ptr() )
+	if( m_write_added && EventLoop::ptr() )
 		EventLoop::ptr()->dropWrite( m_fd ) ;
+	m_write_added = false ;
 }
 
 void GNet::SocketBase::dropOtherHandler() noexcept
 {
-	if( m_added && EventLoop::ptr() )
+	if( m_other_added && EventLoop::ptr() )
 		EventLoop::ptr()->dropOther( m_fd ) ;
+	m_other_added = false ;
 }
 
 SOCKET GNet::SocketBase::fd() const noexcept
@@ -228,13 +216,24 @@ std::string GNet::SocketBase::asString() const
 
 // ==
 
-GNet::Socket::Socket( Address::Family af , int type , int protocol ) :
-	SocketBase(af,type,protocol)
+GNet::Socket::Config::Config()
+= default ;
+
+GNet::Socket::Socket( Address::Family af , int type , int protocol , const Config & config ) :
+	SocketBase(af,type,protocol) ,
+	m_config(config)
 {
 }
 
-GNet::Socket::Socket( Address::Family af , Descriptor s , const Accepted & a ) :
-	SocketBase(af,s,a)
+GNet::Socket::Socket( Address::Family af , Descriptor s , const Accepted & a , const Config & config ) :
+	SocketBase(af,s,a) ,
+	m_config(config)
+{
+}
+
+GNet::Socket::Socket( Address::Family af , Descriptor s , const Adopted & , const Config & config ) :
+	SocketBase(af,s) ,
+	m_config(config)
 {
 }
 
@@ -295,9 +294,6 @@ bool GNet::Socket::connect( const Address & address , bool * done )
 	{
 		saveReason() ;
 
-		if( G::Test::enabled("socket-slow-connect") )
-			sleep( 1 ) ;
-
 		if( eInProgress() )
 		{
 			G_DEBUG( "GNet::Socket::connect: connection in progress" ) ;
@@ -313,9 +309,13 @@ bool GNet::Socket::connect( const Address & address , bool * done )
 	return true ;
 }
 
-void GNet::Socket::listen( int backlog )
+void GNet::Socket::listen()
 {
-	int rc = ::listen( fd() , backlog ) ;
+	int listen_queue = m_config.listen_queue ;
+	if( listen_queue <= 0 )
+		listen_queue = G::limits::net_listen_queue ;
+
+	int rc = ::listen( fd() , std::max(1,listen_queue) ) ;
 	if( error(rc) )
 	{
 		saveReason() ;
@@ -323,6 +323,15 @@ void GNet::Socket::listen( int backlog )
 	}
 }
 
+GNet::Address GNet::Socket::getLocalAddress( Descriptor fd )
+{
+	AddressStorage address_storage ;
+	int rc = ::getsockname( fd.fd() , address_storage.p1() , address_storage.p2() ) ;
+	if( error(rc) )
+		throw SocketError( std::string("no bound address on fd ").append(std::to_string(fd.fd())) ) ;
+	return Address( address_storage ) ;
+}
+
 GNet::Address GNet::Socket::getLocalAddress() const
 {
 	AddressStorage address_storage ;
@@ -359,9 +368,7 @@ void GNet::Socket::setOptionsOnConnect( Address::Family af )
 {
 	if( af == Address::Family::ipv4 || af == Address::Family::ipv6 )
 	{
-		using namespace SocketImp ;
-		Options options ;
-		if( af == Address::Family::ipv6 && options.connect_pureipv6 )
+		if( af == Address::Family::ipv6 && m_config.connect_pureipv6 )
 			setOptionPureV6( std::nothrow ) ; // ignore errors - may fail if already bound
 	}
 }
@@ -370,13 +377,13 @@ void GNet::Socket::setOptionsOnBind( Address::Family af )
 {
 	if( af == Address::Family::ipv4 || af == Address::Family::ipv6 )
 	{
-		using namespace SocketImp ;
-		Options options ;
-		if( options.bind_reuse )
-			setOptionReuse() ; // allow us to rebind another socket's (eg. time-wait zombie's) address
-		if( options.bind_exclusive )
-			setOptionExclusive() ; // don't allow anyone else to bind our address
-		if( af == Address::Family::ipv6 && options.bind_pureipv6 )
+		if( m_config.bind_reuse )
+			setOptionReuse() ;
+		if( m_config.bind_exclusive )
+			setOptionExclusive() ;
+		if( m_config.free_bind )
+			setOptionFreeBind() ;
+		if( af == Address::Family::ipv6 && m_config.bind_pureipv6 )
 			setOptionPureV6() ;
 	}
 }
@@ -386,21 +393,22 @@ void GNet::Socket::setOptionKeepAlive()
 	setOption( SOL_SOCKET , "so_keepalive" , SO_KEEPALIVE , 1 ) ;
 }
 
-void GNet::Socket::setOptionNoLinger()
+void GNet::Socket::setOptionFreeBind()
 {
-	setOptionLingerImp( 0 , 0 ) ;
+	// not tested -- can also use /proc
+	//setOption( IPPROTO_IP , "so_freebind" , IP_FREEBIND , 1 ) ;
 }
 
-void GNet::Socket::setOptionLingerImp( int onoff , int time )
+void GNet::Socket::setOptionLinger( int onoff , int time )
 {
-	struct linger options {} ;
-	options.l_onoff = onoff ;
-	options.l_linger = time ;
-	bool ok = setOptionImp( SOL_SOCKET , SO_LINGER , &options , sizeof(options) ) ;
+	struct linger linger_config {} ;
+	linger_config.l_onoff = onoff ;
+	linger_config.l_linger = time ;
+	bool ok = setOptionImp( SOL_SOCKET , SO_LINGER , &linger_config , sizeof(linger_config) ) ;
 	if( !ok )
 	{
 		saveReason() ;
-		throw SocketError( "cannot set no_linger" , reason() ) ;
+		throw SocketError( "cannot set socket linger option" , reason() ) ;
 	}
 }
 
@@ -421,6 +429,14 @@ void GNet::Socket::setOption( int level , const char * opp , int op , int arg )
 
 //==
 
+GNet::StreamSocket::Config::Config()
+= default ;
+
+GNet::StreamSocket::Config::Config( const Socket::Config & base ) :
+	Socket::Config(base)
+{
+}
+
 bool GNet::StreamSocket::supports( Address::Family af )
 {
 	if( af == Address::Family::ipv6 )
@@ -449,24 +465,38 @@ bool GNet::StreamSocket::supports( Address::Family af )
 	}
 }
 
-GNet::StreamSocket::StreamSocket( Address::Family af ) :
-	Socket(af,SOCK_STREAM,0)
+GNet::StreamSocket::StreamSocket( Address::Family af , const Config & config ) :
+	Socket(af,SOCK_STREAM,0,config) ,
+	m_config(config)
 {
 	setOptionsOnCreate( af , /*listener=*/false ) ;
 }
 
-GNet::StreamSocket::StreamSocket( Address::Family af , const Listener & ) :
-	Socket(af,SOCK_STREAM,0)
+GNet::StreamSocket::StreamSocket( Address::Family af , const Listener & , const Config & config ) :
+	Socket(af,SOCK_STREAM,0,config) ,
+	m_config(config)
 {
 	setOptionsOnCreate( af , /*listener=*/true ) ;
 }
 
-GNet::StreamSocket::StreamSocket( Address::Family af , Descriptor s , const Accepted & accepted ) :
-	Socket(af,s,accepted)
+GNet::StreamSocket::StreamSocket( const Listener & , Descriptor fd , const Config & config ) :
+	Socket(family(fd),fd,Socket::Adopted(),config) ,
+	m_config(config)
+{
+}
+
+GNet::StreamSocket::StreamSocket( Address::Family af , Descriptor fd , const Accepted & accepted , const Config & config ) :
+	Socket(af,fd,accepted,config) ,
+	m_config(config)
 {
 	setOptionsOnAccept( af ) ;
 }
 
+GNet::Address::Family GNet::StreamSocket::family( Descriptor fd )
+{
+	return getLocalAddress(fd).family() ;
+}
+
 GNet::Socket::ssize_type GNet::StreamSocket::read( char * buffer , size_type length )
 {
 	if( length == 0 ) return 0 ;
@@ -486,7 +516,7 @@ GNet::Socket::ssize_type GNet::StreamSocket::write( const char * buffer , size_t
 	return writeImp( buffer , length ) ; // SocketBase
 }
 
-GNet::AcceptPair GNet::StreamSocket::accept()
+GNet::AcceptInfo GNet::StreamSocket::accept()
 {
 	AddressStorage addr ;
 	Descriptor new_fd( ::accept(fd(),addr.p1(),addr.p2()) ) ;
@@ -502,9 +532,9 @@ GNet::AcceptPair GNet::StreamSocket::accept()
 	if( G::Test::enabled("socket-accept-throws") )
 		throw SocketError( "testing" ) ;
 
-	AcceptPair info ;
+	AcceptInfo info ;
 	info.address = Address( addr ) ;
-	info.socket_ptr.reset( new StreamSocket( info.address.family() , new_fd , SocketBase::Accepted() ) ) ; // 'new' for access
+	info.socket_ptr.reset( new StreamSocket( info.address.family() , new_fd , SocketBase::Accepted() , m_config ) ) ; // 'new' sic
 
 	G_DEBUG( "GNet::StreamSocket::accept: accepted from " << fd()
 		<< " to " << new_fd << " (" << info.address.displayString() << ")" ) ;
@@ -516,13 +546,11 @@ void GNet::StreamSocket::setOptionsOnCreate( Address::Family af , bool /*listene
 {
 	if( af == Address::Family::ipv4 || af == Address::Family::ipv6 )
 	{
-		using namespace StreamSocketImp ;
-		Options options ;
-		if( options.create_linger == Options::Linger::zero )
-			setOptionLingerImp( 1 , 0 ) ;
-		else if( options.create_linger == Options::Linger::nolinger )
-			setOptionNoLinger() ;
-		if( options.create_keepalive )
+		if( m_config.create_linger_onoff == 1 )
+			setOptionLinger( 1 , m_config.create_linger_time ) ;
+		else if( m_config.create_linger_onoff == 0 )
+			setOptionLinger( 0 , 0 ) ;
+		if( m_config.create_keepalive )
 			setOptionKeepAlive() ;
 	}
 }
@@ -531,21 +559,27 @@ void GNet::StreamSocket::setOptionsOnAccept( Address::Family af )
 {
 	if( af == Address::Family::ipv4 || af == Address::Family::ipv6 )
 	{
-		using namespace StreamSocketImp ;
-		Options options ;
-		if( options.accept_linger == Options::Linger::zero )
-			setOptionLingerImp( 1 , 0 ) ;
-		else if( options.accept_linger == Options::Linger::nolinger )
-			setOptionNoLinger() ;
-		if( options.accept_keepalive )
+		if( m_config.accept_linger_onoff == 1 )
+			setOptionLinger( 1 , m_config.accept_linger_time ) ;
+		else if( m_config.accept_linger_onoff == 0 )
+			setOptionLinger( 0 , 0 ) ;
+		if( m_config.accept_keepalive )
 			setOptionKeepAlive() ;
 	}
 }
 
 //==
 
-GNet::DatagramSocket::DatagramSocket( Address::Family af , int protocol ) :
-	Socket( af , SOCK_DGRAM , protocol )
+GNet::DatagramSocket::Config::Config()
+= default ;
+
+GNet::DatagramSocket::Config::Config( const Socket::Config & base ) :
+	Socket::Config(base)
+{
+}
+
+GNet::DatagramSocket::DatagramSocket( Address::Family af , int protocol , const Config & config ) :
+	Socket(af,SOCK_DGRAM,protocol,config)
 {
 }
 
diff --git a/src/gnet/gsocket.h b/src/gnet/gsocket.h
index 8bf2a2d..4f2c8c2 100644
--- a/src/gnet/gsocket.h
+++ b/src/gnet/gsocket.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -30,6 +30,7 @@
 #include "greadwrite.h"
 #include "gstringview.h"
 #include <string>
+#include <utility>
 #include <memory>
 #include <new>
 
@@ -41,7 +42,7 @@ namespace GNet
 	class StreamSocket ;
 	class DatagramSocket ;
 	class RawSocket ;
-	class AcceptPair ;
+	class AcceptInfo ;
 }
 
 //| \class GNet::SocketBase
@@ -51,10 +52,10 @@ namespace GNet
 class GNet::SocketBase : public G::ReadWrite
 {
 public:
-	G_EXCEPTION( SocketError , "socket error" ) ;
-	G_EXCEPTION_CLASS( SocketCreateError , "socket create error" ) ;
-	G_EXCEPTION_CLASS( SocketBindError , "socket bind error" ) ;
-	G_EXCEPTION_CLASS( SocketTooMany , "socket accept error" ) ;
+	G_EXCEPTION( SocketError , tx("socket error") ) ;
+	G_EXCEPTION_CLASS( SocketCreateError , tx("socket create error") ) ;
+	G_EXCEPTION_CLASS( SocketBindError , tx("socket bind error") ) ;
+	G_EXCEPTION_CLASS( SocketTooMany , tx("socket accept error") ) ;
 	using size_type = G::ReadWrite::size_type ;
 	using ssize_type = G::ReadWrite::ssize_type ;
 	struct Accepted /// Overload discriminator class for GNet::SocketBase.
@@ -102,7 +103,8 @@ public:
 		///< the given handler receives read events.
 
 	void dropReadHandler() noexcept ;
-		///< Reverses addReadHandler().
+		///< Reverses addReadHandler(). Does nothing if no
+		///< read handler is currently installed.
 
 	void addWriteHandler( EventHandler & , ExceptionSink ) ;
 		///< Adds this socket to the event source list so that
@@ -111,7 +113,8 @@ public:
 		///< sockets.)
 
 	void dropWriteHandler() noexcept ;
-		///< Reverses addWriteHandler().
+		///< Reverses addWriteHandler(). Does nothing if no
+		///< write handler is currently installed.
 
 	void addOtherHandler( EventHandler & , ExceptionSink ) ;
 		///< Adds this socket to the event source list so that
@@ -121,7 +124,8 @@ public:
 		///< sockets.)
 
 	void dropOtherHandler() noexcept ;
-		///< Reverses addOtherHandler().
+		///< Reverses addOtherHandler(). Does nothing if no
+		///< 'other' handler is currently installed.
 
 	std::string asString() const ;
 		///< Returns the socket handle as a string.
@@ -185,15 +189,17 @@ private:
 public:
 	SocketBase( const SocketBase & ) = delete ;
 	SocketBase( SocketBase && ) = delete ;
-	void operator=( const SocketBase & ) = delete ;
-	void operator=( SocketBase && ) = delete ;
+	SocketBase & operator=( const SocketBase & ) = delete ;
+	SocketBase & operator=( SocketBase && ) = delete ;
 
 private:
 	int m_reason ;
 	int m_domain ;
 	Address::Family m_family ; // valid depending on m_domain
 	Descriptor m_fd ;
-	bool m_added ;
+	bool m_read_added ;
+	bool m_write_added ;
+	bool m_other_added ;
 	bool m_accepted ;
 } ;
 
@@ -205,8 +211,26 @@ private:
 class GNet::Socket : public SocketBase
 {
 public:
+	struct Adopted /// Overload discriminator class for GNet::Socket.
+		{} ;
+	struct Config /// A configuration structure for GNet::Socket.
+	{
+		Config() ;
+		int listen_queue {0} ; // zero for compile-time default
+		bool connect_pureipv6 {true} ;
+		bool bind_pureipv6 {true} ;
+		bool bind_reuse {true} ;
+		bool bind_exclusive {false} ; // (windows, einval if also bind_reuse)
+		bool free_bind {false} ; // (linux) (not yet implemented)
+		Config & set_listen_queue( int ) ;
+		Config & set_bind_reuse( bool ) ;
+		Config & set_bind_exclusive( bool ) ;
+		Config & set_free_bind( bool ) ;
+		template <typename T> const T & set_last() ;
+	} ;
+
 	Address getLocalAddress() const ;
-		///< Retrieves local address of the socket.
+		///< Retrieves the local address of the socket.
 
 	std::pair<bool,Address> getPeerAddress() const ;
 		///< Retrieves address of socket's peer.
@@ -219,7 +243,7 @@ public:
 	bool bind( const Address & , std::nothrow_t ) ;
 		///< No-throw overload. Returns false on error.
 
-	static std::string canBindHint( const Address & address , bool stream_socket = true ) ;
+	static std::string canBindHint( const Address & address , bool stream_socket , const Config & ) ;
 		///< Returns the empty string if a socket could probably be
 		///< bound with the given address or a failure reason.
 		///< Some implementations will always return the empty
@@ -246,13 +270,13 @@ public:
 		///< between two addresses. The socket should first be
 		///< bound with a local address.
 
-	void listen( int backlog = 1 ) ;
+	void listen() ;
 		///< Starts the socket listening on the bound
 		///< address for incoming connections or incoming
 		///< datagrams.
 
 	void shutdown( int how = 1 ) ;
-		///< Modifies the local socket state so that so that new
+		///< Modifies the local socket state so that new
 		///< sends (1 or 2) and/or receives (0 or 2) will fail.
 		///<
 		///< If receives are shut-down then anything received
@@ -268,40 +292,46 @@ public:
 	~Socket() override = default ;
 	Socket( const Socket & ) = delete ;
 	Socket( Socket && ) = delete ;
-	void operator=( const Socket & ) = delete ;
-	void operator=( Socket && ) = delete ;
+	Socket & operator=( const Socket & ) = delete ;
+	Socket & operator=( Socket && ) = delete ;
 
 protected:
-	Socket( Address::Family , int type , int protocol ) ;
-	Socket( Address::Family , Descriptor s , const Accepted & ) ;
-	std::pair<bool,Address> getLocalAddress( std::nothrow_t ) const ;
+	Socket( Address::Family , int type , int protocol , const Config & ) ;
+	Socket( Address::Family , Descriptor s , const Accepted & , const Config & ) ;
+	Socket( Address::Family , Descriptor s , const Adopted & , const Config & ) ;
+	static Address getLocalAddress( Descriptor ) ;
+
+protected:
+	void setOptionLinger( int onoff , int time ) ;
+	void setOptionKeepAlive() ;
+	void setOptionFreeBind() ;
+
+private:
 	void setOption( int , const char * , int , int ) ;
 	bool setOption( int , const char * , int , int , std::nothrow_t ) ;
 	bool setOptionImp( int , int , const void * , socklen_t ) ;
 	void setOptionsOnBind( Address::Family ) ;
 	void setOptionsOnConnect( Address::Family ) ;
-	void setOptionLingerImp( int , int ) ;
-	void setOptionNoLinger() ;
 	void setOptionReuse() ;
 	void setOptionExclusive() ;
 	void setOptionPureV6() ;
 	bool setOptionPureV6( std::nothrow_t ) ;
-	void setOptionKeepAlive() ;
 
 private:
-	unsigned long m_bound_scope_id{0UL} ;
+	Config m_config ;
+	unsigned long m_bound_scope_id {0UL} ;
 } ;
 
-//| \class GNet::AcceptPair
-/// A class which is used to return a new()ed socket to calling
+//| \class GNet::AcceptInfo
+/// A move-only class which is used to return a new()ed socket to calling
 /// code, together with associated address information.
 ///
-class GNet::AcceptPair
+class GNet::AcceptInfo
 {
 public:
-	std::shared_ptr<StreamSocket> socket_ptr ;
+	std::unique_ptr<StreamSocket> socket_ptr ;
 	Address address ;
-	AcceptPair() : address(Address::defaultAddress()) {}
+	AcceptInfo() : address(Address::defaultAddress()) {}
 } ;
 
 //| \class GNet::StreamSocket
@@ -314,6 +344,23 @@ public:
 	using ssize_type = Socket::ssize_type ;
 	struct Listener /// Overload discriminator class for GNet::StreamSocket.
 		{} ;
+	struct Config : Socket::Config /// A configuration structure for GNet::StreamSocket.
+	{
+		Config() ;
+		explicit Config( const Socket::Config & ) ;
+		int create_linger_onoff {0} ; // -1 no-op, 0 nolinger, 1 linger with time
+		int create_linger_time {0} ;
+		int accept_linger_onoff {0} ;
+		int accept_linger_time {0} ;
+		bool create_keepalive {false} ;
+		bool accept_keepalive {false} ;
+		Config & set_create_linger( std::pair<int,int> ) ;
+		Config & set_create_linger_onoff( int ) ;
+		Config & set_create_linger_time( int ) ;
+		Config & set_accept_linger( std::pair<int,int> ) ;
+		Config & set_accept_linger_onoff( int ) ;
+		Config & set_accept_linger_time( int ) ;
+	} ;
 
 	static bool supports( Address::Family ) ;
 		///< Returns true if stream sockets can be created with the
@@ -322,21 +369,25 @@ public:
 		///< Note that a run-time check is useful when running a
 		///< new binary on an old operating system.
 
-	explicit StreamSocket( Address::Family ) ;
+	StreamSocket( Address::Family , const Config & config ) ;
 		///< Constructor.
 
-	StreamSocket( Address::Family , const Listener & ) ;
+	StreamSocket( Address::Family , const Listener & , const Config & config ) ;
 		///< Constructor overload specifically for a listening
 		///< socket, which might need slightly different socket
 		///< options.
 
+	StreamSocket( const Listener & , Descriptor fd , const Config & config ) ;
+		///< Constructor overload for adopting an externally-managed
+		///< listening file descriptor.
+
 	ssize_type read( char * buffer , size_type buffer_length ) override ;
 		///< Override from ReadWrite::read().
 
 	ssize_type write( const char * buf , size_type len ) override ;
 		///< Override from Socket::write().
 
-	AcceptPair accept() ;
+	AcceptInfo accept() ;
 		///< Accepts an incoming connection, returning a new()ed
 		///< socket and the peer address.
 
@@ -344,13 +395,17 @@ public:
 	~StreamSocket() override = default ;
 	StreamSocket( const StreamSocket & ) = delete ;
 	StreamSocket( StreamSocket && ) = delete ;
-	void operator=( const StreamSocket & ) = delete ;
-	void operator=( StreamSocket && ) = delete ;
+	StreamSocket & operator=( const StreamSocket & ) = delete ;
+	StreamSocket & operator=( StreamSocket && ) = delete ;
 
 private:
-	StreamSocket( Address::Family , Descriptor s , const Accepted & ) ;
+	StreamSocket( Address::Family , Descriptor s , const Accepted & , const Config & config ) ;
 	void setOptionsOnCreate( Address::Family , bool listener ) ;
 	void setOptionsOnAccept( Address::Family ) ;
+	static Address::Family family( Descriptor ) ;
+
+private:
+	Config m_config ;
 } ;
 
 //| \class GNet::DatagramSocket
@@ -359,7 +414,13 @@ private:
 class GNet::DatagramSocket : public Socket
 {
 public:
-	explicit DatagramSocket( Address::Family , int protocol = 0 ) ;
+	struct Config : Socket::Config /// A configuration structure for GNet::DatagramSocket.
+	{
+		Config() ;
+		explicit Config( const Socket::Config & ) ;
+	} ;
+
+	explicit DatagramSocket( Address::Family , int protocol , const Config & config ) ;
 		///< Constructor.
 
 	ssize_type read( char * buffer , size_type len ) override ;
@@ -377,16 +438,25 @@ public:
 		///< Sends a datagram to the given address. This should be used
 		///< if there is no connect() assocation in effect.
 
+	ssize_type writeto( const std::vector<G::string_view> & , const Address & dst ) ;
+		///< Sends a datagram to the given address, overloaded for
+		///< scatter-gather data chunks.
+
 	void disconnect() ;
 		///< Releases the association between two datagram endpoints
 		///< reversing the effect of the previous Socket::connect().
 
+	std::size_t limit() const ;
+		///< Returns the maximum datagram size or 1024, whichever is
+		///< larger.
+		/// \see SO_SNDBUF, /proc/sys/net/core/wmem_default
+
 public:
 	~DatagramSocket() override = default ;
 	DatagramSocket( const DatagramSocket & ) = delete ;
 	DatagramSocket( DatagramSocket && ) = delete ;
-	void operator=( const DatagramSocket & ) = delete ;
-	void operator=( DatagramSocket && ) = delete ;
+	DatagramSocket & operator=( const DatagramSocket & ) = delete ;
+	DatagramSocket & operator=( DatagramSocket && ) = delete ;
 } ;
 
 //| \class GNet::RawSocket
@@ -409,8 +479,21 @@ public:
 	~RawSocket() override = default ;
 	RawSocket( const RawSocket & ) = delete ;
 	RawSocket( RawSocket && ) = delete ;
-	void operator=( const RawSocket & ) = delete ;
-	void operator=( RawSocket && ) = delete ;
+	RawSocket & operator=( const RawSocket & ) = delete ;
+	RawSocket & operator=( RawSocket && ) = delete ;
 } ;
 
+inline GNet::Socket::Config & GNet::Socket::Config::set_listen_queue( int n ) { listen_queue = n ; return *this ; }
+inline GNet::Socket::Config & GNet::Socket::Config::set_bind_reuse( bool b ) { bind_reuse = b ; return *this ; }
+inline GNet::Socket::Config & GNet::Socket::Config::set_bind_exclusive( bool b ) { bind_exclusive = b ; return *this ; }
+inline GNet::Socket::Config & GNet::Socket::Config::set_free_bind( bool b ) { free_bind = b ; return *this ; }
+template <typename T> const T & GNet::Socket::Config::set_last() { return static_cast<const T&>(*this) ; }
+
+inline GNet::StreamSocket::Config & GNet::StreamSocket::Config::set_create_linger( std::pair<int,int> p ) { create_linger_onoff = p.first ; create_linger_time = p.second ; return *this ; }
+inline GNet::StreamSocket::Config & GNet::StreamSocket::Config::set_create_linger_onoff( int n ) { create_linger_onoff = n ; return *this ; }
+inline GNet::StreamSocket::Config & GNet::StreamSocket::Config::set_create_linger_time( int n ) { create_linger_time = n ; return *this ; }
+inline GNet::StreamSocket::Config & GNet::StreamSocket::Config::set_accept_linger( std::pair<int,int> p ) { accept_linger_onoff = p.first ; accept_linger_time = p.second ; return *this ; }
+inline GNet::StreamSocket::Config & GNet::StreamSocket::Config::set_accept_linger_onoff( int n ) { accept_linger_onoff = n ; return *this ; }
+inline GNet::StreamSocket::Config & GNet::StreamSocket::Config::set_accept_linger_time( int n ) { accept_linger_time = n ; return *this ; }
+
 #endif
diff --git a/src/gnet/gsocket_unix.cpp b/src/gnet/gsocket_unix.cpp
index 6faaa85..bddb15f 100644
--- a/src/gnet/gsocket_unix.cpp
+++ b/src/gnet/gsocket_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -149,18 +149,19 @@ std::string GNet::SocketBase::reasonString( int e )
 
 // ==
 
-std::string GNet::Socket::canBindHint( const Address & address , bool stream )
+std::string GNet::Socket::canBindHint( const Address & address , bool stream , const Config & config )
 {
 	if( address.family() == Address::Family::ipv4 || address.family() == Address::Family::ipv6 )
 	{
 		if( stream )
 		{
-			StreamSocket s( address.family() ) ;
+			StreamSocket s( address.family() , StreamSocket::Config(config) ) ;
 			return s.bind( address , std::nothrow ) ? std::string() : s.reason() ;
 		}
 		else
 		{
-			DatagramSocket s( address.family() ) ;
+			int protocol = 0 ;
+			DatagramSocket s( address.family() , protocol , DatagramSocket::Config(config) ) ;
 			return s.bind( address , std::nothrow ) ? std::string() : s.reason() ;
 		}
 	}
@@ -229,3 +230,16 @@ GNet::SocketBase::ssize_type GNet::RawSocket::write( const char * buffer , size_
 	return writeImp( buffer , length ) ; // SocketBase
 }
 
+// ==
+
+std::size_t GNet::DatagramSocket::limit() const
+{
+	int value = 0 ;
+	socklen_t size = sizeof(int) ;
+	int rc = ::getsockopt( fd() , SOL_SOCKET , SO_SNDBUF , &value , &size ) ;
+	if( rc == 0 && size == sizeof(int) && value > 1024 )
+		return static_cast<std::size_t>(value) ;
+	else
+		return 1024U ;
+}
+
diff --git a/src/gnet/gsocket_win32.cpp b/src/gnet/gsocket_win32.cpp
index ffe5222..4f82157 100644
--- a/src/gnet/gsocket_win32.cpp
+++ b/src/gnet/gsocket_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -132,14 +132,65 @@ bool GNet::SocketBase::setNonBlocking()
 
 std::string GNet::SocketBase::reasonString( int e )
 {
-	return G::Process::strerror( e ) ;
+	const char * p = nullptr ;
+	if( e == WSAEINTR ) p = "interupted" ;
+	//if( e == WSAEBADF ) p = "" ;
+	if( e == WSAEACCES ) p = "access denied" ;
+	//if( e == WSAEFAULT ) p = "" ;
+	if( e == WSAEINVAL ) p = "invalid parameter" ;
+	//if( e == WSAEMFILE ) p = "" ;
+	//if( e == WSAEWOULDBLOCK ) p = "" ;
+	//if( e == WSAEINPROGRESS ) p = "" ;
+	//if( e == WSAEALREADY ) p = "" ;
+	//if( e == WSAENOTSOCK ) p = "" ;
+	//if( e == WSAEDESTADDRREQ ) p = "" ;
+	//if( e == WSAEMSGSIZE ) p = "" ;
+	//if( e == WSAEPROTOTYPE ) p = "" ;
+	//if( e == WSAENOPROTOOPT ) p = "" ;
+	//if( e == WSAEPROTONOSUPPORT ) p = "" ;
+	//if( e == WSAESOCKTNOSUPPORT ) p = "" ;
+	//if( e == WSAEOPNOTSUPP ) p = "" ;
+	//if( e == WSAEPFNOSUPPORT ) p = "" ;
+	//if( e == WSAEAFNOSUPPORT ) p = "" ;
+	if( e == WSAEADDRINUSE ) p = "address already in use" ;
+	if( e == WSAEADDRNOTAVAIL ) p = "address not available" ;
+	if( e == WSAENETDOWN ) p = "network down" ;
+	if( e == WSAENETUNREACH ) p = "network unreachable" ;
+	if( e == WSAENETRESET ) p = "network reset" ;
+	//if( e == WSAECONNABORTED ) p = "" ;
+	//if( e == WSAECONNRESET ) p = "" ;
+	//if( e == WSAENOBUFS ) p = "" ;
+	//if( e == WSAEISCONN ) p = "" ;
+	if( e == WSAENOTCONN ) p = "cannot connect" ;
+	//if( e == WSAESHUTDOWN ) p = "" ;
+	//if( e == WSAETOOMANYREFS ) p = "" ;
+	if( e == WSAETIMEDOUT ) p = "timed out" ;
+	if( e == WSAECONNREFUSED ) p = "connection refused" ;
+	//if( e == WSAELOOP ) p = "" ;
+	//if( e == WSAENAMETOOLONG ) p = "" ;
+	if( e == WSAEHOSTDOWN ) p = "host down" ;
+	if( e == WSAEHOSTUNREACH ) p = "host unreachable" ;
+	//if( e == WSAENOTEMPTY ) p = "" ;
+	//if( e == WSAEPROCLIM ) p = "" ;
+	//if( e == WSAEUSERS ) p = "" ;
+	//if( e == WSAEDQUOT ) p = "" ;
+	//if( e == WSAESTALE ) p = "" ;
+	//if( e == WSAEREMOTE ) p = "" ;
+	if( p )
+		return std::string( p ) ;
+
+	std::string s = G::Process::strerror( e ) ;
+	if( G::Str::imatch(s,"unknown error") )
+		return s.append(" (").append(G::Str::fromInt(e)).append(1U,')') ;
+	else
+		return s ;
 }
 
 // ==
 
-std::string GNet::Socket::canBindHint( const Address & , bool )
+std::string GNet::Socket::canBindHint( const Address & , bool , const Config & )
 {
-	return std::string() ; // rebinding the same port number fails, so a dummy implementation here
+	return std::string() ; // not implemented
 }
 
 void GNet::Socket::setOptionReuse()
@@ -166,6 +217,7 @@ bool GNet::Socket::setOptionImp( int level , int op , const void * arg , socklen
 {
 	const char * cp = static_cast<const char*>(arg) ;
 	int rc = ::setsockopt( fd() , level , op , cp , n ) ;
-	return ! error(rc) ;
+	bool ok = !error( rc ) ;
+	return ok ;
 }
 
diff --git a/src/gnet/gsocketprotocol.cpp b/src/gnet/gsocketprotocol.cpp
index 664dd90..753e922 100644
--- a/src/gnet/gsocketprotocol.cpp
+++ b/src/gnet/gsocketprotocol.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -32,7 +32,6 @@
 #include "glog.h"
 #include <memory>
 #include <numeric>
-#include <algorithm>
 
 //| \class GNet::SocketProtocolImp
 /// A pimple-pattern implementation class used by GNet::SocketProtocol.
@@ -45,44 +44,47 @@ public:
 	using Segments = std::vector<Segment> ;
 	struct Position /// A pointer into the scatter/gather payload of GNet::SocketProtocolImp::send().
 	{
+		Position() = default ;
+		Position( std::size_t s , std::size_t o ) : segment(s) , offset(o) {}
 		std::size_t segment{0U} ;
 		std::size_t offset{0U} ;
-		Position( std::size_t segment_ , std::size_t offset_ ) : segment(segment_) , offset(offset_) {}
-		Position() = default ;
 	} ;
 
 public:
 	SocketProtocolImp( EventHandler & , ExceptionSink , SocketProtocol::Sink & ,
-		StreamSocket & , unsigned int secure_connection_timeout ) ;
+		StreamSocket & , const SocketProtocol::Config & ) ;
 	~SocketProtocolImp() ;
-	void readEvent() ;
+	bool readEvent( bool ) ;
 	bool writeEvent() ;
-	void otherEvent( EventHandler::Reason ) ;
-	bool send( const std::string & data , std::size_t offset ) ;
+	void otherEvent( EventHandler::Reason , bool ) ;
+	bool send( G::string_view data , std::size_t offset ) ;
 	bool send( const Segments & , std::size_t ) ;
 	void shutdown() ;
 	void secureConnect() ;
+	bool secureConnectCapable() const ;
 	void secureAccept() ;
+	bool secureAcceptCapable() const ;
 	bool secure() const ;
+	bool raw() const ;
 	std::string peerCertificate() const ;
-	static void setReadBufferSize( std::size_t ) ;
 
 public:
 	SocketProtocolImp( const SocketProtocolImp & ) = delete ;
 	SocketProtocolImp( SocketProtocolImp && ) = delete ;
-	void operator=( const SocketProtocolImp & ) = delete ;
-	void operator=( SocketProtocolImp && ) = delete ;
+	SocketProtocolImp & operator=( const SocketProtocolImp & ) = delete ;
+	SocketProtocolImp & operator=( SocketProtocolImp && ) = delete ;
 
 private:
 	enum class State { raw , connecting , accepting , writing , idle , shuttingdown } ;
 	static std::unique_ptr<GSsl::Protocol> newProtocol( const std::string & ) ;
 	static void log( int level , const std::string & line ) ;
 	bool failed() const ;
-	void rawReadEvent() ;
+	bool rawReadEvent( bool ) ;
 	bool rawWriteEvent() ;
-	void rawOtherEvent() ;
+	bool rawOtherEvent( EventHandler::Reason ) ;
 	bool rawSend( const Segments & , Position , bool = false ) ;
 	bool rawSendImp( const Segments & , Position , Position & ) ;
+	void rawReset() ;
 	void sslReadImp() ;
 	bool sslSend( const Segments & segments , Position pos ) ;
 	bool sslSendImp() ;
@@ -105,7 +107,7 @@ private:
 	SocketProtocol::Sink & m_sink ;
 	StreamSocket & m_socket ;
 	G::CallStack m_stack ;
-	unsigned int m_secure_connection_timeout ;
+	SocketProtocol::Config m_config ;
 	Segments m_one_segment ;
 	Segments m_segments ;
 	Position m_position ;
@@ -117,7 +119,6 @@ private:
 	ssize_t m_read_buffer_n ;
 	Timer<SocketProtocolImp> m_secure_connection_timer ;
 	std::string m_peer_certificate ;
-	static std::size_t m_read_buffer_size ;
 } ;
 
 namespace GNet
@@ -142,88 +143,92 @@ namespace GNet
 	}
 }
 
-std::size_t GNet::SocketProtocolImp::m_read_buffer_size = G::limits::net_buffer ;
-
 GNet::SocketProtocolImp::SocketProtocolImp( EventHandler & handler , ExceptionSink es ,
-	SocketProtocol::Sink & sink , StreamSocket & socket , unsigned int secure_connection_timeout ) :
+	SocketProtocol::Sink & sink , StreamSocket & socket , const SocketProtocol::Config & config ) :
 		m_handler(handler) ,
 		m_es(es) ,
 		m_sink(sink) ,
 		m_socket(socket) ,
-		m_secure_connection_timeout(secure_connection_timeout) ,
+		m_config(config) ,
 		m_one_segment(1U) ,
 		m_failed(false) ,
 		m_state(State::raw) ,
-		m_read_buffer(m_read_buffer_size) ,
+		m_read_buffer(std::max(std::size_t(1U),config.read_buffer_size)) ,
 		m_read_buffer_n(0) ,
 		m_secure_connection_timer(*this,&SocketProtocolImp::onSecureConnectionTimeout,es)
 {
-	G_ASSERT( m_read_buffer.size() == m_read_buffer_size ) ;
+	if( m_config.server_tls_profile.empty() ) m_config.server_tls_profile = "server" ;
+	if( m_config.client_tls_profile.empty() ) m_config.client_tls_profile = "client" ;
 }
 
 GNet::SocketProtocolImp::~SocketProtocolImp()
 = default;
 
-void GNet::SocketProtocolImp::setReadBufferSize( std::size_t n )
-{
-	m_read_buffer_size = std::max( std::size_t(1U) , n ) ;
-}
-
 void GNet::SocketProtocolImp::onSecureConnectionTimeout()
 {
 	G_DEBUG( "GNet::SocketProtocolImp::onSecureConnectionTimeout: timed out" ) ;
 	throw SocketProtocol::SecureConnectionTimeout() ;
 }
 
-void GNet::SocketProtocolImp::readEvent()
+bool GNet::SocketProtocolImp::readEvent( bool no_throw_on_peer_disconnect )
 {
 	G_DEBUG( "SocketProtocolImp::readEvent: read event: " << m_socket.asString() << ": "
 		<< "state=" << static_cast<int>(m_state) ) ;
+	bool all_sent = false ;
 	if( m_state == State::raw )
-		rawReadEvent() ;
+		rawReadEvent( no_throw_on_peer_disconnect ) ;
 	else if( m_state == State::connecting )
 		secureConnectImp() ;
 	else if( m_state == State::accepting )
 		secureAcceptImp() ;
 	else if( m_state == State::writing )
-		sslSendImp() ;
+		all_sent = sslSendImp() ;
 	else if( m_state == State::shuttingdown )
 		shutdownImp() ;
 	else // State::idle
 		sslReadImp() ;
+	return all_sent ;
 }
 
 bool GNet::SocketProtocolImp::writeEvent()
 {
 	G_DEBUG( "GNet::SocketProtocolImp::writeEvent: write event: " << m_socket.asString() << ": "
 		<< "state=" << static_cast<int>(m_state) ) ;
-	bool rc = false ; // was true
+	bool all_sent = false ;
 	if( m_state == State::raw )
-		rc = rawWriteEvent() ;
+		all_sent = rawWriteEvent() ;
 	else if( m_state == State::connecting )
 		secureConnectImp() ;
 	else if( m_state == State::accepting )
 		secureAcceptImp() ;
 	else if( m_state == State::writing )
-		rc = sslSendImp() ;
+		all_sent = sslSendImp() ;
 	else if( m_state == State::shuttingdown )
 		shutdownImp() ;
 	else // State::idle
 		sslReadImp() ;
-	return rc ;
+	return all_sent ;
 }
 
-void GNet::SocketProtocolImp::otherEvent( EventHandler::Reason reason )
+void GNet::SocketProtocolImp::otherEvent( EventHandler::Reason reason , bool no_throw_on_peer_disconnect )
 {
-	if( m_state == State::raw && reason == EventHandler::Reason::closed
-		&& !G::Test::enabled("socket-protocol-noflush") )
+	m_socket.dropReadHandler() ;
+	m_socket.dropOtherHandler() ; // since event cannot be cleared
+
+	if( m_state == State::raw )
 	{
-		rawOtherEvent() ;
+		bool peer_disconnect = rawOtherEvent( reason ) ;
+		if( peer_disconnect && no_throw_on_peer_disconnect )
+		{
+			m_sink.onPeerDisconnect() ;
+			return ;
+		}
 	}
+
+	if( reason == EventHandler::Reason::closed )
+		throw SocketProtocol::Shutdown() ;
 	else
-	{
-		throw G::Exception( "socket disconnect event" , EventHandler::str(reason) ) ;
-	}
+		throw SocketProtocol::OtherEventError( EventHandler::str(reason) ) ;
 }
 
 std::size_t GNet::SocketProtocolImp::size( const Segments & segments )
@@ -255,16 +260,16 @@ G::string_view GNet::SocketProtocolImp::chunk( const Segments & s , Position pos
 	return s.at(pos.segment).substr( pos.offset ) ;
 }
 
-bool GNet::SocketProtocolImp::send( const std::string & data , std::size_t offset )
+bool GNet::SocketProtocolImp::send( G::string_view data , std::size_t offset )
 {
-	if( data.empty() || offset >= data.length() )
+	if( data.empty() || offset >= data.size() )
 		return true ;
 
 	bool rc = true ;
 	if( m_state == State::raw )
 	{
 		G_ASSERT( m_one_segment.size() == 1U ) ;
-		m_one_segment[0] = G::string_view( data.data() , data.size() ) ;
+		m_one_segment[0] = data ;
 		rc = rawSend( m_one_segment , Position(0U,offset) , true/*copy*/ ) ;
 	}
 	else if( m_state == State::connecting || m_state == State::accepting )
@@ -282,7 +287,7 @@ bool GNet::SocketProtocolImp::send( const std::string & data , std::size_t offse
 	else
 	{
 		// make a copy here because we have to do retries with the same pointer
-		m_data_copy = data.substr( offset ) ;
+		m_data_copy.assign( data.data()+offset , data.size()-offset ) ;
 		G_ASSERT( m_one_segment.size() == 1U ) ;
 		m_one_segment[0] = G::string_view( m_data_copy.data() , m_data_copy.size() ) ;
 		rc = sslSend( m_one_segment , Position() ) ;
@@ -292,7 +297,7 @@ bool GNet::SocketProtocolImp::send( const std::string & data , std::size_t offse
 
 bool GNet::SocketProtocolImp::send( const Segments & segments , std::size_t offset )
 {
-	if( segments.empty() || size(segments) == 0U || offset >= size(segments) )
+	if( segments.empty() || offset >= size(segments) )
 		return true ;
 
 	bool rc = true ;
@@ -321,7 +326,12 @@ bool GNet::SocketProtocolImp::send( const Segments & segments , std::size_t offs
 
 void GNet::SocketProtocolImp::shutdown()
 {
-	if( m_state == State::idle )
+	if( m_state == State::raw )
+	{
+		m_socket.dropWriteHandler() ;
+		m_socket.shutdown() ;
+	}
+	else if( m_state == State::idle )
 	{
 		m_state = State::shuttingdown ;
 		shutdownImp() ;
@@ -337,9 +347,11 @@ void GNet::SocketProtocolImp::shutdownImp()
 	{
 		m_socket.dropWriteHandler() ;
 		m_socket.shutdown() ;
+		m_state = State::idle ; // but possibly only half-open
 	}
 	else if( rc == Result::error )
 	{
+		m_socket.dropReadHandler() ;
 		m_socket.dropWriteHandler() ;
 		throw SocketProtocol::ShutdownError() ;
 	}
@@ -355,18 +367,35 @@ void GNet::SocketProtocolImp::shutdownImp()
 
 bool GNet::SocketProtocolImp::secure() const
 {
-	return m_state == State::writing || m_state == State::idle ;
+	return
+		m_state == State::writing ||
+		m_state == State::idle ||
+		m_state == State::shuttingdown ;
+}
+
+bool GNet::SocketProtocolImp::raw() const
+{
+	return m_state == State::raw ;
+}
+
+bool GNet::SocketProtocolImp::secureConnectCapable() const
+{
+	return GSsl::Library::enabledAs( m_config.client_tls_profile ) ;
 }
 
 void GNet::SocketProtocolImp::secureConnect()
 {
 	G_DEBUG( "SocketProtocolImp::secureConnect" ) ;
+	G_ASSERT( m_state == State::raw ) ;
 	G_ASSERT( m_ssl == nullptr ) ;
+	if( m_state != State::raw || m_ssl != nullptr )
+		throw SocketProtocol::ProtocolError() ;
 
-	m_ssl = newProtocol( "client" ) ;
+	rawReset() ;
+	m_ssl = newProtocol( m_config.client_tls_profile ) ;
 	m_state = State::connecting ;
-	if( m_secure_connection_timeout != 0U )
-		m_secure_connection_timer.startTimer( m_secure_connection_timeout ) ;
+	if( m_config.secure_connection_timeout != 0U )
+		m_secure_connection_timer.startTimer( m_config.secure_connection_timeout ) ;
 	secureConnectImp() ;
 }
 
@@ -396,7 +425,7 @@ void GNet::SocketProtocolImp::secureConnectImp()
 	{
 		m_socket.dropWriteHandler() ;
 		m_state = State::idle ;
-		if( m_secure_connection_timeout != 0U )
+		if( m_config.secure_connection_timeout != 0U )
 			m_secure_connection_timer.cancelTimer() ;
 		m_peer_certificate = m_ssl->peerCertificate() ;
 		std::string protocol = m_ssl->protocol() ;
@@ -406,12 +435,21 @@ void GNet::SocketProtocolImp::secureConnectImp()
 	}
 }
 
+bool GNet::SocketProtocolImp::secureAcceptCapable() const
+{
+	return GSsl::Library::enabledAs( m_config.server_tls_profile ) ;
+}
+
 void GNet::SocketProtocolImp::secureAccept()
 {
 	G_DEBUG( "SocketProtocolImp::secureAccept" ) ;
+	G_ASSERT( m_state == State::raw ) ;
 	G_ASSERT( m_ssl == nullptr ) ;
+	if( m_state != State::raw || m_ssl != nullptr )
+		throw SocketProtocol::ProtocolError() ;
 
-	m_ssl = newProtocol( "server" ) ;
+	rawReset() ;
+	m_ssl = newProtocol( m_config.server_tls_profile ) ;
 	m_state = State::accepting ;
 	secureAcceptImp() ;
 }
@@ -527,7 +565,7 @@ void GNet::SocketProtocolImp::sslReadImp()
 	G_ASSERT( m_ssl != nullptr ) ;
 
 	Result rc = Result::more ;
-	for( int sanity = 0 ; rc == Result::more && sanity < 1000 ; sanity++ )
+	for( int sanity = 0 ; rc == Result::more && sanity < 100000 ; sanity++ )
 	{
 		rc = m_ssl->read( &m_read_buffer[0] , m_read_buffer.size() , m_read_buffer_n ) ;
 		G_DEBUG( "SocketProtocolImp::sslReadImp: result=" << GSsl::Protocol::str(rc) ) ;
@@ -568,31 +606,48 @@ void GNet::SocketProtocolImp::sslReadImp()
 	}
 }
 
-void GNet::SocketProtocolImp::rawOtherEvent()
+bool GNet::SocketProtocolImp::rawOtherEvent( EventHandler::Reason reason )
 {
-	// got a clean socket shutdown indication on windows --  no read events will
-	// follow but there might be data to read -- so try reading in a loop
-	G_DEBUG( "GNet::SocketProtocolImp::rawOtherEvent: clearing receive queue" ) ;
-	for(;;)
+	// got a windows socket shutdown indication, connection failure, etc.
+	if( reason == EventHandler::Reason::closed )
 	{
-		const ssize_t rc = m_socket.read( &m_read_buffer[0] , m_read_buffer.size() ) ;
-		G_DEBUG( "GNet::SocketProtocolImp::rawOtherEvent: read " << m_socket.asString() << ": " << rc ) ;
-		if( rc <= 0 )
+		// no read events will follow but there might be data to read, so try reading in a loop
+		G_DEBUG( "GNet::SocketProtocolImp::rawOtherEvent: shutdown: clearing receive queue" ) ;
+		for(;;)
 		{
-			m_socket.shutdown() ;
-			throw SocketProtocol::ReadError( m_socket.reason() ) ;
+			const ssize_t rc = m_socket.read( &m_read_buffer[0] , m_read_buffer.size() ) ;
+			G_DEBUG( "GNet::SocketProtocolImp::rawOtherEvent: read " << m_socket.asString() << ": " << rc ) ;
+			if( rc == 0 )
+			{
+				break ;
+			}
+			else if( rc < 0 )
+			{
+				throw SocketProtocol::ReadError( m_socket.reason() ) ;
+			}
+			G_ASSERT( static_cast<std::size_t>(rc) <= m_read_buffer.size() ) ;
+			G::CallFrame this_( m_stack ) ;
+			m_sink.onData( &m_read_buffer[0] , static_cast<std::size_t>(rc) ) ;
+			if( this_.deleted() ) break ;
 		}
-		G_ASSERT( static_cast<std::size_t>(rc) <= m_read_buffer.size() ) ;
-		G::CallFrame this_( m_stack ) ;
-		m_sink.onData( &m_read_buffer[0] , static_cast<std::size_t>(rc) ) ;
-		if( this_.deleted() ) break ;
+		return true ;
+	}
+	else
+	{
+		return false ;
 	}
 }
 
-void GNet::SocketProtocolImp::rawReadEvent()
+bool GNet::SocketProtocolImp::rawReadEvent( bool no_throw_on_peer_disconnect )
 {
 	const ssize_t rc = m_socket.read( &m_read_buffer[0] , m_read_buffer.size() ) ;
-	if( rc == 0 || ( rc == -1 && !m_socket.eWouldBlock() ) )
+	if( rc == 0 && no_throw_on_peer_disconnect )
+	{
+		m_socket.dropReadHandler() ;
+		m_sink.onPeerDisconnect() ;
+		return true ;
+	}
+	else if( rc == 0 || ( rc == -1 && !m_socket.eWouldBlock() ) )
 	{
 		throw SocketProtocol::ReadError( rc == 0 ? std::string() : m_socket.reason() ) ;
 	}
@@ -606,6 +661,7 @@ void GNet::SocketProtocolImp::rawReadEvent()
 		G_DEBUG( "GNet::SocketProtocolImp::rawReadEvent: read event read nothing" ) ;
 		; // -1 && eWouldBlock() -- no-op (esp. for windows)
 	}
+	return false ;
 }
 
 bool GNet::SocketProtocolImp::rawSend( const Segments & segments , Position pos , bool do_copy )
@@ -707,6 +763,14 @@ bool GNet::SocketProtocolImp::rawSendImp( const Segments & segments , Position p
 	return true ; // all sent
 }
 
+void GNet::SocketProtocolImp::rawReset()
+{
+	m_segments.clear() ;
+	m_position = Position() ;
+	m_data_copy.clear() ;
+	m_socket.dropWriteHandler() ;
+}
+
 std::unique_ptr<GSsl::Protocol> GNet::SocketProtocolImp::newProtocol( const std::string & profile_name )
 {
 	GSsl::Library * library = GSsl::Library::instance() ;
@@ -753,17 +817,17 @@ void GNet::SocketProtocolImp::logSecure( const std::string & protocol , const st
 //
 
 GNet::SocketProtocol::SocketProtocol( EventHandler & handler , ExceptionSink es ,
-	Sink & sink , StreamSocket & socket , unsigned int secure_connection_timeout ) :
-		m_imp(std::make_unique<SocketProtocolImp>(handler,es,sink,socket,secure_connection_timeout))
+	Sink & sink , StreamSocket & socket , const Config & config ) :
+		m_imp(std::make_unique<SocketProtocolImp>(handler,es,sink,socket,config))
 {
 }
 
 GNet::SocketProtocol::~SocketProtocol()
 = default;
 
-void GNet::SocketProtocol::readEvent()
+bool GNet::SocketProtocol::readEvent( bool no_throw_on_peer_disconnect )
 {
-	m_imp->readEvent() ;
+	return m_imp->readEvent( no_throw_on_peer_disconnect ) ;
 }
 
 bool GNet::SocketProtocol::writeEvent()
@@ -771,14 +835,19 @@ bool GNet::SocketProtocol::writeEvent()
 	return m_imp->writeEvent() ;
 }
 
-void GNet::SocketProtocol::otherEvent( EventHandler::Reason reason )
+void GNet::SocketProtocol::otherEvent( EventHandler::Reason reason , bool no_throw_on_peer_disconnect )
 {
-	m_imp->otherEvent( reason ) ;
+	m_imp->otherEvent( reason , no_throw_on_peer_disconnect ) ;
 }
 
 bool GNet::SocketProtocol::send( const std::string & data , std::size_t offset )
 {
-	return m_imp->send( data , offset ) ;
+	return m_imp->send( G::string_view(data.data(),data.size()) , offset ) ;
+}
+
+bool GNet::SocketProtocol::send( G::string_view data )
+{
+	return m_imp->send( data , 0U ) ;
 }
 
 bool GNet::SocketProtocol::send( const std::vector<G::string_view> & data , std::size_t offset )
@@ -791,9 +860,9 @@ void GNet::SocketProtocol::shutdown()
 	m_imp->shutdown() ;
 }
 
-bool GNet::SocketProtocol::secureConnectCapable()
+bool GNet::SocketProtocol::secureConnectCapable() const
 {
-	return GSsl::Library::enabledAs( "client" ) ;
+	return m_imp->secureConnectCapable() ;
 }
 
 void GNet::SocketProtocol::secureConnect()
@@ -801,9 +870,9 @@ void GNet::SocketProtocol::secureConnect()
 	m_imp->secureConnect() ;
 }
 
-bool GNet::SocketProtocol::secureAcceptCapable()
+bool GNet::SocketProtocol::secureAcceptCapable() const
 {
-	return GSsl::Library::enabledAs( "server" ) ;
+	return m_imp->secureAcceptCapable() ;
 }
 
 void GNet::SocketProtocol::secureAccept()
@@ -811,13 +880,18 @@ void GNet::SocketProtocol::secureAccept()
 	m_imp->secureAccept() ;
 }
 
+bool GNet::SocketProtocol::secure() const
+{
+	return m_imp->secure() ;
+}
+
+bool GNet::SocketProtocol::raw() const
+{
+	return m_imp->raw() ;
+}
+
 std::string GNet::SocketProtocol::peerCertificate() const
 {
 	return m_imp->peerCertificate() ;
 }
 
-void GNet::SocketProtocol::setReadBufferSize( std::size_t n )
-{
-	SocketProtocolImp::setReadBufferSize( n ) ;
-}
-
diff --git a/src/gnet/gsocketprotocol.h b/src/gnet/gsocketprotocol.h
index 9a903ad..888bd7c 100644
--- a/src/gnet/gsocketprotocol.h
+++ b/src/gnet/gsocketprotocol.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -26,9 +26,11 @@
 #include "geventhandler.h"
 #include "gexception.h"
 #include "gstringview.h"
+#include "glimits.h"
 #include <string>
-#include <vector>
+#include <memory>
 #include <utility>
+#include <vector>
 
 namespace GNet
 {
@@ -56,34 +58,54 @@ class GNet::SocketProtocol
 {
 public:
 	using Sink = SocketProtocolSink ;
-	G_EXCEPTION_CLASS( ReadError , "peer disconnected" ) ;
-	G_EXCEPTION( SendError , "peer disconnected" ) ;
-	G_EXCEPTION( ShutdownError , "shutdown error" ) ;
-	G_EXCEPTION( SecureConnectionTimeout , "secure connection timeout" ) ;
+	G_EXCEPTION_CLASS( ReadError , tx("peer disconnected") ) ;
+	G_EXCEPTION( SendError , tx("peer disconnected") ) ;
+	G_EXCEPTION( ShutdownError , tx("shutdown error") ) ;
+	G_EXCEPTION( SecureConnectionTimeout , tx("secure connection timeout") ) ;
+	G_EXCEPTION( Shutdown , tx("peer shutdown") ) ;
+	G_EXCEPTION( OtherEventError , tx("network event") ) ;
+	G_EXCEPTION( ProtocolError , tx("socket protocol error") ) ;
 
-	SocketProtocol( EventHandler & , ExceptionSink ,
-		Sink & , StreamSocket & , unsigned int secure_connection_timeout ) ;
-			///< Constructor. The references are kept.
+	struct Config /// A configuration structure for GNet::SocketProtocol.
+	{
+		std::size_t read_buffer_size {G::limits::net_buffer} ;
+		unsigned int secure_connection_timeout {0U} ;
+		std::string server_tls_profile ;
+		std::string client_tls_profile ;
+		Config & set_read_buffer_size( std::size_t n ) { read_buffer_size = n ; return *this ; }
+		Config & set_secure_connection_timeout( unsigned int t ) { secure_connection_timeout = t ; return *this ; }
+		Config & set_server_tls_profile( const std::string & s ) { server_tls_profile = s ; return *this ; }
+		Config & set_client_tls_profile( const std::string & s ) { client_tls_profile = s ; return *this ; }
+	} ;
+
+	SocketProtocol( EventHandler & , ExceptionSink , Sink & ,
+		StreamSocket & , const Config & ) ;
+			///< Constructor.
 
 	~SocketProtocol() ;
 		///< Destructor.
 
-	void readEvent() ;
-		///< Called on receipt of a read event. Delivers data via the sink
-		///< interface. Throws ReadError on error.
+	bool readEvent( bool no_throw_on_peer_disconnect = false ) ;
+		///< Called on receipt of a read event. Delivers data via the
+		///< sink interface onData() and optionally onPeerDisconnect()
+		///< if the parameter is true. Throws ReadError on error.
+		///< Returns true iff an incomplete send() over TLS has now
+		///< completed.
 
 	bool writeEvent() ;
 		///< Called on receipt of a write event. Sends more pending data
-		///< down the connection. Returns true if all pending data was
-		///< sent. Throws SendError on error.
+		///< down the connection. Returns true if an incomplete send() has
+		///< now completed. Throws SendError on error.
 
-	void otherEvent( EventHandler::Reason ) ;
-		///< Called on receipt of an 'other' event. Throws an exception.
-		///< For simple socket-close events (on Windows) the read queue
-		///< is processed (see SocketProtocolSink::onData()) and the
-		///< socket is shutdown() before the exception is thrown.
+	void otherEvent( EventHandler::Reason , bool no_throw_on_peer_disconnect = false ) ;
+		///< Called on receipt of an 'other' event. Any pending read
+		///< data is delivered via onData() and if this is a peer
+		///< disconnect event on a raw() socket (Windows) and the
+		///< 'no_throw_on_peer_disconnect' parameter is true the
+		///< onPeerDisconnect() is called and the method returns
+		///< normally, otherwise an exception is thrown.
 
-	bool send( const std::string & data , std::size_t offset = 0U ) ;
+	bool send( const std::string & data , std::size_t offset ) ;
 		///< Sends data. Returns false if flow control asserted before
 		///< all the data is sent. Returns true if all the data was sent,
 		///< or if the data passed in (taking the offset into account)
@@ -94,7 +116,10 @@ public:
 		///< portions of the data string are copied internally. When
 		///< the subsequent write-event is triggered the user should
 		///< call writeEvent(). There should be no new calls to send()
-		///< until writeEvent() returns true.
+		///< until writeEvent() or readEvent() returns true.
+
+	bool send( G::string_view data ) ;
+		///< Overload for string_view.
 
 	bool send( const std::vector<G::string_view> & data , std::size_t offset = 0U ) ;
 		///< Overload to send data using scatter-gather segments.
@@ -106,36 +131,39 @@ public:
 		///< Initiates a TLS-close if secure, together with a
 		///< Socket::shutdown(1).
 
-	static bool secureConnectCapable() ;
+	bool secureConnectCapable() const ;
 		///< Returns true if the implementation supports TLS/SSL and a
 		///< "client" profile has been configured. See also GSsl::enabledAs().
 
 	void secureConnect() ;
 		///< Initiates the TLS/SSL handshake, acting as a client.
+		///< Any send() data blocked by flow control is discarded.
 
-	static bool secureAcceptCapable() ;
+	bool secureAcceptCapable() const ;
 		///< Returns true if the implementation supports TLS/SSL and a
 		///< "server" profile has been configured. See also GSsl::enabledAs().
 
 	void secureAccept() ;
 		///< Waits for the TLS/SSL handshake protocol, acting as a server.
+		///< Any send() data blocked by flow control is discarded.
 
 	bool secure() const ;
-		///< Returns true if the connection is currently secure, ie. after
-		///< onSecure().
+		///< Returns true if the connection is currently secure
+		///< ie. after onSecure(). Returns false if busy with the
+		///< TLS/SSL handshake.
+
+	bool raw() const ;
+		///< Returns true if no TLS/SSL.
 
 	std::string peerCertificate() const ;
 		///< Returns the peer's TLS/SSL certificate or the empty
 		///< string.
 
-	static void setReadBufferSize( std::size_t n ) ;
-		///< Sets the read buffer size. Used in testing.
-
 public:
 	SocketProtocol( const SocketProtocol & ) = delete ;
 	SocketProtocol( SocketProtocol && ) = delete ;
-	void operator=( const SocketProtocol & ) = delete ;
-	void operator=( SocketProtocol && ) = delete ;
+	SocketProtocol & operator=( const SocketProtocol & ) = delete ;
+	SocketProtocol & operator=( SocketProtocol && ) = delete ;
 
 private:
 	std::unique_ptr<SocketProtocolImp> m_imp ;
@@ -158,6 +186,15 @@ public:
 		const std::string & protocol , const std::string & cipher ) = 0 ;
 			///< Called once the secure socket protocol has
 			///< been successfully negotiated.
+
+	virtual void onPeerDisconnect() = 0 ;
+		///< Called, if enabled by the readEvent()/otherEvent() parameter,
+		///< when the peer disconnects with a socket shutdown. This tells
+		///< us that the peer will not send any more data but we can
+		///< keep sending. The SocketProtocol class will have already
+		///< dropped the socket read handler. If we have previously
+		///< done our own shutdown then both directions are now closed
+		///< and the connection is defunct.
 } ;
 
 #endif
diff --git a/src/gnet/gsocks.cpp b/src/gnet/gsocks.cpp
index e3dc89f..fba5794 100644
--- a/src/gnet/gsocks.cpp
+++ b/src/gnet/gsocks.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gnet/gsocks.h b/src/gnet/gsocks.h
index b88c3ee..d34d602 100644
--- a/src/gnet/gsocks.h
+++ b/src/gnet/gsocks.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -38,7 +38,7 @@ namespace GNet
 class GNet::Socks
 {
 public:
-	G_EXCEPTION( SocksError , "socks error" ) ;
+	G_EXCEPTION( SocksError , tx("socks error") ) ;
 
 	explicit Socks( const Location & ) ;
 		///< Constructor.
diff --git a/src/gnet/gtask.cpp b/src/gnet/gtask.cpp
index d37ded5..f4360dd 100644
--- a/src/gnet/gtask.cpp
+++ b/src/gnet/gtask.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -46,7 +46,7 @@ public:
 			// the event-loop.
 			//
 			// In a single-threaded build, or if multi-threading is broken,
-			// this contructor runs the task, waits for it to complete
+			// this constructor runs the task, waits for it to complete
 			// and posts the completion message to the event-loop
 			// before this constructor returns.
 
@@ -71,12 +71,12 @@ private: // overrides
 public:
 	TaskImp( const TaskImp & ) = delete ;
 	TaskImp( TaskImp && ) = delete ;
-	void operator=( const TaskImp & ) = delete ;
-	void operator=( TaskImp && ) = delete ;
+	TaskImp & operator=( const TaskImp & ) = delete ;
+	TaskImp & operator=( TaskImp && ) = delete ;
 
 private:
 	void onTimeout() ;
-	static void waitThread( TaskImp * , FutureEvent::handle_type ) ; // thread function
+	static void waitThread( TaskImp * , HANDLE ) ; // thread function
 
 private:
 	Task * m_task ;
@@ -157,7 +157,7 @@ bool GNet::TaskImp::zombify()
 		m_zcount++ ;
 		m_timer.startTimer( 1U ) ;
 
-		std::size_t threshold = G::Test::enabled("task-warning") ? 3U : 100U ;
+		const std::size_t threshold = 30U ;
 		if( m_zcount == threshold )
 			G_WARNING_ONCE( "GNet::Task::dtor: large number of threads waiting for processes to finish" ) ;
 
@@ -191,10 +191,10 @@ std::pair<int,std::string> GNet::TaskImp::wait()
 {
 	m_process.waitable().wait() ;
 	int exit_code = m_process.waitable().get() ;
-	return std::make_pair( exit_code , m_process.waitable().output() ) ;
+	return { exit_code , m_process.waitable().output() } ;
 }
 
-void GNet::TaskImp::waitThread( TaskImp * This , FutureEvent::handle_type handle )
+void GNet::TaskImp::waitThread( TaskImp * This , HANDLE handle )
 {
 	// worker-thread -- keep it simple
 	try
diff --git a/src/gnet/gtask.h b/src/gnet/gtask.h
index c1f7bdc..acbc89f 100644
--- a/src/gnet/gtask.h
+++ b/src/gnet/gtask.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -26,6 +26,7 @@
 #include "genvironment.h"
 #include "gnewprocess.h"
 #include "gexceptionsink.h"
+#include "gexception.h"
 #include "gidentity.h"
 #include "gexecutablecommand.h"
 #include <memory>
@@ -44,10 +45,10 @@ namespace GNet
 class GNet::Task
 {
 public:
-	G_EXCEPTION( Busy , "cannot execute command-line task: still busy from last time" ) ;
+	G_EXCEPTION( Busy , tx("cannot execute command-line task: still busy from last time") ) ;
 
 	Task( TaskCallback & , ExceptionSink es ,
-		const std::string & exec_error_format = std::string() ,
+		const std::string & exec_error_format = {} ,
 		const G::Identity & = G::Identity::invalid() ) ;
 			///< Constructor for an object that can be start()ed or run().
 			///< The two trailing parameters are passed to the G::NewProcess
@@ -89,8 +90,8 @@ public:
 public:
 	Task( const Task & ) = delete ;
 	Task( Task && ) = delete ;
-	void operator=( const Task & ) = delete ;
-	void operator=( Task && ) = delete ;
+	Task & operator=( const Task & ) = delete ;
+	Task & operator=( Task && ) = delete ;
 
 private:
 	friend class GNet::TaskImp ;
diff --git a/src/gnet/gtimer.cpp b/src/gnet/gtimer.cpp
index a8dc54e..0a3b5b1 100644
--- a/src/gnet/gtimer.cpp
+++ b/src/gnet/gtimer.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -27,6 +27,8 @@
 #include <algorithm>
 
 GNet::TimerBase::TimerBase( ExceptionSink es ) :
+	m_active(false) ,
+	m_immediate(false) ,
 	m_time(G::TimerTime::zero())
 {
 	TimerList::instance().add( *this , es ) ;
@@ -46,7 +48,7 @@ GNet::TimerBase::~TimerBase()
 
 bool GNet::TimerBase::expired( G::TimerTime & now ) const
 {
-	if( !active() )
+	if( !m_active )
 	{
 		return false ;
 	}
@@ -56,55 +58,56 @@ bool GNet::TimerBase::expired( G::TimerTime & now ) const
 	}
 	else
 	{
-		if( now == G::TimerTime::zero() ) now = G::TimerTime::now() ; // lazy optimisation
+		// lazy evaluation of caller's idea of now -- no call
+		// to TimerTime::now() if there is a zero-length
+		// timer or no timers at all
+		if( now == G::TimerTime::zero() )
+			now = G::TimerTime::now() ;
+
 		return m_time <= now ;
 	}
 }
 
 void GNet::TimerBase::startTimer( unsigned int time , unsigned int time_us )
 {
-	m_time = (time==0U && time_us==0U) ? history() : ( G::TimerTime::now() + G::TimeInterval(time,time_us) ) ;
+	m_active = true ;
+	m_immediate = time == 0U && time_us == 0U ;
+	m_time = m_immediate ? G::TimerTime::zero() : ( G::TimerTime::now() + G::TimeInterval(time,time_us) ) ;
 	TimerList::instance().updateOnStart( *this ) ; // adjust()
 }
 
 void GNet::TimerBase::startTimer( const G::TimeInterval & i )
 {
-	m_time = i == G::TimeInterval(0U) ? history() : ( G::TimerTime::now() + i ) ;
+	m_active = true ;
+	m_immediate = i == G::TimeInterval(0U) ;
+	m_time = m_immediate ? G::TimerTime::zero() : ( G::TimerTime::now() + i ) ;
 	TimerList::instance().updateOnStart( *this ) ; // adjust()
 }
 
-G::TimerTime GNet::TimerBase::history()
-{
-	// base for an arbitrary historical one-second non-zero epoch
-	// time interval used for all immediate() timers
-	return G::TimerTime::zero() + G::TimeInterval( 1U ) ;
-}
-
 bool GNet::TimerBase::immediate() const
 {
-	return m_time.sameSecond( history() ) ; // history() ignoring any adjust()ment
+	return m_immediate ;
 }
 
-void GNet::TimerBase::adjust( unsigned int us )
+void GNet::TimerBase::adjust( unsigned long order )
 {
-	m_time = history() + G::TimeInterval( 0U , std::min( 999999U , us ) ) ;
-	G_ASSERT( immediate() ) ;
+	G_ASSERT( m_active && m_immediate ) ;
+	m_time += G::TimeInterval( 0 , order ) ;
 }
 
 void GNet::TimerBase::cancelTimer()
 {
-	if( active() )
+	if( m_active )
 	{
-		m_time = G::TimerTime::zero() ;
+		m_active = false ;
 		TimerList::instance().updateOnCancel( *this ) ;
 	}
-	G_ASSERT( !active() ) ;
 }
 
 void GNet::TimerBase::doTimeout()
 {
-	G_ASSERT( active() ) ;
-	m_time = G::TimerTime::zero() ;
+	G_ASSERT( m_active ) ;
+	m_active = false ;
 	onTimeout() ;
 }
 
diff --git a/src/gnet/gtimer.h b/src/gnet/gtimer.h
index e6fed43..35c4e2a 100644
--- a/src/gnet/gtimer.h
+++ b/src/gnet/gtimer.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -30,6 +30,7 @@
 namespace GNet
 {
 	class TimerBase ;
+	template <typename T> class Timer ;
 }
 
 //| \class GNet::TimerBase
@@ -71,17 +72,22 @@ public:
 
 	G::TimerTime t() const ;
 		///< Used by TimerList to get the expiry epoch time. Zero-length
-		///< timers return a value corresponding to some time in ancient
-		///< history (1970).
+		///< timers return TimerTime::zero() plus any adjust()ment,
+		///< ~guaranteed to be less than the t() of any non-immediate
+		///< timer.
 
-	void adjust( unsigned int us ) ;
-		///< Used by TimerList to set the fractional part of the expiry
-		///< time of immediate() timers so that t() is ordered by
-		///< startTimer() time.
+	const G::TimerTime & tref() const noexcept ;
+		///< An inline noexcept alternative to t().
+
+	void adjust( unsigned long ) ;
+		///< Used by TimerList to set the order of immedate() timer
+		///< expiry.
 
 	bool expired( G::TimerTime & ) const ;
 		///< Used by TimerList. Returns true if expired when compared
-		///< to the given epoch time.
+		///< to the given epoch time. If the given epoch time is
+		///< TimerTime::zero() then it is initialised with
+		///< TimerTime::now().
 
 protected:
 	virtual void onTimeout() = 0 ;
@@ -90,25 +96,31 @@ protected:
 public:
 	TimerBase( const TimerBase & ) = delete ;
 	TimerBase( TimerBase && ) = delete ;
-	void operator=( const TimerBase & ) = delete ;
-	void operator=( TimerBase && ) = delete ;
+	TimerBase & operator=( const TimerBase & ) = delete ;
+	TimerBase & operator=( TimerBase && ) = delete ;
 
 private:
 	static G::TimerTime history() ;
 
 private:
+	bool m_active ;
+	bool m_immediate ;
 	G::TimerTime m_time ;
 } ;
 
-inline bool GNet::TimerBase::active() const noexcept
+inline
+const G::TimerTime & GNet::TimerBase::tref() const noexcept
 {
-	return !m_time.isZero() ;
+	return m_time ;
 }
 
-namespace GNet
+inline
+bool GNet::TimerBase::active() const noexcept
 {
+	return m_active ;
+}
 
-//| \class Timer
+//| \class GNet::Timer
 /// A timer class template in which the timeout is delivered to the specified
 /// method. Any exception thrown out of the timeout handler is delivered to
 /// the specified ExceptionHandler interface so that it can be handled or
@@ -125,7 +137,7 @@ namespace GNet
 /// \endcode
 ///
 template <typename T>
-class Timer : private TimerBase
+class GNet::Timer : private TimerBase
 {
 public:
 	using method_type = void (T::*)() ;
@@ -151,8 +163,8 @@ public:
 	~Timer() override = default ;
 	Timer( const Timer<T> & ) = delete ;
 	Timer( Timer<T> && ) = delete ;
-	void operator=( const Timer<T> & ) = delete ;
-	void operator=( Timer<T> && ) = delete ;
+	Timer<T> & operator=( const Timer<T> & ) = delete ;
+	Timer<T> & operator=( Timer<T> && ) = delete ;
 
 private: // overrides
 	void onTimeout() override ; // Override from GNet::TimerBase.
@@ -163,7 +175,7 @@ private:
 } ;
 
 template <typename T>
-Timer<T>::Timer( T & t , method_type m , GNet::ExceptionSink es ) :
+GNet::Timer<T>::Timer( T & t , method_type m , GNet::ExceptionSink es ) :
 	TimerBase(es) ,
 	m_t(t) ,
 	m_m(m)
@@ -171,35 +183,33 @@ Timer<T>::Timer( T & t , method_type m , GNet::ExceptionSink es ) :
 }
 
 template <typename T>
-void Timer<T>::startTimer( unsigned int s , unsigned int us )
+void GNet::Timer<T>::startTimer( unsigned int s , unsigned int us )
 {
 	TimerBase::startTimer( s , us ) ;
 }
 
 template <typename T>
-void Timer<T>::startTimer( const G::TimeInterval & i )
+void GNet::Timer<T>::startTimer( const G::TimeInterval & i )
 {
 	TimerBase::startTimer( i ) ;
 }
 
 template <typename T>
-void Timer<T>::cancelTimer()
+void GNet::Timer<T>::cancelTimer()
 {
 	TimerBase::cancelTimer() ;
 }
 
 template <typename T>
-bool Timer<T>::active() const noexcept
-{
-	return TimerBase::active() ;
-}
-
-template <typename T>
-void Timer<T>::onTimeout()
+void GNet::Timer<T>::onTimeout()
 {
 	(m_t.*m_m)() ;
 }
 
+template <typename T>
+bool GNet::Timer<T>::active() const noexcept
+{
+	return TimerBase::active() ;
 }
 
 #endif
diff --git a/src/gnet/gtimerlist.cpp b/src/gnet/gtimerlist.cpp
index 3b62b6f..f3ac798 100644
--- a/src/gnet/gtimerlist.cpp
+++ b/src/gnet/gtimerlist.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -100,7 +100,7 @@ void GNet::TimerList::remove( TimerBase & timer ) noexcept
 
 void GNet::TimerList::removeFrom( List & list , TimerBase * timer_p ) noexcept
 {
-	for( auto & value : list)
+	for( auto & value : list )
 		value.resetIf( timer_p ) ;
 }
 
@@ -124,12 +124,13 @@ void GNet::TimerList::updateOnStart( TimerBase & timer )
 	if( m_soonest == &timer )
 		m_soonest = nullptr ;
 
-	if( m_soonest != nullptr && timer.t() < m_soonest->t() )
+	if( m_soonest != nullptr && timer.tref() < m_soonest->tref() )
 		m_soonest = &timer ;
 }
 
 void GNet::TimerList::updateOnCancel( TimerBase & timer )
 {
+	G_ASSERT( !timer.active() ) ;
 	if( m_soonest == &timer )
 		m_soonest = nullptr ;
 }
@@ -140,7 +141,7 @@ const GNet::TimerBase * GNet::TimerList::findSoonest() const
 	TimerBase * result = nullptr ;
 	for( const auto & t : m_list )
 	{
-		if( t.m_timer != nullptr && t.m_timer->active() && ( result == nullptr || t.m_timer->t() < result->t() ) )
+		if( t.m_timer != nullptr && t.m_timer->active() && ( result == nullptr || t.m_timer->tref() < result->tref() ) )
 			result = t.m_timer ;
 	}
 	return result ;
@@ -214,7 +215,7 @@ void GNet::TimerList::purgeRemoved()
 	if( m_removed )
 	{
 		m_removed = false ;
-		m_list.erase( std::remove( m_list.begin() , m_list.end() , Value(nullptr,ExceptionSink()) ) , m_list.end() ) ;
+		m_list.erase( std::remove( m_list.begin() , m_list.end() , Value(nullptr,{}) ) , m_list.end() ) ;
 	}
 }
 
@@ -224,39 +225,46 @@ void GNet::TimerList::doTimeouts()
 	Lock lock( *this ) ;
 	m_adjust = 0 ;
 	G::TimerTime now = G::TimerTime::zero() ; // lazy initialisation to G::TimerTime::now() in G::Timer::expired()
-	for( auto & value : m_list )
+
+	auto expired_end = std::partition( m_list.begin() , m_list.end() ,
+		[&now](const Value &value){ return value.m_timer != nullptr && value.m_timer->active() && value.m_timer->expired(now) ; } ) ;
+
+	std::sort( m_list.begin() , expired_end ,
+		[](const Value &a,const Value &b){ return a.m_timer->tref() < b.m_timer->tref() ; } ) ;
+
+	if( expired_end != m_list.begin() )
+		m_soonest = nullptr ; // the soonest timer will in the expired list, so invalidate it
+
+	for( List::iterator value_p = m_list.begin() ; value_p != expired_end ; ++value_p )
 	{
-		if( value.m_timer != nullptr && value.m_timer->active() && value.m_timer->expired(now) )
-		{
-			EventLoggingContext set_logging_context( value.m_es.esrc() ) ;
-			try
-			{
-				if( value.m_timer == m_soonest ) m_soonest = nullptr ;
-				value.m_timer->doTimeout() ;
-			}
-			catch( GNet::Done & e ) // (caught separately to avoid requiring rtti)
-			{
-				if( value.m_es.set() )
-					value.m_es.call( e , true ) ; // call onException()
-				else
-					throw ; // (new)
-			}
-			catch( std::exception & e )
-			{
-				if( value.m_es.set() )
-					value.m_es.call( e , false ) ; // call onException()
-				else
-					throw ; // (new)
-			}
-		}
+		if( value_p->m_timer != nullptr && value_p->m_timer->active() && value_p->m_timer->expired(now) ) // still
+			doTimeout( *value_p ) ;
 	}
+
 	unlock() ; // avoid doing possibly-throwing operations in Lock dtor
 }
 
-std::string GNet::TimerList::report() const
+void GNet::TimerList::doTimeout( Value & value )
 {
-	std::ostringstream ss ;
-	ss << m_list.size() ;
-	return ss.str() ;
+	// see also GNet::EventEmitter::raiseEvent()
+	EventLoggingContext set_logging_context( value.m_es.esrc() ) ;
+	try
+	{
+		value.m_timer->doTimeout() ;
+	}
+	catch( GNet::Done & e ) // (caught separately to avoid requiring rtti)
+	{
+		if( value.m_es.set() )
+			value.m_es.call( e , true ) ; // call onException()
+		else
+			throw ; // (new)
+	}
+	catch( std::exception & e )
+	{
+		if( value.m_es.set() )
+			value.m_es.call( e , false ) ; // call onException()
+		else
+			throw ; // (new)
+	}
 }
 
diff --git a/src/gnet/gtimerlist.h b/src/gnet/gtimerlist.h
index 5bd7406..583de59 100644
--- a/src/gnet/gtimerlist.h
+++ b/src/gnet/gtimerlist.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -75,7 +75,7 @@ namespace GNet
 class GNet::TimerList
 {
 public:
-	G_EXCEPTION( NoInstance , "no TimerList instance" ) ;
+	G_EXCEPTION( NoInstance , tx("no TimerList instance") ) ;
 
 	TimerList() ;
 		///< Default constructor.
@@ -118,19 +118,21 @@ public:
 	static TimerList & instance() ;
 		///< Singleton access. Throws an exception if none.
 
-	std::string report() const ;
-		///< Returns a line of text reporting the status of the timer list.
-		///< Used in debugging and diagnostics.
-
 	void disarm( ExceptionHandler * ) noexcept ;
 		///< Resets any matching ExceptionHandler pointers.
 
+public:
+	TimerList( const TimerList & ) = delete ;
+	TimerList( TimerList && ) = delete ;
+	TimerList & operator=( const TimerList & ) = delete ;
+	TimerList & operator=( TimerList && ) = delete ;
+
 private:
 	struct Value /// A value type for the GNet::TimerList.
 	{
 		TimerBase * m_timer{nullptr} ; // handler for the timeout event
 		ExceptionSink m_es ; // handler for any exception thrown
-		Value() ; // for uclibc++
+		Value() ; // for uclibc++ std::vector
 		Value( TimerBase * t , ExceptionSink es ) ;
 		bool operator==( const Value & v ) const noexcept ;
 		void resetIf( TimerBase * p ) noexcept ;
@@ -143,25 +145,20 @@ private:
 		~Lock() ;
 		Lock( const Lock & ) = delete ;
 		Lock( Lock && ) = delete ;
-		void operator=( const Lock & ) = delete ;
-		void operator=( Lock && ) = delete ;
+		Lock & operator=( const Lock & ) = delete ;
+		Lock & operator=( Lock && ) = delete ;
 		TimerList & m_timer_list ;
 	} ;
-
-public:
-	TimerList( const TimerList & ) = delete ;
-	TimerList( TimerList && ) = delete ;
-	void operator=( const TimerList & ) = delete ;
-	void operator=( TimerList && ) = delete ;
-
-private:
 	friend class GNet::TimerListTest ;
 	friend struct Lock ;
+
+private:
 	const TimerBase * findSoonest() const ;
 	void lock() ;
 	void unlock() ;
 	void purgeRemoved() ;
 	void mergeAdded() ;
+	void doTimeout( Value & ) ;
 	static void removeFrom( List & , TimerBase * ) noexcept ;
 	static void disarmIn( List & , ExceptionHandler * ) noexcept ;
 
diff --git a/src/gpop/Makefile.am b/src/gpop/Makefile.am
index 54e887a..47b629a 100644
--- a/src/gpop/Makefile.am
+++ b/src/gpop/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
diff --git a/src/gpop/gpopserver.cpp b/src/gpop/gpopserver.cpp
index bd0586f..b958eac 100644
--- a/src/gpop/gpopserver.cpp
+++ b/src/gpop/gpopserver.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,22 +24,23 @@
 #include "glocal.h"
 #include "glog.h"
 #include <string>
+#include <utility>
 
-GPop::ServerPeer::ServerPeer( GNet::ExceptionSinkUnbound esu , const GNet::ServerPeerInfo & peer_info , Store & store ,
+GPop::ServerPeer::ServerPeer( GNet::ExceptionSinkUnbound esu , GNet::ServerPeerInfo && peer_info , Store & store ,
 	const GAuth::SaslServerSecrets & server_secrets , const std::string & sasl_server_config ,
 	std::unique_ptr<ServerProtocol::Text> ptext , const ServerProtocol::Config & protocol_config ) :
-		GNet::ServerPeer(esu.bind(this),peer_info,GNet::LineBufferConfig::pop()) ,
+		GNet::ServerPeer(esu.bind(this),std::move(peer_info),GNet::LineBufferConfig::pop()) ,
 		m_ptext(ptext.release()) ,
-		m_protocol(*this,*this,store,server_secrets,sasl_server_config,*m_ptext,peer_info.m_address,protocol_config)
+		m_protocol(*this,*this,store,server_secrets,sasl_server_config,*m_ptext,peerAddress(),protocol_config)
 {
-	G_LOG_S( "GPop::ServerPeer: pop connection from " << peer_info.m_address.displayString() ) ;
+	G_LOG_S( "GPop::ServerPeer: pop connection from " << peerAddress().displayString() ) ;
 	m_protocol.init() ;
 }
 
 void GPop::ServerPeer::onDelete( const std::string & reason )
 {
 	G_LOG_S( "GPop::ServerPeer: pop connection closed: " << reason << (reason.empty()?"":": ")
-		<< peerAddress().second.displayString() ) ;
+		<< peerAddress().displayString() ) ;
 }
 
 bool GPop::ServerPeer::onReceive( const char * line_data , std::size_t line_size , std::size_t , std::size_t , char )
@@ -55,7 +56,9 @@ void GPop::ServerPeer::processLine( const std::string & line )
 
 bool GPop::ServerPeer::protocolSend( const std::string & line , std::size_t offset )
 {
-	return send( line , offset ) ; // ServerPeer::send()
+    offset = std::min( offset , line.size() ) ;
+    G::string_view data( line.data()+offset , line.size()-offset ) ;
+    return data.empty() ? true : send( data ) ; // GNet::ServerPeer::send()
 }
 
 void GPop::ServerPeer::onSendComplete()
@@ -66,7 +69,7 @@ void GPop::ServerPeer::onSendComplete()
 bool GPop::ServerPeer::securityEnabled() const
 {
 	// require a tls server certificate -- see GSsl::Library::addProfile()
-	bool enabled = GNet::SocketProtocol::secureAcceptCapable() ;
+	bool enabled = secureAcceptCapable() ;
 	G_DEBUG( "ServerPeer::securityEnabled: tls library " << (enabled?"enabled":"disabled") ) ;
 	return enabled ;
 }
@@ -102,7 +105,7 @@ void GPop::Server::report() const
 	G_LOG_S( "GPop::Server: pop authentication secrets from \"" << m_secrets.source() << "\"" ) ;
 }
 
-std::unique_ptr<GNet::ServerPeer> GPop::Server::newPeer( GNet::ExceptionSinkUnbound esu , GNet::ServerPeerInfo peer_info , GNet::MultiServer::ServerInfo )
+std::unique_ptr<GNet::ServerPeer> GPop::Server::newPeer( GNet::ExceptionSinkUnbound esu , GNet::ServerPeerInfo && peer_info , GNet::MultiServer::ServerInfo )
 {
 	std::unique_ptr<GNet::ServerPeer> ptr ;
 	try
@@ -114,8 +117,9 @@ std::unique_ptr<GNet::ServerPeer> GPop::Server::newPeer( GNet::ExceptionSinkUnbo
 		}
 		else
 		{
-			ptr = std::make_unique<ServerPeer>( esu , peer_info , m_store , m_secrets , m_config.sasl_server_config ,
-				newProtocolText(peer_info.m_address) , ServerProtocol::Config() ) ; // up-cast (GPop::ServerPeer to GNet::ServerPeer)
+			GNet::Address peer_address = peer_info.m_address ;
+			ptr = std::make_unique<ServerPeer>( esu , std::move(peer_info) , m_store , m_secrets , m_config.sasl_server_config ,
+				newProtocolText(peer_address) , ServerProtocol::Config() ) ; // up-cast (GPop::ServerPeer to GNet::ServerPeer)
 		}
 	}
 	catch( std::exception & e ) // newPeer()
@@ -130,22 +134,3 @@ std::unique_ptr<GPop::ServerProtocol::Text> GPop::Server::newProtocolText( const
 	return std::make_unique<ServerProtocolText>(peer_address) ; // up-cast
 }
 
-// ===
-
-GPop::Server::Config::Config() :
-	server_peer_config(0U)
-{
-}
-
-GPop::Server::Config::Config( bool allow_remote_ , unsigned int port_ , const G::StringArray & addresses_ ,
-	const GNet::ServerPeerConfig & server_peer_config_ , const GNet::ServerConfig & server_config_ ,
-	const std::string & sasl_server_config_ ) :
-		allow_remote(allow_remote_) ,
-		port(port_) ,
-		addresses(addresses_) ,
-		server_peer_config(server_peer_config_) ,
-		server_config(server_config_) ,
-		sasl_server_config(sasl_server_config_)
-{
-}
-
diff --git a/src/gpop/gpopserver.h b/src/gpop/gpopserver.h
index 0c5f4b3..6966417 100644
--- a/src/gpop/gpopserver.h
+++ b/src/gpop/gpopserver.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -47,15 +47,15 @@ namespace GPop
 class GPop::ServerPeer : public GNet::ServerPeer , private ServerProtocol::Sender , private ServerProtocol::Security
 {
 public:
-	G_EXCEPTION( SendError , "network send error" ) ;
+	G_EXCEPTION( SendError , tx("network send error") ) ;
 
-	ServerPeer( GNet::ExceptionSinkUnbound , const GNet::ServerPeerInfo & , Store & ,
+	ServerPeer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo && , Store & ,
 		const GAuth::SaslServerSecrets & , const std::string & sasl_server_config ,
 		std::unique_ptr<ServerProtocol::Text> ptext , const ServerProtocol::Config & ) ;
 			///< Constructor.
 
 private: // overrides
-	bool protocolSend( const std::string & line , std::size_t ) override ; // Override from GPop::ServerProtocol::Sender.
+	bool protocolSend( const std::string & , std::size_t ) override ; // Override from GPop::ServerProtocol::Sender.
 	void onDelete( const std::string & ) override ; // Override from GNet::ServerPeer.
 	bool onReceive( const char * , std::size_t , std::size_t , std::size_t , char ) override ; // Override from GNet::ServerPeer.
 	void onSecure( const std::string & , const std::string & , const std::string & ) override ; // Override from GNet::SocketProtocolSink.
@@ -67,8 +67,8 @@ public:
 	~ServerPeer() override = default ;
 	ServerPeer( const ServerPeer & ) = delete ;
 	ServerPeer( ServerPeer && ) = delete ;
-	void operator=( const ServerPeer & ) = delete ;
-	void operator=( ServerPeer && ) = delete ;
+	ServerPeer & operator=( const ServerPeer & ) = delete ;
+	ServerPeer & operator=( ServerPeer && ) = delete ;
 
 private:
 	void processLine( const std::string & line ) ;
@@ -84,25 +84,21 @@ private:
 class GPop::Server : public GNet::MultiServer
 {
 public:
-	G_EXCEPTION( Overflow , "too many interface addresses" ) ;
+	G_EXCEPTION( Overflow , tx("too many interface addresses") ) ;
 	struct Config /// A structure containing GPop::Server configuration parameters.
 	{
 		bool allow_remote{false} ;
 		unsigned int port{110} ;
 		G::StringArray addresses ;
-		GNet::ServerPeerConfig server_peer_config ;
-		GNet::ServerConfig server_config ;
+		GNet::ServerPeer::Config server_peer_config ;
+		GNet::Server::Config server_config ;
 		std::string sasl_server_config ;
 
-		Config() ;
-		Config( bool , unsigned int port , const G::StringArray & addresses ,
-			const GNet::ServerPeerConfig & , const GNet::ServerConfig & ,
-			const std::string & sasl_server_config ) ;
 		Config & set_allow_remote( bool = true ) ;
 		Config & set_port( unsigned int ) ;
 		Config & set_addresses( const G::StringArray & ) ;
-		Config & set_server_peer_config( const GNet::ServerPeerConfig & ) ;
-		Config & set_server_config( const GNet::ServerConfig & ) ;
+		Config & set_server_peer_config( const GNet::ServerPeer::Config & ) ;
+		Config & set_server_config( const GNet::Server::Config & ) ;
 		Config & set_sasl_server_config( const std::string & ) ;
 	} ;
 
@@ -116,13 +112,13 @@ public:
 		///< Generates helpful diagnostics after construction.
 
 private: // overrides
-	std::unique_ptr<GNet::ServerPeer> newPeer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo , GNet::MultiServer::ServerInfo ) override ;
+	std::unique_ptr<GNet::ServerPeer> newPeer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo && , GNet::MultiServer::ServerInfo ) override ;
 
 public:
 	Server( const Server & ) = delete ;
 	Server( Server && ) = delete ;
-	void operator=( const Server & ) = delete ;
-	void operator=( Server && ) = delete ;
+	Server & operator=( const Server & ) = delete ;
+	Server & operator=( Server && ) = delete ;
 
 private:
 	std::unique_ptr<ServerProtocol::Text> newProtocolText( const GNet::Address & ) const ;
@@ -136,8 +132,8 @@ private:
 inline GPop::Server::Config & GPop::Server::Config::set_allow_remote( bool b ) { allow_remote = b ; return *this ; }
 inline GPop::Server::Config & GPop::Server::Config::set_port( unsigned int p ) { port = p ; return *this ; }
 inline GPop::Server::Config & GPop::Server::Config::set_addresses( const G::StringArray & a ) { addresses = a ; return *this ; }
-inline GPop::Server::Config & GPop::Server::Config::set_server_peer_config( const GNet::ServerPeerConfig & c ) { server_peer_config = c ; return *this ; }
-inline GPop::Server::Config & GPop::Server::Config::set_server_config( const GNet::ServerConfig & c ) { server_config = c ; return *this ; }
+inline GPop::Server::Config & GPop::Server::Config::set_server_peer_config( const GNet::ServerPeer::Config & c ) { server_peer_config = c ; return *this ; }
+inline GPop::Server::Config & GPop::Server::Config::set_server_config( const GNet::Server::Config & c ) { server_config = c ; return *this ; }
 inline GPop::Server::Config & GPop::Server::Config::set_sasl_server_config( const std::string & s ) { sasl_server_config = s ; return *this ; }
 
 #endif
diff --git a/src/gpop/gpopserverprotocol.cpp b/src/gpop/gpopserverprotocol.cpp
index 1820e8b..4a5bbc3 100644
--- a/src/gpop/gpopserverprotocol.cpp
+++ b/src/gpop/gpopserverprotocol.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -37,7 +37,7 @@ GPop::ServerProtocol::ServerProtocol( Sender & sender , Security & security , St
 		m_security(security) ,
 		m_store(store) ,
 		m_store_lock(m_store) ,
-		m_sasl_server(GAuth::SaslServerFactory::newSaslServer(server_secrets,sasl_server_config,true)) ,
+		m_sasl_server(GAuth::SaslServerFactory::newSaslServer(server_secrets,true,sasl_server_config,false)) ,
 		m_peer_address(peer_address) ,
 		m_fsm(State::sStart,State::sEnd,State::s_Same,State::s_Any) ,
 		m_body_limit(-1L) ,
@@ -79,7 +79,7 @@ void GPop::ServerProtocol::init()
 void GPop::ServerProtocol::sendInit()
 {
 	std::string greeting = std::string() + "+OK " + m_text.greeting() ;
-	if( m_sasl_server->active() && m_sasl_server->init("APOP") )
+	if( m_sasl_server->init( m_secure , "APOP" ) )
 	{
 		m_sasl_server_init_apop = true ;
 		std::string apop_challenge = m_sasl_server->initialChallenge() ;
@@ -417,7 +417,7 @@ void GPop::ServerProtocol::doAuth( const std::string & line , bool & ok )
 		ss << "." ;
 		sendLines( ss ) ;
 	}
-	else if( m_sasl_server->requiresEncryption() && !m_secure )
+	else if( mechanisms().empty() )
 	{
 		// reject authentication over an unencrypted transport
 		// if authentication is sensitive
@@ -431,7 +431,7 @@ void GPop::ServerProtocol::doAuth( const std::string & line , bool & ok )
 			initial_response.clear() ; // RFC-5034
 
 		m_sasl_server_init_apop = false ;
-		if( !m_sasl_server->init( mechanism ) )
+		if( !m_sasl_server->init( m_secure , mechanism ) )
 		{
 			ok = false ;
 			sendError( "invalid mechanism" ) ;
@@ -507,13 +507,14 @@ void GPop::ServerProtocol::secure()
 
 bool GPop::ServerProtocol::mechanismsIncludePlain() const
 {
-	return m_sasl_server->active() && mechanisms().find("PLAIN") != std::string::npos ;
+	return mechanisms().find("PLAIN") != std::string::npos ;
 }
 
 std::string GPop::ServerProtocol::mechanisms() const
 {
-	if( G::Test::enabled("pop-server-sasl-plain") ) return "PLAIN" ;
-	return m_sasl_server->active() ? m_sasl_server->mechanisms(' ') : std::string() ;
+	G::StringArray m = m_sasl_server->mechanisms( m_secure ) ;
+	m.erase( std::remove( m.begin() , m.end() , "APOP" ) , m.end() ) ;
+	return G::Str::join( " " , m ) ;
 }
 
 void GPop::ServerProtocol::doCapa( const std::string & , bool & )
@@ -557,7 +558,7 @@ void GPop::ServerProtocol::doUser( const std::string & line , bool & )
 void GPop::ServerProtocol::doPass( const std::string & line , bool & ok )
 {
 	m_sasl_server_init_apop = false ;
-	if( !m_user.empty() && m_sasl_server->init("PLAIN") ) // (USER/PASS uses SASL PLAIN)
+	if( !m_user.empty() && m_sasl_server->init(m_secure,"PLAIN") ) // (USER/PASS uses SASL PLAIN)
 	{
 		std::string rsp = m_user + std::string(1U,'\0') + m_user + std::string(1U,'\0') + commandParameter(line) ;
 		bool done = false ;
@@ -582,7 +583,7 @@ void GPop::ServerProtocol::doPass( const std::string & line , bool & ok )
 
 void GPop::ServerProtocol::doApop( const std::string & line , bool & ok )
 {
-	if( m_sasl_server->active() && m_sasl_server_init_apop )
+	if( m_sasl_server_init_apop )
 	{
 		std::string rsp = commandParameter(line,1) + " " + commandParameter(line,2) ;
 		bool done = false ;
@@ -616,7 +617,7 @@ void GPop::ServerProtocol::sendLine( std::string line )
 void GPop::ServerProtocol::sendLines( std::ostringstream & ss )
 {
 	ss << crlf() ;
-	if( G::LogOutput::instance() && G::LogOutput::instance()->at(G::Log::Severity::s_InfoVerbose) )
+	if( G::LogOutput::instance() && G::LogOutput::instance()->at(G::Log::Severity::InfoVerbose) )
 	{
 		const std::string s = ss.str() ;
 		std::size_t lines = std::count( s.begin() , s.end() , '\n' ) ;
diff --git a/src/gpop/gpopserverprotocol.h b/src/gpop/gpopserverprotocol.h
index ac575b7..811157e 100644
--- a/src/gpop/gpopserverprotocol.h
+++ b/src/gpop/gpopserverprotocol.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -47,7 +47,7 @@ namespace GPop
 class GPop::ServerProtocol
 {
 public:
-	G_EXCEPTION( ProtocolDone , "pop protocol done" ) ;
+	G_EXCEPTION( ProtocolDone , tx("pop protocol done") ) ;
 
 	class Sender /// An interface used by ServerProtocol to send protocol replies.
 	{
@@ -149,8 +149,8 @@ public:
 	~ServerProtocol() = default ;
 	ServerProtocol( const ServerProtocol & ) = delete ;
 	ServerProtocol( ServerProtocol && ) = delete ;
-	void operator=( const ServerProtocol & ) = delete ;
-	void operator=( ServerProtocol && ) = delete ;
+	ServerProtocol & operator=( const ServerProtocol & ) = delete ;
+	ServerProtocol & operator=( ServerProtocol && ) = delete ;
 
 private:
 	void doQuit( const std::string & line , bool & ) ;
@@ -221,8 +221,8 @@ public:
 	~ServerProtocolText() override = default ;
 	ServerProtocolText( const ServerProtocolText & ) = delete ;
 	ServerProtocolText( ServerProtocolText && ) = delete ;
-	void operator=( const ServerProtocolText & ) = delete ;
-	void operator=( ServerProtocolText && ) = delete ;
+	ServerProtocolText & operator=( const ServerProtocolText & ) = delete ;
+	ServerProtocolText & operator=( ServerProtocolText && ) = delete ;
 
 private: // overrides
 	std::string greeting() const override ; // Override from GPop::ServerProtocol::Text.
diff --git a/src/gpop/gpopstore.cpp b/src/gpop/gpopstore.cpp
index 42ba660..0fe31e5 100644
--- a/src/gpop/gpopstore.cpp
+++ b/src/gpop/gpopstore.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -169,6 +169,7 @@ bool GPop::StoreLock::File::operator<( const File & rhs ) const
 
 GPop::StoreLock::Size GPop::StoreLock::File::toSize( const std::string & s )
 {
+	if( s.empty() || !G::Str::isULong(s) ) return 0 ;
 	return G::Str::toULong( s , G::Str::Limited() ) ;
 }
 
diff --git a/src/gpop/gpopstore.h b/src/gpop/gpopstore.h
index ccd2f77..972bcaa 100644
--- a/src/gpop/gpopstore.h
+++ b/src/gpop/gpopstore.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -44,7 +44,7 @@ namespace GPop
 class GPop::Store
 {
 public:
-	G_EXCEPTION( InvalidDirectory , "invalid spool directory" ) ;
+	G_EXCEPTION( InvalidDirectory , tx("invalid spool directory") ) ;
 
 	Store( const G::Path & spool_dir , bool by_name , bool allow_delete ) ;
 		///< Constructor.
@@ -63,8 +63,8 @@ public:
 	~Store() = default ;
 	Store( const Store & ) = delete ;
 	Store( Store && ) = delete ;
-	void operator=( const Store & ) = delete ;
-	void operator=( Store && ) = delete ;
+	Store & operator=( const Store & ) = delete ;
+	Store & operator=( Store && ) = delete ;
 
 private:
 	static void checkPath( const G::Path & , bool , bool ) ;
@@ -102,8 +102,8 @@ public:
 class GPop::StoreLock
 {
 public:
-	G_EXCEPTION( CannotDelete , "cannot delete message file" ) ;
-	G_EXCEPTION( CannotRead , "cannot read message file" ) ;
+	G_EXCEPTION( CannotDelete , tx("cannot delete message file") ) ;
+	G_EXCEPTION( CannotRead , tx("cannot read message file") ) ;
 	using Size = StoreLockEntry::Size ;
 	using Entry = StoreLockEntry ;
 	using List = std::list<Entry> ;
@@ -175,8 +175,8 @@ private:
 public:
 	StoreLock( const StoreLock & ) = delete ;
 	StoreLock( StoreLock && ) = delete ;
-	void operator=( const StoreLock & ) = delete ;
-	void operator=( StoreLock && ) = delete ;
+	StoreLock & operator=( const StoreLock & ) = delete ;
+	StoreLock & operator=( StoreLock && ) = delete ;
 
 private:
 	Set::iterator find( const std::string & ) ;
diff --git a/src/gsmtp/Makefile.am b/src/gsmtp/Makefile.am
index 9da467a..9079ad5 100644
--- a/src/gsmtp/Makefile.am
+++ b/src/gsmtp/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -26,24 +26,6 @@ endif
 ADMIN_SOURCES = gadminserver.cpp gadminserver.h
 ADMIN_EXTRA_DIST =
 
-EXEC_SOURCES = \
-	gexecutablefilter.cpp \
-	gexecutablefilter.h \
-	gexecutableverifier.cpp \
-	gexecutableverifier.h \
-	gnetworkfilter.cpp \
-	gnetworkfilter.h \
-	gnetworkverifier.cpp \
-	gnetworkverifier.h \
-	gfilterfactory.cpp \
-	grequestclient.cpp \
-	grequestclient.h \
-	gspamclient.cpp \
-	gspamclient.h \
-	gspamfilter.cpp \
-	gspamfilter.h \
-	gverifierfactory.cpp
-
 EXTRA_DIST=\
 	$(ADMIN_EXTRA_DIST) \
 	$(OS_SOURCES_EXTRA_DIST)
@@ -59,33 +41,45 @@ noinst_LIBRARIES = libgsmtp.a
 
 libgsmtp_a_SOURCES = \
 	$(ADMIN_SOURCES) \
-	$(EXEC_SOURCES) \
 	$(OS_SOURCES) \
 	genvelope.cpp \
 	genvelope.h \
+	gexecutablefilter.cpp \
+	gexecutablefilter.h \
+	gexecutableverifier.cpp \
+	gexecutableverifier.h \
 	gfactoryparser.cpp \
 	gfactoryparser.h \
 	gfilestore.cpp \
 	gfilestore.h \
 	gfilter.cpp \
 	gfilter.h \
+	gfilterchain.cpp \
+	gfilterchain.h \
+	gfilterfactory.cpp \
 	gfilterfactory.h \
 	ginternalverifier.cpp \
 	ginternalverifier.h \
 	gmessagestore.cpp \
 	gmessagestore.h \
-	gnullfilter.cpp \
-	gnullfilter.h \
+	gnetworkfilter.cpp \
+	gnetworkfilter.h \
+	gnetworkverifier.cpp \
+	gnetworkverifier.h \
 	gnewfile.cpp \
 	gnewfile.h \
 	gnewmessage.cpp \
 	gnewmessage.h \
+	gnullfilter.cpp \
+	gnullfilter.h \
 	gprotocolmessage.cpp \
+	gprotocolmessage.h \
 	gprotocolmessageforward.cpp \
 	gprotocolmessageforward.h \
-	gprotocolmessage.h \
 	gprotocolmessagestore.cpp \
 	gprotocolmessagestore.h \
+	grequestclient.cpp \
+	grequestclient.h \
 	gsmtpclient.cpp \
 	gsmtpclient.h \
 	gsmtpclientprotocol.cpp \
@@ -94,12 +88,17 @@ libgsmtp_a_SOURCES = \
 	gsmtpserver.h \
 	gsmtpserverprotocol.cpp \
 	gsmtpserverprotocol.h \
+	gspamclient.cpp \
+	gspamclient.h \
+	gspamfilter.cpp \
+	gspamfilter.h \
 	gstoredfile.cpp \
 	gstoredfile.h \
 	gstoredmessage.cpp \
 	gstoredmessage.h \
 	gverifier.cpp \
 	gverifier.h \
+	gverifierfactory.cpp \
 	gverifierfactory.h \
 	gverifierstatus.cpp \
 	gverifierstatus.h
diff --git a/src/gsmtp/Makefile.in b/src/gsmtp/Makefile.in
index 1455e7d..16c7f81 100644
--- a/src/gsmtp/Makefile.in
+++ b/src/gsmtp/Makefile.in
@@ -111,44 +111,45 @@ am__v_AR_1 =
 libgsmtp_a_AR = $(AR) $(ARFLAGS)
 libgsmtp_a_LIBADD =
 am__libgsmtp_a_SOURCES_DIST = gadminserver.cpp gadminserver.h \
-	gexecutablefilter.cpp gexecutablefilter.h \
+	gmessagestore_unix.cpp gmessagestore_win32.cpp genvelope.cpp \
+	genvelope.h gexecutablefilter.cpp gexecutablefilter.h \
 	gexecutableverifier.cpp gexecutableverifier.h \
-	gnetworkfilter.cpp gnetworkfilter.h gnetworkverifier.cpp \
-	gnetworkverifier.h gfilterfactory.cpp grequestclient.cpp \
-	grequestclient.h gspamclient.cpp gspamclient.h gspamfilter.cpp \
-	gspamfilter.h gverifierfactory.cpp gmessagestore_unix.cpp \
-	gmessagestore_win32.cpp genvelope.cpp genvelope.h \
 	gfactoryparser.cpp gfactoryparser.h gfilestore.cpp \
-	gfilestore.h gfilter.cpp gfilter.h gfilterfactory.h \
+	gfilestore.h gfilter.cpp gfilter.h gfilterchain.cpp \
+	gfilterchain.h gfilterfactory.cpp gfilterfactory.h \
 	ginternalverifier.cpp ginternalverifier.h gmessagestore.cpp \
-	gmessagestore.h gnullfilter.cpp gnullfilter.h gnewfile.cpp \
-	gnewfile.h gnewmessage.cpp gnewmessage.h gprotocolmessage.cpp \
+	gmessagestore.h gnetworkfilter.cpp gnetworkfilter.h \
+	gnetworkverifier.cpp gnetworkverifier.h gnewfile.cpp \
+	gnewfile.h gnewmessage.cpp gnewmessage.h gnullfilter.cpp \
+	gnullfilter.h gprotocolmessage.cpp gprotocolmessage.h \
 	gprotocolmessageforward.cpp gprotocolmessageforward.h \
-	gprotocolmessage.h gprotocolmessagestore.cpp \
-	gprotocolmessagestore.h gsmtpclient.cpp gsmtpclient.h \
-	gsmtpclientprotocol.cpp gsmtpclientprotocol.h gsmtpserver.cpp \
-	gsmtpserver.h gsmtpserverprotocol.cpp gsmtpserverprotocol.h \
-	gstoredfile.cpp gstoredfile.h gstoredmessage.cpp \
-	gstoredmessage.h gverifier.cpp gverifier.h gverifierfactory.h \
-	gverifierstatus.cpp gverifierstatus.h
+	gprotocolmessagestore.cpp gprotocolmessagestore.h \
+	grequestclient.cpp grequestclient.h gsmtpclient.cpp \
+	gsmtpclient.h gsmtpclientprotocol.cpp gsmtpclientprotocol.h \
+	gsmtpserver.cpp gsmtpserver.h gsmtpserverprotocol.cpp \
+	gsmtpserverprotocol.h gspamclient.cpp gspamclient.h \
+	gspamfilter.cpp gspamfilter.h gstoredfile.cpp gstoredfile.h \
+	gstoredmessage.cpp gstoredmessage.h gverifier.cpp gverifier.h \
+	gverifierfactory.cpp gverifierfactory.h gverifierstatus.cpp \
+	gverifierstatus.h
 am__objects_1 = gadminserver.$(OBJEXT)
-am__objects_2 = gexecutablefilter.$(OBJEXT) \
-	gexecutableverifier.$(OBJEXT) gnetworkfilter.$(OBJEXT) \
-	gnetworkverifier.$(OBJEXT) gfilterfactory.$(OBJEXT) \
-	grequestclient.$(OBJEXT) gspamclient.$(OBJEXT) \
-	gspamfilter.$(OBJEXT) gverifierfactory.$(OBJEXT)
-@GCONFIG_WINDOWS_FALSE@am__objects_3 = gmessagestore_unix.$(OBJEXT)
-@GCONFIG_WINDOWS_TRUE@am__objects_3 = gmessagestore_win32.$(OBJEXT)
+@GCONFIG_WINDOWS_FALSE@am__objects_2 = gmessagestore_unix.$(OBJEXT)
+@GCONFIG_WINDOWS_TRUE@am__objects_2 = gmessagestore_win32.$(OBJEXT)
 am_libgsmtp_a_OBJECTS = $(am__objects_1) $(am__objects_2) \
-	$(am__objects_3) genvelope.$(OBJEXT) gfactoryparser.$(OBJEXT) \
-	gfilestore.$(OBJEXT) gfilter.$(OBJEXT) \
-	ginternalverifier.$(OBJEXT) gmessagestore.$(OBJEXT) \
-	gnullfilter.$(OBJEXT) gnewfile.$(OBJEXT) gnewmessage.$(OBJEXT) \
+	genvelope.$(OBJEXT) gexecutablefilter.$(OBJEXT) \
+	gexecutableverifier.$(OBJEXT) gfactoryparser.$(OBJEXT) \
+	gfilestore.$(OBJEXT) gfilter.$(OBJEXT) gfilterchain.$(OBJEXT) \
+	gfilterfactory.$(OBJEXT) ginternalverifier.$(OBJEXT) \
+	gmessagestore.$(OBJEXT) gnetworkfilter.$(OBJEXT) \
+	gnetworkverifier.$(OBJEXT) gnewfile.$(OBJEXT) \
+	gnewmessage.$(OBJEXT) gnullfilter.$(OBJEXT) \
 	gprotocolmessage.$(OBJEXT) gprotocolmessageforward.$(OBJEXT) \
-	gprotocolmessagestore.$(OBJEXT) gsmtpclient.$(OBJEXT) \
-	gsmtpclientprotocol.$(OBJEXT) gsmtpserver.$(OBJEXT) \
-	gsmtpserverprotocol.$(OBJEXT) gstoredfile.$(OBJEXT) \
-	gstoredmessage.$(OBJEXT) gverifier.$(OBJEXT) \
+	gprotocolmessagestore.$(OBJEXT) grequestclient.$(OBJEXT) \
+	gsmtpclient.$(OBJEXT) gsmtpclientprotocol.$(OBJEXT) \
+	gsmtpserver.$(OBJEXT) gsmtpserverprotocol.$(OBJEXT) \
+	gspamclient.$(OBJEXT) gspamfilter.$(OBJEXT) \
+	gstoredfile.$(OBJEXT) gstoredmessage.$(OBJEXT) \
+	gverifier.$(OBJEXT) gverifierfactory.$(OBJEXT) \
 	gverifierstatus.$(OBJEXT)
 libgsmtp_a_OBJECTS = $(am_libgsmtp_a_OBJECTS)
 AM_V_P = $(am__v_P_@AM_V@)
@@ -170,9 +171,9 @@ am__depfiles_remade = ./$(DEPDIR)/gadminserver.Po \
 	./$(DEPDIR)/genvelope.Po ./$(DEPDIR)/gexecutablefilter.Po \
 	./$(DEPDIR)/gexecutableverifier.Po \
 	./$(DEPDIR)/gfactoryparser.Po ./$(DEPDIR)/gfilestore.Po \
-	./$(DEPDIR)/gfilter.Po ./$(DEPDIR)/gfilterfactory.Po \
-	./$(DEPDIR)/ginternalverifier.Po ./$(DEPDIR)/gmessagestore.Po \
-	./$(DEPDIR)/gmessagestore_unix.Po \
+	./$(DEPDIR)/gfilter.Po ./$(DEPDIR)/gfilterchain.Po \
+	./$(DEPDIR)/gfilterfactory.Po ./$(DEPDIR)/ginternalverifier.Po \
+	./$(DEPDIR)/gmessagestore.Po ./$(DEPDIR)/gmessagestore_unix.Po \
 	./$(DEPDIR)/gmessagestore_win32.Po \
 	./$(DEPDIR)/gnetworkfilter.Po ./$(DEPDIR)/gnetworkverifier.Po \
 	./$(DEPDIR)/gnewfile.Po ./$(DEPDIR)/gnewmessage.Po \
@@ -371,24 +372,6 @@ top_srcdir = @top_srcdir@
 @GCONFIG_WINDOWS_TRUE@OS_SOURCES_EXTRA_DIST = gmessagestore_unix.cpp
 ADMIN_SOURCES = gadminserver.cpp gadminserver.h
 ADMIN_EXTRA_DIST = 
-EXEC_SOURCES = \
-	gexecutablefilter.cpp \
-	gexecutablefilter.h \
-	gexecutableverifier.cpp \
-	gexecutableverifier.h \
-	gnetworkfilter.cpp \
-	gnetworkfilter.h \
-	gnetworkverifier.cpp \
-	gnetworkverifier.h \
-	gfilterfactory.cpp \
-	grequestclient.cpp \
-	grequestclient.h \
-	gspamclient.cpp \
-	gspamclient.h \
-	gspamfilter.cpp \
-	gspamfilter.h \
-	gverifierfactory.cpp
-
 EXTRA_DIST = \
 	$(ADMIN_EXTRA_DIST) \
 	$(OS_SOURCES_EXTRA_DIST)
@@ -403,33 +386,45 @@ AM_CPPFLAGS = \
 noinst_LIBRARIES = libgsmtp.a
 libgsmtp_a_SOURCES = \
 	$(ADMIN_SOURCES) \
-	$(EXEC_SOURCES) \
 	$(OS_SOURCES) \
 	genvelope.cpp \
 	genvelope.h \
+	gexecutablefilter.cpp \
+	gexecutablefilter.h \
+	gexecutableverifier.cpp \
+	gexecutableverifier.h \
 	gfactoryparser.cpp \
 	gfactoryparser.h \
 	gfilestore.cpp \
 	gfilestore.h \
 	gfilter.cpp \
 	gfilter.h \
+	gfilterchain.cpp \
+	gfilterchain.h \
+	gfilterfactory.cpp \
 	gfilterfactory.h \
 	ginternalverifier.cpp \
 	ginternalverifier.h \
 	gmessagestore.cpp \
 	gmessagestore.h \
-	gnullfilter.cpp \
-	gnullfilter.h \
+	gnetworkfilter.cpp \
+	gnetworkfilter.h \
+	gnetworkverifier.cpp \
+	gnetworkverifier.h \
 	gnewfile.cpp \
 	gnewfile.h \
 	gnewmessage.cpp \
 	gnewmessage.h \
+	gnullfilter.cpp \
+	gnullfilter.h \
 	gprotocolmessage.cpp \
+	gprotocolmessage.h \
 	gprotocolmessageforward.cpp \
 	gprotocolmessageforward.h \
-	gprotocolmessage.h \
 	gprotocolmessagestore.cpp \
 	gprotocolmessagestore.h \
+	grequestclient.cpp \
+	grequestclient.h \
 	gsmtpclient.cpp \
 	gsmtpclient.h \
 	gsmtpclientprotocol.cpp \
@@ -438,12 +433,17 @@ libgsmtp_a_SOURCES = \
 	gsmtpserver.h \
 	gsmtpserverprotocol.cpp \
 	gsmtpserverprotocol.h \
+	gspamclient.cpp \
+	gspamclient.h \
+	gspamfilter.cpp \
+	gspamfilter.h \
 	gstoredfile.cpp \
 	gstoredfile.h \
 	gstoredmessage.cpp \
 	gstoredmessage.h \
 	gverifier.cpp \
 	gverifier.h \
+	gverifierfactory.cpp \
 	gverifierfactory.h \
 	gverifierstatus.cpp \
 	gverifierstatus.h
@@ -503,6 +503,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gfactoryparser.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gfilestore.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gfilter.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gfilterchain.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gfilterfactory.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ginternalverifier.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gmessagestore.Po@am__quote@ # am--include-marker
@@ -680,6 +681,7 @@ distclean: distclean-am
 	-rm -f ./$(DEPDIR)/gfactoryparser.Po
 	-rm -f ./$(DEPDIR)/gfilestore.Po
 	-rm -f ./$(DEPDIR)/gfilter.Po
+	-rm -f ./$(DEPDIR)/gfilterchain.Po
 	-rm -f ./$(DEPDIR)/gfilterfactory.Po
 	-rm -f ./$(DEPDIR)/ginternalverifier.Po
 	-rm -f ./$(DEPDIR)/gmessagestore.Po
@@ -757,6 +759,7 @@ maintainer-clean: maintainer-clean-am
 	-rm -f ./$(DEPDIR)/gfactoryparser.Po
 	-rm -f ./$(DEPDIR)/gfilestore.Po
 	-rm -f ./$(DEPDIR)/gfilter.Po
+	-rm -f ./$(DEPDIR)/gfilterchain.Po
 	-rm -f ./$(DEPDIR)/gfilterfactory.Po
 	-rm -f ./$(DEPDIR)/ginternalverifier.Po
 	-rm -f ./$(DEPDIR)/gmessagestore.Po
diff --git a/src/gsmtp/gadminserver.cpp b/src/gsmtp/gadminserver.cpp
index c3c0cbf..f74b703 100644
--- a/src/gsmtp/gadminserver.cpp
+++ b/src/gsmtp/gadminserver.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -31,11 +31,11 @@
 #include "gstr.h"
 #include <utility>
 
-GSmtp::AdminServerPeer::AdminServerPeer( GNet::ExceptionSinkUnbound esu , const GNet::ServerPeerInfo & peer_info ,
+GSmtp::AdminServerPeer::AdminServerPeer( GNet::ExceptionSinkUnbound esu , GNet::ServerPeerInfo && peer_info ,
 	AdminServer & server , const std::string & remote_address ,
 	const G::StringMap & info_commands , const G::StringMap & config_commands ,
 	bool with_terminate ) :
-		GNet::ServerPeer(esu.bind(this),peer_info,GNet::LineBufferConfig::autodetect()) ,
+		GNet::ServerPeer(esu.bind(this),std::move(peer_info),GNet::LineBufferConfig::autodetect()) ,
 		m_es(esu.bind(this)) ,
 		m_server(server) ,
 		m_prompt("E-MailRelay> ") ,
@@ -46,7 +46,7 @@ GSmtp::AdminServerPeer::AdminServerPeer( GNet::ExceptionSinkUnbound esu , const
 		m_config_commands(config_commands) ,
 		m_with_terminate(with_terminate)
 {
-	G_LOG_S( "GSmtp::AdminServerPeer: admin connection from " << peer_info.m_address.displayString() ) ;
+	G_LOG_S( "GSmtp::AdminServerPeer: admin connection from " << peerAddress().displayString() ) ;
 	m_client_ptr.deletedSignal().connect( G::Slot::slot(*this,&AdminServerPeer::clientDone) ) ;
 	// dont prompt here -- it confuses some clients
 }
@@ -67,7 +67,7 @@ void GSmtp::AdminServerPeer::clientDone( const std::string & s )
 void GSmtp::AdminServerPeer::onDelete( const std::string & reason )
 {
 	G_LOG_S( "GSmtp::AdminServerPeer: admin connection closed: " << reason << (reason.empty()?"":": ")
-		<< peerAddress().second.displayString() ) ;
+		<< peerAddress().displayString() ) ;
 }
 
 void GSmtp::AdminServerPeer::onSecure( const std::string & , const std::string & , const std::string & )
@@ -122,7 +122,7 @@ bool GSmtp::AdminServerPeer::onReceive( const char * line_data , std::size_t lin
 	else if( is(line,"terminate") && m_with_terminate )
 	{
 		G_LOG_S( "GSmtp::AdminServerPeer::onReceive: received a terminate command from "
-			<< peerAddress().second.displayString() ) ;
+			<< peerAddress().displayString() ) ;
 		if( GNet::EventLoop::exists() )
 			GNet::EventLoop::instance().quit("") ;
 	}
@@ -130,7 +130,7 @@ bool GSmtp::AdminServerPeer::onReceive( const char * line_data , std::size_t lin
 	{
 		std::string arg = argument( line ) ;
 		if( arg.empty() || !find(arg,m_info_commands).first )
-			sendLine( "usage: info {" + G::Str::join("|",G::Str::keySet(m_info_commands)) + "}" ) ;
+			sendLine( "usage: info {" + G::Str::join("|",G::Str::keys(m_info_commands)) + "}" ) ;
 		else
 			sendLine( find(arg,m_info_commands).second ) ;
 	}
@@ -140,7 +140,7 @@ bool GSmtp::AdminServerPeer::onReceive( const char * line_data , std::size_t lin
 		if( arg.empty() )
 			sendLine( G::Str::join( eol() , m_config_commands , "=[" , "]" ) ) ;
 		else if( !find(arg,m_config_commands).first )
-			sendLine( "usage: config [{" + G::Str::join("|",G::Str::keySet(m_config_commands)) + "}]" ) ;
+			sendLine( "usage: config [{" + G::Str::join("|",G::Str::keys(m_config_commands)) + "}]" ) ;
 		else
 			sendLine( find(arg,m_config_commands).second ) ;
 	}
@@ -187,20 +187,20 @@ std::pair<bool,std::string> GSmtp::AdminServerPeer::find( const std::string & li
 
 void GSmtp::AdminServerPeer::help()
 {
-	std::set<std::string> commands ;
-	commands.insert( "flush" ) ;
-	commands.insert( "forward" ) ;
-	commands.insert( "help" ) ;
-	commands.insert( "status" ) ;
-	commands.insert( "list" ) ;
-	commands.insert( "failures" ) ;
-	commands.insert( "unfail-all" ) ;
-	commands.insert( "notify" ) ;
-	commands.insert( "pid" ) ;
-	commands.insert( "quit" ) ;
-	if( !m_info_commands.empty() ) commands.insert( "info" ) ;
-	if( !m_config_commands.empty() ) commands.insert( "config" ) ;
-	if( m_with_terminate ) commands.insert( "terminate" ) ;
+	G::StringArray commands ;
+	commands.push_back( "flush" ) ;
+	commands.push_back( "forward" ) ;
+	commands.push_back( "help" ) ;
+	commands.push_back( "status" ) ;
+	commands.push_back( "list" ) ;
+	commands.push_back( "failures" ) ;
+	commands.push_back( "unfail-all" ) ;
+	commands.push_back( "notify" ) ;
+	commands.push_back( "pid" ) ;
+	commands.push_back( "quit" ) ;
+	if( !m_info_commands.empty() ) commands.push_back( "info" ) ;
+	if( !m_config_commands.empty() ) commands.push_back( "config" ) ;
+	if( m_with_terminate ) commands.push_back( "terminate" ) ;
 	sendLine( std::string("commands: ") + G::Str::join(", ",commands) ) ;
 }
 
@@ -341,7 +341,7 @@ bool GSmtp::AdminServerPeer::notifying() const
 
 GSmtp::AdminServer::AdminServer( GNet::ExceptionSink es , MessageStore & store ,
 	FilterFactory & ff , G::Slot::Signal<const std::string&> & forward_request ,
-	const GNet::ServerPeerConfig & server_peer_config , const GNet::ServerConfig & server_config ,
+	const GNet::ServerPeer::Config & server_peer_config , const GNet::Server::Config & server_config ,
 	const GSmtp::Client::Config & client_config , const GAuth::SaslClientSecrets & client_secrets ,
 	const G::StringArray & interfaces , unsigned int port , bool allow_remote ,
 	const std::string & remote_address , unsigned int connection_timeout ,
@@ -369,7 +369,7 @@ GSmtp::AdminServer::~AdminServer()
 }
 
 std::unique_ptr<GNet::ServerPeer> GSmtp::AdminServer::newPeer( GNet::ExceptionSinkUnbound esu ,
-	GNet::ServerPeerInfo peer_info , GNet::MultiServer::ServerInfo )
+	GNet::ServerPeerInfo && peer_info , GNet::MultiServer::ServerInfo )
 {
 	std::unique_ptr<GNet::ServerPeer> ptr ;
 	try
@@ -381,7 +381,7 @@ std::unique_ptr<GNet::ServerPeer> GSmtp::AdminServer::newPeer( GNet::ExceptionSi
 		}
 		else
 		{
-			ptr = std::make_unique<AdminServerPeer>( esu , peer_info , *this , m_remote_address ,
+			ptr = std::make_unique<AdminServerPeer>( esu , std::move(peer_info) , *this , m_remote_address ,
 				m_info_commands , m_config_commands , m_with_terminate ) ; // up-cast
 		}
 	}
diff --git a/src/gsmtp/gadminserver.h b/src/gsmtp/gadminserver.h
index 4afe861..578bcaf 100644
--- a/src/gsmtp/gadminserver.h
+++ b/src/gsmtp/gadminserver.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -25,6 +25,8 @@
 #include "gmultiserver.h"
 #include "gtimer.h"
 #include "gstr.h"
+#include "gstringarray.h"
+#include "gstringmap.h"
 #include "glinebuffer.h"
 #include "gsmtpserverprotocol.h"
 #include "gclientptr.h"
@@ -52,7 +54,7 @@ namespace GSmtp
 class GSmtp::AdminServerPeer : public GNet::ServerPeer
 {
 public:
-	AdminServerPeer( GNet::ExceptionSinkUnbound , const GNet::ServerPeerInfo & , AdminServer & ,
+	AdminServerPeer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo && , AdminServer & ,
 		const std::string & remote , const G::StringMap & info_commands ,
 		const G::StringMap & config_commands , bool with_terminate ) ;
 			///< Constructor.
@@ -77,8 +79,8 @@ private: // overrides
 public:
 	AdminServerPeer( const AdminServerPeer & ) = delete ;
 	AdminServerPeer( AdminServerPeer && ) = delete ;
-	void operator=( const AdminServerPeer & ) = delete ;
-	void operator=( AdminServerPeer && ) = delete ;
+	AdminServerPeer & operator=( const AdminServerPeer & ) = delete ;
+	AdminServerPeer & operator=( AdminServerPeer && ) = delete ;
 
 private:
 	void clientDone( const std::string & ) ;
@@ -121,7 +123,7 @@ class GSmtp::AdminServer : public GNet::MultiServer
 public:
 	AdminServer( GNet::ExceptionSink , MessageStore & store , FilterFactory & ff ,
 		G::Slot::Signal<const std::string&> & forward_request ,
-		const GNet::ServerPeerConfig & server_peer_config , const GNet::ServerConfig & server_config ,
+		const GNet::ServerPeer::Config & server_peer_config , const GNet::Server::Config & server_config ,
 		const GSmtp::Client::Config & client_config , const GAuth::SaslClientSecrets & client_secrets ,
 		const G::StringArray & interfaces , unsigned int port , bool allow_remote ,
 		const std::string & remote_address , unsigned int connection_timeout ,
@@ -167,14 +169,14 @@ public:
 			///< users might be interested in.
 
 protected:
-	std::unique_ptr<GNet::ServerPeer> newPeer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo , GNet::MultiServer::ServerInfo ) override ;
+	std::unique_ptr<GNet::ServerPeer> newPeer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo && , GNet::MultiServer::ServerInfo ) override ;
 		///< Override from GNet::MultiServer.
 
 public:
 	AdminServer( const AdminServer & ) = delete ;
 	AdminServer( AdminServer && ) = delete ;
-	void operator=( const AdminServer & ) = delete ;
-	void operator=( AdminServer && ) = delete ;
+	AdminServer & operator=( const AdminServer & ) = delete ;
+	AdminServer & operator=( AdminServer && ) = delete ;
 
 private:
 	void onForwardTimeout() ;
diff --git a/src/gsmtp/genvelope.cpp b/src/gsmtp/genvelope.cpp
index 9f11e80..8c35cb4 100644
--- a/src/gsmtp/genvelope.cpp
+++ b/src/gsmtp/genvelope.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -38,6 +38,8 @@ namespace GSmtp
 		void readFrom( std::istream & , Envelope & ) ;
 		void readFromAuthIn( std::istream & , Envelope & ) ;
 		void readFromAuthOut( std::istream & , Envelope & ) ;
+		void readForwardTo( std::istream & , Envelope & ) ;
+		void readForwardToAddress( std::istream & , Envelope & ) ;
 		void readToList( std::istream & , Envelope & ) ;
 		void readAuthentication( std::istream & , Envelope & ) ;
 		void readClientSocketAddress( std::istream & , Envelope & ) ;
@@ -76,6 +78,8 @@ std::size_t GSmtp::Envelope::write( std::ostream & stream , const GSmtp::Envelop
 	stream << x << "ClientCertificate: " << imp::folded(e.m_client_certificate) << crlf ;
 	stream << x << "MailFromAuthIn: " << imp::xnormalise(e.m_from_auth_in) << crlf ;
 	stream << x << "MailFromAuthOut: " << imp::xnormalise(e.m_from_auth_out) << crlf ;
+	stream << x << "ForwardTo: " << imp::xnormalise(e.m_forward_to) << crlf ;
+	stream << x << "ForwardToAddress: " << e.m_forward_to_address << crlf ;
 	stream << x << "End: 1" << crlf ;
 	stream.flush() ;
 	return stream.fail() ? std::size_t(0U) : static_cast<std::size_t>( stream.tellp() - pos ) ;
@@ -114,8 +118,16 @@ void GSmtp::Envelope::read( std::istream & stream , GSmtp::Envelope & e )
 		imp::readClientCertificate( stream , e ) ;
 		imp::readFromAuthIn( stream , e ) ;
 		imp::readFromAuthOut( stream , e ) ;
+		imp::readForwardTo( stream , e ) ; // 2.4
+		imp::readForwardToAddress( stream , e ) ; // 2.4
 	}
 	else if( format == GSmtp::FileStore::format(-1) )
+	{
+		imp::readClientCertificate( stream , e ) ;
+		imp::readFromAuthIn( stream , e ) ;
+		imp::readFromAuthOut( stream , e ) ;
+	}
+	else if( format == GSmtp::FileStore::format(-2) )
 	{
 		imp::readClientSocketName( stream , e ) ;
 		imp::readClientCertificate( stream , e ) ;
@@ -182,6 +194,16 @@ void GSmtp::EnvelopeImp::readFromAuthOut( std::istream & stream , Envelope & e )
 		throw Envelope::ReadError( "invalid mail-from-auth-out encoding" ) ;
 }
 
+void GSmtp::EnvelopeImp::readForwardTo( std::istream & stream , Envelope & e )
+{
+	e.m_forward_to = readValue( stream , "ForwardTo" ) ;
+}
+
+void GSmtp::EnvelopeImp::readForwardToAddress( std::istream & stream , Envelope & e )
+{
+	e.m_forward_to_address = readValue( stream , "ForwardToAddress" ) ;
+}
+
 void GSmtp::EnvelopeImp::readToList( std::istream & stream , Envelope & e )
 {
 	e.m_to_local.clear() ;
diff --git a/src/gsmtp/genvelope.h b/src/gsmtp/genvelope.h
index f7adf6b..5308378 100644
--- a/src/gsmtp/genvelope.h
+++ b/src/gsmtp/genvelope.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,7 +22,7 @@
 #define G_SMTP_ENVELOPE_H
 
 #include "gdef.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gexception.h"
 #include <iostream>
 
@@ -38,7 +38,7 @@ namespace GSmtp
 class GSmtp::Envelope
 {
 public:
-	G_EXCEPTION( ReadError , "cannot read envelope file" ) ;
+	G_EXCEPTION( ReadError , tx("cannot read envelope file") ) ;
 
 public:
 	static void read( std::istream & , Envelope & ) ;
@@ -69,6 +69,8 @@ public:
 	std::string m_client_certificate ;
 	std::string m_from_auth_in ;
 	std::string m_from_auth_out ;
+	std::string m_forward_to ;
+	std::string m_forward_to_address ;
 	std::size_t m_endpos{0U} ;
 } ;
 
diff --git a/src/gsmtp/gexecutablefilter.cpp b/src/gsmtp/gexecutablefilter.cpp
index 960cadc..5281a0f 100644
--- a/src/gsmtp/gexecutablefilter.cpp
+++ b/src/gsmtp/gexecutablefilter.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -30,10 +30,11 @@
 #include <tuple>
 
 GSmtp::ExecutableFilter::ExecutableFilter( GNet::ExceptionSink es , FileStore & file_store ,
-	bool server_side , const std::string & path , unsigned int timeout ) :
+	bool server_side , const std::string & path , unsigned int timeout ,
+	const std::string & log_prefix ) :
 		m_file_store(file_store) ,
 		m_server_side(server_side) ,
-		m_prefix(server_side?"filter":"client filter") ,
+		m_prefix(log_prefix.empty()?std::string(server_side?"filter":"client filter"):log_prefix) ,
 		m_exit(0,server_side) ,
 		m_path(path) ,
 		m_timeout(timeout) ,
@@ -142,7 +143,7 @@ std::pair<std::string,std::string> GSmtp::ExecutableFilter::parseOutput( std::st
 	G::StringArray lines ;
 	while( G::Str::replaceAll( s , "\r\n" , "\n" ) ) {;}
 	G::Str::replaceAll( s , "\r" , "\n" ) ;
-	G::Str::splitIntoFields( s , lines , "\n" ) ;
+	G::Str::splitIntoFields( s , lines , '\n' ) ;
 
 	for( auto p = lines.begin() ; p != lines.end() ; )
 	{
diff --git a/src/gsmtp/gexecutablefilter.h b/src/gsmtp/gexecutablefilter.h
index 68a2ab4..3c6803b 100644
--- a/src/gsmtp/gexecutablefilter.h
+++ b/src/gsmtp/gexecutablefilter.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -43,7 +43,8 @@ class GSmtp::ExecutableFilter : public Filter, private GNet::TaskCallback
 {
 public:
 	ExecutableFilter( GNet::ExceptionSink , FileStore & , bool server_side ,
-		const std::string & path , unsigned int timeout ) ;
+		const std::string & path , unsigned int timeout ,
+		const std::string & log_prefix ) ;
 			///< Constructor.
 
 	~ExecutableFilter() override ;
@@ -64,8 +65,8 @@ private: // overrides
 public:
 	ExecutableFilter( const ExecutableFilter & ) = delete ;
 	ExecutableFilter( ExecutableFilter && ) = delete ;
-	void operator=( const ExecutableFilter & ) = delete ;
-	void operator=( ExecutableFilter && ) = delete ;
+	ExecutableFilter & operator=( const ExecutableFilter & ) = delete ;
+	ExecutableFilter & operator=( ExecutableFilter && ) = delete ;
 
 private:
 	std::pair<std::string,std::string> parseOutput( std::string , const std::string & ) const ;
diff --git a/src/gsmtp/gexecutableverifier.cpp b/src/gsmtp/gexecutableverifier.cpp
index 7e59a34..3d14260 100644
--- a/src/gsmtp/gexecutableverifier.cpp
+++ b/src/gsmtp/gexecutableverifier.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -65,7 +65,7 @@ void GSmtp::ExecutableVerifier::onTaskDone( int exit_code , const std::string &
 
 	G::StringArray result_parts ;
 	result_parts.reserve( 2U ) ;
-	G::Str::splitIntoFields( result , result_parts , {"\n",1U} ) ;
+	G::Str::splitIntoFields( result , result_parts , '\n' ) ;
 	std::size_t parts = result_parts.size() ;
 	result_parts.resize( 2U ) ;
 
diff --git a/src/gsmtp/gexecutableverifier.h b/src/gsmtp/gexecutableverifier.h
index a7d9bf3..e52a52f 100644
--- a/src/gsmtp/gexecutableverifier.h
+++ b/src/gsmtp/gexecutableverifier.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -52,8 +52,8 @@ public:
 	~ExecutableVerifier() override = default ;
 	ExecutableVerifier( const ExecutableVerifier & ) = delete ;
 	ExecutableVerifier( ExecutableVerifier && ) = delete ;
-	void operator=( const ExecutableVerifier & ) = delete ;
-	void operator=( ExecutableVerifier && ) = delete ;
+	ExecutableVerifier & operator=( const ExecutableVerifier & ) = delete ;
+	ExecutableVerifier & operator=( ExecutableVerifier && ) = delete ;
 
 private:
 	G::Path m_path ;
diff --git a/src/gsmtp/gfactoryparser.cpp b/src/gsmtp/gfactoryparser.cpp
index ed7a9eb..f77dba5 100644
--- a/src/gsmtp/gfactoryparser.cpp
+++ b/src/gsmtp/gfactoryparser.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,75 +23,136 @@
 #include "gaddress.h"
 #include "gresolver.h"
 #include "gexecutablecommand.h"
+#include "glocation.h"
+#include "gstringtoken.h"
 #include "gstr.h"
 #include "gfile.h"
 #include "glog.h"
 
-GSmtp::FactoryParser::Result GSmtp::FactoryParser::parse( const std::string & identifier , bool allow_spam )
+GSmtp::FactoryParser::Result GSmtp::FactoryParser::parse( const std::string & spec , bool is_filter ,
+	const G::Path & base_dir , const G::Path & app_dir , G::StringArray * warnings_p )
 {
-	G_DEBUG( "GSmtp::FactoryParser::parse: [" << identifier << "]" ) ;
-	if( identifier.find("net:") == 0U )
+	bool allow_spam = is_filter ;
+	bool allow_chain = is_filter ;
+	return parseImp( spec , is_filter , base_dir , app_dir , warnings_p , allow_spam , allow_chain ) ;
+}
+
+GSmtp::FactoryParser::Result GSmtp::FactoryParser::parseImp( const std::string & spec , bool is_filter ,
+	const G::Path & base_dir , const G::Path & app_dir , G::StringArray * warnings_p ,
+	bool allow_spam , bool allow_chain )
+{
+	//G_DEBUG( "GSmtp::FactoryParser::parse: [" << spec << "]" ) ;
+	Result result ;
+	if( spec.empty() )
 	{
-		return Result( "net" , G::Str::tail(identifier,":") ) ;
+		result = Result( "exit" , "0" ) ;
 	}
-	else if( allow_spam && identifier.find("spam:") == 0U )
+	else if( allow_chain && spec.find(',') != std::string::npos )
 	{
-		return Result( "spam" , G::Str::tail(identifier,":") , 0 ) ;
+		std::string new_spec ;
+		std::string error ;
+		for( G::StringToken t( spec , ","_sv ) ; t ; ++t )
+		{
+			// (one level of recursion)
+			Result sub_result = parseImp( t() , is_filter , base_dir , app_dir , warnings_p , allow_spam , false ) ;
+			if( sub_result.first.empty() )
+				error = sub_result.second ;
+			new_spec.append(",",new_spec.empty()?0U:1U).append(sub_result.first).append(1U,':').append(sub_result.second) ;
+		}
+		result = error.empty() ? Result( "chain" , new_spec ) : Result( "" , error ) ;
 	}
-	else if( allow_spam && identifier.find("spam-edit:") == 0U )
+	else if( spec.find("net:") == 0U )
 	{
-		return Result( "spam" , G::Str::tail(identifier,":") , 1 ) ;
+		result = Result( "net" , G::Str::tail(spec,":") ) ;
 	}
-	else if( identifier.find("file:") == 0U )
+	else if( allow_spam && spec.find("spam:") == 0U )
 	{
-		return Result( "file" , G::Str::tail(identifier,":") ) ;
+		result = Result( "spam" , G::Str::tail(spec,":") , 0 ) ;
 	}
-	else if( identifier.find("exit:") == 0U )
+	else if( allow_spam && spec.find("spam-edit:") == 0U )
 	{
-		return Result( "exit" , G::Str::tail(identifier,":") ) ;
+		result = Result( "spam" , G::Str::tail(spec,":") , 1 ) ;
 	}
-	else if( !identifier.empty() )
+	else if( spec.find("exit:") == 0U )
 	{
-		return Result( "file" , identifier ) ;
+		result = Result( "exit" , G::Str::tail(spec,":") ) ;
+	}
+	else if( spec.find("file:") == 0U )
+	{
+		result = Result( "file" , G::Str::tail(spec,":") ) ;
 	}
 	else
 	{
-		return Result() ;
+		result = Result( "file" , spec ) ;
+	}
+	normalise( result , base_dir , app_dir ) ;
+	check( result , is_filter , warnings_p ) ;
+	//G_DEBUG( "GSmtp::FactoryParser::parse: [" << spec << "] -> [" << result.first << "],[" << result.second << "]" ) ;
+	return result ;
+}
+
+void GSmtp::FactoryParser::normalise( Result & result , const G::Path & base_dir , const G::Path & app_dir )
+{
+	if( result.first == "file" )
+	{
+		if( !app_dir.empty() && result.second.find("@app") == 0U )
+		{
+			G::Str::replace( result.second , "@app" , app_dir.str() ) ;
+		}
+		else if( !base_dir.empty() && G::Path(result.second).isRelative() )
+		{
+			result.second = (base_dir+result.second).str() ;
+		}
 	}
 }
 
-std::string GSmtp::FactoryParser::check( const std::string & identifier , bool allow_spam )
+void GSmtp::FactoryParser::check( Result & result , bool is_filter , G::StringArray * warnings_p )
 {
-	Result p = parse( identifier , allow_spam ) ;
-	if( p.first == "net" || ( allow_spam && p.first == "spam" ) )
+	if( result.first == "chain" )
 	{
-		return std::string() ;
+		// no-op -- sub-parts already checked
 	}
-	else if( p.first == "file" )
+	else if( result.first == "file" )
 	{
-		G::Path exe = p.second ;
-		if( !G::File::exists(exe,std::nothrow) )
-			return "no such file" ;
-		else if( !G::is_windows() && !G::File::isExecutable(exe,std::nothrow) )
-			return "probably not executable" ;
-		else if( !exe.isAbsolute() )
-			return "not an absolute path" ;
-		else
-			return std::string() ;
+		if( result.second.empty() )
+		{
+			result.first.clear() ;
+			result.second = "empty file path" ;
+		}
+		else if( warnings_p && !G::File::exists(result.second) )
+		{
+			warnings_p->push_back( std::string(is_filter?"filter":"verifier")
+				.append(" program does not exist: ").append(result.second) ) ;
+		}
+		else if( warnings_p && G::File::isDirectory(result.second,std::nothrow) )
+		{
+			warnings_p->push_back( std::string("invalid program: ").append(result.second) ) ;
+		}
 	}
-	else if( p.first == "exit" )
+	else if( result.first == "exit" )
 	{
-		if( !G::Str::isUInt(p.second) )
-			return "not a numeric exit code" ;
-		else
-			return std::string() ;
+		if( !G::Str::isUInt(result.second) )
+		{
+			result.first.clear() ;
+			result.second = "not a numeric exit code: " + G::Str::printable(result.second) ;
+		}
 	}
-	else
+	else if( result.first == "net" || result.first == "spam" )
 	{
-		return std::string() ;
+		try
+		{
+			GNet::Location::nosocks( result.second ) ;
+		}
+		catch( std::exception & e )
+		{
+			result.first.clear() ;
+			result.second = e.what() ;
+		}
 	}
 }
 
+// ==
+
 GSmtp::FactoryParser::Result::Result()
 = default ;
 
diff --git a/src/gsmtp/gfactoryparser.h b/src/gsmtp/gfactoryparser.h
index a320383..c60fdb4 100644
--- a/src/gsmtp/gfactoryparser.h
+++ b/src/gsmtp/gfactoryparser.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,6 +22,10 @@
 #define G_SMTP_FACTORY_PARSER_H
 
 #include "gdef.h"
+#include "ggettext.h"
+#include "gpath.h"
+#include "gstringarray.h"
+#include "gexception.h"
 #include <utility>
 #include <string>
 
@@ -31,37 +35,57 @@ namespace GSmtp
 }
 
 //| \class GSmtp::FactoryParser
-/// A simple static class to parse identifiers that are either a
-/// program path or a network address. Used by the filter factory
-/// and the address-verifier factory.
+/// A static class to parse filter and verifier specifications that are
+/// either a program path or a network address etc. Used by the filter
+/// factory and the address-verifier factory classes.
 ///
 class GSmtp::FactoryParser
 {
 public:
+	G_EXCEPTION( Error , tx("invalid specification") ) ;
+
 	struct Result /// Result tuple for GSmtp::FactoryParser::parse().
 	{
 		Result() ;
 		Result( const std::string & , const std::string & ) ;
 		Result( const std::string & , const std::string & , int ) ;
-		std::string first ; // eg. "file", "net", "spam"
-		std::string second ; // eg. "localhost:99"
+		std::string first ; // "exit", "file", "net", "spam", "chain", empty on error
+		std::string second ; // reason on error, or eg. "/bin/a" if "file", eg. "file:/bin/a,file:/bin/b" if "chain"
 		int third{0} ; // eg. 1 for spam-edit
 	} ;
 
-	static Result parse( const std::string & identifier , bool allow_spam ) ;
-		///< Parses an identifier like "/usr/bin/foo" or "net:127.0.0.1:99"
-		///< or "net:/run/spamd.s", returning the type and the specification
-		///< in a result tuple, eg. ("file","/usr/bin/foo") or
-		///< ("net","127.0.0.1:99"). Returns a default-constructed Result
-		///< if not parsable.
-
-	static std::string check( const std::string & identifier , bool allow_spam ) ;
-		///< Parses and checks an identifier. Returns a diagnostic if
-		///< the identifier is invalid, or the empty string if valid
-		///< or empty.
+	static Result parse( const std::string & spec , bool is_filter ,
+		const G::Path & base_dir = {} , const G::Path & app_dir = {} ,
+		G::StringArray * warnings_p = nullptr ) ;
+			///< Parses a filter or verifier specification like "/usr/bin/foo" or
+			///< "net:127.0.0.1:99" or "net:/run/spamd.s", returning the
+			///< type and value in a result tuple, eg. ("file","/usr/bin/foo")
+			///< or ("net","127.0.0.1:99").
+			///<
+			///< If 'is-filter' then the spec can be a comma-separated list with
+			///< the component parts checked separately and the returned Result
+			///< is like ("chain","file:foo,net:bar").
+			///<
+			///< Any relative file paths are made absolute using the given
+			///< base directory, if given. (This is normally from
+			///< G::Process::cwd() called at startup).
+			///<
+			///< Any "@app" sub-strings in file paths are substituted with
+			///< the given application directory, if given.
+			///<
+			///< Returns 'first' empty if a fatal parsing error, with the
+			///< reason in 'second'.
+			///<
+			///< Returns warnings by reference for non-fatal errors, such
+			///< as missing files.
 
 public:
 	FactoryParser() = delete ;
+
+private:
+	static Result parseImp( const std::string & , bool , const G::Path & , const G::Path & , G::StringArray * , bool , bool ) ;
+	static void normalise( Result & , const G::Path & , const G::Path & ) ;
+	static void check( Result & , bool , G::StringArray * ) ;
 } ;
 
 #endif
diff --git a/src/gsmtp/gfilestore.cpp b/src/gsmtp/gfilestore.cpp
index e3d0902..fe2c44b 100644
--- a/src/gsmtp/gfilestore.cpp
+++ b/src/gsmtp/gfilestore.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -53,8 +53,8 @@ private: // overrides
 public:
 	FileIterator( const FileIterator & ) = delete ;
 	FileIterator( FileIterator && ) = delete ;
-	void operator=( const FileIterator & ) = delete ;
-	void operator=( FileIterator && ) = delete ;
+	FileIterator & operator=( const FileIterator & ) = delete ;
+	FileIterator & operator=( FileIterator && ) = delete ;
 
 private:
 	FileStore & m_store ;
@@ -134,12 +134,14 @@ std::string GSmtp::FileStore::x()
 std::string GSmtp::FileStore::format( int generation )
 {
 	// use a weird prefix to help with file(1) and magic(5)
-	if( generation == -2 )
+	if( generation == -3 )
 		return "#2821.3" ; // original
-	else if( generation == -1 )
+	else if( generation == -2 )
 		return "#2821.4" ; // new for 1.9
-	else
+	else if( generation == -1 )
 		return "#2821.5" ; // new for 2.0
+	else
+		return "#2821.6" ; // new for 2.4
 }
 
 bool GSmtp::FileStore::knownFormat( const std::string & format_in )
@@ -147,7 +149,8 @@ bool GSmtp::FileStore::knownFormat( const std::string & format_in )
 	return
 		format_in == format(0) ||
 		format_in == format(-1) ||
-		format_in == format(-2) ;
+		format_in == format(-2) ||
+		format_in == format(-3) ;
 }
 
 void GSmtp::FileStore::checkPath( const G::Path & directory_path )
@@ -177,8 +180,8 @@ void GSmtp::FileStore::checkPath( const G::Path & directory_path )
 	if( !ok )
 	{
 		using G::format ;
-		using G::gettext ;
-		G_WARNING( "GSmtp::MessageStore: " << format(gettext("directory not writable: \"%1%\"")) % directory_path ) ;
+		using G::txt ;
+		G_WARNING( "GSmtp::MessageStore: " << format(txt("directory not writable: \"%1%\"")) % directory_path ) ;
 	}
 }
 
diff --git a/src/gsmtp/gfilestore.h b/src/gsmtp/gfilestore.h
index 43c503e..de6c5e4 100644
--- a/src/gsmtp/gfilestore.h
+++ b/src/gsmtp/gfilestore.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -57,8 +57,8 @@ namespace GSmtp
 class GSmtp::FileStore : public MessageStore
 {
 public:
-	G_EXCEPTION( InvalidDirectory , "invalid spool directory" ) ;
-	G_EXCEPTION( GetError , "error reading specific message" ) ;
+	G_EXCEPTION( InvalidDirectory , tx("invalid spool directory") ) ;
+	G_EXCEPTION( GetError , tx("error reading specific message") ) ;
 
 	FileStore( const G::Path & dir , unsigned long max_size , bool test_for_eight_bit ) ;
 		///< Constructor. Throws an exception if the storage directory
@@ -123,8 +123,8 @@ public:
 	~FileStore() override = default ;
 	FileStore( const FileStore & ) = delete ;
 	FileStore( FileStore && ) = delete ;
-	void operator=( const FileStore & ) = delete ;
-	void operator=( FileStore && ) = delete ;
+	FileStore & operator=( const FileStore & ) = delete ;
+	FileStore & operator=( FileStore && ) = delete ;
 
 private:
 	static void checkPath( const G::Path & dir ) ;
@@ -166,8 +166,8 @@ public:
 public:
 	FileReader( const FileReader & ) = delete ;
 	FileReader( FileReader && ) = delete ;
-	void operator=( const FileReader & ) = delete ;
-	void operator=( FileReader && ) = delete ;
+	FileReader & operator=( const FileReader & ) = delete ;
+	FileReader & operator=( FileReader && ) = delete ;
 } ;
 
 //| \class GSmtp::DirectoryReader
@@ -188,8 +188,8 @@ public:
 public:
 	DirectoryReader( const DirectoryReader & ) = delete ;
 	DirectoryReader( DirectoryReader && ) = delete ;
-	void operator=( const DirectoryReader & ) = delete ;
-	void operator=( DirectoryReader && ) = delete ;
+	DirectoryReader & operator=( const DirectoryReader & ) = delete ;
+	DirectoryReader & operator=( DirectoryReader && ) = delete ;
 } ;
 
 //| \class GSmtp::FileWriter
@@ -210,8 +210,8 @@ public:
 public:
 	FileWriter( const FileWriter & ) = delete ;
 	FileWriter( FileWriter && ) = delete ;
-	void operator=( const FileWriter & ) = delete ;
-	void operator=( FileWriter && ) = delete ;
+	FileWriter & operator=( const FileWriter & ) = delete ;
+	FileWriter & operator=( FileWriter && ) = delete ;
 } ;
 
 #endif
diff --git a/src/gsmtp/gfilter.cpp b/src/gsmtp/gfilter.cpp
index 485c8b4..bad53ee 100644
--- a/src/gsmtp/gfilter.cpp
+++ b/src/gsmtp/gfilter.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/gfilter.h b/src/gsmtp/gfilter.h
index 86616b1..21cf07b 100644
--- a/src/gsmtp/gfilter.h
+++ b/src/gsmtp/gfilter.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/gfilterchain.cpp b/src/gsmtp/gfilterchain.cpp
new file mode 100644
index 0000000..6618cc4
--- /dev/null
+++ b/src/gsmtp/gfilterchain.cpp
@@ -0,0 +1,145 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file gfilterchain.cpp
+///
+
+#include "gdef.h"
+#include "gfilterchain.h"
+#include "gslot.h"
+#include "gstringtoken.h"
+#include "gstr.h"
+#include <utility>
+#include <algorithm>
+
+GSmtp::FilterChain::FilterChain( GNet::ExceptionSink es , FilterFactory & ff ,
+	bool server_side , const FactoryParser::Result & spec , unsigned int timeout ,
+	const std::string & log_prefix ) :
+		m_filter_index(0U) ,
+		m_filter(nullptr) ,
+		m_running(false) ,
+		m_message_id(MessageId::none())
+{
+	G_ASSERT( spec.first == "chain" ) ;
+	for( G::StringToken t( spec.second , ","_sv ) ; t ; ++t )
+		add( es , ff , server_side , FactoryParser::parse(t(),true) , timeout , log_prefix ) ;
+
+	if( m_filters.empty() )
+		add( es , ff , server_side , {"exit","0"} , timeout , log_prefix ) ;
+}
+
+void GSmtp::FilterChain::add( GNet::ExceptionSink es , FilterFactory & ff ,
+	bool server_side , const FactoryParser::Result & spec , unsigned int timeout ,
+	const std::string & log_prefix )
+{
+	m_filters.push_back( ff.newFilter( es , server_side , spec , timeout , log_prefix ) ) ;
+	m_filter_id.append(m_filter_id.empty()?0U:1U,',').append( m_filters.back()->id() ) ;
+}
+
+GSmtp::FilterChain::~FilterChain()
+{
+	if( m_filter )
+		m_filter->doneSignal().disconnect() ;
+}
+
+std::string GSmtp::FilterChain::id() const
+{
+	return m_filter_id ;
+}
+
+bool GSmtp::FilterChain::simple() const
+{
+	return std::all_of( m_filters.begin() , m_filters.end() ,
+		[](const std::unique_ptr<Filter> & ptr){ return ptr->simple() ; } ) ;
+}
+
+G::Slot::Signal<int> & GSmtp::FilterChain::doneSignal()
+{
+	return m_done_signal ;
+}
+
+void GSmtp::FilterChain::start( const MessageId & id )
+{
+	if( m_running )
+	{
+		m_filter->cancel() ;
+		m_filter->doneSignal().disconnect() ;
+	}
+	m_running = true ;
+	m_message_id = id ;
+	m_filter_index = 0U ;
+	m_filter = m_filters.at(0U).get() ;
+	m_filter->doneSignal().connect( G::Slot::slot(*this,&FilterChain::onFilterDone) ) ;
+	m_filter->start( m_message_id ) ;
+}
+
+void GSmtp::FilterChain::onFilterDone( int ok_abandon_fail )
+{
+	m_filter->doneSignal().disconnect() ;
+	if( ok_abandon_fail == 0 ) // ok
+	{
+		m_filter_index++ ;
+		G_ASSERT( m_filter_index <= m_filters.size() ) ;
+		if( m_filter_index >= m_filters.size() )
+		{
+			m_running = false ;
+			m_done_signal.emit( 0 ) ;
+		}
+		else
+		{
+			m_filter = m_filters.at(m_filter_index).get() ;
+			m_filter->doneSignal().connect( G::Slot::slot(*this,&FilterChain::onFilterDone) ) ;
+			m_filter->start( m_message_id ) ;
+		}
+	}
+	else // abandon/fail
+	{
+		m_running = false ;
+		m_done_signal.emit( ok_abandon_fail ) ;
+	}
+}
+
+void GSmtp::FilterChain::cancel()
+{
+	if( m_running )
+	{
+		m_filter->cancel() ;
+		m_filter->doneSignal().disconnect() ;
+	}
+	m_running = false ;
+}
+
+bool GSmtp::FilterChain::abandoned() const
+{
+	return m_filter->abandoned() ;
+}
+
+std::string GSmtp::FilterChain::response() const
+{
+	return m_filter->response() ;
+}
+
+std::string GSmtp::FilterChain::reason() const
+{
+	return m_filter->reason() ;
+}
+
+bool GSmtp::FilterChain::special() const
+{
+	return m_filter->special() ;
+}
+
diff --git a/src/gsmtp/gfilterchain.h b/src/gsmtp/gfilterchain.h
new file mode 100644
index 0000000..794ea6f
--- /dev/null
+++ b/src/gsmtp/gfilterchain.h
@@ -0,0 +1,86 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file gfilterchain.h
+///
+
+#ifndef G_SMTP_FILTER_CHAIN_H
+#define G_SMTP_FILTER_CHAIN_H
+
+#include "gdef.h"
+#include "gfilter.h"
+#include "gfilterfactory.h"
+#include "gfactoryparser.h"
+#include "gtimer.h"
+#include "gslot.h"
+#include "gexceptionsink.h"
+#include <memory>
+#include <vector>
+
+namespace GSmtp
+{
+	class FilterChain ;
+	class FileStore ;
+}
+
+//| \class GSmtp::FilterChain
+/// A Filter class that runs a sequence of sub-filters. The sub-filters are run
+/// in sequence only as long as they return success.
+///
+class GSmtp::FilterChain : public Filter
+{
+public:
+	FilterChain( GNet::ExceptionSink , FilterFactory & , bool server_side ,
+		const FactoryParser::Result & spec , unsigned int timeout ,
+		const std::string & log_prefix ) ;
+			///< Constructor.
+
+	~FilterChain() override ;
+		///< Destructor.
+
+public:
+	FilterChain( const FilterChain & ) = delete ;
+	FilterChain( FilterChain && ) = delete ;
+	FilterChain & operator=( const FilterChain & ) = delete ;
+	FilterChain & operator=( FilterChain && ) = delete ;
+
+private: // overrides
+	std::string id() const override ; // Override from from GSmtp::Filter.
+	bool simple() const override ; // Override from from GSmtp::Filter.
+	G::Slot::Signal<int> & doneSignal() override ; // Override from from GSmtp::Filter.
+	void start( const MessageId & ) override ; // Override from from GSmtp::Filter.
+	void cancel() override ; // Override from from GSmtp::Filter.
+	bool abandoned() const override ; // Override from from GSmtp::Filter.
+	std::string response() const override ; // Override from from GSmtp::Filter.
+	std::string reason() const override ; // Override from from GSmtp::Filter.
+	bool special() const override ; // Override from from GSmtp::Filter.
+
+private:
+	void add( GNet::ExceptionSink , FilterFactory & , bool , const FactoryParser::Result & , unsigned int , const std::string & ) ;
+	void onFilterDone( int ) ;
+
+private:
+	G::Slot::Signal<int> m_done_signal ;
+	std::string m_filter_id ;
+	std::vector<std::unique_ptr<Filter>> m_filters ;
+	std::size_t m_filter_index ;
+	Filter * m_filter ;
+	bool m_running ;
+	MessageId m_message_id ;
+} ;
+
+#endif
diff --git a/src/gsmtp/gfilterfactory.cpp b/src/gsmtp/gfilterfactory.cpp
index bf109f7..6b52986 100644
--- a/src/gsmtp/gfilterfactory.cpp
+++ b/src/gsmtp/gfilterfactory.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,6 +21,8 @@
 #include "gdef.h"
 #include "gstr.h"
 #include "gfilterfactory.h"
+#include "gfilterchain.h"
+#include "gfilestore.h"
 #include "gnullfilter.h"
 #include "gnetworkfilter.h"
 #include "gexecutablefilter.h"
@@ -34,33 +36,38 @@ GSmtp::FilterFactoryFileStore::FilterFactoryFileStore( FileStore & file_store )
 }
 
 std::unique_ptr<GSmtp::Filter> GSmtp::FilterFactoryFileStore::newFilter( GNet::ExceptionSink es ,
-	bool server_side , const std::string & identifier , unsigned int timeout )
+	bool server_side , const FactoryParser::Result & spec , unsigned int timeout ,
+	const std::string & log_prefix )
 {
-	FactoryParser::Result p = FactoryParser::parse( identifier , true ) ;
-	if( p.first.empty() )
+	if( spec.first == "chain" )
 	{
-		return std::make_unique<NullFilter>( es , server_side ) ; // up-cast
+		// (one level of recursion -- FilterChain::ctor calls newFilter())
+		return std::make_unique<FilterChain>( es , *this , server_side , spec , timeout , log_prefix ) ;
 	}
-	else if( p.first == "spam" )
+	else if( spec.first == "spam" )
 	{
 		// "spam:" is read-only, not-always-pass
 		// "spam-edit:" is read-write, always-pass
-		bool edit = p.third == 1 ;
+		bool edit = spec.third == 1 ;
 		bool read_only = !edit ;
 		bool always_pass = edit ;
-		return std::make_unique<SpamFilter>( es , m_file_store , p.second , read_only , always_pass , timeout , timeout ) ; // up-cast
+		return std::make_unique<SpamFilter>( es , m_file_store , spec.second , read_only , always_pass , timeout , timeout ) ;
 	}
-	else if( p.first == "net" )
+	else if( spec.first == "net" )
 	{
-		return std::make_unique<NetworkFilter>( es , m_file_store , p.second , timeout , timeout ) ; // up-cast
+		return std::make_unique<NetworkFilter>( es , m_file_store , spec.second , timeout , timeout ) ;
 	}
-	else if( p.first == "exit" )
+	else if( spec.first == "exit" )
 	{
-		return std::make_unique<NullFilter>( es , server_side , G::Str::toUInt(p.second) ) ; // up-cast
+		return std::make_unique<NullFilter>( es , server_side , G::Str::toUInt(spec.second) ) ;
+	}
+	else if( spec.first == "file" )
+	{
+		return std::make_unique<ExecutableFilter>( es , m_file_store , server_side , spec.second , timeout , log_prefix ) ;
 	}
 	else
 	{
-		return std::make_unique<ExecutableFilter>( es , m_file_store , server_side , p.second , timeout ) ; // up-cast
+		throw G::Exception( "invalid filter" , spec.second ) ;
 	}
 }
 
diff --git a/src/gsmtp/gfilterfactory.h b/src/gsmtp/gfilterfactory.h
index 43d6ad7..297f694 100644
--- a/src/gsmtp/gfilterfactory.h
+++ b/src/gsmtp/gfilterfactory.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,36 +23,34 @@
 
 #include "gdef.h"
 #include "gfilter.h"
-#include "gfilestore.h"
 #include "gfactoryparser.h"
 #include "gexceptionsink.h"
+#include "gexception.h"
 #include <string>
 #include <utility>
+#include <memory>
 
 namespace GSmtp
 {
 	class FilterFactory ;
 	class FilterFactoryFileStore ;
+	class FileStore ;
 }
 
 //| \class GSmtp::FilterFactory
-/// A factory interface for GSmtp::Filter message processors.
+/// A factory interface for making GSmtp::Filter message processors.
 ///
 class GSmtp::FilterFactory
 {
 public:
 	virtual std::unique_ptr<Filter> newFilter( GNet::ExceptionSink ,
-		bool server_side , const std::string & identifier , unsigned int timeout ) = 0 ;
-			///< Returns a Filter on the heap. The identifier
-			///< is normally prefixed with a processor type, or it
-			///< is the file system path of an exectuable.
+		bool server_side , const FactoryParser::Result & spec ,
+		unsigned int timeout , const std::string & log_prefix ) = 0 ;
+			///< Returns a Filter on the heap. Throws if an
+			///< invalid or unsupported specification.
 
 	virtual ~FilterFactory() = default ;
 		///< Destructor.
-
-	static std::string check( const std::string & identifier ) ;
-		///< Checks an identifier. Returns an empty string if okay,
-		///< or a diagnostic reason string.
 } ;
 
 //| \class GSmtp::FilterFactoryFileStore
@@ -68,16 +66,12 @@ public:
 		///< the content and envelope files that they process.
 
 	std::unique_ptr<Filter> newFilter( GNet::ExceptionSink ,
-		bool server_side , const std::string & identifier , unsigned int timeout ) override ;
+		bool server_side , const FactoryParser::Result & spec ,
+		unsigned int timeout , const std::string & log_prefix ) override ;
+			///< Override from FilterFactory.
 
 private:
 	FileStore & m_file_store ;
 } ;
 
-inline
-std::string GSmtp::FilterFactory::check( const std::string & identifier )
-{
-	return FactoryParser::check( identifier , true ) ;
-}
-
 #endif
diff --git a/src/gsmtp/ginternalverifier.cpp b/src/gsmtp/ginternalverifier.cpp
index af8569f..299d87f 100644
--- a/src/gsmtp/ginternalverifier.cpp
+++ b/src/gsmtp/ginternalverifier.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/ginternalverifier.h b/src/gsmtp/ginternalverifier.h
index 65a9042..7af4be6 100644
--- a/src/gsmtp/ginternalverifier.h
+++ b/src/gsmtp/ginternalverifier.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -52,8 +52,8 @@ public:
 	~InternalVerifier() override = default ;
 	InternalVerifier( const InternalVerifier & ) = delete ;
 	InternalVerifier( InternalVerifier && ) = delete ;
-	void operator=( const InternalVerifier & ) = delete ;
-	void operator=( InternalVerifier && ) = delete ;
+	InternalVerifier & operator=( const InternalVerifier & ) = delete ;
+	InternalVerifier & operator=( InternalVerifier && ) = delete ;
 
 private:
 	G::Slot::Signal<const VerifierStatus&> m_done_signal ;
diff --git a/src/gsmtp/gmessagestore.cpp b/src/gsmtp/gmessagestore.cpp
index 0a35b83..f673a6f 100644
--- a/src/gsmtp/gmessagestore.cpp
+++ b/src/gsmtp/gmessagestore.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/gmessagestore.h b/src/gsmtp/gmessagestore.h
index d9bfd02..0b6bab0 100644
--- a/src/gsmtp/gmessagestore.h
+++ b/src/gsmtp/gmessagestore.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,7 +24,7 @@
 #include "gdef.h"
 #include "gexception.h"
 #include "gslot.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gpath.h"
 #include <memory>
 
diff --git a/src/gsmtp/gmessagestore_unix.cpp b/src/gsmtp/gmessagestore_unix.cpp
index e70829a..2ac1c6a 100644
--- a/src/gsmtp/gmessagestore_unix.cpp
+++ b/src/gsmtp/gmessagestore_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -29,7 +29,7 @@
 
 G::Path GSmtp::MessageStore::defaultDirectory()
 {
-	std::string spooldir( G_STR(G_SPOOLDIR) ) ;
+	std::string spooldir = G_STR(G_SPOOLDIR) ; // NOLINT readability-redundant-string-init
 	if( spooldir.empty() )
 		spooldir = "/var/spool/emailrelay" ;
 	return G::Path( spooldir ) ;
diff --git a/src/gsmtp/gmessagestore_win32.cpp b/src/gsmtp/gmessagestore_win32.cpp
index a9d79ff..fad87b6 100644
--- a/src/gsmtp/gmessagestore_win32.cpp
+++ b/src/gsmtp/gmessagestore_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/gnetworkfilter.cpp b/src/gsmtp/gnetworkfilter.cpp
index 21c2e9a..a119a23 100644
--- a/src/gsmtp/gnetworkfilter.cpp
+++ b/src/gsmtp/gnetworkfilter.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/gnetworkfilter.h b/src/gsmtp/gnetworkfilter.h
index 0c37a7d..96a3e50 100644
--- a/src/gsmtp/gnetworkfilter.h
+++ b/src/gsmtp/gnetworkfilter.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -64,8 +64,8 @@ private: // overrides
 public:
 	NetworkFilter( const NetworkFilter & ) = delete ;
 	NetworkFilter( NetworkFilter && ) = delete ;
-	void operator=( const NetworkFilter & ) = delete ;
-	void operator=( NetworkFilter && ) = delete ;
+	NetworkFilter & operator=( const NetworkFilter & ) = delete ;
+	NetworkFilter & operator=( NetworkFilter && ) = delete ;
 
 private:
 	void clientEvent( const std::string & , const std::string & , const std::string & ) ;
diff --git a/src/gsmtp/gnetworkverifier.cpp b/src/gsmtp/gnetworkverifier.cpp
index 50d2c7f..1581213 100644
--- a/src/gsmtp/gnetworkverifier.cpp
+++ b/src/gsmtp/gnetworkverifier.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -91,7 +91,7 @@ void GSmtp::NetworkVerifier::clientEvent( const std::string & s1 , const std::st
 		// fields based on the script-based verifier interface, but backwards
 		//
 		G::StringArray parts ;
-		G::Str::splitIntoFields( s2 , parts , {"|",1U} ) ;
+		G::Str::splitIntoFields( s2 , parts , '|' ) ;
 		VerifierStatus status = VerifierStatus::invalid( m_to_address ) ;
 		if( !parts.empty() && parts[0U] == "100" )
 		{
diff --git a/src/gsmtp/gnetworkverifier.h b/src/gsmtp/gnetworkverifier.h
index ab26a7c..e298428 100644
--- a/src/gsmtp/gnetworkverifier.h
+++ b/src/gsmtp/gnetworkverifier.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -55,8 +55,8 @@ private: // overrides
 public:
 	NetworkVerifier( const NetworkVerifier & ) = delete ;
 	NetworkVerifier( NetworkVerifier && ) = delete ;
-	void operator=( const NetworkVerifier & ) = delete ;
-	void operator=( NetworkVerifier && ) = delete ;
+	NetworkVerifier & operator=( const NetworkVerifier & ) = delete ;
+	NetworkVerifier & operator=( NetworkVerifier && ) = delete ;
 
 private:
 	void clientEvent( const std::string & , const std::string & , const std::string & ) ;
diff --git a/src/gsmtp/gnewfile.cpp b/src/gsmtp/gnewfile.cpp
index b8e68e3..5ff6655 100644
--- a/src/gsmtp/gnewfile.cpp
+++ b/src/gsmtp/gnewfile.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/gnewfile.h b/src/gsmtp/gnewfile.h
index 98f0f21..c4254c7 100644
--- a/src/gsmtp/gnewfile.h
+++ b/src/gsmtp/gnewfile.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,7 +24,7 @@
 #include "gdef.h"
 #include "gfilestore.h"
 #include "genvelope.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gnewmessage.h"
 #include "gexception.h"
 #include <fstream>
@@ -42,9 +42,7 @@ namespace GSmtp
 class GSmtp::NewFile : public NewMessage
 {
 public:
-	G_EXCEPTION( InvalidPath , "invalid path: must be absolute" ) ;
-	G_EXCEPTION( FileError , "message store error" ) ;
-	G_EXCEPTION( TooBig , "message too big" ) ;
+	G_EXCEPTION( FileError , tx("message store error") ) ;
 
 	NewFile( FileStore & store , const std::string & from , const std::string & from_auth_in ,
 		const std::string & from_auth_out , std::size_t max_size , bool test_for_eight_bit ) ;
@@ -60,8 +58,8 @@ public:
 public:
 	NewFile( const NewFile & ) = delete ;
 	NewFile( NewFile && ) = delete ;
-	void operator=( const NewFile & ) = delete ;
-	void operator=( NewFile && ) = delete ;
+	NewFile & operator=( const NewFile & ) = delete ;
+	NewFile & operator=( NewFile && ) = delete ;
 
 private: // overrides
 	void commit( bool strict ) override ; // Override from GSmtp::NewMessage.
diff --git a/src/gsmtp/gnewmessage.cpp b/src/gsmtp/gnewmessage.cpp
index 1571035..ccc3a2b 100644
--- a/src/gsmtp/gnewmessage.cpp
+++ b/src/gsmtp/gnewmessage.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/gnewmessage.h b/src/gsmtp/gnewmessage.h
index 3c3417f..ce12dab 100644
--- a/src/gsmtp/gnewmessage.h
+++ b/src/gsmtp/gnewmessage.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/gnullfilter.cpp b/src/gsmtp/gnullfilter.cpp
index 90eb891..a7432fe 100644
--- a/src/gsmtp/gnullfilter.cpp
+++ b/src/gsmtp/gnullfilter.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/gnullfilter.h b/src/gsmtp/gnullfilter.h
index 1b71089..27ac240 100644
--- a/src/gsmtp/gnullfilter.h
+++ b/src/gsmtp/gnullfilter.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -59,8 +59,8 @@ public:
 	~NullFilter() override = default ;
 	NullFilter( const NullFilter & ) = delete ;
 	NullFilter( NullFilter && ) = delete ;
-	void operator=( const NullFilter & ) = delete ;
-	void operator=( NullFilter && ) = delete ;
+	NullFilter & operator=( const NullFilter & ) = delete ;
+	NullFilter & operator=( NullFilter && ) = delete ;
 
 private:
 	void onTimeout() ;
diff --git a/src/gsmtp/gprotocolmessage.cpp b/src/gsmtp/gprotocolmessage.cpp
index cc758f4..8e46078 100644
--- a/src/gsmtp/gprotocolmessage.cpp
+++ b/src/gsmtp/gprotocolmessage.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/gprotocolmessage.h b/src/gsmtp/gprotocolmessage.h
index d8ad6c3..93c1d62 100644
--- a/src/gsmtp/gprotocolmessage.h
+++ b/src/gsmtp/gprotocolmessage.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,7 +24,7 @@
 #include "gdef.h"
 #include "gmessagestore.h"
 #include "gslot.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gverifier.h"
 #include "gexception.h"
 #include <string>
diff --git a/src/gsmtp/gprotocolmessageforward.cpp b/src/gsmtp/gprotocolmessageforward.cpp
index 23742bc..b98f022 100644
--- a/src/gsmtp/gprotocolmessageforward.cpp
+++ b/src/gsmtp/gprotocolmessageforward.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -29,12 +29,12 @@
 
 GSmtp::ProtocolMessageForward::ProtocolMessageForward( GNet::ExceptionSink es ,
 	MessageStore & store , FilterFactory & ff , std::unique_ptr<ProtocolMessage> pm ,
-	const GSmtp::Client::Config & client_config ,
-	const GAuth::SaslClientSecrets & client_secrets , const std::string & server ) :
+	const GSmtp::Client::Config & client_config , const GAuth::SaslClientSecrets & client_secrets ,
+	const std::string & forward_to , int forward_to_family ) :
 		m_es(es) ,
 		m_store(store) ,
 		m_ff(ff) ,
-		m_client_location(server) ,
+		m_client_location(forward_to,forward_to_family) ,
 		m_client_config(client_config) ,
 		m_client_secrets(client_secrets) ,
 		m_pm(pm.release()) ,
diff --git a/src/gsmtp/gprotocolmessageforward.h b/src/gsmtp/gprotocolmessageforward.h
index b15002a..d5a428e 100644
--- a/src/gsmtp/gprotocolmessageforward.h
+++ b/src/gsmtp/gprotocolmessageforward.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -59,7 +59,7 @@ public:
 		std::unique_ptr<ProtocolMessage> pm ,
 		const GSmtp::Client::Config & client_config ,
 		const GAuth::SaslClientSecrets & client_secrets ,
-		const std::string & remote_server_address ) ;
+		const std::string & forward_to , int forward_to_family ) ;
 			///< Constructor. The 'store' and 'client-secrets' references
 			///< are kept.
 
@@ -93,8 +93,8 @@ private: // overrides
 public:
 	ProtocolMessageForward( const ProtocolMessageForward & ) = delete ;
 	ProtocolMessageForward( ProtocolMessageForward && ) = delete ;
-	void operator=( const ProtocolMessageForward & ) = delete ;
-	void operator=( ProtocolMessageForward && ) = delete ;
+	ProtocolMessageForward & operator=( const ProtocolMessageForward & ) = delete ;
+	ProtocolMessageForward & operator=( ProtocolMessageForward && ) = delete ;
 
 private:
 	void clientDone( const std::string & ) ; // GNet::Client::doneSignal()
diff --git a/src/gsmtp/gprotocolmessagestore.cpp b/src/gsmtp/gprotocolmessagestore.cpp
index ef608fa..474aca0 100644
--- a/src/gsmtp/gprotocolmessagestore.cpp
+++ b/src/gsmtp/gprotocolmessagestore.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/gprotocolmessagestore.h b/src/gsmtp/gprotocolmessagestore.h
index 715c0db..26b209f 100644
--- a/src/gsmtp/gprotocolmessagestore.h
+++ b/src/gsmtp/gprotocolmessagestore.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -80,8 +80,8 @@ public:
 public:
 	ProtocolMessageStore( const ProtocolMessageStore & ) = delete ;
 	ProtocolMessageStore( ProtocolMessageStore && ) = delete ;
-	void operator=( const ProtocolMessageStore & ) = delete ;
-	void operator=( ProtocolMessageStore && ) = delete ;
+	ProtocolMessageStore & operator=( const ProtocolMessageStore & ) = delete ;
+	ProtocolMessageStore & operator=( ProtocolMessageStore && ) = delete ;
 
 private:
 	void filterDone( int ) ;
diff --git a/src/gsmtp/grequestclient.cpp b/src/gsmtp/grequestclient.cpp
index eef6d9d..a5d4a29 100644
--- a/src/gsmtp/grequestclient.cpp
+++ b/src/gsmtp/grequestclient.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -36,7 +36,8 @@ GSmtp::RequestClient::RequestClient( GNet::ExceptionSink es , const std::string
 
 GNet::Client::Config GSmtp::RequestClient::netConfig( unsigned int connection_timeout , unsigned int response_timeout )
 {
-	GNet::Client::Config net_config( GNet::LineBufferConfig::newline() ) ;
+	GNet::Client::Config net_config ;
+	net_config.line_buffer_config = GNet::LineBufferConfig::newline() ;
 	net_config.connection_timeout = connection_timeout ;
 	net_config.response_timeout = response_timeout ;
 	return net_config ;
diff --git a/src/gsmtp/grequestclient.h b/src/gsmtp/grequestclient.h
index bf7b76f..1c26bf5 100644
--- a/src/gsmtp/grequestclient.h
+++ b/src/gsmtp/grequestclient.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -46,7 +46,7 @@ namespace GSmtp
 class GSmtp::RequestClient : public GNet::Client
 {
 public:
-	G_EXCEPTION( ProtocolError , "protocol error" ) ;
+	G_EXCEPTION( ProtocolError , tx("protocol error") ) ;
 
 	RequestClient( GNet::ExceptionSink , const std::string & key , const std::string & ok ,
 		const GNet::Location & host_and_service , unsigned int connect_timeout ,
@@ -88,8 +88,8 @@ public:
 	~RequestClient() override = default ;
 	RequestClient( const RequestClient & ) = delete ;
 	RequestClient( RequestClient && ) = delete ;
-	void operator=( const RequestClient & ) = delete ;
-	void operator=( RequestClient && ) = delete ;
+	RequestClient & operator=( const RequestClient & ) = delete ;
+	RequestClient & operator=( RequestClient && ) = delete ;
 
 private:
 	void onTimeout() ;
diff --git a/src/gsmtp/gsmtpclient.cpp b/src/gsmtp/gsmtpclient.cpp
index 36d334d..46d36f8 100644
--- a/src/gsmtp/gsmtpclient.cpp
+++ b/src/gsmtp/gsmtpclient.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -32,17 +32,22 @@
 #include "glog.h"
 
 GSmtp::Client::Client( GNet::ExceptionSink es , FilterFactory & ff , const GNet::Location & remote ,
-	const GAuth::SaslClientSecrets & client_secrets , const Config & config ) :
+	const GAuth::SaslClientSecrets & secrets , const Config & config ) :
 		GNet::Client(es,remote,netConfig(config)) ,
+		m_es(es) ,
+		m_ff(ff) ,
+		m_config(config) ,
+		m_secrets(secrets) ,
 		m_store(nullptr) ,
-		m_filter(ff.newFilter(es,false,config.filter_address,config.filter_timeout)) ,
-		m_protocol(es,*this,client_secrets,config.sasl_client_config,config.client_protocol_config,config.secure_tunnel) ,
-		m_secure_tunnel(config.secure_tunnel) ,
+		m_filter(ff.newFilter(es,false,config.filter_spec,config.filter_timeout,std::string())) ,
+		m_routing_filter(ff.newFilter(es,false,config.filter_spec,config.filter_timeout,"routing filter")) ,
+		m_protocol(es,*this,secrets,config.sasl_client_config,config.client_protocol_config,config.secure_tunnel) ,
 		m_message_count(0U)
 {
 	m_protocol.doneSignal().connect( G::Slot::slot(*this,&Client::protocolDone) ) ;
 	m_protocol.filterSignal().connect( G::Slot::slot(*this,&Client::filterStart) ) ;
 	m_filter->doneSignal().connect( G::Slot::slot(*this,&Client::filterDone) ) ;
+	m_routing_filter->doneSignal().connect( G::Slot::slot(*this,&Client::routingFilterDone) ) ;
 }
 
 GSmtp::Client::~Client()
@@ -50,18 +55,24 @@ GSmtp::Client::~Client()
 	m_protocol.doneSignal().disconnect() ;
 	m_protocol.filterSignal().disconnect() ;
 	m_filter->doneSignal().disconnect() ;
+	m_routing_filter->doneSignal().disconnect() ;
 }
 
 GNet::Client::Config GSmtp::Client::netConfig( const Config & smtp_config )
 {
-	GNet::Client::Config net_config( GNet::LineBufferConfig::smtp() ) ;
-	net_config.bind_local_address = smtp_config.bind_local_address ;
-	net_config.local_address = smtp_config.local_address ;
-	net_config.connection_timeout = smtp_config.connection_timeout ;
-	net_config.secure_connection_timeout = smtp_config.secure_connection_timeout ;
-	//net_config.response_timeout = 0U ; // the protocol class does this
-	//net_config.idle_timeout = 0U ; // not needed
-	return net_config ;
+	return
+		GNet::Client::Config()
+			.set_stream_socket_config( smtp_config.stream_socket_config )
+			.set_line_buffer_config( GNet::LineBufferConfig::smtp() )
+			.set_bind_local_address( smtp_config.bind_local_address )
+			.set_local_address( smtp_config.local_address )
+			.set_connection_timeout( smtp_config.connection_timeout )
+			//.set_response_timeout( 0U ) // the protocol class does this
+			//.set_idle_timeout( 0U ) // not needed
+			.set_socket_protocol_config(
+				GNet::SocketProtocol::Config()
+					.set_client_tls_profile( smtp_config.client_tls_profile )
+					.set_secure_connection_timeout( smtp_config.secure_connection_timeout ) ) ;
 }
 
 G::Slot::Signal<const std::string&> & GSmtp::Client::messageDoneSignal()
@@ -74,22 +85,28 @@ void GSmtp::Client::sendMessagesFrom( MessageStore & store )
 	G_ASSERT( m_store == nullptr ) ;
 	G_ASSERT( !connected() ) ; // ie. immediately after construction
 	m_store = &store ;
+	m_iter = m_store->iterator( true ) ;
 }
 
 void GSmtp::Client::sendMessage( std::unique_ptr<StoredMessage> message )
 {
 	G_ASSERT( message && message->toCount() ) ;
-	if( message && message->toCount() )
-	{
-		m_message.reset( message.release() ) ;
-		if( connected() )
-			start() ;
-	}
+	m_message = std::move( message ) ;
+	if( connected() )
+		start() ;
+}
+
+void GSmtp::Client::sendMessage( std::shared_ptr<StoredMessage> message )
+{
+	G_ASSERT( message && message->toCount() ) ;
+	m_message = message ;
+	if( connected() )
+		start() ;
 }
 
 void GSmtp::Client::onConnect()
 {
-	if( m_secure_tunnel )
+	if( m_config.secure_tunnel )
 		secureConnect() ; // GNet::SocketProtocol
 	else
 		startSending() ;
@@ -97,7 +114,7 @@ void GSmtp::Client::onConnect()
 
 void GSmtp::Client::onSecure( const std::string & , const std::string & , const std::string & )
 {
-	if( m_secure_tunnel )
+	if( m_config.secure_tunnel )
 		startSending() ;
 	else
 		m_protocol.secure() ; // tell the protocol that STARTTLS is done
@@ -105,12 +122,9 @@ void GSmtp::Client::onSecure( const std::string & , const std::string & , const
 
 void GSmtp::Client::startSending()
 {
-	G_LOG_S( "GSmtp::Client::startSending: smtp connection to " << peerAddress().second.displayString() ) ;
-	if( m_store != nullptr )
+	G_LOG_S( "GSmtp::Client::startSending: smtp connection to " << peerAddress().displayString() ) ;
+	if( m_store != nullptr && m_message.get() == nullptr )
 	{
-		// initialise the message iterator
-		m_iter = m_store->iterator( true ) ;
-
 		// start sending the first message
 		bool started = sendNext() ;
 		if( !started )
@@ -140,7 +154,7 @@ bool GSmtp::Client::sendNext()
 			m_message_count = 0U ;
 			return false ;
 		}
-		m_message.reset( message.release() ) ;
+		m_message = std::move( message ) ;
 	}
 
 	start() ;
@@ -152,6 +166,18 @@ void GSmtp::Client::start()
 	G_ASSERT( message()->toCount() != 0U ) ;
 	m_message_count++ ;
 
+	// basic routing if forward-to is defined in the envelope
+	if( m_config.with_routing && !message()->forwardTo().empty() )
+	{
+		if( !m_routing_filter->simple() )
+		{
+			G_LOG( "GSmtp::Client::filterStart: routing filter start: [" << m_filter->id() << "]" << " [" << message()->location() << "]" ) ;
+			message()->close() ;
+		}
+		m_routing_filter->start( message()->id() ) ;
+		return ;
+	}
+
 	G::CallFrame this_( m_stack ) ;
 	eventSignal().emit( "sending" , message()->location() , std::string() ) ;
 	if( this_.deleted() ) return ;
@@ -170,7 +196,9 @@ std::shared_ptr<GSmtp::StoredMessage> GSmtp::Client::message()
 
 bool GSmtp::Client::protocolSend( const std::string & line , std::size_t offset , bool go_secure )
 {
-	bool rc = send( line , offset ) ; // GNet::Client::send()
+    offset = std::min( offset , line.size() ) ;
+    G::string_view data( line.data()+offset , line.size()-offset ) ;
+    bool rc = data.empty() ? true : send( data ) ; // GNet::Client::send()
 	if( go_secure )
 		secureConnect() ; // GNet::Client -> GNet::SocketProtocol
 	return rc ;
@@ -180,7 +208,7 @@ void GSmtp::Client::filterStart()
 {
 	if( !m_filter->simple() )
 	{
-		G_LOG( "GSmtp::Client::filterStart: client filter: [" << m_filter->id() << "]" ) ;
+		G_LOG( "GSmtp::Client::filterStart: client filter start: [" << m_filter->id() << "]" << " [" << message()->location() << "]" ) ;
 		message()->close() ; // allow external editing
 	}
 	m_filter->start( message()->id() ) ;
@@ -274,13 +302,13 @@ void GSmtp::Client::protocolDone( int response_code , const std::string & respon
 	{
 		if( !sendNext() )
 		{
-			G_DEBUG( "GSmtp::Client::protocolDone: all sent" ) ;
 			quitAndFinish() ;
 			throw GNet::Done() ;
 		}
 	}
 	else
 	{
+		m_message.reset() ;
 		messageDoneSignal().emit( response ) ;
 	}
 }
@@ -288,7 +316,7 @@ void GSmtp::Client::protocolDone( int response_code , const std::string & respon
 void GSmtp::Client::quitAndFinish()
 {
 	m_protocol.finish() ; // send QUIT
-	finish( true ) ; // GNet::Client::finish() -- expect a disconnect
+	finish() ; // GNet::Client::finish() -- expect a disconnect
 }
 
 void GSmtp::Client::messageDestroy()
@@ -314,6 +342,7 @@ bool GSmtp::Client::onReceive( const char * line_data , std::size_t line_size ,
 
 	if( done )
 	{
+		m_message.reset() ;
 		quitAndFinish() ;
 		throw GNet::Done() ;
 	}
@@ -337,6 +366,68 @@ void GSmtp::Client::onSendComplete()
 	m_protocol.sendComplete() ;
 }
 
+void GSmtp::Client::routingFilterDone( int filter_result )
+{
+	G_ASSERT( m_config.with_routing ) ;
+	G_LOG( "GSmtp::Client::routingFilterDone: routing filter done: " << m_routing_filter->str(false) ) ;
+	std::string reopen_error = filter_result == 0 && !m_routing_filter->simple() ? message()->reopen() : std::string() ;
+	bool move_on = false ;
+	if( filter_result == 1 ) // abandon
+	{
+		move_on  = true ;
+	}
+	else if( filter_result == 2 ) // fail
+	{
+		messageFail( 550 , "routing filter failed" ) ;
+		move_on = true ;
+	}
+	else if( !reopen_error.empty() ) // ok but cannot open
+	{
+		messageFail( 550 , "routing filter error" ) ;
+		move_on = true ;
+	}
+	if( move_on )
+	{
+		G_ASSERT( m_store != nullptr ) ;
+		if( !sendNext() )
+		{
+			quitAndFinish() ;
+			throw GNet::Done() ;
+		}
+	}
+	else // ok and reopened
+	{
+		std::string forward_to_address = message()->forwardToAddress() ;
+
+		G::CallFrame this_( m_stack ) ;
+		eventSignal().emit( "sending" , message()->location() , std::string() ) ;
+		if( this_.deleted() ) return ;
+
+		if( forward_to_address.empty() )
+		{
+			// no special routing -- send to the default smarthost
+			m_protocol.start( std::weak_ptr<StoredMessage>(message()) ) ;
+		}
+		else
+		{
+			G_LOG( "GSmtp::Client::routingFilterDone: routing to " << forward_to_address ) ;
+			m_routing_client.reset( new Client( m_es , m_ff , GNet::Location(forward_to_address) ,
+				m_secrets , Config(m_config).set_with_routing(false) ) ) ;
+			m_routing_client->messageDoneSignal().connect( G::Slot::slot( *this , &GSmtp::Client::routedMessageDone ) ) ;
+			m_routing_client->sendMessage( message() ) ;
+		}
+	}
+}
+
+void GSmtp::Client::routedMessageDone( const std::string & )
+{
+	if( !sendNext() )
+	{
+		quitAndFinish() ;
+		throw GNet::Done() ;
+	}
+}
+
 // ==
 
 GSmtp::Client::Config::Config() :
@@ -344,20 +435,3 @@ GSmtp::Client::Config::Config() :
 {
 }
 
-GSmtp::Client::Config::Config( const std::string & filter_address_ , unsigned int filter_timeout_ ,
-	bool bind_local_address_ , const GNet::Address & local_address_ ,
-	const ClientProtocol::Config & protocol_config_ , unsigned int connection_timeout_ ,
-	unsigned int secure_connection_timeout_ , bool secure_tunnel_ ,
-	const std::string & sasl_client_config_ ) :
-		filter_address(filter_address_) ,
-		filter_timeout(filter_timeout_) ,
-		bind_local_address(bind_local_address_) ,
-		local_address(local_address_) ,
-		client_protocol_config(protocol_config_) ,
-		connection_timeout(connection_timeout_) ,
-		secure_connection_timeout(secure_connection_timeout_) ,
-		secure_tunnel(secure_tunnel_) ,
-		sasl_client_config(sasl_client_config_)
-{
-}
-
diff --git a/src/gsmtp/gsmtpclient.h b/src/gsmtp/gsmtpclient.h
index d027bbe..9a62e3f 100644
--- a/src/gsmtp/gsmtpclient.h
+++ b/src/gsmtp/gsmtpclient.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -26,6 +26,7 @@
 #include "gsecrets.h"
 #include "glinebuffer.h"
 #include "gclient.h"
+#include "gclientptr.h"
 #include "gsmtpclientprotocol.h"
 #include "gmessagestore.h"
 #include "gstoredmessage.h"
@@ -35,7 +36,7 @@
 #include "gsocket.h"
 #include "gslot.h"
 #include "gtimer.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gexception.h"
 #include <memory>
 #include <iostream>
@@ -55,36 +56,36 @@ class GSmtp::Client : public GNet::Client , private ClientProtocol::Sender
 public:
 	struct Config /// A structure containing GSmtp::Client configuration parameters.
 	{
-		std::string filter_address ;
+		GNet::StreamSocket::Config stream_socket_config ;
+		ClientProtocol::Config client_protocol_config ;
+		FactoryParser::Result filter_spec ;
 		unsigned int filter_timeout{0U} ;
 		bool bind_local_address{false} ;
 		GNet::Address local_address ;
-		ClientProtocol::Config client_protocol_config ;
 		unsigned int connection_timeout{0U} ;
 		unsigned int secure_connection_timeout{0U} ;
 		bool secure_tunnel{false} ;
 		std::string sasl_client_config ;
+		std::string client_tls_profile ;
+		bool with_routing{true} ;
 
 		Config() ;
-		Config( const std::string & filter_address , unsigned int filter_timeout ,
-			bool bind_local_address , const GNet::Address & local_address ,
-			const ClientProtocol::Config & protocol_config ,
-			unsigned int connection_timeout , unsigned int secure_connection_timeout ,
-			bool secure_tunnel , const std::string & sasl_client_config ) ;
-
-		Config & set_filter_address( const std::string & ) ;
+		Config & set_stream_socket_config( const GNet::StreamSocket::Config & ) ;
+		Config & set_client_protocol_config( const ClientProtocol::Config & ) ;
+		Config & set_filter_spec( const FactoryParser::Result & ) ;
 		Config & set_filter_timeout( unsigned int ) ;
 		Config & set_bind_local_address( bool = true ) ;
 		Config & set_local_address( const GNet::Address & ) ;
-		Config & set_client_protocol_config( const ClientProtocol::Config & ) ;
 		Config & set_connection_timeout( unsigned int ) ;
 		Config & set_secure_connection_timeout( unsigned int ) ;
 		Config & set_secure_tunnel( bool = true ) ;
 		Config & set_sasl_client_config( const std::string & ) ;
+		Config & set_client_tls_profile( const std::string & ) ;
+		Config & set_with_routing( bool = true ) ;
 	} ;
 
 	Client( GNet::ExceptionSink , FilterFactory & , const GNet::Location & remote ,
-		const GAuth::SaslClientSecrets & client_secrets , const Config & config ) ;
+		const GAuth::SaslClientSecrets & secrets , const Config & config ) ;
 			///< Constructor. Starts connecting immediately.
 			///<
 			///< Use sendMessagesFrom() once, or use sendMessage()
@@ -123,7 +124,7 @@ public:
 		///< has completed or failed.
 
 private: // overrides
-	void onConnect() override ; // Override from GNet::SimpleClient.
+	void onConnect() override ; // Override from GNet::Client.
 	bool onReceive( const char * , std::size_t , std::size_t , std::size_t , char ) override ; // Override from GNet::Client.
 	void onDelete( const std::string & ) override ; // Override from GNet::HeapClient.
 	void onSendComplete() override ; // Override from GNet::BufferedClient.
@@ -133,8 +134,8 @@ private: // overrides
 public:
 	Client( const Client & ) = delete ;
 	Client( Client && ) = delete ;
-	void operator=( const Client & ) = delete ;
-	void operator=( Client && ) = delete ;
+	Client & operator=( const Client & ) = delete ;
+	Client & operator=( Client && ) = delete ;
 
 private:
 	std::shared_ptr<StoredMessage> message() ;
@@ -148,27 +149,38 @@ private:
 	void startSending() ;
 	void quitAndFinish() ;
 	static GNet::Client::Config netConfig( const Config & smtp_config ) ;
+	void sendMessage( std::shared_ptr<StoredMessage> message ) ;
+	void routingFilterDone( int ) ;
+	void routedMessageDone( const std::string & ) ;
 
 private:
-	MessageStore * m_store ;
+	GNet::ExceptionSink m_es ;
+	FilterFactory & m_ff ;
 	G::CallStack m_stack ;
+	Config m_config ;
+	const GAuth::SaslClientSecrets & m_secrets ;
+	MessageStore * m_store ;
 	std::unique_ptr<Filter> m_filter ;
+	std::unique_ptr<Filter> m_routing_filter ;
+	GNet::ClientPtr<Client> m_routing_client ;
 	std::shared_ptr<StoredMessage> m_message ;
 	std::shared_ptr<MessageStore::Iterator> m_iter ;
 	ClientProtocol m_protocol ;
-	bool m_secure_tunnel ;
 	G::Slot::Signal<const std::string&> m_message_done_signal ;
 	unsigned int m_message_count ;
 } ;
 
-inline GSmtp::Client::Config & GSmtp::Client::Config::set_filter_address( const std::string & s ) { filter_address = s ; return *this ; }
+inline GSmtp::Client::Config & GSmtp::Client::Config::set_stream_socket_config( const GNet::StreamSocket::Config & c ) { stream_socket_config = c ; return *this ; }
+inline GSmtp::Client::Config & GSmtp::Client::Config::set_client_protocol_config( const ClientProtocol::Config & c ) { client_protocol_config = c ; return *this ; }
+inline GSmtp::Client::Config & GSmtp::Client::Config::set_filter_spec( const FactoryParser::Result & r ) { filter_spec = r ; return *this ; }
 inline GSmtp::Client::Config & GSmtp::Client::Config::set_filter_timeout( unsigned int t ) { filter_timeout = t ; return *this ; }
 inline GSmtp::Client::Config & GSmtp::Client::Config::set_bind_local_address( bool b ) { bind_local_address = b ; return *this ; }
 inline GSmtp::Client::Config & GSmtp::Client::Config::set_local_address( const GNet::Address & a ) { local_address = a ; return *this ; }
-inline GSmtp::Client::Config & GSmtp::Client::Config::set_client_protocol_config( const ClientProtocol::Config & c ) { client_protocol_config = c ; return *this ; }
 inline GSmtp::Client::Config & GSmtp::Client::Config::set_connection_timeout( unsigned int t ) { connection_timeout = t ; return *this ; }
 inline GSmtp::Client::Config & GSmtp::Client::Config::set_secure_connection_timeout( unsigned int t ) { secure_connection_timeout = t ; return *this ; }
 inline GSmtp::Client::Config & GSmtp::Client::Config::set_secure_tunnel( bool b ) { secure_tunnel = b ; return *this ; }
 inline GSmtp::Client::Config & GSmtp::Client::Config::set_sasl_client_config( const std::string & s ) { sasl_client_config = s ; return *this ; }
+inline GSmtp::Client::Config & GSmtp::Client::Config::set_client_tls_profile( const std::string & s ) { client_tls_profile = s ; return *this ; }
+inline GSmtp::Client::Config & GSmtp::Client::Config::set_with_routing( bool b ) { with_routing = b ; return *this ; }
 
 #endif
diff --git a/src/gsmtp/gsmtpclientprotocol.cpp b/src/gsmtp/gsmtpclientprotocol.cpp
index b7e4f9c..d1c75e1 100644
--- a/src/gsmtp/gsmtpclientprotocol.cpp
+++ b/src/gsmtp/gsmtpclientprotocol.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,6 +24,7 @@
 #include "gsaslclient.h"
 #include "gbase64.h"
 #include "gstr.h"
+#include "gstringfield.h"
 #include "gssl.h"
 #include "gxtext.h"
 #include "gsmtpclientprotocol.h"
@@ -97,12 +98,13 @@ void GSmtp::ClientProtocol::sendComplete()
 	if( m_state == State::sData )
 	{
 		std::size_t n = sendLines() ;
+        n++ ; // since the socket protocol has now sent the line that was blocked
 
 		G_LOG( "GSmtp::ClientProtocol: tx>>: [" << n << " line(s) of content]" ) ;
 		if( endOfContent() )
 		{
 			m_state = State::sSentDot ;
-			send( "." , true ) ;
+			sendEot() ; // "."
 		}
 	}
 }
@@ -187,25 +189,33 @@ void GSmtp::ClientProtocol::sendMailCore()
 {
 	std::string mail_from_tail = message()->from() ;
 	mail_from_tail.append( 1U , '>' ) ;
-	if( m_server_has_8bitmime && message()->eightBit() != -1 )
+	if( m_server_has_8bitmime ) // BODY=
 	{
-		mail_from_tail.append( message()->eightBit() ? " BODY=8BITMIME" : " BODY=7BIT" ) ; // RFC-6152
+		if( message()->eightBit() != -1 )
+			mail_from_tail.append( message()->eightBit() ? " BODY=8BITMIME" : " BODY=7BIT" ) ; // RFC-6152
 	}
-	if( m_authenticated_with_server && message()->fromAuthOut().empty() && !m_sasl->id().empty() )
+	if( m_authenticated_with_server ) // AUTH=
 	{
-		// default policy is to use the session authentication id, although
-		// this is not strictly conforming with RFC-2554
-		mail_from_tail.append( " AUTH=" ) ;
-		mail_from_tail.append( G::Xtext::encode(m_sasl->id()) ) ;
-	}
-	else if( m_authenticated_with_server && G::Xtext::valid(message()->fromAuthOut()) )
-	{
-		mail_from_tail.append( " AUTH=" ) ;
-		mail_from_tail.append( message()->fromAuthOut() ) ;
-	}
-	else if( m_authenticated_with_server )
-	{
-		mail_from_tail.append( " AUTH=<>" ) ;
+		if( m_config.anonymous )
+		{
+			mail_from_tail.append( " AUTH=<>" ) ;
+		}
+		else if( message()->fromAuthOut().empty() && !m_sasl->id().empty() )
+		{
+			// default policy is to use the session authentication id, although
+			// this is not strictly conforming with RFC-2554
+			mail_from_tail.append( " AUTH=" ) ;
+			mail_from_tail.append( G::Xtext::encode(m_sasl->id()) ) ;
+		}
+		else if( G::Xtext::valid(message()->fromAuthOut()) )
+		{
+			mail_from_tail.append( " AUTH=" ) ;
+			mail_from_tail.append( message()->fromAuthOut() ) ;
+		}
+		else
+		{
+			mail_from_tail.append( " AUTH=<>" ) ;
+		}
 	}
 	send( "MAIL FROM:<" , mail_from_tail ) ;
 }
@@ -305,7 +315,8 @@ bool GSmtp::ClientProtocol::applyEvent( const Reply & reply , bool is_start_even
 		else if( m_server_has_auth && m_sasl->active() )
 		{
 			m_state = State::sAuth ;
-			send( "AUTH " , m_auth_mechanism , initialResponse(*m_sasl) ) ;
+			auto rsp = initialResponse( *m_sasl ) ;
+			send( "AUTH " , m_auth_mechanism , base64(' ',rsp.data) , rsp.sensitive ) ;
 		}
 		else if( !m_server_has_auth && m_sasl->active() && m_config.must_authenticate )
 		{
@@ -342,7 +353,7 @@ bool GSmtp::ClientProtocol::applyEvent( const Reply & reply , bool is_start_even
 		if( rsp.error )
 			send( "*" ) ; // expect 501
 		else
-			send( G::Base64::encode(rsp.data) , false , rsp.sensitive ) ;
+			sendImp( G::Base64::encode(rsp.data) , false , rsp.sensitive , "[response not logged]" ) ;
 	}
 	else if( m_state == State::sAuth && reply.is(Reply::Value::Challenge_334) )
 	{
@@ -364,7 +375,8 @@ bool GSmtp::ClientProtocol::applyEvent( const Reply & reply , bool is_start_even
 		G_LOG( "GSmtp::ClientProtocol::applyEvent: " << AuthError(*m_sasl,reply).str()
 			<< ": trying [" << G::Str::lower(m_sasl->mechanism()) << "]" ) ;
 		m_auth_mechanism = m_sasl->mechanism() ;
-		send( "AUTH " , m_auth_mechanism , initialResponse(*m_sasl) ) ;
+		auto rsp = initialResponse( *m_sasl ) ;
+		send( "AUTH " , m_auth_mechanism , base64(' ',rsp.data) , rsp.sensitive ) ;
 	}
 	else if( m_state == State::sAuth && !reply.positive() && m_config.must_authenticate )
 	{
@@ -445,7 +457,7 @@ bool GSmtp::ClientProtocol::applyEvent( const Reply & reply , bool is_start_even
 		if( endOfContent() )
 		{
 			m_state = State::sSentDot ;
-			send( "." , true ) ;
+			sendEot() ; // "."
 		}
 	}
 	else if( m_state == State::sSentDataStub )
@@ -483,10 +495,14 @@ bool GSmtp::ClientProtocol::applyEvent( const Reply & reply , bool is_start_even
 	return protocol_done ;
 }
 
-std::string GSmtp::ClientProtocol::initialResponse( const GAuth::SaslClient & sasl )
+GAuth::SaslClient::Response GSmtp::ClientProtocol::initialResponse( const GAuth::SaslClient & sasl )
 {
-	std::string rsp = sasl.initialResponse( 450U ) ; // RFC-2821 total command line length of 512
-	return rsp.empty() ? rsp : ( " " + G::Base64::encode(rsp) ) ;
+	return sasl.initialResponse( 450U ) ; // RFC-2821 total command line length of 512
+}
+
+std::string GSmtp::ClientProtocol::base64( char sep , const std::string & data )
+{
+	return data.empty() ? std::string() : std::string(1U,sep).append( G::Base64::encode(data) ) ;
 }
 
 void GSmtp::ClientProtocol::onTimeout()
@@ -613,33 +629,62 @@ bool GSmtp::ClientProtocol::sendLine( std::string & line )
 	return ok ;
 }
 
-void GSmtp::ClientProtocol::send( const char * p )
+void GSmtp::ClientProtocol::sendEot()
 {
-	send( std::string(p) , false , false ) ;
+	sendImp( std::string(1U,'.') , true , false ) ;
 }
 
-void GSmtp::ClientProtocol::send( const char * p , const std::string & s , const std::string & p2 )
+void GSmtp::ClientProtocol::send( const char * p0 )
 {
-	std::string line( p ) ;
-	line.append( s ) ;
+	sendImp( std::string(p0) , false , false ) ;
+}
+
+void GSmtp::ClientProtocol::send( const char * p0 , const std::string & s1 , const std::string & p2 )
+{
+	std::string line( p0 ) ;
+	line.append( s1 ) ;
 	line.append( p2 ) ;
-	send( line , false , false ) ;
+	sendImp( line , false , false ) ;
 }
 
-void GSmtp::ClientProtocol::send( const char * p , const std::string & s )
+void GSmtp::ClientProtocol::send( const char * p0 , const std::string & s1 , const std::string & p2 , bool p2_sensitive )
 {
-	send( std::string(p) + s , false , false ) ;
+	std::string line( p0 ) ;
+	line.append( s1 ) ;
+	line.append( p2 ) ;
+	if( p2_sensitive )
+	{
+		std::string log_text = std::string(p0).append(s1).append(" [not logged]") ;
+		sendImp( line , false , true , log_text ) ;
+	}
+	else
+	{
+		sendImp( line , false , false ) ;
+	}
 }
 
-bool GSmtp::ClientProtocol::send( const std::string & line , bool eot , bool sensitive )
+void GSmtp::ClientProtocol::send( const char * p0 , const std::string & s1 )
+{
+	sendImp( std::string(p0).append(s1) , false , false ) ;
+}
+
+bool GSmtp::ClientProtocol::sendImp( const std::string & line , bool eot , bool with_log_text , const std::string & log_text )
 {
 	if( m_config.response_timeout != 0U )
 		startTimer( m_config.response_timeout ) ;
 
 	bool dot_prefix = !eot && line.length() && line.at(0U) == '.' ;
-	if( sensitive )
+	if( with_log_text )
 	{
-		G_LOG( "GSmtp::ClientProtocol: tx>>: [response not logged]" ) ;
+		G_LOG( "GSmtp::ClientProtocol: tx>>: \"" << log_text << "\"" ) ;
+	}
+	else if( line.find("\r\n",0U,2U) != std::string::npos )
+	{
+		for( G::StringField f(line,"\r\n",2U) ; f && !f.last() ; ++f )
+		{
+			G_LOG( "GSmtp::ClientProtocol: tx>>: \""
+				<< G::Str::printable(G::string_view(f.data(),f.size())) << "\"" ) ;
+		}
 	}
 	else
 	{
@@ -805,26 +850,7 @@ bool GSmtp::ClientProtocolReply::textContains( std::string key ) const
 // ===
 
 GSmtp::ClientProtocol::Config::Config()
-= default;
-
-GSmtp::ClientProtocol::Config::Config( const std::string & name_ ,
-	unsigned int response_timeout_ ,
-	unsigned int ready_timeout_ , unsigned int filter_timeout_ ,
-	bool use_starttls_if_possible_ , bool must_use_tls_ ,
-	bool must_authenticate_ , bool anonymous_ ,
-	bool must_accept_all_recipients_ , bool eight_bit_strict_ ) :
-		thishost_name(name_) ,
-		response_timeout(response_timeout_) ,
-		ready_timeout(ready_timeout_) ,
-		filter_timeout(filter_timeout_) ,
-		use_starttls_if_possible(use_starttls_if_possible_) ,
-		must_use_tls(must_use_tls_) ,
-		must_authenticate(must_authenticate_) ,
-		anonymous(anonymous_) ,
-		must_accept_all_recipients(must_accept_all_recipients_) ,
-		eight_bit_strict(eight_bit_strict_)
-{
-}
+= default ;
 
 // ==
 
diff --git a/src/gsmtp/gsmtpclientprotocol.h b/src/gsmtp/gsmtpclientprotocol.h
index 10ef5f1..7ece8c2 100644
--- a/src/gsmtp/gsmtpclientprotocol.h
+++ b/src/gsmtp/gsmtpclientprotocol.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -27,7 +27,7 @@
 #include "gsaslclient.h"
 #include "gsecrets.h"
 #include "gslot.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gtimer.h"
 #include "gexception.h"
 #include <memory>
@@ -155,9 +155,9 @@ private:
 class GSmtp::ClientProtocol : private GNet::TimerBase
 {
 public:
-	G_EXCEPTION( NotReady , "not ready" ) ;
-	G_EXCEPTION( TlsError , "tls/ssl error" ) ;
-	G_EXCEPTION_CLASS( SmtpError , "smtp error" ) ;
+	G_EXCEPTION( NotReady , tx("not ready") ) ;
+	G_EXCEPTION( TlsError , tx("tls/ssl error") ) ;
+	G_EXCEPTION_CLASS( SmtpError , tx("smtp error") ) ;
 	using Reply = ClientProtocolReply ;
 
 	class Sender /// An interface used by ClientProtocol to send protocol messages.
@@ -189,15 +189,10 @@ public:
 		bool use_starttls_if_possible{false} ;
 		bool must_use_tls{false} ;
 		bool must_authenticate{false} ;
-		bool anonymous{false} ; // MAIL..AUTH=
+		bool anonymous{false} ; // force MAIL..AUTH=<>
 		bool must_accept_all_recipients{false} ;
 		bool eight_bit_strict{false} ; // fail 8bit messages to 7bit server
 		Config() ;
-		Config( const std::string & name , unsigned int response_timeout ,
-			unsigned int ready_timeout , unsigned int filter_timeout ,
-			bool use_starttls_if_possible , bool must_use_tls ,
-			bool must_authenticate , bool anonymous ,
-			bool must_accept_all_recipients , bool eight_bit_strict ) ;
 		Config & set_thishost_name( const std::string & ) ;
 		Config & set_response_timeout( unsigned int ) ;
 		Config & set_ready_timeout( unsigned int ) ;
@@ -263,8 +258,8 @@ public:
 	~ClientProtocol() override = default ;
 	ClientProtocol( const ClientProtocol & ) = delete ;
 	ClientProtocol( ClientProtocol && ) = delete ;
-	void operator=( const ClientProtocol & ) = delete ;
-	void operator=( ClientProtocol && ) = delete ;
+	ClientProtocol & operator=( const ClientProtocol & ) = delete ;
+	ClientProtocol & operator=( ClientProtocol && ) = delete ;
 
 private:
 	struct AuthError : public SmtpError
@@ -278,10 +273,12 @@ private: // overrides
 
 private:
 	std::shared_ptr<StoredMessage> message() ;
+	void sendEot() ;
 	void send( const char * ) ;
 	void send( const char * , const std::string & ) ;
 	void send( const char * , const std::string & , const std::string & ) ;
-	bool send( const std::string & , bool eot , bool sensitive = false ) ;
+	void send( const char * , const std::string & , const std::string & , bool ) ;
+	bool sendImp( const std::string & , bool eot , bool sensitive , const std::string & = {} ) ;
 	bool sendLine( std::string & ) ;
 	std::size_t sendLines() ;
 	void sendEhlo() ;
@@ -295,7 +292,8 @@ private:
 	bool serverAuth( const ClientProtocolReply & reply ) const ;
 	G::StringArray serverAuthMechanisms( const ClientProtocolReply & reply ) const ;
 	void startFiltering() ;
-	static std::string initialResponse( const GAuth::SaslClient & ) ;
+	static GAuth::SaslClient::Response initialResponse( const GAuth::SaslClient & ) ;
+	static std::string base64( char , const std::string & ) ;
 
 private:
 	enum class State {
diff --git a/src/gsmtp/gsmtpserver.cpp b/src/gsmtp/gsmtpserver.cpp
index 9d17634..2acc4d2 100644
--- a/src/gsmtp/gsmtpserver.cpp
+++ b/src/gsmtp/gsmtpserver.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,7 +21,6 @@
 #include "gdef.h"
 #include "gsmtpserver.h"
 #include "gresolver.h"
-#include "gdnsblock.h"
 #include "gprotocolmessagestore.h"
 #include "gprotocolmessageforward.h"
 #include "gfilterfactory.h"
@@ -33,27 +32,31 @@
 #include "gassert.h"
 #include "gtest.h"
 #include <string>
+#include <utility>
 #include <functional>
 
 namespace GSmtp
 {
 	struct AnonymousText : public ServerProtocol::Text /// Provides anodyne SMTP protocol text.
 	{
-		explicit AnonymousText( const std::string & = std::string() ) ;
+		AnonymousText( bool with_received_line , const std::string & this_host , const GNet::Address & peer_address ) ;
 		std::string greeting() const override ;
 		std::string hello( const std::string & peer_name ) const override ;
 		std::string received( const std::string & smtp_peer_name ,
 			bool auth , bool secure , const std::string & protocol ,
 			const std::string & cipher ) const override ;
+
+		bool m_with_received_line ;
 		std::string m_thishost ;
+		GNet::Address m_peer_address ;
 	} ;
 }
 
-GSmtp::AnonymousText::AnonymousText( const std::string & thishost ) :
-	m_thishost(thishost)
+GSmtp::AnonymousText::AnonymousText( bool with_received_line , const std::string & thishost , const GNet::Address & peer_address ) :
+	m_with_received_line(with_received_line) ,
+	m_thishost(thishost) ,
+	m_peer_address(peer_address)
 {
-	if( m_thishost.empty() )
-		m_thishost = "smtp" ;
 }
 
 std::string GSmtp::AnonymousText::greeting() const
@@ -63,39 +66,43 @@ std::string GSmtp::AnonymousText::greeting() const
 
 std::string GSmtp::AnonymousText::hello( const std::string & ) const
 {
-	return m_thishost + " says hello" ;
+	return "smtp says hello" ;
 }
 
-std::string GSmtp::AnonymousText::received( const std::string & , bool , bool ,
-	const std::string & , const std::string & ) const
+std::string GSmtp::AnonymousText::received( const std::string & smtp_peer_name ,
+	bool authenticated , bool secure , const std::string & protocol , const std::string & cipher ) const
 {
-	return std::string() ; // no Received line
+	if( m_with_received_line )
+		return ServerProtocolText::receivedLine( smtp_peer_name , m_peer_address.hostPartString() , m_thishost ,
+			authenticated , secure , protocol , cipher ) ;
+	else
+		return {} ;
 }
 
 // ===
 
 GSmtp::ServerPeer::ServerPeer( GNet::ExceptionSinkUnbound esu ,
-	const GNet::ServerPeerInfo & peer_info , Server & server ,
+	GNet::ServerPeerInfo && peer_info , Server & server ,
 	const GAuth::SaslServerSecrets & server_secrets , const Server::Config & server_config ,
 	std::unique_ptr<ServerProtocol::Text> ptext ) :
-		GNet::ServerPeer(esu.bind(this),peer_info,GNet::LineBufferConfig::transparent()) ,
+		GNet::ServerPeer(esu.bind(this),std::move(peer_info),GNet::LineBufferConfig::transparent()) ,
 		m_server(server) ,
-		m_block(*this,esu.bind(this),server_config.dnsbl_config) ,
+		m_block(std::bind(&ServerPeer::onDnsBlockResult,this,std::placeholders::_1),esu.bind(this),server_config.dnsbl_config) ,
 		m_flush_timer(*this,&ServerPeer::onFlushTimeout,esu.bind(this)) ,
 		m_check_timer(*this,&ServerPeer::onCheckTimeout,esu.bind(this)) ,
 		m_verifier(VerifierFactory::newVerifier(esu.bind(this),
-			server_config.verifier_address,server_config.verifier_timeout)) ,
+			server_config.verifier_spec,server_config.verifier_timeout)) ,
 		m_pmessage(server.newProtocolMessage(esu.bind(this))) ,
 		m_ptext(ptext.release()) ,
 		m_line_buffer(GNet::LineBufferConfig::smtp()) ,
 		m_protocol(*this,*m_verifier,*m_pmessage,server_secrets,server_config.sasl_server_config,
-			*m_ptext,peer_info.m_address,server_config.protocol_config)
+			*m_ptext,peerAddress(),server_config.protocol_config)
 {
-	G_LOG_S( "GSmtp::ServerPeer: smtp connection from " << peer_info.m_address.displayString() ) ;
+	G_LOG_S( "GSmtp::ServerPeer: smtp connection from " << peerAddress().displayString() ) ;
 	if( server_config.dnsbl_config.empty() )
 		m_protocol.init() ;
 	else
-		m_block.start( peer_info.m_address ) ;
+		m_block.start( peerAddress() ) ;
 
 	if( !server_config.protocol_config.tls_connection )
 		m_check_timer.startTimer( 1U ) ;
@@ -104,7 +111,7 @@ GSmtp::ServerPeer::ServerPeer( GNet::ExceptionSinkUnbound esu ,
 void GSmtp::ServerPeer::onDelete( const std::string & reason )
 {
 	G_LOG_S( "GSmtp::ServerPeer: smtp connection closed: " << reason << (reason.empty()?"":": ")
-		<< peerAddress().second.displayString() ) ;
+		<< peerAddress().displayString() ) ;
 
 	m_server.eventSignal().emit( "done" , std::string(reason) ) ;
 }
@@ -161,7 +168,7 @@ void GSmtp::ServerPeer::onSecure( const std::string & certificate , const std::s
 
 void GSmtp::ServerPeer::protocolSend( const std::string & line , bool go_secure )
 {
-	if( !send( line , 0U ) ) // GNet::ServerPeer::send()
+	if( !send( line ) ) // GNet::ServerPeer::send()
 		throw SendError() ; // we only send short half-duplex responses, so treat flow control as fatal
 
 	if( go_secure )
@@ -180,11 +187,9 @@ void GSmtp::ServerPeer::protocolShutdown()
 	socket().shutdown() ; // fwiw
 }
 
-void GSmtp::ServerPeer::onDnsBlockResult( const GNet::DnsBlockResult & result )
+void GSmtp::ServerPeer::onDnsBlockResult( bool allow )
 {
-	result.log() ;
-	result.warn() ;
-	if( result.allow() )
+	if( allow )
 		m_protocol.init() ;
 	else
 		throw GNet::Done() ;
@@ -205,7 +210,7 @@ void GSmtp::ServerPeer::onCheckTimeout()
 
 GSmtp::Server::Server( GNet::ExceptionSink es , MessageStore & store , FilterFactory & ff ,
 	const GAuth::SaslClientSecrets & client_secrets , const GAuth::SaslServerSecrets & server_secrets ,
-	const Config & server_config , const std::string & forward_to ,
+	const Config & server_config , const std::string & forward_to , int forward_to_family ,
 	const GSmtp::Client::Config & client_config ) :
 		GNet::MultiServer(es,server_config.interfaces,server_config.port,"smtp",server_config.server_peer_config,server_config.server_config) ,
 		m_store(store) ,
@@ -214,6 +219,7 @@ GSmtp::Server::Server( GNet::ExceptionSink es , MessageStore & store , FilterFac
 		m_client_config(client_config) ,
 		m_server_secrets(server_secrets) ,
 		m_forward_to(forward_to) ,
+		m_forward_to_family(forward_to_family) ,
 		m_client_secrets(client_secrets)
 {
 }
@@ -234,10 +240,10 @@ void GSmtp::Server::report() const
 }
 
 std::unique_ptr<GNet::ServerPeer> GSmtp::Server::newPeer( GNet::ExceptionSinkUnbound esu ,
-	GNet::ServerPeerInfo peer_info , GNet::MultiServer::ServerInfo )
+	GNet::ServerPeerInfo && peer_info , GNet::MultiServer::ServerInfo )
 {
 	using G::format ;
-	using G::gettext ;
+	using G::txt ;
 	std::unique_ptr<ServerPeer> ptr ;
 	try
 	{
@@ -245,13 +251,14 @@ std::unique_ptr<GNet::ServerPeer> GSmtp::Server::newPeer( GNet::ExceptionSinkUnb
 		if( ! m_server_config.allow_remote && ! GNet::Local::isLocal(peer_info.m_address,reason) )
 		{
 			G_WARNING( "GSmtp::Server: "
-				<< format(gettext("configured to reject non-local smtp connection: %1%")) % reason ) ;
+				<< format(txt("configured to reject non-local smtp connection: %1%")) % reason ) ;
 		}
 		else
 		{
-			ptr = std::make_unique<ServerPeer>( esu , peer_info , *this ,
+			GNet::Address peer_address = peer_info.m_address ;
+			ptr = std::make_unique<ServerPeer>( esu , std::move(peer_info) , *this ,
 				m_server_secrets , m_server_config ,
-				newProtocolText(m_server_config.anonymous,peer_info.m_address) ) ;
+				newProtocolText(m_server_config.anonymous_smtp,m_server_config.anonymous_content,peer_address) ) ;
 		}
 	}
 	catch( std::exception & e ) // newPeer()
@@ -261,19 +268,20 @@ std::unique_ptr<GNet::ServerPeer> GSmtp::Server::newPeer( GNet::ExceptionSinkUnb
 	return std::unique_ptr<GNet::ServerPeer>( ptr.release() ) ; // up-cast
 }
 
-std::unique_ptr<GSmtp::ServerProtocol::Text> GSmtp::Server::newProtocolText( bool anonymous ,
-	const GNet::Address & peer_address ) const
+std::unique_ptr<GSmtp::ServerProtocol::Text> GSmtp::Server::newProtocolText( bool anonymous_smtp ,
+	bool anonymous_content , const GNet::Address & peer_address ) const
 {
-	if( anonymous )
-		return std::make_unique<AnonymousText>() ; // up-cast
+	if( anonymous_smtp )
+		return std::make_unique<AnonymousText>( !anonymous_content ,
+			GNet::Local::canonicalName() , peer_address ) ;
 	else
 		return std::make_unique<ServerProtocolText>( m_server_config.ident ,
-			GNet::Local::canonicalName() , peer_address ) ; // up-cast
+			!anonymous_content , GNet::Local::canonicalName() , peer_address ) ;
 }
 
 std::unique_ptr<GSmtp::Filter> GSmtp::Server::newFilter( GNet::ExceptionSink es ) const
 {
-	return m_ff.newFilter( es , true , m_server_config.filter_address , m_server_config.filter_timeout ) ;
+	return m_ff.newFilter( es , true , m_server_config.filter_spec , m_server_config.filter_timeout , {} ) ;
 }
 
 std::unique_ptr<GSmtp::ProtocolMessage> GSmtp::Server::newProtocolMessageStore( std::unique_ptr<Filter> filter )
@@ -286,7 +294,7 @@ std::unique_ptr<GSmtp::ProtocolMessage> GSmtp::Server::newProtocolMessageForward
 {
 	// wrap the given 'store' object in a 'forward' one
 	return std::make_unique<ProtocolMessageForward>( es , m_store , m_ff , std::move(pm) , m_client_config ,
-		m_client_secrets , m_forward_to ) ; // up-cast
+		m_client_secrets , m_forward_to , m_forward_to_family ) ; // up-cast
 }
 
 std::unique_ptr<GSmtp::ProtocolMessage> GSmtp::Server::newProtocolMessage( GNet::ExceptionSink es )
@@ -297,35 +305,3 @@ std::unique_ptr<GSmtp::ProtocolMessage> GSmtp::Server::newProtocolMessage( GNet:
 		newProtocolMessageStore( newFilter(es) ) ;
 }
 
-// ===
-
-GSmtp::Server::Config::Config()
-= default;
-
-GSmtp::Server::Config::Config( bool allow_remote_ , const G::StringArray & interfaces_ ,
-	unsigned int port_ ,
-	const std::string & ident_ , bool anonymous_ ,
-	const std::string & filter_address_ ,
-	unsigned int filter_timeout_ ,
-	const std::string & verifier_address_ ,
-	unsigned int verifier_timeout_ ,
-	GNet::ServerPeerConfig server_peer_config_ ,
-	ServerProtocol::Config protocol_config_ ,
-	const std::string & sasl_server_config_ ,
-	const std::string & dnsbl_config_ ) :
-		allow_remote(allow_remote_) ,
-		interfaces(interfaces_) ,
-		port(port_) ,
-		ident(ident_) ,
-		anonymous(anonymous_) ,
-		filter_address(filter_address_) ,
-		filter_timeout(filter_timeout_) ,
-		verifier_address(verifier_address_) ,
-		verifier_timeout(verifier_timeout_) ,
-		server_peer_config(server_peer_config_) ,
-		protocol_config(protocol_config_) ,
-		sasl_server_config(sasl_server_config_) ,
-		dnsbl_config(dnsbl_config_)
-{
-}
-
diff --git a/src/gsmtp/gsmtpserver.h b/src/gsmtp/gsmtpserver.h
index 26eaf8d..d2db748 100644
--- a/src/gsmtp/gsmtpserver.h
+++ b/src/gsmtp/gsmtpserver.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -25,7 +25,8 @@
 #include "gmultiserver.h"
 #include "gsmtpclient.h"
 #include "gfilterfactory.h"
-#include "gdnsblock.h"
+#include "gfactoryparser.h"
+#include "gdnsbl.h"
 #include "glinebuffer.h"
 #include "gverifier.h"
 #include "gmessagestore.h"
@@ -57,35 +58,31 @@ public:
 		G::StringArray interfaces ;
 		unsigned int port{0U} ;
 		std::string ident ;
-		bool anonymous{false} ;
-		std::string filter_address ;
+		bool anonymous_smtp{false} ;
+		bool anonymous_content{false} ;
+		FactoryParser::Result filter_spec ;
 		unsigned int filter_timeout{0U} ;
-		std::string verifier_address ;
+		FactoryParser::Result verifier_spec ;
 		unsigned int verifier_timeout{0U} ;
-		GNet::ServerPeerConfig server_peer_config ;
-		GNet::ServerConfig server_config ;
+		GNet::ServerPeer::Config server_peer_config ;
+		GNet::Server::Config server_config ;
 		ServerProtocol::Config protocol_config ;
 		std::string sasl_server_config ;
 		std::string dnsbl_config ;
 
-		Config() ;
-		Config( bool allow_remote , const G::StringArray & interfaces , unsigned int port ,
-			const std::string & ident , bool anonymous , const std::string & filter_address ,
-			unsigned int filter_timeout , const std::string & verifier_adress ,
-			unsigned int verifier_timeout , GNet::ServerPeerConfig server_peer_config ,
-			ServerProtocol::Config protocol_config , const std::string & sasl_server_config ,
-			const std::string & dnsbl_config ) ;
 		Config & set_allow_remote( bool = true ) ;
 		Config & set_interfaces( const G::StringArray & ) ;
 		Config & set_port( unsigned int ) ;
 		Config & set_ident( const std::string & ) ;
 		Config & set_anonymous( bool = true ) ;
-		Config & set_filter_address( const std::string & ) ;
+		Config & set_anonymous_smtp( bool = true ) ;
+		Config & set_anonymous_content( bool = true ) ;
+		Config & set_filter_spec( const FactoryParser::Result & ) ;
 		Config & set_filter_timeout( unsigned int ) ;
-		Config & set_verifier_address( const std::string & ) ;
+		Config & set_verifier_spec( const FactoryParser::Result & ) ;
 		Config & set_verifier_timeout( unsigned int ) ;
-		Config & set_server_peer_config( const GNet::ServerPeerConfig & ) ;
-		Config & set_server_config( const GNet::ServerConfig & ) ;
+		Config & set_server_peer_config( const GNet::ServerPeer::Config & ) ;
+		Config & set_server_config( const GNet::Server::Config & ) ;
 		Config & set_protocol_config( const ServerProtocol::Config & ) ;
 		Config & set_sasl_server_config( const std::string & ) ;
 		Config & set_dnsbl_config( const std::string & ) ;
@@ -93,7 +90,7 @@ public:
 
 	Server( GNet::ExceptionSink es , MessageStore & store , FilterFactory & ,
 		const GAuth::SaslClientSecrets & client_secrets , const GAuth::SaslServerSecrets & server_secrets ,
-		const Config & server_config , const std::string & forward_to ,
+		const Config & server_config , const std::string & forward_to , int forward_to_family ,
 		const GSmtp::Client::Config & client_config ) ;
 			///< Constructor. Listens on the given port number using INET_ANY
 			///< if 'server_config.interfaces' is empty, or on specific
@@ -115,19 +112,19 @@ public:
 		///< Called by GSmtp::ServerPeer to construct a ProtocolMessage.
 
 private: // overrides
-	std::unique_ptr<GNet::ServerPeer> newPeer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo , GNet::MultiServer::ServerInfo ) override ; // Override from GNet::MultiServer.
+	std::unique_ptr<GNet::ServerPeer> newPeer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo && , GNet::MultiServer::ServerInfo ) override ; // Override from GNet::MultiServer.
 
 public:
 	Server( const Server & ) = delete ;
 	Server( Server && ) = delete ;
-	void operator=( const Server & ) = delete ;
-	void operator=( Server && ) = delete ;
+	Server & operator=( const Server & ) = delete ;
+	Server & operator=( Server && ) = delete ;
 
 private:
 	std::unique_ptr<Filter> newFilter( GNet::ExceptionSink ) const ;
 	std::unique_ptr<ProtocolMessage> newProtocolMessageStore( std::unique_ptr<Filter> ) ;
 	std::unique_ptr<ProtocolMessage> newProtocolMessageForward( GNet::ExceptionSink , std::unique_ptr<ProtocolMessage> ) ;
-	std::unique_ptr<ServerProtocol::Text> newProtocolText( bool , const GNet::Address & ) const ;
+	std::unique_ptr<ServerProtocol::Text> newProtocolText( bool , bool , const GNet::Address & ) const ;
 
 private:
 	MessageStore & m_store ;
@@ -137,6 +134,7 @@ private:
 	const GAuth::SaslServerSecrets & m_server_secrets ;
 	std::string m_sasl_server_config ;
 	std::string m_forward_to ;
+	int m_forward_to_family ;
 	const GAuth::SaslClientSecrets & m_client_secrets ;
 	std::string m_sasl_client_config ;
 	G::Slot::Signal<const std::string&,const std::string&> m_event_signal ;
@@ -146,12 +144,12 @@ private:
 /// Handles a connection from a remote SMTP client.
 /// \see GSmtp::Server
 ///
-class GSmtp::ServerPeer : public GNet::ServerPeer , private ServerProtocol::Sender , private GNet::DnsBlockCallback
+class GSmtp::ServerPeer : public GNet::ServerPeer , private ServerProtocol::Sender
 {
 public:
-	G_EXCEPTION( SendError , "failed to send smtp response" ) ;
+	G_EXCEPTION( SendError , tx("failed to send smtp response") ) ;
 
-	ServerPeer( GNet::ExceptionSinkUnbound , const GNet::ServerPeerInfo & peer_info , Server & server ,
+	ServerPeer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo && peer_info , Server & server ,
 		const GAuth::SaslServerSecrets & server_secrets , const Server::Config & server_config ,
 		std::unique_ptr<ServerProtocol::Text> ptext ) ;
 			///< Constructor.
@@ -163,23 +161,23 @@ private: // overrides
 	void onSecure( const std::string & , const std::string & , const std::string & ) override ; // Override from GNet::SocketProtocolSink.
 	void protocolSend( const std::string & line , bool ) override ; // Override from ServerProtocol::Sender.
 	void protocolShutdown() override ; // Override from ServerProtocol::Sender.
-	void onDnsBlockResult( const GNet::DnsBlockResult & ) override ; // Override from GNet::DnsBlockCallback.
 	void onData( const char * , std::size_t ) override ; // Override from GNet::ServerPeer.
 
 public:
 	~ServerPeer() override = default ;
 	ServerPeer( const ServerPeer & ) = delete ;
 	ServerPeer( ServerPeer && ) = delete ;
-	void operator=( const ServerPeer & ) = delete ;
-	void operator=( ServerPeer && ) = delete ;
+	ServerPeer & operator=( const ServerPeer & ) = delete ;
+	ServerPeer & operator=( ServerPeer && ) = delete ;
 
 private:
 	void onCheckTimeout() ;
 	void onFlushTimeout() ;
+	void onDnsBlockResult( bool allow ) ;
 
 private:
 	Server & m_server ;
-	GNet::DnsBlock m_block ;
+	GNet::Dnsbl m_block ;
 	GNet::Timer<ServerPeer> m_flush_timer ;
 	GNet::Timer<ServerPeer> m_check_timer ;
 	std::unique_ptr<Verifier> m_verifier ;
@@ -193,13 +191,15 @@ inline GSmtp::Server::Config & GSmtp::Server::Config::set_allow_remote( bool b )
 inline GSmtp::Server::Config & GSmtp::Server::Config::set_interfaces( const G::StringArray & a ) { interfaces = a ; return *this ; }
 inline GSmtp::Server::Config & GSmtp::Server::Config::set_port( unsigned int n ) { port = n ; return *this ; }
 inline GSmtp::Server::Config & GSmtp::Server::Config::set_ident( const std::string & s ) { ident = s ; return *this ; }
-inline GSmtp::Server::Config & GSmtp::Server::Config::set_anonymous( bool b ) { anonymous = b ; return *this ; }
-inline GSmtp::Server::Config & GSmtp::Server::Config::set_filter_address( const std::string & s ) { filter_address = s ; return *this ; }
+inline GSmtp::Server::Config & GSmtp::Server::Config::set_anonymous( bool b ) { anonymous_smtp = anonymous_content = b ; return *this ; }
+inline GSmtp::Server::Config & GSmtp::Server::Config::set_anonymous_smtp( bool b ) { anonymous_smtp = b ; return *this ; }
+inline GSmtp::Server::Config & GSmtp::Server::Config::set_anonymous_content( bool b ) { anonymous_content = b ; return *this ; }
+inline GSmtp::Server::Config & GSmtp::Server::Config::set_filter_spec( const FactoryParser::Result & r ) { filter_spec = r ; return *this ; }
 inline GSmtp::Server::Config & GSmtp::Server::Config::set_filter_timeout( unsigned int t ) { filter_timeout = t ; return *this ; }
-inline GSmtp::Server::Config & GSmtp::Server::Config::set_verifier_address( const std::string & s ) { verifier_address = s ; return *this ; }
+inline GSmtp::Server::Config & GSmtp::Server::Config::set_verifier_spec( const FactoryParser::Result & r ) { verifier_spec = r ; return *this ; }
 inline GSmtp::Server::Config & GSmtp::Server::Config::set_verifier_timeout( unsigned int t ) { verifier_timeout = t ; return *this ; }
-inline GSmtp::Server::Config & GSmtp::Server::Config::set_server_peer_config( const GNet::ServerPeerConfig & c ) { server_peer_config = c ; return *this ; }
-inline GSmtp::Server::Config & GSmtp::Server::Config::set_server_config( const GNet::ServerConfig & c ) { server_config = c ; return *this ; }
+inline GSmtp::Server::Config & GSmtp::Server::Config::set_server_peer_config( const GNet::ServerPeer::Config & c ) { server_peer_config = c ; return *this ; }
+inline GSmtp::Server::Config & GSmtp::Server::Config::set_server_config( const GNet::Server::Config & c ) { server_config = c ; return *this ; }
 inline GSmtp::Server::Config & GSmtp::Server::Config::set_protocol_config( const ServerProtocol::Config & c ) { protocol_config = c ; return *this ; }
 inline GSmtp::Server::Config & GSmtp::Server::Config::set_sasl_server_config( const std::string & s ) { sasl_server_config = s ; return *this ; }
 inline GSmtp::Server::Config & GSmtp::Server::Config::set_dnsbl_config( const std::string & s ) { dnsbl_config = s ; return *this ; }
diff --git a/src/gsmtp/gsmtpserverprotocol.cpp b/src/gsmtp/gsmtpserverprotocol.cpp
index 30d593f..f8152ae 100644
--- a/src/gsmtp/gsmtpserverprotocol.cpp
+++ b/src/gsmtp/gsmtpserverprotocol.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -42,7 +42,7 @@ GSmtp::ServerProtocol::ServerProtocol( Sender & sender ,
 		m_verifier(verifier) ,
 		m_text(text) ,
 		m_message(pmessage) ,
-		m_sasl(GAuth::SaslServerFactory::newSaslServer(secrets,sasl_server_config,false/*apop*/)) ,
+		m_sasl(GAuth::SaslServerFactory::newSaslServer(secrets,false,sasl_server_config,false)) ,
 		m_config(config) ,
 		m_fsm(State::sStart,State::sEnd,State::s_Same,State::s_Any) ,
 		m_with_starttls(false) ,
@@ -88,18 +88,10 @@ GSmtp::ServerProtocol::ServerProtocol( Sender & sender ,
 	m_fsm( Event::eDone , State::sProcessing , State::sIdle , &ServerProtocol::doComplete ) ;
 	m_fsm( Event::eContent , State::sDiscarding , State::sDiscarding , &ServerProtocol::doDiscard ) ;
 	m_fsm( Event::eEot , State::sDiscarding , State::sIdle , &ServerProtocol::doDiscarded ) ;
+	m_fsm( Event::eAuth , State::sIdle , State::sAuth , &ServerProtocol::doAuth , State::sIdle ) ;
+	m_fsm( Event::eAuthData, State::sAuth , State::sAuth , &ServerProtocol::doAuthData , State::sIdle ) ;
 
-	if( m_sasl->active() )
-	{
-		m_fsm( Event::eAuth , State::sIdle , State::sAuth , &ServerProtocol::doAuth , State::sIdle ) ;
-		m_fsm( Event::eAuthData, State::sAuth , State::sAuth , &ServerProtocol::doAuthData , State::sIdle ) ;
-	}
-	else
-	{
-		m_fsm( Event::eAuth , State::sIdle , State::sIdle , &ServerProtocol::doAuthInvalid ) ;
-	}
-
-	if( m_config.tls_starttls && GNet::SocketProtocol::secureAcceptCapable() )
+	if( m_config.tls_starttls )
 	{
 		m_with_starttls = true ;
 		m_fsm( Event::eStartTls , State::sIdle , State::sStartingTls , &ServerProtocol::doStartTls , State::sIdle ) ;
@@ -214,8 +206,8 @@ bool GSmtp::ServerProtocol::apply( const char * line_data , std::size_t line_dat
 	else
 	{
 		std::string line( line_data , line_data_size ) ;
-		G_LOG( "GSmtp::ServerProtocol: rx<<: \"" << G::Str::printable(line) << "\"" ) ;
 		event = commandEvent( commandWord(line) ) ;
+		G_LOG( "GSmtp::ServerProtocol: rx<<: \"" << (event == Event::eAuth ? printableAuth(line) : G::Str::printable(line)) << "\"" ) ;
 		m_buffer = commandLine( line ) ;
 		event_data = EventData( m_buffer.data() , m_buffer.size() ) ;
 	}
@@ -351,9 +343,9 @@ void GSmtp::ServerProtocol::doVrfy( EventData event_data , bool & predicate )
 
 void GSmtp::ServerProtocol::verify( const std::string & to , const std::string & from )
 {
-	std::string mechanism = m_sasl->active() ? m_sasl->mechanism() : std::string() ;
-	std::string id = m_sasl->active() ? m_sasl->id() : std::string() ;
-	if( m_sasl->active() && !m_session_authenticated )
+	std::string mechanism = m_sasl->authenticated() ? m_sasl->mechanism() : std::string() ;
+	std::string id = m_sasl->id() ;
+	if( mechanism.empty() )
 		mechanism = "NONE" ;
 	m_verifier.verify( to , from , m_peer_address , mechanism , id ) ;
 }
@@ -431,16 +423,25 @@ void GSmtp::ServerProtocol::doHelo( EventData event_data , bool & predicate )
 
 bool GSmtp::ServerProtocol::authenticationRequiresEncryption() const
 {
-	bool encryption_required_by_user = m_config.authentication_requires_encryption ;
-	bool encryption_required_by_sasl = m_sasl->active() && m_sasl->requiresEncryption() ;
-	return encryption_required_by_user || encryption_required_by_sasl ;
+	return mechanisms().empty() && !mechanisms(true).empty() ;
 }
 
-void GSmtp::ServerProtocol::doAuthInvalid( EventData , bool & )
+std::string GSmtp::ServerProtocol::printableAuth( const std::string & auth_line ) const
 {
-	// (workround with "--server-auth" pointing to an empty file)
-	G_WARNING( "GSmtp::ServerProtocol: client protocol error: AUTH requested but not advertised" ) ;
-	sendNotImplemented() ;
+	constexpr std::size_t npos = std::string::npos ;
+	std::size_t pos1 = auth_line.find_first_not_of( " \t" , 0U , 2U ) ;
+	std::size_t pos2 = auth_line.find_first_of( " \t" , pos1 , 2U ) ;
+	std::size_t pos3 = auth_line.find_first_not_of( " \t" , pos2 , 2U ) ;
+	std::size_t pos4 = auth_line.find_first_of( " \t" , pos3 , 2U ) ;
+	std::size_t pos5 = auth_line.find_first_not_of( " \t" , pos4 , 2U ) ;
+	if( pos1 != npos && pos2 != npos && pos3 != npos && pos4 != npos && pos5 != npos )
+	{
+		return auth_line.substr(0U,pos5).append(" [not logged]" ) ;
+	}
+	else
+	{
+		return auth_line ;
+	}
 }
 
 void GSmtp::ServerProtocol::doAuth( EventData event_data , bool & predicate )
@@ -466,7 +467,14 @@ void GSmtp::ServerProtocol::doAuth( EventData event_data , bool & predicate )
 		predicate = false ; // => idle
 		sendOutOfSequence() ; // see RFC-2554 "Restrictions"
 	}
-	else if( ! m_sasl->init(mechanism) )
+	else if( mechanisms().empty() )
+	{
+		// (workround with "--server-auth" pointing to an empty file)
+		G_WARNING( "GSmtp::ServerProtocol: client protocol error: AUTH requested but not advertised" ) ;
+		predicate = false ; // => idle
+		sendNotImplemented() ;
+	}
+	else if( ! m_sasl->init(m_secure,mechanism) )
 	{
 		G_WARNING( "GSmtp::ServerProtocol: request for unsupported server AUTH mechanism: " << mechanism ) ;
 		predicate = false ; // => idle
@@ -508,7 +516,7 @@ void GSmtp::ServerProtocol::doAuth( EventData event_data , bool & predicate )
 
 void GSmtp::ServerProtocol::doAuthData( EventData event_data , bool & predicate )
 {
-	G_LOG( "GSmtp::ServerProtocol: rx<<: [authentication response not logged]" ) ;
+	G_LOG( "GSmtp::ServerProtocol: rx<<: \"[authentication response not logged]\"" ) ;
 	std::string line( event_data.ptr , event_data.size ) ;
 	if( line == "*" )
 	{
@@ -547,7 +555,7 @@ void GSmtp::ServerProtocol::doAuthData( EventData event_data , bool & predicate
 void GSmtp::ServerProtocol::doMail( EventData event_data , bool & predicate )
 {
 	std::string line( event_data.ptr , event_data.size ) ;
-	if( !m_session_authenticated && m_sasl->active() && !m_sasl->trusted(m_peer_address) )
+	if( m_config.mail_requires_authentication && !m_sasl->authenticated() && !m_sasl->trusted(m_peer_address) )
 	{
 		G_LOG( "GSmtp::ServerProtocol::doMail: server authentication enabled "
 			"but not a trusted address: " << m_peer_address.hostPartString() ) ;
@@ -870,8 +878,8 @@ void GSmtp::ServerProtocol::sendEhloReply()
 	if( m_config.max_size != 0U )
 		ss << "250-SIZE " << m_config.max_size << crlf() ;
 
-	if( m_sasl->active() && !( authenticationRequiresEncryption() && !m_secure ) )
-		ss << "250-AUTH " << m_sasl->mechanisms(' ') << crlf() ;
+	if( !mechanisms().empty() )
+		ss << "250-AUTH " << G::Str::join(" ",mechanisms()) << crlf() ;
 
 	if( m_with_starttls && !m_secure )
 		ss << "250-STARTTLS" << crlf() ;
@@ -1005,9 +1013,11 @@ std::string GSmtp::ServerProtocol::parsePeerName( const std::string & line ) con
 
 // ===
 
-GSmtp::ServerProtocolText::ServerProtocolText( const std::string & code_ident , const std::string & thishost ,
+GSmtp::ServerProtocolText::ServerProtocolText( const std::string & code_ident ,
+	bool with_received_line , const std::string & thishost ,
 	const GNet::Address & peer_address ) :
 		m_code_ident(code_ident) ,
+		m_with_received_line(with_received_line) ,
 		m_thishost(thishost) ,
 		m_peer_address(peer_address)
 {
@@ -1026,8 +1036,8 @@ std::string GSmtp::ServerProtocolText::hello( const std::string & ) const
 std::string GSmtp::ServerProtocolText::received( const std::string & smtp_peer_name ,
 	bool authenticated , bool secure , const std::string & protocol , const std::string & cipher ) const
 {
-	return receivedLine( smtp_peer_name , m_peer_address.hostPartString() , m_thishost ,
-		authenticated , secure , protocol , cipher ) ;
+	return m_with_received_line ? receivedLine( smtp_peer_name , m_peer_address.hostPartString() , m_thishost ,
+		authenticated , secure , protocol , cipher ) : std::string() ;
 }
 
 std::string GSmtp::ServerProtocolText::receivedLine( const std::string & smtp_peer_name ,
@@ -1064,6 +1074,16 @@ std::string GSmtp::ServerProtocolText::receivedLine( const std::string & smtp_pe
 	return ss.str() ;
 }
 
+G::StringArray GSmtp::ServerProtocol::mechanisms() const
+{
+	return m_sasl->mechanisms( m_secure ) ;
+}
+
+G::StringArray GSmtp::ServerProtocol::mechanisms( bool secure ) const
+{
+	return m_sasl->mechanisms( secure ) ;
+}
+
 // ===
 
 GSmtp::ServerProtocol::Config::Config()
diff --git a/src/gsmtp/gsmtpserverprotocol.h b/src/gsmtp/gsmtpserverprotocol.h
index 1e59751..95a297b 100644
--- a/src/gsmtp/gsmtpserverprotocol.h
+++ b/src/gsmtp/gsmtpserverprotocol.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -55,7 +55,7 @@ namespace GSmtp
 class GSmtp::ServerProtocol
 {
 public:
-	G_EXCEPTION( ProtocolDone , "smtp protocol done" ) ;
+	G_EXCEPTION( ProtocolDone , tx("smtp protocol done") ) ;
 
 	class Sender /// An interface used by ServerProtocol to send protocol replies.
 	{
@@ -96,6 +96,7 @@ public:
 		unsigned int filter_timeout{0U} ;
 		std::size_t max_size{0U} ;
 		bool authentication_requires_encryption{false} ;
+		bool mail_requires_authentication{false} ; // for MAIL or VRFY, unless a trusted address
 		bool mail_requires_encryption{false} ;
 		bool disconnect_on_max_size{false} ;
 		bool tls_starttls{false} ;
@@ -113,6 +114,7 @@ public:
 		Config & set_filter_timeout( unsigned int ) ;
 		Config & set_max_size( std::size_t ) ;
 		Config & set_authentication_requires_encryption( bool = true ) ;
+		Config & set_mail_requires_authentication( bool = true ) ;
 		Config & set_mail_requires_encryption( bool = true ) ;
 		Config & set_disconnect_on_max_size( bool = true ) ;
 		Config & set_tls_starttls( bool = true ) ;
@@ -241,8 +243,8 @@ private:
 public:
 	ServerProtocol( const ServerProtocol & ) = delete ;
 	ServerProtocol( ServerProtocol && ) = delete ;
-	void operator=( const ServerProtocol & ) = delete ;
-	void operator=( ServerProtocol && ) = delete ;
+	ServerProtocol & operator=( const ServerProtocol & ) = delete ;
+	ServerProtocol & operator=( ServerProtocol && ) = delete ;
 
 private:
 	void send( const char * ) ;
@@ -253,6 +255,8 @@ private:
 	static const std::string & crlf() ;
 	bool authenticationRequiresEncryption() const ;
 	void reset() ;
+	G::StringArray mechanisms() const ;
+	G::StringArray mechanisms( bool secure ) const ;
 	void badClientEvent() ;
 	void processDone( bool , const MessageId & , const std::string & , const std::string & ) ; // ProtocolMessage::doneSignal()
 	void prepareDone( bool , bool , std::string ) ;
@@ -271,7 +275,6 @@ private:
 	void doHelo( EventData , bool & ) ;
 	void sendReadyForTls() ;
 	void sendBadMechanism() ;
-	void doAuthInvalid( EventData , bool & ) ;
 	void doAuth( EventData , bool & ) ;
 	void doAuthData( EventData , bool & ) ;
 	void doMail( EventData , bool & ) ;
@@ -327,6 +330,7 @@ private:
 	std::string parseRcptParameter( const std::string & ) const ;
 	std::string parsePeerName( const std::string & ) const ;
 	void verify( const std::string & , const std::string & ) ;
+	std::string printableAuth( const std::string & auth_line ) const ;
 
 private:
 	Sender & m_sender ;
@@ -356,8 +360,8 @@ private:
 class GSmtp::ServerProtocolText : public ServerProtocol::Text
 {
 public:
-	ServerProtocolText( const std::string & code_ident , const std::string & thishost ,
-		const GNet::Address & peer_address ) ;
+	ServerProtocolText( const std::string & code_ident , bool with_received_line ,
+		const std::string & thishost , const GNet::Address & peer_address ) ;
 			///< Constructor.
 
 	static std::string receivedLine( const std::string & smtp_peer_name_from_helo ,
@@ -370,8 +374,8 @@ public:
 	~ServerProtocolText() override = default ;
 	ServerProtocolText( const ServerProtocolText & ) = delete ;
 	ServerProtocolText( ServerProtocolText && ) = delete ;
-	void operator=( const ServerProtocolText & ) = delete ;
-	void operator=( ServerProtocolText && ) = delete ;
+	ServerProtocolText & operator=( const ServerProtocolText & ) = delete ;
+	ServerProtocolText & operator=( ServerProtocolText && ) = delete ;
 
 private: // overrides
 	std::string greeting() const override ; // Override from GSmtp::ServerProtocol::Text.
@@ -380,6 +384,7 @@ private: // overrides
 
 private:
 	std::string m_code_ident ;
+	bool m_with_received_line ;
 	std::string m_thishost ;
 	GNet::Address m_peer_address ;
 } ;
@@ -388,6 +393,7 @@ inline GSmtp::ServerProtocol::Config & GSmtp::ServerProtocol::Config::set_with_v
 inline GSmtp::ServerProtocol::Config & GSmtp::ServerProtocol::Config::set_filter_timeout( unsigned int t ) { filter_timeout = t ; return *this ; }
 inline GSmtp::ServerProtocol::Config & GSmtp::ServerProtocol::Config::set_max_size( std::size_t n ) { max_size = n ; return *this ; }
 inline GSmtp::ServerProtocol::Config & GSmtp::ServerProtocol::Config::set_authentication_requires_encryption( bool b ) { authentication_requires_encryption = b ; return *this ; }
+inline GSmtp::ServerProtocol::Config & GSmtp::ServerProtocol::Config::set_mail_requires_authentication( bool b ) { mail_requires_authentication = b ; return *this ; }
 inline GSmtp::ServerProtocol::Config & GSmtp::ServerProtocol::Config::set_mail_requires_encryption( bool b ) { mail_requires_encryption = b ; return *this ; }
 inline GSmtp::ServerProtocol::Config & GSmtp::ServerProtocol::Config::set_disconnect_on_max_size( bool b ) { disconnect_on_max_size = b ; return *this ; }
 inline GSmtp::ServerProtocol::Config & GSmtp::ServerProtocol::Config::set_tls_starttls( bool b ) { tls_starttls = b ; return *this ; }
diff --git a/src/gsmtp/gspamclient.cpp b/src/gsmtp/gspamclient.cpp
index cbb05c7..81c31d2 100644
--- a/src/gsmtp/gspamclient.cpp
+++ b/src/gsmtp/gspamclient.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -43,7 +43,8 @@ GSmtp::SpamClient::SpamClient( GNet::ExceptionSink es , const GNet::Location & l
 
 GNet::Client::Config GSmtp::SpamClient::netConfig( unsigned int connect_timeout , unsigned int response_timeout )
 {
-	GNet::Client::Config net_config( GNet::LineBufferConfig::newline() ) ;
+	GNet::Client::Config net_config ;
+	net_config.line_buffer_config = GNet::LineBufferConfig::newline() ;
 	net_config.connection_timeout = connect_timeout ;
 	net_config.response_timeout = response_timeout ;
 	return net_config ;
diff --git a/src/gsmtp/gspamclient.h b/src/gsmtp/gspamclient.h
index 97d0577..00c19e1 100644
--- a/src/gsmtp/gspamclient.h
+++ b/src/gsmtp/gspamclient.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -46,7 +46,7 @@ namespace GSmtp
 class GSmtp::SpamClient : public GNet::Client
 {
 public:
-	G_EXCEPTION( Error , "spam client error" ) ;
+	G_EXCEPTION( Error , tx("spam client error") ) ;
 
 	SpamClient( GNet::ExceptionSink , const GNet::Location & host_and_service ,
 		bool read_only , unsigned int connect_timeout , unsigned int response_timeout ) ;
@@ -82,8 +82,8 @@ public:
 	~SpamClient() override = default ;
 	SpamClient( const SpamClient & ) = delete ;
 	SpamClient( SpamClient && ) = delete ;
-	void operator=( const SpamClient & ) = delete ;
-	void operator=( SpamClient && ) = delete ;
+	SpamClient & operator=( const SpamClient & ) = delete ;
+	SpamClient & operator=( SpamClient && ) = delete ;
 
 private:
 	void onTimeout() ;
@@ -107,8 +107,8 @@ private:
 		~Response() ;
 		Response( const Response & ) = delete ;
 		Response( Response && ) = delete ;
-		void operator=( const Response & ) = delete ;
-		void operator=( Response && ) = delete ;
+		Response & operator=( const Response & ) = delete ;
+		Response & operator=( Response && ) = delete ;
 		void add( const std::string & , const std::string & ) ;
 		bool ok( const std::string & ) const ;
 		bool complete() const ;
diff --git a/src/gsmtp/gspamfilter.cpp b/src/gsmtp/gspamfilter.cpp
index a5d32a5..2b18974 100644
--- a/src/gsmtp/gspamfilter.cpp
+++ b/src/gsmtp/gspamfilter.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/gspamfilter.h b/src/gsmtp/gspamfilter.h
index 51813e8..7f00a94 100644
--- a/src/gsmtp/gspamfilter.h
+++ b/src/gsmtp/gspamfilter.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -63,8 +63,8 @@ private: // overrides
 public:
 	SpamFilter( const SpamFilter & ) = delete ;
 	SpamFilter( SpamFilter && ) = delete ;
-	void operator=( const SpamFilter & ) = delete ;
-	void operator=( SpamFilter && ) = delete ;
+	SpamFilter & operator=( const SpamFilter & ) = delete ;
+	SpamFilter & operator=( SpamFilter && ) = delete ;
 
 private:
 	void clientEvent( const std::string & , const std::string & , const std::string & ) ;
diff --git a/src/gsmtp/gstoredfile.cpp b/src/gsmtp/gstoredfile.cpp
index 3c4c34d..b13b68b 100644
--- a/src/gsmtp/gstoredfile.cpp
+++ b/src/gsmtp/gstoredfile.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -30,7 +30,6 @@
 
 GSmtp::StoredFile::StoredFile( FileStore & store , const G::Path & envelope_path ) :
 	m_store(store) ,
-	m_content(std::make_unique<std::ifstream>()) , // up-cast
 	m_id(MessageId::none()) ,
 	m_state(State::Normal)
 {
@@ -144,18 +143,18 @@ bool GSmtp::StoredFile::openContent( std::string & reason )
 	try
 	{
 		G_DEBUG( "GSmtp::FileStore::openContent: \"" << cpath() << "\"" ) ;
-		auto stream = std::make_unique<std::ifstream>() ;
+		auto stream = std::make_unique<Stream>() ;
 		{
 			FileReader claim_reader ;
-			G::File::open( *stream , cpath() ) ;
+			stream->open( cpath() ) ;
 		}
 		if( !stream->good() )
 		{
 			reason = "cannot open content file" ;
 			return false ;
 		}
-		stream->exceptions( std::ios_base::badbit ) ; // (new)
-		m_content = std::unique_ptr<std::istream>( stream.release() ) ; // up-cast
+		stream->exceptions( std::ios_base::badbit ) ;
+		m_content = std::move( stream ) ;
 		return true ;
 	}
 	catch( std::exception & e ) // invalid file in store
@@ -203,18 +202,20 @@ void GSmtp::StoredFile::edit( const G::StringArray & rejectees )
 
 	// create new file
 	std::ofstream out ;
+	int e = 0 ;
 	{
 		FileWriter claim_writer ;
 		G::File::open( out , path_out ) ;
+		e = G::Process::errno_() ;
 	}
 	if( !out.good() )
-		throw EditError( path_in.str() ) ;
-	G::ScopeExit file_deleter( [=](){G::File::remove(path_out,std::nothrow);} ) ;
+		throw EditError( path_in.basename() , G::Process::strerror(e) ) ;
+	G::ScopeExit file_deleter( [&](){out.close();G::File::remove(path_out,std::nothrow);} ) ;
 
 	// write new file
 	std::size_t endpos = GSmtp::Envelope::write( out , env_copy ) ;
 	if( endpos == 0U )
-		throw EditError( path_in.str() ) ;
+		throw EditError( path_in.basename() ) ;
 
 	// open existing file
 	std::ifstream in ;
@@ -223,7 +224,7 @@ void GSmtp::StoredFile::edit( const G::StringArray & rejectees )
 		G::File::open( in , path_in ) ;
 	}
 	if( !in.good() )
-		throw EditError( path_in.str() ) ;
+		throw EditError( path_in.basename() ) ;
 
 	// re-read the existing file's endpos, just in case
 	GSmtp::Envelope env_check ;
@@ -234,22 +235,24 @@ void GSmtp::StoredFile::edit( const G::StringArray & rejectees )
 	// copy the existing file's tail to the new file
 	in.seekg( env_check.m_endpos ) ; // NOLINT narrowing
 	if( !in.good() )
-		throw EditError( path_in.str() ) ;
+		throw EditError( path_in.basename() ) ;
 	GSmtp::Envelope::copy( in , out ) ;
 
 	in.close() ;
 	out.close() ;
 	if( out.fail() )
-		throw EditError( path_in.str() ) ;
+		throw EditError( path_in.basename() ) ;
 
 	// commit the file
 	bool ok = false ;
+	e = 0 ;
 	{
 		FileWriter claim_writer ;
-		ok = G::File::rename( path_out , path_in , std::nothrow ) ;
+		ok = G::File::remove( path_in , std::nothrow ) && G::File::rename( path_out , path_in , std::nothrow ) ;
+		e = G::Process::errno_() ;
 	}
 	if( !ok )
-		throw EditError( path_in.str() ) ;
+		throw EditError( path_in.basename() , G::Process::strerror(e) ) ;
 	file_deleter.release() ;
 
 	m_env.m_crlf = true ;
@@ -321,17 +324,25 @@ void GSmtp::StoredFile::addReason( const G::Path & path , const std::string & re
 void GSmtp::StoredFile::destroy()
 {
 	G_LOG( "GSmtp::StoredMessage: deleting file: \"" << epath(m_state).basename() << "\"" ) ;
+	int e = 0 ;
 	{
 		FileWriter claim_writer ;
-		G::File::remove( epath(m_state) , std::nothrow ) ;
+		if( !G::File::remove( epath(m_state) , std::nothrow ) )
+			e = G::Process::errno_() ;
 	}
+	if( e )
+		G_WARNING( "GSmtp::StoredFile::destroy: failed to delete envelope file: " << G::Process::strerror(e) ) ;
 
 	G_LOG( "GSmtp::StoredMessage: deleting file: \"" << cpath().basename() << "\"" ) ;
 	m_content.reset() ; // close it before deleting
+	e = 0 ;
 	{
 		FileWriter claim_writer ;
-		G::File::remove( cpath() , std::nothrow ) ;
+		if( !G::File::remove( cpath() , std::nothrow ) )
+			e = G::Process::errno_() ;
 	}
+	if( e )
+		G_WARNING( "GSmtp::StoredFile::destroy: failed to delete content file: " << G::Process::strerror(e) ) ;
 }
 
 std::string GSmtp::StoredFile::from() const
@@ -351,10 +362,8 @@ std::size_t GSmtp::StoredFile::toCount() const
 
 std::istream & GSmtp::StoredFile::contentStream()
 {
-	G_ASSERT( m_content != nullptr ) ;
 	if( m_content == nullptr )
-		m_content = std::make_unique<std::ifstream>() ; // up-cast
-
+		m_content = std::make_unique<Stream>() ;
 	return *m_content ;
 }
 
@@ -373,3 +382,37 @@ std::string GSmtp::StoredFile::fromAuthOut() const
 	return m_env.m_from_auth_out ;
 }
 
+std::string GSmtp::StoredFile::forwardTo() const
+{
+	return m_env.m_forward_to ;
+}
+
+std::string GSmtp::StoredFile::forwardToAddress() const
+{
+	return m_env.m_forward_to_address ;
+}
+
+// ==
+
+
+GSmtp::StoredFile::Stream::Stream() :
+	StreamBuf(&G::File::read,&G::File::write,&G::File::close),
+	std::istream(static_cast<StreamBuf*>(this))
+{
+}
+
+void GSmtp::StoredFile::Stream::open( const G::Path & path )
+{
+	// File::open() because we want _O_NOINHERIT and _SH_DENYNO on windows
+	int fd = G::File::open( path.cstr() , G::File::InOutAppend::In ) ;
+	if( fd >= 0 )
+	{
+		StreamBuf::open( fd ) ;
+		clear() ;
+	}
+	else
+	{
+		clear( std::ios_base::failbit ) ;
+	}
+}
+
diff --git a/src/gsmtp/gstoredfile.h b/src/gsmtp/gstoredfile.h
index 6be8bf8..8061e11 100644
--- a/src/gsmtp/gstoredfile.h
+++ b/src/gsmtp/gstoredfile.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -26,10 +26,12 @@
 #include "gstoredmessage.h"
 #include "genvelope.h"
 #include "gexception.h"
+#include "gfbuf.h"
 #include "gpath.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include <iostream>
 #include <memory>
+#include <cstdio>
 
 namespace GSmtp
 {
@@ -43,10 +45,10 @@ namespace GSmtp
 class GSmtp::StoredFile : public StoredMessage
 {
 public:
-	G_EXCEPTION( FormatError , "invalid envelope file" ) ;
-	G_EXCEPTION( FilenameError , "invalid envelope filename" ) ;
-	G_EXCEPTION( ReadError , "cannot read envelope file" ) ;
-	G_EXCEPTION( EditError , "cannot update envelope file" ) ;
+	G_EXCEPTION( FormatError , tx("invalid envelope file") ) ;
+	G_EXCEPTION( FilenameError , tx("invalid envelope filename") ) ;
+	G_EXCEPTION( ReadError , tx("cannot read envelope file") ) ;
+	G_EXCEPTION( EditError , tx("cannot update envelope file") ) ;
 
 	StoredFile( FileStore & store , const G::Path & envelope_path ) ;
 		///< Constructor.
@@ -85,6 +87,8 @@ private: // overrides
 	std::string authentication() const override ; // Override from GSmtp::StoredMessage.
 	std::string fromAuthIn() const override ; // Override from GSmtp::StoredMessage.
 	std::string fromAuthOut() const override ; // Override from GSmtp::StoredMessage.
+	std::string forwardTo() const override ; // Override from GSmtp::StoredMessage.
+	std::string forwardToAddress() const override ; // Override from GSmtp::StoredMessage.
 	void close() override ; // Override from GSmtp::StoredMessage.
 	std::string reopen() override ; // Override from GSmtp::StoredMessage.
 	void destroy() override ; // Override from GSmtp::StoredMessage.
@@ -94,8 +98,17 @@ private: // overrides
 public:
 	StoredFile( const StoredFile & ) = delete ;
 	StoredFile( StoredFile && ) = delete ;
-	void operator=( const StoredFile & ) = delete ;
-	void operator=( StoredFile && ) = delete ;
+	StoredFile & operator=( const StoredFile & ) = delete ;
+	StoredFile & operator=( StoredFile && ) = delete ;
+
+private:
+	using StreamBuf = G::fbuf<int,BUFSIZ> ;
+	struct Stream : StreamBuf , std::istream
+	{
+		Stream() ;
+		void open( const G::Path & ) ;
+		std::streamoff size() const ;
+	} ;
 
 private:
 	enum class State { Normal , Locked , Bad } ;
@@ -103,12 +116,11 @@ private:
 	G::Path epath( State ) const ;
 	void readEnvelopeCore( bool check_recipients ) ;
 	const std::string & eol() const ;
-	G::Path contentPath() const ;
 	void addReason( const G::Path & path , const std::string & , int ) const ;
 
 private:
 	FileStore & m_store ;
-	std::unique_ptr<std::istream> m_content ;
+	std::unique_ptr<Stream> m_content ;
 	MessageId m_id ;
 	Envelope m_env ;
 	State m_state ;
diff --git a/src/gsmtp/gstoredmessage.cpp b/src/gsmtp/gstoredmessage.cpp
index 11389c8..539f721 100644
--- a/src/gsmtp/gstoredmessage.cpp
+++ b/src/gsmtp/gstoredmessage.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/gstoredmessage.h b/src/gsmtp/gstoredmessage.h
index da8ed40..b7d6124 100644
--- a/src/gsmtp/gstoredmessage.h
+++ b/src/gsmtp/gstoredmessage.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,7 +23,7 @@
 
 #include "gdef.h"
 #include "gmessagestore.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gpath.h"
 #include <iostream>
 #include <fstream>
@@ -98,6 +98,12 @@ public:
 		///< Returns the outgoing "mail from" auth parameter,
 		///< either empty, xtext-encoded or "<>".
 
+	virtual std::string forwardTo() const = 0 ;
+		///< Returns the routing override or the empty string.
+
+	virtual std::string forwardToAddress() const = 0 ;
+		///< Returns the forwardTo() address or the empty string.
+
 	virtual ~StoredMessage() = default ;
 		///< Destructor.
 } ;
@@ -132,12 +138,14 @@ private: // overrides
 	std::string authentication() const override ;
 	std::string fromAuthIn() const override ;
 	std::string fromAuthOut() const override ;
+	std::string forwardTo() const override ;
+	std::string forwardToAddress() const override ;
 
 public:
 	StoredMessageStub( const StoredMessageStub & ) = delete ;
 	StoredMessageStub( StoredMessageStub && ) = delete ;
-	void operator=( const StoredMessageStub & ) = delete ;
-	void operator=( StoredMessageStub && ) = delete ;
+	StoredMessageStub & operator=( const StoredMessageStub & ) = delete ;
+	StoredMessageStub & operator=( StoredMessageStub && ) = delete ;
 
 private:
 	G::StringArray m_to_list ;
@@ -160,5 +168,7 @@ inline int GSmtp::StoredMessageStub::eightBit() const { return false ; }
 inline std::string GSmtp::StoredMessageStub::authentication() const { return std::string() ; }
 inline std::string GSmtp::StoredMessageStub::fromAuthIn() const { return std::string() ; }
 inline std::string GSmtp::StoredMessageStub::fromAuthOut() const { return std::string() ; }
+inline std::string GSmtp::StoredMessageStub::forwardTo() const { return std::string() ; }
+inline std::string GSmtp::StoredMessageStub::forwardToAddress() const { return std::string() ; }
 
 #endif
diff --git a/src/gsmtp/gverifier.cpp b/src/gsmtp/gverifier.cpp
index 476c838..d4aa824 100644
--- a/src/gsmtp/gverifier.cpp
+++ b/src/gsmtp/gverifier.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/gverifier.h b/src/gsmtp/gverifier.h
index 3d56449..78d4c4a 100644
--- a/src/gsmtp/gverifier.h
+++ b/src/gsmtp/gverifier.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gsmtp/gverifierfactory.cpp b/src/gsmtp/gverifierfactory.cpp
index 41c4c16..9148ee9 100644
--- a/src/gsmtp/gverifierfactory.cpp
+++ b/src/gsmtp/gverifierfactory.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -19,35 +19,30 @@
 ///
 
 #include "gdef.h"
-#include "gfactoryparser.h"
-#include "gexception.h"
 #include "gverifierfactory.h"
 #include "ginternalverifier.h"
 #include "gexecutableverifier.h"
 #include "gnetworkverifier.h"
-
-std::string GSmtp::VerifierFactory::check( const std::string & identifier )
-{
-	return FactoryParser::check( identifier , false ) ;
-}
+#include "gexception.h"
 
 std::unique_ptr<GSmtp::Verifier> GSmtp::VerifierFactory::newVerifier( GNet::ExceptionSink es ,
-	const std::string & identifier , unsigned int timeout )
+	const FactoryParser::Result & spec , unsigned int timeout )
 {
-	std::unique_ptr<Verifier> ptr ;
-	FactoryParser::Result p = FactoryParser::parse( identifier , false ) ;
-	if( p.first.empty() || p.first == "exit" )
+	if( spec.first == "exit" )
 	{
-		ptr = std::make_unique<InternalVerifier>() ; // up-cast
+		return std::make_unique<InternalVerifier>() ;
 	}
-	else if( p.first == "net" )
+	else if( spec.first == "net" )
 	{
-		ptr = std::make_unique<NetworkVerifier>( es , p.second , timeout , timeout ) ; // up-cast
+		return std::make_unique<NetworkVerifier>( es , spec.second , timeout , timeout ) ;
+	}
+	else if( spec.first == "file" )
+	{
+		return std::make_unique<ExecutableVerifier>( es , G::Path(spec.second) ) ;
 	}
 	else
 	{
-		ptr = std::make_unique<ExecutableVerifier>( es , G::Path(p.second) ) ; // up-cast
+		throw G::Exception( "invalid verifier" , spec.second ) ; // never gets here
 	}
-	return ptr ;
 }
 
diff --git a/src/gsmtp/gverifierfactory.h b/src/gsmtp/gverifierfactory.h
index 090462a..b90d570 100644
--- a/src/gsmtp/gverifierfactory.h
+++ b/src/gsmtp/gverifierfactory.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,6 +24,7 @@
 #include "gdef.h"
 #include "gverifier.h"
 #include "gexceptionsink.h"
+#include "gfactoryparser.h"
 #include <string>
 #include <utility>
 #include <memory>
@@ -40,14 +41,9 @@ class GSmtp::VerifierFactory
 {
 public:
 	static std::unique_ptr<Verifier> newVerifier( GNet::ExceptionSink ,
-		const std::string & identifier , unsigned int timeout ) ;
-			///< Returns a Verifier on the heap. The identifier
-			///< is normally prefixed with a verifier type, or it
-			///< is the file system path of an exectuable.
-
-	static std::string check( const std::string & identifier ) ;
-		///< Checks an identifier. Returns an empty string if okay,
-		///< or a diagnostic reason string.
+		const FactoryParser::Result & spec , unsigned int timeout ) ;
+			///< Returns a Verifier on the heap. Throws if
+			///< an invalid or unsupported specification.
 
 public:
 	VerifierFactory() = delete ;
diff --git a/src/gsmtp/gverifierstatus.cpp b/src/gsmtp/gverifierstatus.cpp
index d8178ca..eb055d1 100644
--- a/src/gsmtp/gverifierstatus.cpp
+++ b/src/gsmtp/gverifierstatus.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -68,7 +68,7 @@ GSmtp::VerifierStatus GSmtp::VerifierStatus::parse( const std::string & line )
 	try
 	{
 		G::StringArray part ;
-		G::Str::splitIntoFields( line , part , {"|",1U} , '\\' ) ;
+		G::Str::splitIntoFields( line , part , '|' , '\\' ) ;
 		if( part.size() != 9U )
 			throw InvalidStatus() ;
 
diff --git a/src/gsmtp/gverifierstatus.h b/src/gsmtp/gverifierstatus.h
index 848a4a4..678ff9f 100644
--- a/src/gsmtp/gverifierstatus.h
+++ b/src/gsmtp/gverifierstatus.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -51,7 +51,7 @@ namespace GSmtp
 class GSmtp::VerifierStatus
 {
 public:
-	G_EXCEPTION( InvalidStatus , "invalid verifier status" ) ;
+	G_EXCEPTION( InvalidStatus , tx("invalid verifier status") ) ;
 
 	static VerifierStatus invalid( const std::string & recipient ,
 		bool temporary = false ,
diff --git a/src/gssl/Makefile.am b/src/gssl/Makefile.am
index 7ae0015..cb04908 100644
--- a/src/gssl/Makefile.am
+++ b/src/gssl/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
diff --git a/src/gssl/gssl.cpp b/src/gssl/gssl.cpp
index ec49159..bcc90c4 100644
--- a/src/gssl/gssl.cpp
+++ b/src/gssl/gssl.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -96,7 +96,7 @@ bool GSsl::Library::hasProfile( const std::string & profile_name ) const
 const GSsl::Profile & GSsl::Library::profile( const std::string & profile_name ) const
 {
 	if( !imp().hasProfile(profile_name) )
-		throw G::Exception( "invalid tls profile name [" + profile_name + "]" ) ;
+		throw BadProfileName( profile_name ) ;
 	return imp().profile( profile_name ) ;
 }
 
@@ -108,21 +108,21 @@ bool GSsl::Library::enabledAs( const std::string & profile_name )
 GSsl::LibraryImpBase & GSsl::Library::impstance()
 {
 	if( instance() == nullptr )
-		throw G::Exception( "no tls library instance" ) ;
+		throw NoInstance() ;
 	return instance()->imp() ;
 }
 
 GSsl::LibraryImpBase & GSsl::Library::imp()
 {
 	if( m_imp == nullptr )
-		throw G::Exception( "no tls library instance" ) ;
+		throw NoInstance() ;
 	return *m_imp ;
 }
 
 const GSsl::LibraryImpBase & GSsl::Library::imp() const
 {
 	if( m_imp == nullptr )
-		throw G::Exception( "no tls library instance" ) ;
+		throw NoInstance() ;
 	return *m_imp ;
 }
 
@@ -222,9 +222,9 @@ GSsl::Digester::Digester( std::unique_ptr<DigesterImpBase> p ) :
 {
 }
 
-void GSsl::Digester::add( const std::string & s )
+void GSsl::Digester::add( G::string_view sv )
 {
-	m_imp->add( s ) ;
+	m_imp->add( sv ) ;
 }
 
 std::string GSsl::Digester::value()
@@ -254,9 +254,9 @@ std::size_t GSsl::Digester::statesize() const
 
 // ==
 
-bool GSsl::LibraryImpBase::consume( G::StringArray & list , const std::string & key )
+bool GSsl::LibraryImpBase::consume( G::StringArray & list , G::string_view key )
 {
-	auto p = std::find( list.begin() , list.end() , key ) ;
+	auto p = std::find( list.begin() , list.end() , G::sv_to_string(key) ) ;
 	if( p != list.end() )
 	{
 		list.erase( p ) ;
diff --git a/src/gssl/gssl.h b/src/gssl/gssl.h
index db48de6..358f5d9 100644
--- a/src/gssl/gssl.h
+++ b/src/gssl/gssl.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,11 +24,13 @@
 #define G_SSL_H
 
 #include "gdef.h"
-#include "gstrings.h"
+#include "gstringarray.h"
+#include "gstringview.h"
+#include "gexception.h"
 #include "greadwrite.h"
 #include <string>
-#include <utility>
 #include <memory>
+#include <utility>
 
 namespace GSsl
 {
@@ -74,8 +76,8 @@ public:
 		more
 	} ;
 
-	explicit Protocol( const Profile & , const std::string & peer_certificate_name = std::string() ,
-		const std::string & peer_host_name = std::string() ) ;
+	explicit Protocol( const Profile & , const std::string & peer_certificate_name = {} ,
+		const std::string & peer_host_name = {} ) ;
 			///< Constructor.
 			///<
 			///< The optional "peer-certificate-name" parameter is used as an
@@ -190,8 +192,8 @@ public:
 public:
 	Protocol( const Protocol & ) = delete ;
 	Protocol( Protocol && ) = delete ;
-	void operator=( const Protocol & ) = delete ;
-	void operator=( Protocol && ) = delete ;
+	Protocol & operator=( const Protocol & ) = delete ;
+	Protocol & operator=( Protocol && ) = delete ;
 
 private:
 	std::unique_ptr<ProtocolImpBase> m_imp ;
@@ -225,7 +227,7 @@ public:
 		///< Returns the size of the state() string in bytes,
 		///< or zero if state() is not implemented.
 
-	void add( const std::string & ) ;
+	void add( G::string_view ) ;
 		///< Adds data of arbitrary size.
 
 	std::string state() ;
@@ -252,9 +254,11 @@ private:
 class GSsl::Library
 {
 public:
+	G_EXCEPTION( NoInstance , tx("no tls library object") ) ;
+	G_EXCEPTION( BadProfileName , tx("invalid tls profile name") ) ;
 	using LogFn = void (*)(int, const std::string &) ;
 
-	explicit Library( bool active = true , const std::string & library_config = std::string() ,
+	explicit Library( bool active = true , const std::string & library_config = {} ,
 		LogFn = Library::log , bool verbose = true ) ;
 			///< Constructor.
 			///<
@@ -279,11 +283,11 @@ public:
 		///< Returns a pointer to a library object, if any.
 
 	void addProfile( const std::string & profile_name , bool is_server_profile ,
-		const std::string & key_file = std::string() , const std::string & cert_file = std::string() ,
-		const std::string & ca_path = std::string() ,
-		const std::string & default_peer_certificate_name = std::string() ,
-		const std::string & default_peer_host_name = std::string() ,
-		const std::string & profile_config = std::string() ) ;
+		const std::string & key_file = {} , const std::string & cert_file = {} ,
+		const std::string & ca_path = {} ,
+		const std::string & default_peer_certificate_name = {} ,
+		const std::string & default_peer_host_name = {} ,
+		const std::string & profile_config = {} ) ;
 			///< Creates a named Profile object that can be retrieved by profile().
 			///<
 			///< A typical application will have two profiles named "client" and "server".
@@ -335,8 +339,8 @@ public:
 	std::string generateKey( const std::string & name ) const ;
 		///< Generates a test certificate as a PEM string with embedded newlines,
 		///< also containing the private-key. Returns the empty string if not
-		///< implemented. Throws on error. The implementation will
-		///< normally be slow and blocking.
+		///< implemented. Throws on error. The implementation will normally
+		///< be slow and blocking.
 
 	static LibraryImpBase & impstance() ;
 		///< Returns a reference to the pimple object when enabled(). Used in
@@ -363,14 +367,14 @@ public:
 		///< hash functions that can generate and be initialised with an
 		///< intermediate state.
 
-	Digester digester( const std::string & name , const std::string & state = std::string() , bool need_state = false ) const ;
+	Digester digester( const std::string & name , const std::string & state = {} , bool need_state = false ) const ;
 		///< Returns a digester object.
 
 public:
 	Library( const Library & ) = delete ;
 	Library( Library && ) = delete ;
-	void operator=( const Library & ) = delete ;
-	void operator=( Library && ) = delete ;
+	Library & operator=( const Library & ) = delete ;
+	Library & operator=( Library && ) = delete ;
 
 private:
 	const LibraryImpBase & imp() const ;
@@ -417,7 +421,7 @@ public:
 	virtual std::string generateKey( const std::string & ) const = 0 ;
 		///< Implements Library::generateKey().
 
-	static bool consume( G::StringArray & list , const std::string & item ) ;
+	static bool consume( G::StringArray & list , G::string_view item ) ;
 		///< A convenience function that removes the item from
 		///< the list and returns true iff is was removed.
 } ;
@@ -433,7 +437,7 @@ public:
 		///< Destructor.
 
 	virtual std::unique_ptr<ProtocolImpBase> newProtocol( const std::string & , const std::string & ) const = 0 ;
-		///< Factory method for a new Protocol object on the heap.
+		///< Factory method for a new Protocol object.
 } ;
 
 //| \class GSsl::ProtocolImpBase
@@ -485,7 +489,7 @@ public:
 	virtual ~DigesterImpBase() = default ;
 		///< Destructor.
 
-	virtual void add( const std::string & ) = 0 ;
+	virtual void add( G::string_view ) = 0 ;
 		///< Implements Digester::add().
 
 	virtual std::string value() = 0 ;
diff --git a/src/gssl/gssl_mbedtls.cpp b/src/gssl/gssl_mbedtls.cpp
index f31781d..55082fc 100644
--- a/src/gssl/gssl_mbedtls.cpp
+++ b/src/gssl/gssl_mbedtls.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -42,7 +42,6 @@
 #include <mbedtls/pem.h>
 #include <mbedtls/base64.h>
 #include <mbedtls/debug.h>
-#include <type_traits>
 #include <array>
 #include <sstream>
 #include <fstream>
@@ -74,6 +73,7 @@
 
 // we need access to structure fields that are private in mbedtls v3.0 -- see
 // mbedtls migration guide
+// TODO dont use private mbedtls structure fields
 #if MBEDTLS_VERSION_MAJOR >= 3
 #define GET MBEDTLS_PRIVATE
 #if MBEDTLS_VERSION_MINOR >= 1
@@ -86,10 +86,21 @@
 #define GET_RAW(field) field
 #endif
 
+#ifndef GCONFIG_HAVE_MBEDTLS_HASH_STATE
+#if MBEDTLS_VERSION_MAJOR >= 3
+#define GCONFIG_HAVE_MBEDTLS_HASH_STATE 0
+#else
+#define GCONFIG_HAVE_MBEDTLS_HASH_STATE 1
+#endif
+#endif
+
 namespace GSsl
 {
 	namespace MbedTls
 	{
+		G_EXCEPTION_CLASS( ErrorDevRandomOpen , tx("cannot open /dev/random") ) ;
+		G_EXCEPTION_CLASS( ErrorDevRandomRead , tx("cannot read /dev/random") ) ;
+
 		void randomFillImp( char * p , std::size_t n ) ;
 		int randomFill( void * , unsigned char * output , std::size_t len , std::size_t * olen ) ;
 
@@ -145,8 +156,8 @@ namespace GSsl
 			const X * operator&() const = delete ;
 			X( const X<T> & ) = delete ;
 			X( X<T> && ) = delete ;
-			void operator=( const X<T> & ) = delete ;
-			void operator=( X<T> && ) = delete ;
+			X<T> & operator=( const X<T> & ) = delete ;
+			X<T> & operator=( X<T> && ) = delete ;
 		} ;
 	}
 }
@@ -294,7 +305,7 @@ std::string GSsl::MbedTls::LibraryImp::generateKey( const std::string & issuer_n
 		s_crt = reinterpret_cast<const char*>( &crt_buffer[0] ) ;
 	}
 
-	return s_key + s_crt ;
+	return s_key.append( s_crt ) ;
 }
 
 GSsl::MbedTls::Config GSsl::MbedTls::LibraryImp::config() const
@@ -392,53 +403,75 @@ bool GSsl::MbedTls::Config::servernoverify() const
 	return m_servernoverify ;
 }
 
-bool GSsl::MbedTls::Config::consume( G::StringArray & list , const std::string & item )
+bool GSsl::MbedTls::Config::consume( G::StringArray & list , G::string_view item )
 {
 	return LibraryImp::consume( list , item ) ;
 }
 
 // ==
 
-GSsl::MbedTls::DigesterImp::DigesterImp( const std::string & hash_name , const std::string & state , bool )
+GSsl::MbedTls::DigesterImp::DigesterImp( const std::string & hash_name , const std::string & state , bool need_state )
 {
+	bool have_state = !state.empty() ;
+	m_state_size = 0U ;
+
+	#if ! GCONFIG_HAVE_MBEDTLS_HASH_STATE
+	if( have_state || need_state )
+	{
+		throw Error( std::string("hash state resoration not implemented for ").append(hash_name) ) ;
+	}
+	#endif
+
 	if( hash_name == "MD5" )
 	{
 		m_hash_type = Type::Md5 ;
 		m_block_size = 64U ;
 		m_value_size = 16U ;
-		m_state_size = m_value_size + 4U ;
 
 		mbedtls_md5_init( &m_md5 ) ;
-		if( state.empty() )
-			call( FN_RETv3(mbedtls_md5_starts) , &m_md5 ) ;
-		else
+		#if GCONFIG_HAVE_MBEDTLS_HASH_STATE
+		m_state_size = m_value_size + 4U ;
+		if( have_state )
 			G::HashState<16,uint32_t,uint32_t>::decode( state , m_md5.GET(state) , m_md5.GET(total)[0] ) ;
+		else
+			call( FN_RETv3(mbedtls_md5_starts) , &m_md5 ) ;
+		#else
+		call( FN_RETv3(mbedtls_md5_starts) , &m_md5 ) ;
+		#endif
 	}
 	else if( hash_name == "SHA1" )
 	{
 		m_hash_type = Type::Sha1 ;
 		m_block_size = 64U ;
 		m_value_size = 20U ;
-		m_state_size = m_value_size + 4U ;
 
 		mbedtls_sha1_init( &m_sha1 ) ;
-		if( state.empty() )
-			call( FN_RETv3(mbedtls_sha1_starts) , &m_sha1 ) ;
-		else
+		#if GCONFIG_HAVE_MBEDTLS_HASH_STATE
+		m_state_size = m_value_size + 4U ;
+		if( have_state )
 			G::HashState<20,uint32_t,uint32_t>::decode( state , m_sha1.GET(state) , m_sha1.GET(total)[0] ) ;
+		else
+			call( FN_RETv3(mbedtls_sha1_starts) , &m_sha1 ) ;
+		#else
+		call( FN_RETv3(mbedtls_sha1_starts) , &m_sha1 ) ;
+		#endif
 	}
 	else if( hash_name == "SHA256" )
 	{
 		m_hash_type = Type::Sha256 ;
 		m_block_size = 64U ;
 		m_value_size = 32U ;
-		m_state_size = m_value_size + 4U ;
 
 		mbedtls_sha256_init( &m_sha256 ) ;
-		if( state.empty() )
-			call( FN_RETv3(mbedtls_sha256_starts) , &m_sha256 , 0 ) ;
-		else
+		#if GCONFIG_HAVE_MBEDTLS_HASH_STATE
+		m_state_size = m_value_size + 4U ;
+		if( have_state )
 			G::HashState<32,uint32_t,uint32_t>::decode( state , m_sha256.GET(state) , m_sha256.GET(total)[0] ) ;
+		else
+			call( FN_RETv3(mbedtls_sha256_starts) , &m_sha256 , 0 ) ;
+		#else
+		call( FN_RETv3(mbedtls_sha256_starts) , &m_sha256 , 0 ) ;
+		#endif
 	}
 	else
 	{
@@ -456,14 +489,14 @@ GSsl::MbedTls::DigesterImp::~DigesterImp()
 		mbedtls_sha256_free( &m_sha256 ) ;
 }
 
-void GSsl::MbedTls::DigesterImp::add( const std::string & s )
+void GSsl::MbedTls::DigesterImp::add( G::string_view sv )
 {
 	if( m_hash_type == Type::Md5 )
-		call( FN_RETv3(mbedtls_md5_update) , &m_md5 , reinterpret_cast<const unsigned char*>(s.data()) , s.size() ) ;
+		call( FN_RETv3(mbedtls_md5_update) , &m_md5 , reinterpret_cast<const unsigned char*>(sv.data()) , sv.size() ) ;
 	else if( m_hash_type == Type::Sha1 )
-		call( FN_RETv3(mbedtls_sha1_update) , &m_sha1 , reinterpret_cast<const unsigned char*>(s.data()) , s.size() ) ;
+		call( FN_RETv3(mbedtls_sha1_update) , &m_sha1 , reinterpret_cast<const unsigned char*>(sv.data()) , sv.size() ) ;
 	else if( m_hash_type == Type::Sha256 )
-		call( FN_RETv3(mbedtls_sha256_update) , &m_sha256 , reinterpret_cast<const unsigned char*>(s.data()) , s.size() ) ;
+		call( FN_RETv3(mbedtls_sha256_update) , &m_sha256 , reinterpret_cast<const unsigned char*>(sv.data()) , sv.size() ) ;
 }
 
 std::string GSsl::MbedTls::DigesterImp::value()
@@ -494,6 +527,7 @@ std::string GSsl::MbedTls::DigesterImp::value()
 
 std::string GSsl::MbedTls::DigesterImp::state()
 {
+	#if GCONFIG_HAVE_MBEDTLS_HASH_STATE
 	if( m_hash_type == Type::Md5 )
 		return G::HashState<16,uint32_t,uint32_t>::encode( m_md5.GET(state) , m_md5.GET(total)[0] ) ;
 	else if( m_hash_type == Type::Sha1 )
@@ -501,7 +535,10 @@ std::string GSsl::MbedTls::DigesterImp::state()
 	else if( m_hash_type == Type::Sha256 )
 		return G::HashState<32,uint32_t,uint32_t>::encode( m_sha256.GET(state) , m_sha256.GET(total)[0] ) ;
 	else
-		return std::string() ;
+		return {} ;
+	#else
+	return {} ;
+	#endif
 }
 
 std::size_t GSsl::MbedTls::DigesterImp::blocksize() const
@@ -827,8 +864,8 @@ std::string GSsl::MbedTls::ProtocolImp::verifyResultString( int rc )
 		auto verify_result = mbedtls_ssl_get_verify_result( m_ssl.ptr() ) ; // MBEDTLS_X509_BADCERT_...
 		std::vector<char> buffer( 1024U ) ;
 		mbedtls_x509_crt_verify_info( &buffer[0] , buffer.size() , "" , verify_result ) ;
-		buffer[buffer.size()-1U] = '\0' ;
-		return G::Str::printable( &buffer[0] ) ;
+		buffer.back() = '\0' ;
+		return G::Str::printable( std::string(&buffer[0]) ) ;
 	}
 	else
 	{
@@ -1054,7 +1091,7 @@ void GSsl::MbedTls::SecureFile::clear( std::vector<char> & buffer )
 	}
 }
 
-GSsl::MbedTls::SecureFile::SecureFile( const std::string & path , bool with_nul )
+GSsl::MbedTls::SecureFile::SecureFile( const std::string & path , bool with_counted_nul )
 {
 	G::ScopeExit clearer( [&](){ clear(m_buffer); } ) ;
 	std::filebuf f ;
@@ -1068,12 +1105,13 @@ GSsl::MbedTls::SecureFile::SecureFile( const std::string & path , bool with_nul
 	if( n == 0U )
 		return ;
 
-	m_buffer.resize( n+1U ) ;
+	m_buffer.reserve( n+1U ) ;
+	m_buffer.resize( n ) ;
 	bool ok = fileRead( f , &m_buffer[0] , n ) ;
 	if( !ok )
 		return ;
 
-	if( with_nul )
+	if( with_counted_nul )
 		m_buffer.push_back( '\0' ) ;
 
 	clearer.release() ;
@@ -1211,10 +1249,10 @@ std::string GSsl::MbedTls::Error::format( const std::string & fnname , int rc ,
 	std::vector<char> buffer( 200U ) ;
 	buffer[0] = '\0' ;
 	mbedtls_strerror( rc , &buffer[0] , buffer.size() ) ;
-	buffer[buffer.size()-1U] = '\0' ;
+	buffer.back() = '\0' ;
 
 	std::ostringstream ss ;
-	ss << "tls error: " << fnname << "(): mbedtls [" << G::Str::printable(&buffer[0]) << "]" ;
+	ss << "tls error: " << fnname << "(): mbedtls [" << G::Str::printable(std::string(&buffer[0])) << "]" ;
 	if( !more.empty() )
 		ss << " [" << more << "]" ;
 
@@ -1231,7 +1269,7 @@ void GSsl::MbedTls::randomFillImp( char * p , std::size_t n )
 	if( fd < 0 )
 	{
 		int e = G::Process::errno_() ;
-		throw G::Exception( "cannot open /dev/random" , G::Process::strerror(e) ) ;
+		throw ErrorDevRandomOpen( G::Process::strerror(e) ) ;
 	}
 	G::ScopeExit closer( [&](){G::File::close(fd);} ) ;
 
@@ -1239,15 +1277,17 @@ void GSsl::MbedTls::randomFillImp( char * p , std::size_t n )
 	{
 		ssize_t nread_s = G::File::read( fd , p , n ) ;
 		if( nread_s < 0 )
-			throw Error( "cannot read /dev/random" ) ;
+			throw ErrorDevRandomRead() ;
 
 		std::size_t nread = static_cast<std::size_t>( nread_s ) ;
 		if( nread > n ) // sanity check
-			throw Error( "cannot read /dev/random" ) ;
+			throw ErrorDevRandomRead() ;
 
 		n -= nread ;
 		p += nread ;
-		sleep( 1 ) ;
+
+		if( n )
+			sleep( 1 ) ; // wait for more entropy -- moot
 	}
 }
 
diff --git a/src/gssl/gssl_mbedtls.h b/src/gssl/gssl_mbedtls.h
index 700017e..f4b38c5 100644
--- a/src/gssl/gssl_mbedtls.h
+++ b/src/gssl/gssl_mbedtls.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -80,8 +80,8 @@ public:
 public:
 	Certificate( const Certificate & ) = delete ;
 	Certificate( Certificate && ) = delete ;
-	void operator=( const Certificate & ) = delete ;
-	void operator=( Certificate && ) = delete ;
+	Certificate & operator=( const Certificate & ) = delete ;
+	Certificate & operator=( Certificate && ) = delete ;
 
 private:
 	bool m_loaded{false} ;
@@ -102,8 +102,8 @@ public:
 public:
 	Rng( const Rng & ) = delete ;
 	Rng( Rng && ) = delete ;
-	void operator=( const Rng & ) = delete ;
-	void operator=( Rng && ) = delete ;
+	Rng & operator=( const Rng & ) = delete ;
+	Rng & operator=( Rng && ) = delete ;
 
 private:
 	mbedtls_ctr_drbg_context x ; // "counter-mode deterministic random byte generator"
@@ -125,8 +125,8 @@ public:
 public:
 	Key( const Key & ) = delete ;
 	Key( Key && ) = delete ;
-	void operator=( const Key & ) = delete ;
-	void operator=( Key && ) = delete ;
+	Key & operator=( const Key & ) = delete ;
+	Key & operator=( Key && ) = delete ;
 
 private:
 	mbedtls_pk_context x ;
@@ -146,8 +146,8 @@ public:
 public:
 	Context( const Context & ) = delete ;
 	Context( Context && ) = delete ;
-	void operator=( const Context & ) = delete ;
-	void operator=( Context && ) = delete ;
+	Context & operator=( const Context & ) = delete ;
+	Context & operator=( Context && ) = delete ;
 
 private:
 	mbedtls_ssl_context x ;
@@ -173,7 +173,7 @@ private:
 class GSsl::MbedTls::SecureFile
 {
 public:
-	SecureFile( const std::string & path , bool with_nul ) ;
+	SecureFile( const std::string & path , bool with_counted_nul ) ;
 	~SecureFile() ;
 	const char * p() const ;
 	const unsigned char * pu() const ;
@@ -184,8 +184,8 @@ public:
 public:
 	SecureFile( const SecureFile & ) = delete ;
 	SecureFile( SecureFile && ) = delete ;
-	void operator=( const SecureFile & ) = delete ;
-	void operator=( SecureFile && ) = delete ;
+	SecureFile & operator=( const SecureFile & ) = delete ;
+	SecureFile & operator=( SecureFile && ) = delete ;
 
 private:
 	static std::size_t fileSize( std::filebuf & ) ;
@@ -211,7 +211,7 @@ public:
 	bool servernoverify() const ;
 
 private:
-	static bool consume( G::StringArray & , const std::string & ) ;
+	static bool consume( G::StringArray & , G::string_view ) ;
 
 private:
 	bool m_noverify ;
@@ -254,8 +254,8 @@ private: // overrides
 public:
 	LibraryImp( const LibraryImp & ) = delete ;
 	LibraryImp( LibraryImp && ) = delete ;
-	void operator=( const LibraryImp & ) = delete ;
-	void operator=( LibraryImp && ) = delete ;
+	LibraryImp & operator=( const LibraryImp & ) = delete ;
+	LibraryImp & operator=( LibraryImp && ) = delete ;
 
 private:
 	static int minVersionFrom( G::StringArray & ) ;
@@ -297,8 +297,8 @@ private: // overrides
 public:
 	ProfileImp( const ProfileImp & ) = delete ;
 	ProfileImp( ProfileImp && ) = delete ;
-	void operator=( const ProfileImp & ) = delete ;
-	void operator=( ProfileImp && ) = delete ;
+	ProfileImp & operator=( const ProfileImp & ) = delete ;
+	ProfileImp & operator=( ProfileImp && ) = delete ;
 
 private:
 	static void onDebug( void * , int , const char * , int , const char * ) ;
@@ -348,8 +348,8 @@ private: // overrides
 public:
 	ProtocolImp( const ProtocolImp & ) = delete ;
 	ProtocolImp( ProtocolImp && ) = delete ;
-	void operator=( const ProtocolImp & ) = delete ;
-	void operator=( ProtocolImp && ) = delete ;
+	ProtocolImp & operator=( const ProtocolImp & ) = delete ;
+	ProtocolImp & operator=( ProtocolImp && ) = delete ;
 
 private:
 	Result convert( const char * , int , bool more = false ) ;
@@ -377,7 +377,7 @@ public:
 	~DigesterImp() override ;
 
 private: // overrides
-	void add( const std::string & ) override ;
+	void add( G::string_view ) override ;
 	std::string value() override ;
 	std::string state() override ;
 	std::size_t blocksize() const override ;
@@ -387,8 +387,8 @@ private: // overrides
 public:
 	DigesterImp( const DigesterImp & ) = delete ;
 	DigesterImp( DigesterImp && ) = delete ;
-	void operator=( const DigesterImp & ) = delete ;
-	void operator=( DigesterImp && ) = delete ;
+	DigesterImp & operator=( const DigesterImp & ) = delete ;
+	DigesterImp & operator=( DigesterImp && ) = delete ;
 
 private:
 	static void check_ret( int , const char * ) ;
diff --git a/src/gssl/gssl_none.cpp b/src/gssl/gssl_none.cpp
index 004de22..fd2923a 100644
--- a/src/gssl/gssl_none.cpp
+++ b/src/gssl/gssl_none.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,6 +21,7 @@
 #include "gdef.h"
 #include "gssl.h"
 #include "gexception.h"
+#include <memory>
 #include <utility>
 
 GSsl::Library * GSsl::Library::m_this = nullptr ;
@@ -58,7 +59,7 @@ bool GSsl::Library::generateKeyAvailable() const
 
 std::string GSsl::Library::generateKey( const std::string & ) const
 {
-	return std::string() ;
+	return {} ;
 }
 
 GSsl::Library * GSsl::Library::instance()
@@ -93,7 +94,7 @@ bool GSsl::Library::enabledAs( const std::string & )
 
 std::string GSsl::Library::credit( const std::string & , const std::string & , const std::string & )
 {
-	return std::string() ;
+	return {} ;
 }
 
 std::string GSsl::Library::ids()
@@ -103,7 +104,7 @@ std::string GSsl::Library::ids()
 
 G::StringArray GSsl::Library::digesters( bool )
 {
-	return G::StringArray() ;
+	return {} ;
 }
 
 GSsl::Digester GSsl::Library::digester( const std::string & , const std::string & , bool ) const
@@ -148,27 +149,27 @@ GSsl::Protocol::Result GSsl::Protocol::write( const char * , std::size_t , ssize
 
 std::string GSsl::Protocol::str( Protocol::Result )
 {
-	return std::string() ;
+	return {} ;
 }
 
 std::string GSsl::Protocol::peerCertificate() const
 {
-	return std::string() ;
+	return {} ;
 }
 
 std::string GSsl::Protocol::peerCertificateChain() const
 {
-	return std::string() ;
+	return {} ;
 }
 
 std::string GSsl::Protocol::protocol() const
 {
-	return std::string() ;
+	return {} ;
 }
 
 std::string GSsl::Protocol::cipher() const
 {
-	return std::string() ;
+	return {} ;
 }
 
 bool GSsl::Protocol::verified() const
@@ -183,18 +184,18 @@ GSsl::Digester::Digester( std::unique_ptr<DigesterImpBase> p ) :
 {
 }
 
-void GSsl::Digester::add( const std::string & )
+void GSsl::Digester::add( G::string_view )
 {
 }
 
 std::string GSsl::Digester::value()
 {
-	return std::string() ;
+	return {} ;
 }
 
 std::string GSsl::Digester::state()
 {
-	return std::string() ;
+	return {} ;
 }
 
 std::size_t GSsl::Digester::blocksize() const
diff --git a/src/gssl/gssl_openssl.cpp b/src/gssl/gssl_openssl.cpp
index e69f9a6..421d524 100644
--- a/src/gssl/gssl_openssl.cpp
+++ b/src/gssl/gssl_openssl.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -32,31 +32,19 @@
 #include "groot.h"
 #include "gexception.h"
 #include "glog.h"
-#include <openssl/ssl.h>
-#include <openssl/err.h>
-#include <openssl/rand.h>
-#include <openssl/conf.h>
-#include <openssl/evp.h>
-#include <openssl/hmac.h>
 #include <exception>
 #include <functional>
 #include <vector>
 #include <sstream>
 #include <utility>
 #include <algorithm>
+#include <memory>
 
 GSsl::OpenSSL::LibraryImp::LibraryImp( G::StringArray & library_config , Library::LogFn log_fn , bool verbose ) :
 	m_log_fn(log_fn) ,
 	m_verbose(verbose) ,
 	m_config(library_config)
 {
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
-	// library initialisation -- not required for OpenSSL v1.1 (August 2016)
-	SSL_load_error_strings() ;
-	SSL_library_init() ;
-	OpenSSL_add_all_digests() ;
-#endif
-
 	// "on systems without /dev/*random devices providing entropy from the kernel the EGD entropy
 	// gathering daemon can be used to collect entropy... OpenSSL automatically queries EGD when
 	// entropy is ... checked via RAND_status() for the first time" (man RAND_egd(3))
@@ -78,20 +66,11 @@ GSsl::OpenSSL::LibraryImp::~LibraryImp()
 
 void GSsl::OpenSSL::LibraryImp::cleanup()
 {
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
-	ERR_free_strings() ;
-	RAND_cleanup() ;
-	CRYPTO_cleanup_all_ex_data();
-#endif
 }
 
 std::string GSsl::OpenSSL::LibraryImp::sid()
 {
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
-	std::string v = SSLeay_version(SSLEAY_VERSION) ;
-#else
 	std::string v = OpenSSL_version(OPENSSL_VERSION) ;
-#endif
 	return G::Str::unique( G::Str::printable(v) , ' ' ) ;
 }
 
@@ -145,7 +124,7 @@ bool GSsl::OpenSSL::LibraryImp::hasProfile( const std::string & profile_name ) c
 const GSsl::Profile & GSsl::OpenSSL::LibraryImp::profile( const std::string & profile_name ) const
 {
 	auto p = m_profile_map.find( profile_name ) ;
-	if( p == m_profile_map.end() ) throw Error( "no such profile: [" + profile_name + "]" ) ;
+	if( p == m_profile_map.end() ) throw Error( std::string("no such profile: [").append(profile_name).append(1U,']') ) ;
 	return *(*p).second ;
 }
 
@@ -185,6 +164,9 @@ GSsl::OpenSSL::DigesterImp::DigesterImp( const std::string & hash_type , const s
 	m_evp_ctx(nullptr)
 {
 	bool have_state = !state.empty() ;
+	m_state_size = 0U ;
+
+	#if GCONFIG_HAVE_OPENSSL_HASH_FUNCTIONS
 	if( hash_type == "MD5" && ( have_state || need_state ) )
 	{
 		m_hash_type = Type::Md5 ;
@@ -215,21 +197,22 @@ GSsl::OpenSSL::DigesterImp::DigesterImp( const std::string & hash_type , const s
 		m_value_size = 32U ;
 		m_state_size = m_value_size + 4U ;
 	}
-	else
+	#endif
+
+	if( m_state_size == 0U )
 	{
+		if( have_state || need_state )
+			throw Error( std::string("hash state resoration not implemented for ").append(hash_type) ) ;
+
 		m_hash_type = Type::Other ;
 		m_evp_ctx = EVP_MD_CTX_create() ;
 
 		const EVP_MD * md = EVP_get_digestbyname( hash_type.c_str() ) ;
 		if( md == nullptr )
-			throw Error( "unsupported hash function name: [" + hash_type + "]" ) ;
+			throw Error( std::string("unsupported hash function name: [").append(hash_type).append(1U,']') ) ;
 
 		m_block_size = static_cast<std::size_t>( EVP_MD_block_size(md) ) ;
 		m_value_size = static_cast<std::size_t>( EVP_MD_size(md) ) ;
-		m_state_size = 0U ; // intermediate state not available
-
-		if( m_state_size == 0U && !state.empty() )
-			throw Error( "hash state resoration not implemented for " + hash_type ) ;
 
 		EVP_DigestInit_ex( m_evp_ctx , md , nullptr ) ;
 	}
@@ -258,18 +241,20 @@ std::size_t GSsl::OpenSSL::DigesterImp::statesize() const
 
 std::string GSsl::OpenSSL::DigesterImp::state()
 {
+	#if GCONFIG_HAVE_OPENSSL_HASH_FUNCTIONS
 	if( m_hash_type == Type::Md5 )
 		return G::HashState<16,MD5_LONG,MD5_LONG>::encode( m_md5.Nh , m_md5.Nl , m_md5.A , m_md5.B , m_md5.C , m_md5.D ) ;
 	else if( m_hash_type == Type::Sha1 )
 		return G::HashState<20,SHA_LONG,SHA_LONG>::encode( m_sha1.Nh , m_sha1.Nl , m_sha1.h0 , m_sha1.h1 , m_sha1.h2 , m_sha1.h3 , m_sha1.h4 ) ;
 	else if( m_hash_type == Type::Sha256 )
 		return G::HashState<32,SHA_LONG,SHA_LONG>::encode( m_sha256.Nh , m_sha256.Nl , m_sha256.h ) ;
-	else
-		return std::string() ; // not available
+	#endif
+	return std::string() ; // not available
 }
 
-void GSsl::OpenSSL::DigesterImp::add( const std::string & data )
+void GSsl::OpenSSL::DigesterImp::add( G::string_view data )
 {
+	#if GCONFIG_HAVE_OPENSSL_HASH_FUNCTIONS
 	if( m_hash_type == Type::Md5 )
 		MD5_Update( &m_md5 , data.data() , data.size() ) ;
 	else if( m_hash_type == Type::Sha1 )
@@ -278,12 +263,16 @@ void GSsl::OpenSSL::DigesterImp::add( const std::string & data )
 		SHA256_Update( &m_sha256 , data.data() , data.size() ) ;
 	else
 		EVP_DigestUpdate( m_evp_ctx , data.data() , data.size() ) ;
+	#else
+		EVP_DigestUpdate( m_evp_ctx , data.data() , data.size() ) ;
+	#endif
 }
 
 std::string GSsl::OpenSSL::DigesterImp::value()
 {
 	std::vector<unsigned char> output ;
 	std::size_t n = 0U ;
+	#if GCONFIG_HAVE_OPENSSL_HASH_FUNCTIONS
 	if( m_hash_type == Type::Md5 )
 	{
 		n = MD5_DIGEST_LENGTH ;
@@ -302,7 +291,8 @@ std::string GSsl::OpenSSL::DigesterImp::value()
 		output.resize( n ) ;
 		SHA256_Final( &output[0] , &m_sha256 ) ;
 	}
-	else
+	#endif
+	if( n == 0U )
 	{
 		unsigned int output_size = 0 ;
 		output.resize( EVP_MAX_MD_SIZE ) ;
@@ -326,7 +316,7 @@ GSsl::OpenSSL::ProfileImp::ProfileImp( const LibraryImp & library_imp , bool is_
 		m_ssl_ctx(nullptr,std::function<void(SSL_CTX*)>(deleter))
 {
 	using G::format ;
-	using G::gettext ;
+	using G::txt ;
 	Config extra_config = m_library_imp.config() ;
 	if( !profile_config.empty() )
 	{
@@ -352,7 +342,7 @@ GSsl::OpenSSL::ProfileImp::ProfileImp( const LibraryImp & library_imp , bool is_
 	{
 		G::Root claim_root ;
 		if( !G::File::exists(key_file) )
-			G_WARNING( "GSsl::Profile: " << format(gettext("cannot open ssl key file: %1%")) % key_file ) ;
+			G_WARNING( "GSsl::Profile: " << format(txt("cannot open ssl key file: %1%")) % key_file ) ;
 
 		check( SSL_CTX_use_PrivateKey_file(m_ssl_ctx.get(),key_file.c_str(),SSL_FILETYPE_PEM) ,
 			"use_PrivateKey_file" , key_file ) ;
@@ -362,7 +352,7 @@ GSsl::OpenSSL::ProfileImp::ProfileImp( const LibraryImp & library_imp , bool is_
 	{
 		G::Root claim_root ;
 		if( !G::File::exists(cert_file) )
-			G_WARNING( "GSsl::Profile: " << format(gettext("cannot open ssl certificate file: %1%")) % cert_file ) ;
+			G_WARNING( "GSsl::Profile: " << format(txt("cannot open ssl certificate file: %1%")) % cert_file ) ;
 
 		check( SSL_CTX_use_certificate_chain_file(m_ssl_ctx.get(),cert_file.c_str()) ,
 			"use_certificate_chain_file" , cert_file ) ;
@@ -496,7 +486,11 @@ int GSsl::OpenSSL::ProfileImp::verifyPeerName( int ok , X509_STORE_CTX * ctx )
 				std::string subject = name(X509_get_subject_name(cert)) ;
 				G::StringArray subject_parts = G::Str::splitIntoTokens( subject , "/" ) ;
 				bool found = std::find( subject_parts.begin() , subject_parts.end() , "CN="+required_peer_certificate_name ) != subject_parts.end() ;
-				library.log()( 2 , "certificate-subject=[" + subject + "] required-peer-name=[" + required_peer_certificate_name + "] ok=" + (found?"1":"0") ) ;
+				library.log()( 2 , std::string("certificate-subject=[")
+					.append(subject)
+					.append("] required-peer-name=[")
+					.append(required_peer_certificate_name)
+					.append("] ok=").append(1U,found?'1':'0') ) ;
 				if( !found )
 				{
 					ok = 0 ;
@@ -593,12 +587,6 @@ void GSsl::OpenSSL::ProtocolImp::set( int fd )
 		if( rc == 0 )
 			throw Error( "SSL_set_fd" , ERR_get_error() ) ;
 
-		if( G::Test::enabled("log-openssl-bio") ) // log bio activity directly to stderr
-		{
-			BIO_set_callback( SSL_get_rbio(m_ssl.get()) , BIO_debug_callback ) ;
-			BIO_set_callback( SSL_get_wbio(m_ssl.get()) , BIO_debug_callback ) ;
-		}
-
 		m_fd_set = true ;
 	}
 }
@@ -612,11 +600,7 @@ GSsl::Protocol::Result GSsl::OpenSSL::ProtocolImp::connect()
 		saveResult() ;
 		return Protocol::Result::ok ;
 	}
-	else if( rc == 0 )
-	{
-		return convert(error("SSL_connect",rc)) ;
-	}
-	else // rc < 0
+	else
 	{
 		return convert(error("SSL_connect",rc)) ;
 	}
@@ -631,11 +615,7 @@ GSsl::Protocol::Result GSsl::OpenSSL::ProtocolImp::accept()
 		saveResult() ;
 		return Protocol::Result::ok ;
 	}
-	else if( rc == 0 )
-	{
-		return convert(error("SSL_accept",rc)) ;
-	}
-	else // rc < 0
+	else
 	{
 		return convert(error("SSL_accept",rc)) ;
 	}
@@ -669,11 +649,7 @@ GSsl::Protocol::Result GSsl::OpenSSL::ProtocolImp::read( char * buffer , std::si
 		read_size = static_cast<ssize_t>(rc) ;
 		return SSL_pending(m_ssl.get()) ? Protocol::Result::more : Protocol::Result::ok ;
 	}
-	else if( rc == 0 )
-	{
-		return convert(error("SSL_read",rc)) ;
-	}
-	else // rc < 0
+	else
 	{
 		return convert(error("SSL_read",rc)) ;
 	}
@@ -690,11 +666,7 @@ GSsl::Protocol::Result GSsl::OpenSSL::ProtocolImp::write( const char * buffer ,
 		size_out = static_cast<ssize_t>(rc) ;
 		return Protocol::Result::ok ;
 	}
-	else if( rc == 0 )
-	{
-		return convert(error("SSL_write",rc)) ;
-	}
-	else // rc < 0
+	else
 	{
 		return convert(error("SSL_write",rc)) ;
 	}
@@ -714,18 +686,14 @@ std::string GSsl::OpenSSL::ProtocolImp::cipher() const
 {
 	const SSL_CIPHER * cipher = SSL_get_current_cipher( const_cast<SSL*>(m_ssl.get()) ) ;
 	const char * name = cipher ? SSL_CIPHER_get_name(cipher) : nullptr ;
-	return name ? G::Str::printable(name) : std::string() ;
+	return name ? G::Str::printable(std::string(name)) : std::string() ;
 }
 
 std::string GSsl::OpenSSL::ProtocolImp::protocol() const
 {
-	#if OPENSSL_VERSION_NUMBER < 0x10100000L
-		int v = SSL_version( m_ssl.get() ) ;
-	#else
-		const SSL_SESSION * session = SSL_get_session( const_cast<SSL*>(m_ssl.get()) ) ;
-		if( session == nullptr ) return std::string() ;
-		int v = SSL_SESSION_get_protocol_version( session ) ;
-	#endif
+	const SSL_SESSION * session = SSL_get_session( const_cast<SSL*>(m_ssl.get()) ) ;
+	if( session == nullptr ) return std::string() ;
+	int v = SSL_SESSION_get_protocol_version( session ) ;
 	#ifdef TLS1_VERSION
 		if( v == TLS1_VERSION ) return "TLSv1.0" ; // cf. mbedtls
 	#endif
@@ -740,7 +708,7 @@ std::string GSsl::OpenSSL::ProtocolImp::protocol() const
 	#else
 		if( v == 0x304 ) return "TLSv1.3" ; // grr libressl
 	#endif
-	return "#" + G::Str::fromInt(v) ;
+	return std::string(1U,'#').append(G::Str::fromInt(v)) ;
 }
 
 bool GSsl::OpenSSL::ProtocolImp::verified() const
@@ -777,18 +745,18 @@ std::string GSsl::OpenSSL::ProtocolImp::requiredPeerCertificateName() const
 // ==
 
 GSsl::OpenSSL::Error::Error( const std::string & s ) :
-	std::runtime_error( "tls error: " + s )
+	std::runtime_error( std::string("tls error: ").append(s) )
 {
 }
 
 GSsl::OpenSSL::Error::Error( const std::string & fnname , unsigned long e ) :
-	std::runtime_error( "tls error: " + fnname + "(): [" + text(e) + "]" )
+	std::runtime_error( std::string("tls error: ").append(fnname).append("(): [").append(text(e)).append(1U,']') )
 {
 	clearErrors() ;
 }
 
 GSsl::OpenSSL::Error::Error( const std::string & fnname , unsigned long e , const std::string & file ) :
-	std::runtime_error( "tls error: " + fnname + "(): [" + text(e) + "]: file=[" + file + "]" )
+	std::runtime_error( std::string("tls error: ").append(fnname).append("(): [").append(text(e)).append("]: file=[").append(file).append(1U,']') )
 {
 	clearErrors() ;
 }
@@ -830,10 +798,11 @@ GSsl::OpenSSL::Certificate::Certificate( X509 * x509 , bool do_free )
 {
 	if( x509 == nullptr ) return ;
 	BIO * bio = BIO_new( BIO_s_mem() ) ;
+	if( bio == nullptr ) return ;
 	int rc = PEM_write_bio_X509( bio , x509 ) ;
-	if( !rc ) return ;
+	if( !rc ) { BIO_free(bio) ; return ; }
 	BUF_MEM * mem = nullptr ;
-	BIO_get_mem_ptr( bio , &mem ) ;
+	BIO_get_mem_ptr( bio , &mem ) ; // NOLINT
 	std::size_t n = mem ? static_cast<std::size_t>(mem->length) : 0U ;
 	const char * p = mem ? mem->data : nullptr ;
 	std::string data = p&&n ? std::string(p,n) : std::string() ;
@@ -842,7 +811,7 @@ GSsl::OpenSSL::Certificate::Certificate( X509 * x509 , bool do_free )
 
 	// sanitise to be strictly printable with embedded newlines
 	std::string result = G::Str::printable( data , '\0' ) ;
-	G::Str::replaceAll( result , std::string(1U,'\0')+"n" , "\n" ) ;
+	G::Str::replaceAll( result , std::string("\0n",2U) , "\n" ) ;
 	G::Str::replaceAll( result , std::string(1U,'\0') , "\\" ) ;
 	m_str = result ;
 }
@@ -915,7 +884,7 @@ GSsl::OpenSSL::Config::Config( G::StringArray & cfg ) :
 	#endif
 }
 
-bool GSsl::OpenSSL::Config::consume( G::StringArray & list , const std::string & item )
+bool GSsl::OpenSSL::Config::consume( G::StringArray & list , G::string_view item )
 {
 	return LibraryImp::consume( list , item ) ;
 }
diff --git a/src/gssl/gssl_openssl.h b/src/gssl/gssl_openssl.h
index 5115af5..1dadf6a 100644
--- a/src/gssl/gssl_openssl.h
+++ b/src/gssl/gssl_openssl.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -27,13 +27,26 @@
 #include <openssl/ssl.h>
 #include <openssl/err.h>
 #include <openssl/rand.h>
+#include <openssl/conf.h>
+#include <openssl/evp.h>
 #include <openssl/md5.h>
 #include <openssl/sha.h>
-#include <openssl/evp.h>
+#include <openssl/hmac.h>
+#include <memory>
 #include <stdexcept>
 #include <functional>
 #include <map>
-#include <memory>
+
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#error "openssl is too old"
+#endif
+#ifndef GCONFIG_HAVE_OPENSSL_HASH_FUNCTIONS
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+#define GCONFIG_HAVE_OPENSSL_HASH_FUNCTIONS 0
+#else
+#define GCONFIG_HAVE_OPENSSL_HASH_FUNCTIONS 1
+#endif
+#endif
 
 // debugging...
 //  * network logging
@@ -94,7 +107,7 @@ public:
 	bool noverify() const ;
 
 private:
-	static bool consume( G::StringArray & , const std::string & ) ;
+	static bool consume( G::StringArray & , G::string_view ) ;
 	static int map( int , int ) ;
 
 private:
@@ -160,11 +173,11 @@ private: // overrides
 public:
 	ProfileImp( const ProfileImp & ) = delete ;
 	ProfileImp( ProfileImp && ) = delete ;
-	void operator=( const ProfileImp & ) = delete ;
-	void operator=( ProfileImp && ) = delete ;
+	ProfileImp & operator=( const ProfileImp & ) = delete ;
+	ProfileImp & operator=( ProfileImp && ) = delete ;
 
 private:
-	static void check( int , const std::string & , const std::string & = std::string() ) ;
+	static void check( int , const std::string & , const std::string & = {} ) ;
 	static int verifyPass( int , X509_STORE_CTX * ) ;
 	static int verifyPeerName( int , X509_STORE_CTX * ) ;
 	static std::string name( X509_NAME * ) ;
@@ -212,8 +225,8 @@ private: // overrides
 public:
 	LibraryImp( const LibraryImp & ) = delete ;
 	LibraryImp( LibraryImp && ) = delete ;
-	void operator=( const LibraryImp & ) = delete ;
-	void operator=( LibraryImp && ) = delete ;
+	LibraryImp & operator=( const LibraryImp & ) = delete ;
+	LibraryImp & operator=( LibraryImp && ) = delete ;
 
 private:
 	static void cleanup() ;
@@ -258,8 +271,8 @@ private: // overrides
 public:
 	ProtocolImp( const ProtocolImp & ) = delete ;
 	ProtocolImp( ProtocolImp && ) = delete ;
-	void operator=( const ProtocolImp & ) = delete ;
-	void operator=( ProtocolImp && ) = delete ;
+	ProtocolImp & operator=( const ProtocolImp & ) = delete ;
+	ProtocolImp & operator=( ProtocolImp && ) = delete ;
 
 private:
 	int error( const char * , int ) const ;
@@ -293,7 +306,7 @@ public:
 	~DigesterImp() override ;
 
 private: // overrides
-	void add( const std::string & ) override ;
+	void add( G::string_view ) override ;
 	std::string value() override ;
 	std::string state() override ;
 	std::size_t blocksize() const override ;
@@ -303,15 +316,17 @@ private: // overrides
 public:
 	DigesterImp( const DigesterImp & ) = delete ;
 	DigesterImp( DigesterImp && ) = delete ;
-	void operator=( const DigesterImp & ) = delete ;
-	void operator=( DigesterImp && ) = delete ;
+	DigesterImp & operator=( const DigesterImp & ) = delete ;
+	DigesterImp & operator=( DigesterImp && ) = delete ;
 
 private:
 	enum class Type { Md5 , Sha1 , Sha256 , Other } ;
 	Type m_hash_type ;
+	#if GCONFIG_HAVE_OPENSSL_HASH_FUNCTIONS
 	MD5_CTX m_md5 {} ;
 	SHA_CTX m_sha1 {} ;
 	SHA256_CTX m_sha256 {} ;
+	#endif
 	EVP_MD_CTX * m_evp_ctx ;
 	std::size_t m_block_size {0} ;
 	std::size_t m_value_size {0} ;
diff --git a/src/gssl/gssl_use_both.cpp b/src/gssl/gssl_use_both.cpp
index 4354e89..5042f3f 100644
--- a/src/gssl/gssl_use_both.cpp
+++ b/src/gssl/gssl_use_both.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gssl/gssl_use_mbedtls.cpp b/src/gssl/gssl_use_mbedtls.cpp
index 84a7291..c163122 100644
--- a/src/gssl/gssl_use_mbedtls.cpp
+++ b/src/gssl/gssl_use_mbedtls.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gssl/gssl_use_openssl.cpp b/src/gssl/gssl_use_openssl.cpp
index 85f3596..ce6de38 100644
--- a/src/gssl/gssl_use_openssl.cpp
+++ b/src/gssl/gssl_use_openssl.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gui/Makefile.am b/src/gui/Makefile.am
index a0e46c3..160ed4a 100644
--- a/src/gui/Makefile.am
+++ b/src/gui/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -32,32 +32,32 @@
 #	directory getting cleaned up.
 #
 
-MAC_SOURCES = access_mac.cpp dir_mac.cpp boot_mac.cpp glink_mac.cpp
-WIN32_SOURCES = access_win32.cpp dir_win32.cpp boot_win32.cpp glink_win32.cpp emailrelay-gui.rc
-UNIX_SOURCES = access_unix.cpp dir_unix.cpp boot_unix.cpp glink_unix.cpp
+MAC_SOURCES = guiaccess_mac.cpp guidir_mac.cpp guiboot_mac.cpp guilink_mac.cpp
+WIN32_SOURCES = guiaccess_win32.cpp guidir_win32.cpp guiboot_win32.cpp guilink_win32.cpp emailrelay-gui.rc
+UNIX_SOURCES = guiaccess_unix.cpp guidir_unix.cpp guiboot_unix.cpp guilink_unix.cpp
 
 QT_SOURCES = \
 	installer.cpp \
-	gdialog.cpp \
-	gdialog.h \
-	gpage.cpp \
-	gpage.h \
+	guidialog.cpp \
+	guidialog.h \
+	guipage.cpp \
+	guipage.h \
 	pages.h \
 	pages.cpp \
 	gqt.h
 
 LIB_SOURCES = \
 	$(OS_SOURCES) \
-	access.h \
-	boot.h \
-	dir.cpp \
-	dir.h \
+	guidir.cpp \
+	guidir.h \
 	gcominit.h \
 	glibsources.cpp \
-	glink.h \
+	guiaccess.h \
+	guiboot.h \
+	guilink.h \
+	guilegal.cpp \
+	guilegal.h \
 	installer.h \
-	legal.cpp \
-	legal.h \
 	serverconfiguration.cpp \
 	serverconfiguration.h
 
@@ -89,23 +89,18 @@ EXTRA_DIST=\
 	$(TS_FILES) \
 	$(QM_IN_FILES) \
 	emailrelay-gui.exe.manifest \
-	messages.mc \
 	emailrelay-gui.pro \
+	messages.mc \
 	$(OS_EXTRA_DIST)
 
 # force symbol stripping on 'make install' -- see also make 'install-strip'
 AM_INSTALL_PROGRAM_FLAGS=-s
 
 MOC_OUTPUT=\
-	moc_gdialog.cpp \
-	moc_gpage.cpp \
+	moc_guidialog.cpp \
+	moc_guipage.cpp \
 	moc_pages.cpp
 
-MOC_OBJECTS=\
-	moc_gdialog.o \
-	moc_gpage.o \
-	moc_pages.o
-
 CLEANFILES = $(MOC_OUTPUT) $(QM_FILES)
 DISTCLEANFILES = ./.deps/moc*
 
@@ -113,8 +108,6 @@ AM_CPPFLAGS=\
 	-I$(top_srcdir)/src/glib \
 	-I$(top_srcdir)/src/gssl \
 	-I$(top_srcdir)/src/gnet \
-	-I$(top_srcdir)/src/gsmtp \
-	-I$(top_srcdir)/src/gpop \
 	-I$(top_srcdir)/src/main \
 	-D "G_SBINDIR=$(sbindir)" \
 	-D "G_SPOOLDIR=$(e_spooldir)" \
@@ -129,14 +122,18 @@ AM_CPPFLAGS=\
 
 if GCONFIG_GUI
 
-moc_gdialog.cpp: $(srcdir)/gdialog.h
-	$(GCONFIG_QT_MOC) $(srcdir)/gdialog.h -o $@
+moc_guidialog.cpp: $(srcdir)/guidialog.h
+	$(GCONFIG_QT_MOC) $< -o $@
 
-moc_gpage.cpp: $(srcdir)/gpage.h
-	$(GCONFIG_QT_MOC) $(srcdir)/gpage.h -o $@
+moc_guipage.cpp: $(srcdir)/guipage.h
+	$(GCONFIG_QT_MOC) $< -o $@
 
 moc_pages.cpp: $(srcdir)/pages.h
-	$(GCONFIG_QT_MOC) $(srcdir)/pages.h -o $@
+	$(GCONFIG_QT_MOC) $< -o $@
+
+guidialog.o: moc_guidialog.cpp
+guipage.o: moc_guipage.cpp
+pages.o: moc_pages.cpp
 
 noinst_SCRIPTS = $(OS_NOINST)
 noinst_LIBRARIES = libguimain.a
@@ -148,9 +145,8 @@ if GCONFIG_WINDOWS
 sbin_PROGRAMS = emailrelay-gui
 
 emailrelay_gui_SOURCES = guimain.cpp $(QT_SOURCES)
-emailrelay_gui_DEPENDENCIES = $(MOC_OBJECTS) libguimain.a
+emailrelay_gui_DEPENDENCIES = libguimain.a
 emailrelay_gui_LDADD = \
-	$(MOC_OBJECTS) \
 	libguimain.a \
 	$(GCONFIG_QT_LIBS)
 
@@ -159,9 +155,8 @@ else
 sbin_PROGRAMS = emailrelay-gui.real
 
 emailrelay_gui_real_SOURCES = guimain.cpp $(QT_SOURCES)
-emailrelay_gui_real_DEPENDENCIES = $(MOC_OBJECTS) libguimain.a
+emailrelay_gui_real_DEPENDENCIES = libguimain.a
 emailrelay_gui_real_LDADD = \
-	$(MOC_OBJECTS) \
 	libguimain.a \
 	$(GCONFIG_QT_LIBS)
 
@@ -199,4 +194,3 @@ payload: $(top_srcdir)/bin/make-setup.sh
 lrelease:
 	$(QT_LRELEASE) emailrelay_tr.no_NO.ts -qm emailrelay.no.qm
 
-	
diff --git a/src/gui/Makefile.in b/src/gui/Makefile.in
index b1320a1..2fcc874 100644
--- a/src/gui/Makefile.in
+++ b/src/gui/Makefile.in
@@ -134,41 +134,43 @@ am__v_AR_0 = @echo "  AR      " $@;
 am__v_AR_1 = 
 libguimain_a_AR = $(AR) $(ARFLAGS)
 libguimain_a_LIBADD =
-am__libguimain_a_SOURCES_DIST = access_unix.cpp dir_unix.cpp \
-	boot_unix.cpp glink_unix.cpp access_mac.cpp dir_mac.cpp \
-	boot_mac.cpp glink_mac.cpp access_win32.cpp dir_win32.cpp \
-	boot_win32.cpp glink_win32.cpp emailrelay-gui.rc access.h \
-	boot.h dir.cpp dir.h gcominit.h glibsources.cpp glink.h \
-	installer.h legal.cpp legal.h serverconfiguration.cpp \
+am__libguimain_a_SOURCES_DIST = guiaccess_unix.cpp guidir_unix.cpp \
+	guiboot_unix.cpp guilink_unix.cpp guiaccess_mac.cpp \
+	guidir_mac.cpp guiboot_mac.cpp guilink_mac.cpp \
+	guiaccess_win32.cpp guidir_win32.cpp guiboot_win32.cpp \
+	guilink_win32.cpp emailrelay-gui.rc guidir.cpp guidir.h \
+	gcominit.h glibsources.cpp guiaccess.h guiboot.h guilink.h \
+	guilegal.cpp guilegal.h installer.h serverconfiguration.cpp \
 	serverconfiguration.h
-am__objects_1 = access_unix.$(OBJEXT) dir_unix.$(OBJEXT) \
-	boot_unix.$(OBJEXT) glink_unix.$(OBJEXT)
-am__objects_2 = access_mac.$(OBJEXT) dir_mac.$(OBJEXT) \
-	boot_mac.$(OBJEXT) glink_mac.$(OBJEXT)
-am__objects_3 = access_win32.$(OBJEXT) dir_win32.$(OBJEXT) \
-	boot_win32.$(OBJEXT) glink_win32.$(OBJEXT)
+am__objects_1 = guiaccess_unix.$(OBJEXT) guidir_unix.$(OBJEXT) \
+	guiboot_unix.$(OBJEXT) guilink_unix.$(OBJEXT)
+am__objects_2 = guiaccess_mac.$(OBJEXT) guidir_mac.$(OBJEXT) \
+	guiboot_mac.$(OBJEXT) guilink_mac.$(OBJEXT)
+am__objects_3 = guiaccess_win32.$(OBJEXT) guidir_win32.$(OBJEXT) \
+	guiboot_win32.$(OBJEXT) guilink_win32.$(OBJEXT)
 @GCONFIG_MAC_FALSE@@GCONFIG_WINDOWS_FALSE@am__objects_4 =  \
 @GCONFIG_MAC_FALSE@@GCONFIG_WINDOWS_FALSE@	$(am__objects_1)
 @GCONFIG_MAC_TRUE@@GCONFIG_WINDOWS_FALSE@am__objects_4 =  \
 @GCONFIG_MAC_TRUE@@GCONFIG_WINDOWS_FALSE@	$(am__objects_2)
 @GCONFIG_WINDOWS_TRUE@am__objects_4 = $(am__objects_3)
-am__objects_5 = $(am__objects_4) dir.$(OBJEXT) glibsources.$(OBJEXT) \
-	legal.$(OBJEXT) serverconfiguration.$(OBJEXT)
+am__objects_5 = $(am__objects_4) guidir.$(OBJEXT) \
+	glibsources.$(OBJEXT) guilegal.$(OBJEXT) \
+	serverconfiguration.$(OBJEXT)
 @GCONFIG_GUI_TRUE@am_libguimain_a_OBJECTS = $(am__objects_5)
 libguimain_a_OBJECTS = $(am_libguimain_a_OBJECTS)
 am__emailrelay_gui_SOURCES_DIST = guimain.cpp installer.cpp \
-	gdialog.cpp gdialog.h gpage.cpp gpage.h pages.h pages.cpp \
-	gqt.h
-am__objects_6 = installer.$(OBJEXT) gdialog.$(OBJEXT) gpage.$(OBJEXT) \
-	pages.$(OBJEXT)
+	guidialog.cpp guidialog.h guipage.cpp guipage.h pages.h \
+	pages.cpp gqt.h
+am__objects_6 = installer.$(OBJEXT) guidialog.$(OBJEXT) \
+	guipage.$(OBJEXT) pages.$(OBJEXT)
 @GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_TRUE@am_emailrelay_gui_OBJECTS =  \
 @GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_TRUE@	guimain.$(OBJEXT) \
 @GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_TRUE@	$(am__objects_6)
 emailrelay_gui_OBJECTS = $(am_emailrelay_gui_OBJECTS)
 am__DEPENDENCIES_1 =
 am__emailrelay_gui_real_SOURCES_DIST = guimain.cpp installer.cpp \
-	gdialog.cpp gdialog.h gpage.cpp gpage.h pages.h pages.cpp \
-	gqt.h
+	guidialog.cpp guidialog.h guipage.cpp guipage.h pages.h \
+	pages.cpp gqt.h
 @GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_FALSE@am_emailrelay_gui_real_OBJECTS =  \
 @GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_FALSE@	guimain.$(OBJEXT) \
 @GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_FALSE@	$(am__objects_6)
@@ -189,16 +191,16 @@ am__v_at_1 =
 DEFAULT_INCLUDES = -I.@am__isrc@ -I$(top_builddir)/src
 depcomp = $(SHELL) $(top_srcdir)/depcomp
 am__maybe_remake_depfiles = depfiles
-am__depfiles_remade = ./$(DEPDIR)/access_mac.Po \
-	./$(DEPDIR)/access_unix.Po ./$(DEPDIR)/access_win32.Po \
-	./$(DEPDIR)/boot_mac.Po ./$(DEPDIR)/boot_unix.Po \
-	./$(DEPDIR)/boot_win32.Po ./$(DEPDIR)/dir.Po \
-	./$(DEPDIR)/dir_mac.Po ./$(DEPDIR)/dir_unix.Po \
-	./$(DEPDIR)/dir_win32.Po ./$(DEPDIR)/gdialog.Po \
-	./$(DEPDIR)/glibsources.Po ./$(DEPDIR)/glink_mac.Po \
-	./$(DEPDIR)/glink_unix.Po ./$(DEPDIR)/glink_win32.Po \
-	./$(DEPDIR)/gpage.Po ./$(DEPDIR)/guimain.Po \
-	./$(DEPDIR)/installer.Po ./$(DEPDIR)/legal.Po \
+am__depfiles_remade = ./$(DEPDIR)/glibsources.Po \
+	./$(DEPDIR)/guiaccess_mac.Po ./$(DEPDIR)/guiaccess_unix.Po \
+	./$(DEPDIR)/guiaccess_win32.Po ./$(DEPDIR)/guiboot_mac.Po \
+	./$(DEPDIR)/guiboot_unix.Po ./$(DEPDIR)/guiboot_win32.Po \
+	./$(DEPDIR)/guidialog.Po ./$(DEPDIR)/guidir.Po \
+	./$(DEPDIR)/guidir_mac.Po ./$(DEPDIR)/guidir_unix.Po \
+	./$(DEPDIR)/guidir_win32.Po ./$(DEPDIR)/guilegal.Po \
+	./$(DEPDIR)/guilink_mac.Po ./$(DEPDIR)/guilink_unix.Po \
+	./$(DEPDIR)/guilink_win32.Po ./$(DEPDIR)/guimain.Po \
+	./$(DEPDIR)/guipage.Po ./$(DEPDIR)/installer.Po \
 	./$(DEPDIR)/pages.Po ./$(DEPDIR)/serverconfiguration.Po
 am__mv = mv -f
 CXXCOMPILE = $(CXX) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) \
@@ -411,31 +413,31 @@ target_alias = @target_alias@
 top_build_prefix = @top_build_prefix@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
-MAC_SOURCES = access_mac.cpp dir_mac.cpp boot_mac.cpp glink_mac.cpp
-WIN32_SOURCES = access_win32.cpp dir_win32.cpp boot_win32.cpp glink_win32.cpp emailrelay-gui.rc
-UNIX_SOURCES = access_unix.cpp dir_unix.cpp boot_unix.cpp glink_unix.cpp
+MAC_SOURCES = guiaccess_mac.cpp guidir_mac.cpp guiboot_mac.cpp guilink_mac.cpp
+WIN32_SOURCES = guiaccess_win32.cpp guidir_win32.cpp guiboot_win32.cpp guilink_win32.cpp emailrelay-gui.rc
+UNIX_SOURCES = guiaccess_unix.cpp guidir_unix.cpp guiboot_unix.cpp guilink_unix.cpp
 QT_SOURCES = \
 	installer.cpp \
-	gdialog.cpp \
-	gdialog.h \
-	gpage.cpp \
-	gpage.h \
+	guidialog.cpp \
+	guidialog.h \
+	guipage.cpp \
+	guipage.h \
 	pages.h \
 	pages.cpp \
 	gqt.h
 
 LIB_SOURCES = \
 	$(OS_SOURCES) \
-	access.h \
-	boot.h \
-	dir.cpp \
-	dir.h \
+	guidir.cpp \
+	guidir.h \
 	gcominit.h \
 	glibsources.cpp \
-	glink.h \
+	guiaccess.h \
+	guiboot.h \
+	guilink.h \
+	guilegal.cpp \
+	guilegal.h \
 	installer.h \
-	legal.cpp \
-	legal.h \
 	serverconfiguration.cpp \
 	serverconfiguration.h
 
@@ -455,31 +457,24 @@ EXTRA_DIST = \
 	$(TS_FILES) \
 	$(QM_IN_FILES) \
 	emailrelay-gui.exe.manifest \
-	messages.mc \
 	emailrelay-gui.pro \
+	messages.mc \
 	$(OS_EXTRA_DIST)
 
 
 # force symbol stripping on 'make install' -- see also make 'install-strip'
 AM_INSTALL_PROGRAM_FLAGS = -s
 MOC_OUTPUT = \
-	moc_gdialog.cpp \
-	moc_gpage.cpp \
+	moc_guidialog.cpp \
+	moc_guipage.cpp \
 	moc_pages.cpp
 
-MOC_OBJECTS = \
-	moc_gdialog.o \
-	moc_gpage.o \
-	moc_pages.o
-
 CLEANFILES = $(MOC_OUTPUT) $(QM_FILES)
 DISTCLEANFILES = ./.deps/moc*
 AM_CPPFLAGS = \
 	-I$(top_srcdir)/src/glib \
 	-I$(top_srcdir)/src/gssl \
 	-I$(top_srcdir)/src/gnet \
-	-I$(top_srcdir)/src/gsmtp \
-	-I$(top_srcdir)/src/gpop \
 	-I$(top_srcdir)/src/main \
 	-D "G_SBINDIR=$(sbindir)" \
 	-D "G_SPOOLDIR=$(e_spooldir)" \
@@ -497,16 +492,14 @@ AM_CPPFLAGS = \
 @GCONFIG_GUI_TRUE@libguimain_a_SOURCES = $(LIB_SOURCES)
 @GCONFIG_GUI_TRUE@e_tr_DATA = $(QM_FILES)
 @GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_TRUE@emailrelay_gui_SOURCES = guimain.cpp $(QT_SOURCES)
-@GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_TRUE@emailrelay_gui_DEPENDENCIES = $(MOC_OBJECTS) libguimain.a
+@GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_TRUE@emailrelay_gui_DEPENDENCIES = libguimain.a
 @GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_TRUE@emailrelay_gui_LDADD = \
-@GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_TRUE@	$(MOC_OBJECTS) \
 @GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_TRUE@	libguimain.a \
 @GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_TRUE@	$(GCONFIG_QT_LIBS)
 
 @GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_FALSE@emailrelay_gui_real_SOURCES = guimain.cpp $(QT_SOURCES)
-@GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_FALSE@emailrelay_gui_real_DEPENDENCIES = $(MOC_OBJECTS) libguimain.a
+@GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_FALSE@emailrelay_gui_real_DEPENDENCIES = libguimain.a
 @GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_FALSE@emailrelay_gui_real_LDADD = \
-@GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_FALSE@	$(MOC_OBJECTS) \
 @GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_FALSE@	libguimain.a \
 @GCONFIG_GUI_TRUE@@GCONFIG_WINDOWS_FALSE@	$(GCONFIG_QT_LIBS)
 
@@ -608,25 +601,25 @@ mostlyclean-compile:
 distclean-compile:
 	-rm -f *.tab.c
 
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/access_mac.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/access_unix.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/access_win32.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/boot_mac.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/boot_unix.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/boot_win32.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/dir.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/dir_mac.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/dir_unix.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/dir_win32.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gdialog.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/glibsources.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/glink_mac.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/glink_unix.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/glink_win32.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/gpage.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guiaccess_mac.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guiaccess_unix.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guiaccess_win32.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guiboot_mac.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guiboot_unix.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guiboot_win32.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guidialog.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guidir.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guidir_mac.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guidir_unix.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guidir_win32.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guilegal.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guilink_mac.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guilink_unix.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guilink_win32.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guimain.Po@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/guipage.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/installer.Po@am__quote@ # am--include-marker
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/legal.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pages.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/serverconfiguration.Po@am__quote@ # am--include-marker
 
@@ -802,25 +795,25 @@ clean-am: clean-generic clean-local clean-noinstLIBRARIES \
 	clean-sbinPROGRAMS mostlyclean-am
 
 distclean: distclean-am
-		-rm -f ./$(DEPDIR)/access_mac.Po
-	-rm -f ./$(DEPDIR)/access_unix.Po
-	-rm -f ./$(DEPDIR)/access_win32.Po
-	-rm -f ./$(DEPDIR)/boot_mac.Po
-	-rm -f ./$(DEPDIR)/boot_unix.Po
-	-rm -f ./$(DEPDIR)/boot_win32.Po
-	-rm -f ./$(DEPDIR)/dir.Po
-	-rm -f ./$(DEPDIR)/dir_mac.Po
-	-rm -f ./$(DEPDIR)/dir_unix.Po
-	-rm -f ./$(DEPDIR)/dir_win32.Po
-	-rm -f ./$(DEPDIR)/gdialog.Po
-	-rm -f ./$(DEPDIR)/glibsources.Po
-	-rm -f ./$(DEPDIR)/glink_mac.Po
-	-rm -f ./$(DEPDIR)/glink_unix.Po
-	-rm -f ./$(DEPDIR)/glink_win32.Po
-	-rm -f ./$(DEPDIR)/gpage.Po
+		-rm -f ./$(DEPDIR)/glibsources.Po
+	-rm -f ./$(DEPDIR)/guiaccess_mac.Po
+	-rm -f ./$(DEPDIR)/guiaccess_unix.Po
+	-rm -f ./$(DEPDIR)/guiaccess_win32.Po
+	-rm -f ./$(DEPDIR)/guiboot_mac.Po
+	-rm -f ./$(DEPDIR)/guiboot_unix.Po
+	-rm -f ./$(DEPDIR)/guiboot_win32.Po
+	-rm -f ./$(DEPDIR)/guidialog.Po
+	-rm -f ./$(DEPDIR)/guidir.Po
+	-rm -f ./$(DEPDIR)/guidir_mac.Po
+	-rm -f ./$(DEPDIR)/guidir_unix.Po
+	-rm -f ./$(DEPDIR)/guidir_win32.Po
+	-rm -f ./$(DEPDIR)/guilegal.Po
+	-rm -f ./$(DEPDIR)/guilink_mac.Po
+	-rm -f ./$(DEPDIR)/guilink_unix.Po
+	-rm -f ./$(DEPDIR)/guilink_win32.Po
 	-rm -f ./$(DEPDIR)/guimain.Po
+	-rm -f ./$(DEPDIR)/guipage.Po
 	-rm -f ./$(DEPDIR)/installer.Po
-	-rm -f ./$(DEPDIR)/legal.Po
 	-rm -f ./$(DEPDIR)/pages.Po
 	-rm -f ./$(DEPDIR)/serverconfiguration.Po
 	-rm -f Makefile
@@ -869,25 +862,25 @@ install-ps-am:
 installcheck-am:
 
 maintainer-clean: maintainer-clean-am
-		-rm -f ./$(DEPDIR)/access_mac.Po
-	-rm -f ./$(DEPDIR)/access_unix.Po
-	-rm -f ./$(DEPDIR)/access_win32.Po
-	-rm -f ./$(DEPDIR)/boot_mac.Po
-	-rm -f ./$(DEPDIR)/boot_unix.Po
-	-rm -f ./$(DEPDIR)/boot_win32.Po
-	-rm -f ./$(DEPDIR)/dir.Po
-	-rm -f ./$(DEPDIR)/dir_mac.Po
-	-rm -f ./$(DEPDIR)/dir_unix.Po
-	-rm -f ./$(DEPDIR)/dir_win32.Po
-	-rm -f ./$(DEPDIR)/gdialog.Po
-	-rm -f ./$(DEPDIR)/glibsources.Po
-	-rm -f ./$(DEPDIR)/glink_mac.Po
-	-rm -f ./$(DEPDIR)/glink_unix.Po
-	-rm -f ./$(DEPDIR)/glink_win32.Po
-	-rm -f ./$(DEPDIR)/gpage.Po
+		-rm -f ./$(DEPDIR)/glibsources.Po
+	-rm -f ./$(DEPDIR)/guiaccess_mac.Po
+	-rm -f ./$(DEPDIR)/guiaccess_unix.Po
+	-rm -f ./$(DEPDIR)/guiaccess_win32.Po
+	-rm -f ./$(DEPDIR)/guiboot_mac.Po
+	-rm -f ./$(DEPDIR)/guiboot_unix.Po
+	-rm -f ./$(DEPDIR)/guiboot_win32.Po
+	-rm -f ./$(DEPDIR)/guidialog.Po
+	-rm -f ./$(DEPDIR)/guidir.Po
+	-rm -f ./$(DEPDIR)/guidir_mac.Po
+	-rm -f ./$(DEPDIR)/guidir_unix.Po
+	-rm -f ./$(DEPDIR)/guidir_win32.Po
+	-rm -f ./$(DEPDIR)/guilegal.Po
+	-rm -f ./$(DEPDIR)/guilink_mac.Po
+	-rm -f ./$(DEPDIR)/guilink_unix.Po
+	-rm -f ./$(DEPDIR)/guilink_win32.Po
 	-rm -f ./$(DEPDIR)/guimain.Po
+	-rm -f ./$(DEPDIR)/guipage.Po
 	-rm -f ./$(DEPDIR)/installer.Po
-	-rm -f ./$(DEPDIR)/legal.Po
 	-rm -f ./$(DEPDIR)/pages.Po
 	-rm -f ./$(DEPDIR)/serverconfiguration.Po
 	-rm -f Makefile
@@ -933,14 +926,18 @@ emailrelay.no.qm: emailrelay.no.qm_in
 	-$(AWK) '/^[0123456789]/ {for(i=1;i<NF;i++){printf("%c",$$i)}}' $(srcdir)/emailrelay.no.qm_in > emailrelay.no.qm
 	@test -s $(QM_FILES)
 
-@GCONFIG_GUI_TRUE@moc_gdialog.cpp: $(srcdir)/gdialog.h
-@GCONFIG_GUI_TRUE@	$(GCONFIG_QT_MOC) $(srcdir)/gdialog.h -o $@
+@GCONFIG_GUI_TRUE@moc_guidialog.cpp: $(srcdir)/guidialog.h
+@GCONFIG_GUI_TRUE@	$(GCONFIG_QT_MOC) $< -o $@
 
-@GCONFIG_GUI_TRUE@moc_gpage.cpp: $(srcdir)/gpage.h
-@GCONFIG_GUI_TRUE@	$(GCONFIG_QT_MOC) $(srcdir)/gpage.h -o $@
+@GCONFIG_GUI_TRUE@moc_guipage.cpp: $(srcdir)/guipage.h
+@GCONFIG_GUI_TRUE@	$(GCONFIG_QT_MOC) $< -o $@
 
 @GCONFIG_GUI_TRUE@moc_pages.cpp: $(srcdir)/pages.h
-@GCONFIG_GUI_TRUE@	$(GCONFIG_QT_MOC) $(srcdir)/pages.h -o $@
+@GCONFIG_GUI_TRUE@	$(GCONFIG_QT_MOC) $< -o $@
+
+@GCONFIG_GUI_TRUE@guidialog.o: moc_guidialog.cpp
+@GCONFIG_GUI_TRUE@guipage.o: moc_guipage.cpp
+@GCONFIG_GUI_TRUE@pages.o: moc_pages.cpp
 
 @GCONFIG_GUI_TRUE@install-exec-hook:
 @GCONFIG_GUI_TRUE@	-mkdir -p "$(DESTDIR)$(sbindir)" 2>/dev/null
diff --git a/src/gui/access_win32.cpp b/src/gui/access_win32.cpp
deleted file mode 100644
index 12a34be..0000000
--- a/src/gui/access_win32.cpp
+++ /dev/null
@@ -1,186 +0,0 @@
-//
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-// ===
-///
-/// \file access_win32.cpp
-///
-
-#include "gdef.h"
-#include "access.h"
-#include "gbuffer.h"
-#include "gexception.h"
-#include "gassert.h"
-#include <processthreadsapi.h>
-#include <sddl.h>
-#include <aclapi.h>
-
-static void add_user_write_permissions_to_directory( const std::string & ) ;
-
-bool Access::modify( const G::Path & path , bool b )
-{
-	try
-	{
-		// this is used to open up permissions on ProgramData/E-MailRelay so
-		// that the installing-user can edit emailrelay-start.bat (etc) -- if
-		// it fails then it doesn't stop anything else working, but it becomes
-		// a pain to modify server startup options
-		if( !b )
-			add_user_write_permissions_to_directory( path.str() ) ;
-		return true ;
-	}
-	catch( std::exception & )
-	{
-	}
-	return false ;
-}
-
-namespace
-{
-	struct Error : public G::Exception
-	{
-		explicit Error( DWORD e = GetLastError() ) :
-			G::Exception("error") ,
-			m_e(e)
-		{
-		}
-		DWORD m_e ;
-	} ;
-	struct Token
-	{
-		explicit Token( HANDLE hprocess = GetCurrentProcess() ) :
-			m_h(0)
-		{
-			BOOL rc = OpenProcessToken( hprocess , TOKEN_READ , &m_h ) ;
-			if( rc == 0 )
-				throw Error() ;
-		}
-		~Token()
-		{
-			CloseHandle( m_h ) ;
-		}
-		HANDLE handle() const
-		{
-			return m_h ;
-		}
-		Token( const Token & ) = delete ;
-		Token( Token && ) = delete ;
-		void operator=( const Token & ) = delete ;
-		void operator=( Token && ) = delete ;
-		HANDLE m_h ;
-	} ;
-	struct Sid
-	{
-		virtual ~Sid() = default ;
-		virtual PSID ptr() const = 0 ;
-	} ;
-	struct UserSid : Sid
-	{
-		UserSid( const Token & token )
-		{
-			DWORD size = 0 ;
-			GetTokenInformation( token.handle() , TokenUser , nullptr , 0 , &size ) ;
-			if( size == 0 ) throw Error() ;
-			m_buffer.resize( static_cast<std::size_t>(size) ) ;
-			BOOL rc = GetTokenInformation( token.handle() , TokenUser , &m_buffer[0] , size , &size ) ;
-			if( rc == 0 )
-				throw Error() ;
-		}
-		virtual PSID ptr() const override
-		{
-			const TOKEN_USER * user_info = G::buffer_cast<TOKEN_USER*>( m_buffer ) ;
-			return user_info->User.Sid ;
-		}
-		std::string str() const
-		{
-			char * p = nullptr ;
-			ConvertSidToStringSidA( ptr() , &p ) ;
-			std::string s ;
-			if( p )
-			{
-				s = std::string( p ) ;
-				LocalFree( p ) ;
-			}
-			return s ;
-		}
-		~UserSid() override = default ;
-		G::Buffer<char> m_buffer ;
-	} ;
-	struct DirectoryWriteAccessFor : public EXPLICIT_ACCESS_A
-	{
-		explicit DirectoryWriteAccessFor( const Sid & sid )
-		{
-			EXPLICIT_ACCESS_A zero{} ;
-			*static_cast<EXPLICIT_ACCESS_A*>(this) = zero ;
-			grfAccessPermissions = GENERIC_ALL ;
-			grfAccessMode = GRANT_ACCESS ;
-			grfInheritance = OBJECT_INHERIT_ACE | CONTAINER_INHERIT_ACE ;
-			Trustee.TrusteeForm = TRUSTEE_IS_SID ;
-			Trustee.TrusteeType = TRUSTEE_IS_USER ;
-			Trustee.ptstrName = reinterpret_cast<LPSTR>(sid.ptr()) ;
-		}
-	} ;
-	struct Dacl
-	{
-		explicit Dacl( const std::string & path ) :
-			m_sd(nullptr) ,
-			m_dacl(nullptr) ,
-			m_free_me(false)
-		{
-			DWORD rc = GetNamedSecurityInfoA( path.c_str() , SE_FILE_OBJECT , DACL_SECURITY_INFORMATION ,
-				nullptr , nullptr , &m_dacl , nullptr , &m_sd ) ;
-			if( rc != ERROR_SUCCESS || m_dacl == nullptr )
-				throw Error() ;
-		}
-		~Dacl()
-		{
-			if( m_sd )
-				LocalFree( m_sd ) ;
-			if( m_free_me )
-				LocalFree( m_dacl ) ;
-		}
-		void add( const EXPLICIT_ACCESS_A & access )
-		{
-			ACL * new_dacl = nullptr ;
-			DWORD rc = SetEntriesInAclA( 1 , const_cast<EXPLICIT_ACCESS_A*>(&access) , m_dacl , &new_dacl ) ;
-			if( rc != ERROR_SUCCESS || new_dacl == nullptr )
-				throw Error() ;
-			m_dacl = new_dacl ;
-			m_free_me = true ;
-		}
-		void applyTo( const std::string & path )
-		{
-			DWORD rc = SetNamedSecurityInfoA( const_cast<char*>(path.c_str()) , SE_FILE_OBJECT ,
-				DACL_SECURITY_INFORMATION , nullptr , nullptr , m_dacl , nullptr ) ;
-			if( rc != ERROR_SUCCESS )
-				throw Error() ;
-		}
-		Dacl( const Dacl & ) = delete ;
-		Dacl( Dacl && ) = delete ;
-		void operator=( const Dacl & ) = delete ;
-		void operator=( Dacl && ) = delete ;
-		PSECURITY_DESCRIPTOR m_sd ;
-		ACL * m_dacl ;
-		bool m_free_me ;
-	} ;
-}
-
-static void add_user_write_permissions_to_directory( const std::string & path )
-{
-	Dacl dacl( path ) ;
-	dacl.add( DirectoryWriteAccessFor( UserSid(Token()) ) ) ;
-	dacl.applyTo( path ) ;
-}
-
diff --git a/src/gui/emailrelay-gui.pro b/src/gui/emailrelay-gui.pro
index 5e12f14..1dd2542 100644
--- a/src/gui/emailrelay-gui.pro
+++ b/src/gui/emailrelay-gui.pro
@@ -1,89 +1,97 @@
-#
-# emailrelay-gui.pro
-#
-# QMake project file for the emailrelay gui.
-#
-# Eg:
-#   $ qmake --qt=5 CONFIG+=unix emailrelay-gui.pro
-#   $ make release
-#
-# On windows a static build of emailrelay-gui needs a
-# static build of the Qt library code.
-#
-# Eg:
-#	msvc> cd <qt-source>\qtbase
-#   msvc> edit mkspecs\common\msvc-desktop.conf (/MT)
-#   msvc> PATH=<qt-source>\qtbase\bin;%PATH%
-#   msvc> configure.bat -static -release -prefix "<qt-install>" ... etc
-#   msvc> nmake -f Makefile release
-#   msvc> nmake -f Makefile install
-#
-# Then:
-#   msvc> PATH=<qt-install>\bin;%PATH%
-#   msvc> qmake CONFIG+="win static" emailrelay-gui.pro
-#   msvc> copy ..\main\icon\*.ico .
-#   msvc> mc messages.mc
-#   msvc> nmake -f Makefile release
-#
-
-CONFIG += \
-	warn_on \
-	strict_c++ \
-	debug_and_release \
-	build_all
-
-TEMPLATE = app
-
-QT += widgets
-
-win {
-	QMAKE_LFLAGS += "/MANIFESTUAC:level='highestAvailable'"
-	LIBS += advapi32.lib ole32.lib oleaut32.lib
-	SOURCES += \
-		access_win32.cpp \
-		boot_win32.cpp \
-		dir_win32.cpp \
-		glink_win32.cpp
-}
-
-unix {
-	TARGET = emailrelay-gui.real
-	#LIBS += ...
-	SOURCES += \
-		access_unix.cpp \
-		boot_unix.cpp \
-		dir_unix.cpp \
-		glink_unix.cpp
-}
-
-RC_FILE = emailrelay-gui.rc
-
-build_pass:CONFIG(debug,debug|release) {
-	DEFINES += _DEBUG=1
-}
-
-build_pass:CONFIG(release,debug|release) {
-}
-
-SOURCES += \
-	guimain.cpp \
-	gdialog.cpp \
-	gpage.cpp \
-	pages.cpp \
-	installer.cpp \
-	dir.cpp \
-	glibsources.cpp \
-	legal.cpp \
-	serverconfiguration.cpp
-
-HEADERS += \
-	gdialog.h \
-	gpage.h \
-	pages.h
-
-INCLUDEPATH += \
-	.. \
-	../main \
-	../gssl \
-	../glib
-
+#
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+# 
+# Copying and distribution of this file, with or without modification,
+# are permitted in any medium without royalty provided the copyright
+# notice and this notice are preserved.  This file is offered as-is,
+# without any warranty.
+# ===
+#
+# emailrelay-gui.pro
+#
+# QMake project file for the emailrelay gui.
+#
+# Eg:
+#   $ qmake --qt=5 CONFIG+=unix emailrelay-gui.pro
+#   $ make release
+#
+# On windows a static build of emailrelay-gui needs a
+# static build of the Qt library code.
+#
+# Eg:
+#	msvc> cd <qt-source>\qtbase
+#   msvc> edit mkspecs\common\msvc-desktop.conf (/MT)
+#   msvc> PATH=<qt-source>\qtbase\bin;%PATH%
+#   msvc> configure.bat -static -release -prefix "<qt-install>" ... etc
+#   msvc> nmake -f Makefile release
+#   msvc> nmake -f Makefile install
+#
+# Then:
+#   msvc> PATH=<qt-install>\bin;%PATH%
+#   msvc> qmake CONFIG+="win static" emailrelay-gui.pro
+#   msvc> copy ..\main\icon\*.ico .
+#   msvc> mc messages.mc
+#   msvc> nmake -f Makefile release
+#
+
+CONFIG += \
+	warn_on \
+	strict_c++ \
+	debug_and_release \
+	build_all
+
+TEMPLATE = app
+
+QT += widgets
+
+win {
+	QMAKE_LFLAGS += "/MANIFESTUAC:level='highestAvailable'"
+	LIBS += advapi32.lib ole32.lib oleaut32.lib
+	SOURCES += \
+		guiaccess_win32.cpp \
+		guiboot_win32.cpp \
+		guidir_win32.cpp \
+		guilink_win32.cpp
+}
+
+unix {
+	TARGET = emailrelay-gui.real
+	#LIBS += ...
+	SOURCES += \
+		guiaccess_unix.cpp \
+		guiboot_unix.cpp \
+		guidir_unix.cpp \
+		guilink_unix.cpp
+}
+
+RC_FILE = emailrelay-gui.rc
+
+build_pass:CONFIG(debug,debug|release) {
+	DEFINES += _DEBUG=1
+}
+
+build_pass:CONFIG(release,debug|release) {
+}
+
+SOURCES += \
+	guimain.cpp \
+	guidialog.cpp \
+	guipage.cpp \
+	pages.cpp \
+	installer.cpp \
+	guidir.cpp \
+	glibsources.cpp \
+	guilegal.cpp \
+	serverconfiguration.cpp
+
+HEADERS += \
+	guidialog.h \
+	guipage.h \
+	pages.h
+
+INCLUDEPATH += \
+	.. \
+	../main \
+	../gssl \
+	../glib
+
diff --git a/src/gui/emailrelay-gui.rc b/src/gui/emailrelay-gui.rc
index 898a8fb..9bb4ffa 100644
--- a/src/gui/emailrelay-gui.rc
+++ b/src/gui/emailrelay-gui.rc
@@ -7,8 +7,8 @@ LANGUAGE 0x9,0x1
 IDI_ICON1 ICON DISCARDABLE "emailrelay-icon.ico"
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 2, 3, 1, 0
- PRODUCTVERSION 2, 3, 1, 0
+ FILEVERSION 2, 4, 0, 0
+ PRODUCTVERSION 2, 4, 0, 0
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -26,12 +26,12 @@ BEGIN
             VALUE "Comments", "GPL v3 license"
             VALUE "CompanyName", " "
             VALUE "FileDescription", "E-MailRelay GUI Application"
-            VALUE "FileVersion", "2, 3, 1, 0"
+            VALUE "FileVersion", "2, 4, 0, 0"
             VALUE "InternalName", "emailrelay"
             VALUE "LegalCopyright", "Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>"
             VALUE "OriginalFilename", "emailrelay-gui.exe"
             VALUE "ProductName", "E-MailRelay"
-            VALUE "ProductVersion", "2, 3, 1, 0"
+            VALUE "ProductVersion", "2, 4, 0, 0"
         END
     END
     BLOCK "VarFileInfo"
diff --git a/src/gui/emailrelay_tr.no_NO.ts b/src/gui/emailrelay_tr.no_NO.ts
index 3532d0f..ea136e3 100644
--- a/src/gui/emailrelay_tr.no_NO.ts
+++ b/src/gui/emailrelay_tr.no_NO.ts
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!DOCTYPE TS>
+<!-- Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>. All rights reserved. -->
 <TS version="2.1" language="nb_NO">
 <context>
     <name>CopyPayloadFile</name>
@@ -1296,3 +1297,4 @@ client-side filtering options: none or script</extracomment>
     </message>
 </context>
 </TS>
+
diff --git a/src/gui/gcominit.h b/src/gui/gcominit.h
index 2036411..2ae4abb 100644
--- a/src/gui/gcominit.h
+++ b/src/gui/gcominit.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/gui/glibsources.cpp b/src/gui/glibsources.cpp
index 6d894ba..09043dc 100644
--- a/src/gui/glibsources.cpp
+++ b/src/gui/glibsources.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -28,10 +28,12 @@
 #include "genvironment.cpp"
 #include "genvironment_win32.cpp"
 #include "gdatetime.cpp"
+#include "ggettext_win32.cpp"
 #else
 #include "genvironment.cpp"
 #include "genvironment_unix.cpp"
 #include "gdatetime.cpp"
+#include "ggettext_unix.cpp"
 #endif
 
 #include "garg.cpp"
@@ -46,15 +48,19 @@
 #include "ggetopt.cpp"
 #include "ghash.cpp"
 #include "glog.cpp"
+#include "glogstream.cpp"
 #include "glogoutput.cpp"
 #include "gmapfile.cpp"
 #include "gmd5.cpp"
+#include "goption.cpp"
+#include "goptionmap.cpp"
 #include "goptionparser.cpp"
 #include "goptions.cpp"
-#include "goptionmap.cpp"
+#include "goptionsusage.cpp"
 #include "gpath.cpp"
 #include "groot.cpp"
 #include "gstr.cpp"
+#include "gstringview.cpp"
 #include "gstringwrap.cpp"
 #include "gtest.cpp"
 #include "gtime.cpp"
diff --git a/src/gui/gqt.h b/src/gui/gqt.h
index 4884935..634b911 100644
--- a/src/gui/gqt.h
+++ b/src/gui/gqt.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,6 +21,11 @@
 #ifndef G_MAIN_GUI_QT_H
 #define G_MAIN_GUI_QT_H
 
+#include "gdef.h"
+#include "gpath.h"
+#include <string>
+#include <cstring>
+
 #ifdef MemoryBarrier
 #undef MemoryBarrier
 #endif
@@ -33,28 +38,47 @@
 #include <QtWidgets/QtWidgets>
 #include <QtCore/QtPlugin>
 
-#include <string>
 namespace GQt
 {
-	struct Utf8 {} ;
+	struct Utf8Overload {} ;
+	constexpr Utf8Overload Utf8 ;
+	struct PathOverload {} ;
+	constexpr PathOverload Path ;
 	inline std::string stdstr( QString q )
 	{
 		QByteArray a = q.toLocal8Bit() ;
 		return std::string( a.constData() , a.length() ) ;
 	}
-	inline std::string stdstr( QString q , Utf8 )
+	inline std::string stdstr( QString q , Utf8Overload )
 	{
 		QByteArray a = q.toUtf8() ;
 		return std::string( a.constData() , a.length() ) ;
 	}
+	inline std::string stdstr( QString q , PathOverload )
+	{
+		QByteArray a = q.toLocal8Bit() ;
+		return std::string( a.constData() , a.length() ) ;
+	}
+	inline QString qstr( const char * p )
+	{
+		return QString::fromLocal8Bit( p , static_cast<int>(std::strlen(p)) ) ;
+	}
 	inline QString qstr( const std::string & s )
 	{
 		return QString::fromLocal8Bit( s.data() , static_cast<int>(s.size()) ) ;
 	}
-	inline QString qstr( const std::string & s , Utf8 )
+	inline QString qstr( const std::string & s , Utf8Overload )
 	{
 		return QString::fromUtf8( s.data() , static_cast<int>(s.size()) ) ;
 	}
+	inline QString qstr( const std::string & s , PathOverload )
+	{
+		return QString::fromLocal8Bit( s.data() , static_cast<int>(s.size()) ) ;
+	}
+	inline QString qstr( const G::Path & p )
+	{
+		return qstr( p.str() , Path ) ;
+	}
 }
 
 #endif
diff --git a/src/gui/access.h b/src/gui/guiaccess.h
similarity index 80%
rename from src/gui/access.h
rename to src/gui/guiaccess.h
index bd2fb07..3515345 100644
--- a/src/gui/access.h
+++ b/src/gui/guiaccess.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,22 +15,27 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file access.h
+/// \file guiaccess.h
 ///
 
-#ifndef G_MAIN_GUI_INSTALLER_ACCESS_H
-#define G_MAIN_GUI_INSTALLER_ACCESS_H
+#ifndef GUI_INSTALLER_ACCESS_H
+#define GUI_INSTALLER_ACCESS_H
 
 #include "gdef.h"
 #include "gpath.h"
 #include "gexception.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include <string>
 
-//| \class Access
+namespace Gui
+{
+	class Access ;
+}
+
+//| \class Gui::Access
 /// A static class for modifying file-system permissions.
 ///
-class Access
+class Gui::Access
 {
 public:
 	static bool modify( const G::Path & , bool ) ;
diff --git a/src/gui/access_unix.cpp b/src/gui/guiaccess_mac.cpp
similarity index 81%
rename from src/gui/access_unix.cpp
rename to src/gui/guiaccess_mac.cpp
index f27e2e6..4052939 100644
--- a/src/gui/access_unix.cpp
+++ b/src/gui/guiaccess_mac.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,13 +15,13 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file access_unix.cpp
+/// \file guiaccess_mac.cpp
 ///
 
 #include "gdef.h"
-#include "access.h"
+#include "guiaccess.h"
 
-bool Access::modify( const G::Path & , bool )
+bool Gui::Access::modify( const G::Path & , bool )
 {
 	return true ;
 }
diff --git a/src/gui/access_mac.cpp b/src/gui/guiaccess_unix.cpp
similarity index 81%
rename from src/gui/access_mac.cpp
rename to src/gui/guiaccess_unix.cpp
index f7ebf6e..fc1c781 100644
--- a/src/gui/access_mac.cpp
+++ b/src/gui/guiaccess_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,13 +15,13 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file access_mac.cpp
+/// \file guiaccess_unix.cpp
 ///
 
 #include "gdef.h"
-#include "access.h"
+#include "guiaccess.h"
 
-bool Access::modify( const G::Path & , bool )
+bool Gui::Access::modify( const G::Path & , bool )
 {
 	return true ;
 }
diff --git a/src/gui/guiaccess_win32.cpp b/src/gui/guiaccess_win32.cpp
new file mode 100644
index 0000000..faa7926
--- /dev/null
+++ b/src/gui/guiaccess_win32.cpp
@@ -0,0 +1,201 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file guiaccess_win32.cpp
+///
+
+#include "gdef.h"
+#include "guiaccess.h"
+#include "gbuffer.h"
+#include "gexception.h"
+#include "gassert.h"
+#include <processthreadsapi.h>
+#include <sddl.h>
+#include <aclapi.h>
+
+namespace Gui
+{
+	namespace AccessImp
+	{
+		void add_user_write_permissions_to_directory( const std::string & ) ;
+		struct Error ;
+		struct Token ;
+		struct Sid ;
+		struct UserSid ;
+		struct DirectoryWriteAccessFor ;
+		struct Dacl ;
+	}
+}
+
+
+bool Gui::Access::modify( const G::Path & path , bool b )
+{
+	try
+	{
+		// this is used to open up permissions on ProgramData/E-MailRelay so
+		// that the installing-user can edit emailrelay-start.bat (etc) -- if
+		// it fails then it doesn't stop anything else working, but it becomes
+		// a pain to modify server startup options
+		if( !b )
+			AccessImp::add_user_write_permissions_to_directory( path.str() ) ;
+		return true ;
+	}
+	catch( std::exception & )
+	{
+	}
+	return false ;
+}
+
+struct Gui::AccessImp::Error : public G::Exception
+{
+	explicit Error( DWORD e = GetLastError() ) :
+		G::Exception("error") ,
+		m_e(e)
+	{
+	}
+	DWORD m_e ;
+} ;
+
+struct Gui::AccessImp::Token
+{
+	explicit Token( HANDLE hprocess = GetCurrentProcess() ) :
+		m_h(0)
+	{
+		BOOL rc = OpenProcessToken( hprocess , TOKEN_READ , &m_h ) ;
+		if( rc == 0 )
+			throw Error() ;
+	}
+	~Token()
+	{
+		CloseHandle( m_h ) ;
+	}
+	HANDLE handle() const
+	{
+		return m_h ;
+	}
+	Token( const Token & ) = delete ;
+	Token( Token && ) = delete ;
+	Token & operator=( const Token & ) = delete ;
+	Token & operator=( Token && ) = delete ;
+	HANDLE m_h ;
+} ;
+
+struct Gui::AccessImp::Sid
+{
+	virtual ~Sid() = default ;
+	virtual PSID ptr() const = 0 ;
+} ;
+
+struct Gui::AccessImp::UserSid : Sid
+{
+	UserSid( const Token & token )
+	{
+		DWORD size = 0 ;
+		GetTokenInformation( token.handle() , TokenUser , nullptr , 0 , &size ) ;
+		if( size == 0 ) throw Error() ;
+		m_buffer.resize( static_cast<std::size_t>(size) ) ;
+		BOOL rc = GetTokenInformation( token.handle() , TokenUser , &m_buffer[0] , size , &size ) ;
+		if( rc == 0 )
+			throw Error() ;
+	}
+	virtual PSID ptr() const override
+	{
+		const TOKEN_USER * user_info = G::buffer_cast<TOKEN_USER*>( m_buffer ) ;
+		return user_info->User.Sid ;
+	}
+	std::string str() const
+	{
+		char * p = nullptr ;
+		ConvertSidToStringSidA( ptr() , &p ) ;
+		std::string s ;
+		if( p )
+		{
+			s = std::string( p ) ;
+			LocalFree( p ) ;
+		}
+		return s ;
+	}
+	~UserSid() override = default ;
+	G::Buffer<char> m_buffer ;
+} ;
+
+struct Gui::AccessImp::DirectoryWriteAccessFor : public EXPLICIT_ACCESS_A
+{
+	explicit DirectoryWriteAccessFor( const Sid & sid )
+	{
+		EXPLICIT_ACCESS_A zero{} ;
+		*static_cast<EXPLICIT_ACCESS_A*>(this) = zero ;
+		grfAccessPermissions = GENERIC_ALL ;
+		grfAccessMode = GRANT_ACCESS ;
+		grfInheritance = OBJECT_INHERIT_ACE | CONTAINER_INHERIT_ACE ;
+		Trustee.TrusteeForm = TRUSTEE_IS_SID ;
+		Trustee.TrusteeType = TRUSTEE_IS_USER ;
+		Trustee.ptstrName = reinterpret_cast<LPSTR>(sid.ptr()) ;
+	}
+} ;
+
+struct Gui::AccessImp::Dacl
+{
+	explicit Dacl( const std::string & path ) :
+		m_sd(nullptr) ,
+		m_dacl(nullptr) ,
+		m_free_me(false)
+	{
+		DWORD rc = GetNamedSecurityInfoA( path.c_str() , SE_FILE_OBJECT , DACL_SECURITY_INFORMATION ,
+			nullptr , nullptr , &m_dacl , nullptr , &m_sd ) ;
+		if( rc != ERROR_SUCCESS || m_dacl == nullptr )
+			throw Error() ;
+	}
+	~Dacl()
+	{
+		if( m_sd )
+			LocalFree( m_sd ) ;
+		if( m_free_me )
+			LocalFree( m_dacl ) ;
+	}
+	void add( const EXPLICIT_ACCESS_A & access )
+	{
+		ACL * new_dacl = nullptr ;
+		DWORD rc = SetEntriesInAclA( 1 , const_cast<EXPLICIT_ACCESS_A*>(&access) , m_dacl , &new_dacl ) ;
+		if( rc != ERROR_SUCCESS || new_dacl == nullptr )
+			throw Error() ;
+		m_dacl = new_dacl ;
+		m_free_me = true ;
+	}
+	void applyTo( const std::string & path )
+	{
+		DWORD rc = SetNamedSecurityInfoA( const_cast<char*>(path.c_str()) , SE_FILE_OBJECT ,
+			DACL_SECURITY_INFORMATION , nullptr , nullptr , m_dacl , nullptr ) ;
+		if( rc != ERROR_SUCCESS )
+			throw Error() ;
+	}
+	Dacl( const Dacl & ) = delete ;
+	Dacl( Dacl && ) = delete ;
+	Dacl & operator=( const Dacl & ) = delete ;
+	Dacl & operator=( Dacl && ) = delete ;
+	PSECURITY_DESCRIPTOR m_sd ;
+	ACL * m_dacl ;
+	bool m_free_me ;
+} ;
+
+void Gui::AccessImp::add_user_write_permissions_to_directory( const std::string & path )
+{
+	Dacl dacl( path ) ;
+	dacl.add( DirectoryWriteAccessFor( UserSid(Token()) ) ) ;
+	dacl.applyTo( path ) ;
+}
+
diff --git a/src/gui/boot.h b/src/gui/guiboot.h
similarity index 90%
rename from src/gui/boot.h
rename to src/gui/guiboot.h
index ccfff07..fd6a146 100644
--- a/src/gui/boot.h
+++ b/src/gui/guiboot.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,19 +15,25 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file boot.h
+/// \file guiboot.h
 ///
 
-#ifndef G_MAIN_GUI_BOOT_H
-#define G_MAIN_GUI_BOOT_H
+#ifndef GUI_BOOT_H
+#define GUI_BOOT_H
 
 #include "gdef.h"
 #include "gpath.h"
+#include "gstringarray.h"
 
-//| \class Boot
+namespace Gui
+{
+	class Boot ;
+}
+
+//| \class Gui::Boot
 /// Provides support for installing as a boot-time service.
 ///
-class Boot
+class Gui::Boot
 {
 public:
 	static bool installable( const G::Path & dir_boot ) ;
diff --git a/src/gui/boot_mac.cpp b/src/gui/guiboot_mac.cpp
similarity index 73%
rename from src/gui/boot_mac.cpp
rename to src/gui/guiboot_mac.cpp
index 334b662..1d5d5de 100644
--- a/src/gui/boot_mac.cpp
+++ b/src/gui/guiboot_mac.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,17 +15,17 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file boot_mac.cpp
+/// \file guiboot_mac.cpp
 ///
 
 #include "gdef.h"
-#include "boot.h"
+#include "guiboot.h"
 #include "gpath.h"
 #include "gfile.h"
 #include "gdirectory.h"
 #include <stdexcept>
 
-bool Boot::installable( const G::Path & dir )
+bool Gui::Boot::installable( const G::Path & dir )
 {
 	// nasty side-effect required because Library/StartupItems may not exist
 	if( !dir.empty() )
@@ -37,7 +37,7 @@ bool Boot::installable( const G::Path & dir )
 		G::Directory(dir).writeable() ; // (creates a probe file)
 }
 
-bool Boot::install( const G::Path & dir_boot , const std::string & , const G::Path & , const G::Path & exe )
+bool Gui::Boot::install( const G::Path & dir_boot , const std::string & , const G::Path & , const G::Path & exe )
 {
 	G::Path plist_src = exe.dirname() + "StartupParameters.plist" ;
 	G::File::mkdirs( dir_boot + exe.basename() , std::nothrow , 6 ) ;
@@ -46,7 +46,7 @@ bool Boot::install( const G::Path & dir_boot , const std::string & , const G::Pa
 		G::File::copy( plist_src , dir_boot + exe.basename() + plist_src.basename() , std::nothrow ) ;
 }
 
-bool Boot::uninstall( const G::Path & dir_boot , const std::string & , const G::Path & , const G::Path & exe )
+bool Gui::Boot::uninstall( const G::Path & dir_boot , const std::string & , const G::Path & , const G::Path & exe )
 {
 	return
 		G::File::remove( dir_boot + exe.basename() + exe.basename() , std::nothrow ) &&
@@ -54,19 +54,19 @@ bool Boot::uninstall( const G::Path & dir_boot , const std::string & , const G::
 		G::File::remove( dir_boot + exe.basename() , std::nothrow ) ;
 }
 
-bool Boot::installed( const G::Path & dir_boot , const std::string & name )
+bool Gui::Boot::installed( const G::Path & dir_boot , const std::string & name )
 {
 	return G::File::exists( dir_boot + name + name , std::nothrow ) ; // not tested
 }
 
-void Boot::launchable( const G::Path & , const std::string & )
+void Gui::Boot::launchable( const G::Path & , const std::string & )
 {
 	return false ;
 }
 
-void Boot::launch( const G::Path & , const std::string & )
+void Gui::Boot::launch( const G::Path & , const std::string & )
 {
-	// TODO
+	// TODO Gui::Boot::launch() for mac
 	throw std::runtime_error( "startup failed: not implemented" ) ;
 }
 
diff --git a/src/gui/boot_unix.cpp b/src/gui/guiboot_unix.cpp
similarity index 80%
rename from src/gui/boot_unix.cpp
rename to src/gui/guiboot_unix.cpp
index e4130f9..3b0861c 100644
--- a/src/gui/boot_unix.cpp
+++ b/src/gui/guiboot_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,11 +15,11 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file boot_unix.cpp
+/// \file guiboot_unix.cpp
 ///
 
 #include "gdef.h"
-#include "boot.h"
+#include "guiboot.h"
 #include "gpath.h"
 #include "gstr.h"
 #include "gfile.h"
@@ -29,13 +29,16 @@
 #include <sstream>
 #include <stdexcept>
 
-namespace BootImp
+namespace Gui
 {
-	bool link( const G::Path & target , const G::Path & new_link , std::nothrow_t ) ;
-	bool remove( const G::Path & path , std::nothrow_t ) ;
+	namespace BootImp
+	{
+		bool link( const G::Path & target , const G::Path & new_link , std::nothrow_t ) ;
+		bool remove( const G::Path & path , std::nothrow_t ) ;
+	}
 }
 
-bool BootImp::link( const G::Path & target , const G::Path & new_link , std::nothrow_t )
+bool Gui::BootImp::link( const G::Path & target , const G::Path & new_link , std::nothrow_t )
 {
 	return
 		G::File::isDirectory( new_link.dirname() , std::nothrow ) ?
@@ -43,7 +46,7 @@ bool BootImp::link( const G::Path & target , const G::Path & new_link , std::not
 			true ; // do nothing successfully if no "/etc/rc?.d" directory
 }
 
-bool BootImp::remove( const G::Path & path , std::nothrow_t )
+bool Gui::BootImp::remove( const G::Path & path , std::nothrow_t )
 {
 	return
 		G::File::isDirectory( path.dirname() , std::nothrow ) ?
@@ -51,7 +54,7 @@ bool BootImp::remove( const G::Path & path , std::nothrow_t )
 			true ; // do nothing successfully if no "/etc/rc?.d" directory
 }
 
-bool Boot::installable( const G::Path & dir_boot )
+bool Gui::Boot::installable( const G::Path & dir_boot )
 {
 	// check /etc/init.d and /etc/rc2.d etc are writable
 	return
@@ -68,7 +71,7 @@ bool Boot::installable( const G::Path & dir_boot )
 		G::Directory(dir_boot+".."+"rc5.d").writeable() ;
 }
 
-void Boot::install( const G::Path & dir_boot , const std::string & name , const G::Path & startstop_src , const G::Path & )
+void Gui::Boot::install( const G::Path & dir_boot , const std::string & name , const G::Path & startstop_src , const G::Path & )
 {
 	G::Path startstop_dst = dir_boot + name ;
 	bool ok0 = G::File::copy( startstop_src , startstop_dst , std::nothrow ) ;
@@ -84,7 +87,7 @@ void Boot::install( const G::Path & dir_boot , const std::string & name , const
 		throw std::runtime_error( "failed to create symlinks [" + (dir_boot+".."+"rc2.d"+linkname).str() + "] etc" ) ;
 }
 
-bool Boot::uninstall( const G::Path & dir_boot , const std::string & name , const G::Path & , const G::Path & )
+bool Gui::Boot::uninstall( const G::Path & dir_boot , const std::string & name , const G::Path & , const G::Path & )
 {
 	std::string linkname = "S50" + name ;
 	bool ok0 = BootImp::remove( dir_boot+".."+"rc2.d"+linkname , std::nothrow ) ;
@@ -94,17 +97,17 @@ bool Boot::uninstall( const G::Path & dir_boot , const std::string & name , cons
 	return ok0 && ok1 && ok2 && ok3 ;
 }
 
-bool Boot::installed( const G::Path & dir_boot , const std::string & name )
+bool Gui::Boot::installed( const G::Path & dir_boot , const std::string & name )
 {
 	return G::File::exists( dir_boot + ".." + "rc2.d" + ( "S50" + name ) , std::nothrow ) ;
 }
 
-bool Boot::launchable( const G::Path & dir_boot , const std::string & )
+bool Gui::Boot::launchable( const G::Path & dir_boot , const std::string & )
 {
 	return dir_boot == "/etc/init.d" && G::File::exists( "/usr/sbin/service" , std::nothrow ) ;
 }
 
-void Boot::launch( const G::Path & dir_boot , const std::string & name )
+void Gui::Boot::launch( const G::Path & dir_boot , const std::string & name )
 {
 	if( dir_boot != "/etc/init.d" )
 		throw std::runtime_error( "cannot launch from non-standard install directory ["+dir_boot.str()+"]" ) ;
diff --git a/src/gui/boot_win32.cpp b/src/gui/guiboot_win32.cpp
similarity index 64%
rename from src/gui/boot_win32.cpp
rename to src/gui/guiboot_win32.cpp
index c9a0959..0a3efe8 100644
--- a/src/gui/boot_win32.cpp
+++ b/src/gui/guiboot_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,33 +15,36 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file boot_win32.cpp
+/// \file guiboot_win32.cpp
 ///
 
 #include "gdef.h"
-#include "boot.h"
+#include "guiboot.h"
 #include "gpath.h"
 #include "gmapfile.h"
 #include "gfile.h"
 #include "servicecontrol.h"
 #include <stdexcept>
 
-namespace
+namespace Gui
 {
-	bool createConfigurationFile( const G::Path & bat , const G::Path & wrapper_exe , bool do_throw )
+	namespace BootImp
 	{
-		G::Path config_file = wrapper_exe.withoutExtension() ;
-		std::ofstream file ;
-		G::File::open( file , config_file.str()+".cfg" , G::File::Text() ) ;
-		G::MapFile::writeItem( file , "dir-config" , bat.dirname().str() ) ;
-		file.close() ;
-		if( file.fail() && do_throw )
-			throw std::runtime_error( "failed to create service wrapper configuration file " + config_file.str() ) ;
-		return !file.fail() ;
+		bool createConfigurationFile( const G::Path & bat , const G::Path & wrapper_exe , bool do_throw )
+		{
+			G::Path config_file = wrapper_exe.withoutExtension() ;
+			std::ofstream file ;
+			G::File::open( file , config_file.str()+".cfg" , G::File::Text() ) ;
+			G::MapFile::writeItem( file , "dir-config" , bat.dirname().str() ) ;
+			file.close() ;
+			if( file.fail() && do_throw )
+				throw std::runtime_error( "failed to create service wrapper configuration file " + config_file.str() ) ;
+			return !file.fail() ;
+		}
 	}
 }
 
-bool Boot::installable( const G::Path & )
+bool Gui::Boot::installable( const G::Path & )
 {
 	SC_HANDLE hmanager = OpenSCManager( nullptr , nullptr , SC_MANAGER_ALL_ACCESS ) ;
 	bool ok = hmanager != HNULL ;
@@ -49,7 +52,7 @@ bool Boot::installable( const G::Path & )
 	return ok ;
 }
 
-void Boot::install( const G::Path & , const std::string & name , const G::Path & bat , const G::Path & wrapper_exe )
+void Gui::Boot::install( const G::Path & , const std::string & name , const G::Path & bat , const G::Path & wrapper_exe )
 {
 	// the 'bat' path is the batch file containing the full command-line
 	// for the server process -- the service wrapper knows how to read it
@@ -70,29 +73,29 @@ void Boot::install( const G::Path & , const std::string & name , const G::Path &
 
 	// create the config file
 	bool do_throw = true ;
-	createConfigurationFile( bat , wrapper_exe , do_throw ) ;
+	BootImp::createConfigurationFile( bat , wrapper_exe , do_throw ) ;
 }
 
-bool Boot::uninstall( const G::Path & , const std::string & name , const G::Path & bat , const G::Path & wrapper_exe )
+bool Gui::Boot::uninstall( const G::Path & , const std::string & name , const G::Path & bat , const G::Path & wrapper_exe )
 {
 	// create an unused config file -- the user can edit it for a manual service install
 	bool do_throw = false ;
-	createConfigurationFile( bat , wrapper_exe , do_throw ) ;
+	BootImp::createConfigurationFile( bat , wrapper_exe , do_throw ) ;
 
 	return ::service_remove(name).empty() ;
 }
 
-bool Boot::installed( const G::Path & , const std::string & name )
+bool Gui::Boot::installed( const G::Path & , const std::string & name )
 {
 	return ::service_installed( name ) ;
 }
 
-bool Boot::launchable( const G::Path & dir , const std::string & )
+bool Gui::Boot::launchable( const G::Path & dir , const std::string & )
 {
 	return installable( dir ) ;
 }
 
-void Boot::launch( const G::Path & , const std::string & name )
+void Gui::Boot::launch( const G::Path & , const std::string & name )
 {
 	std::string e = ::service_start( name ) ;
 	if( !e.empty() )
diff --git a/src/gui/gdialog.cpp b/src/gui/guidialog.cpp
similarity index 80%
rename from src/gui/gdialog.cpp
rename to src/gui/guidialog.cpp
index 2a526de..09c34f7 100644
--- a/src/gui/gdialog.cpp
+++ b/src/gui/guidialog.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,18 +15,20 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file gdialog.cpp
+/// \file guidialog.cpp
 ///
 
 #include "gdef.h"
 #include "gqt.h"
-#include "gdialog.h"
+#include "guidialog.h"
 #include "gfile.h"
 #include "glog.h"
 #include <algorithm>
 #include <stdexcept>
 
-GDialog::GDialog( const G::Path & virgin_flag_file , bool with_launch ) :
+#include "moc_guidialog.cpp"
+
+Gui::Dialog::Dialog( const G::Path & virgin_flag_file , bool with_launch ) :
 	QDialog(nullptr) ,
 	m_first(true) ,
 	m_with_launch(with_launch) ,
@@ -66,13 +68,13 @@ GDialog::GDialog( const G::Path & virgin_flag_file , bool with_launch ) :
 	setLayout( m_main_layout ) ;
 }
 
-void GDialog::add( GPage * page , const std::string & conditional_name )
+void Gui::Dialog::add( Page * page , const std::string & conditional_name )
 {
 	if( conditional_name.empty() || page->name() == conditional_name )
 		add( page ) ;
 }
 
-void GDialog::add( GPage * page )
+void Gui::Dialog::add( Page * page )
 {
 	m_map.insert( Map::value_type(page->name(),page) ) ;
 	if( m_first )
@@ -80,25 +82,25 @@ void GDialog::add( GPage * page )
 	m_first = false ;
 }
 
-void GDialog::add()
+void Gui::Dialog::add()
 {
 	if( !empty() )
 		pageUpdated() ;
 }
 
-bool GDialog::empty() const
+bool Gui::Dialog::empty() const
 {
 	return m_map.empty() ;
 }
 
-GPage & GDialog::page( const std::string & name )
+Gui::Page & Gui::Dialog::page( const std::string & name )
 {
 	if( m_map.find(name) == m_map.end() )
 		throw std::runtime_error( std::string() + "internal error: no such page: " + name ) ;
 	return *m_map[name] ;
 }
 
-const GPage & GDialog::page( const std::string & name ) const
+const Gui::Page & Gui::Dialog::page( const std::string & name ) const
 {
 	auto p = m_map.find( name ) ;
 	if( p == m_map.end() )
@@ -106,20 +108,20 @@ const GPage & GDialog::page( const std::string & name ) const
 	return *(*p).second ;
 }
 
-void GDialog::setFirstPage( GPage & page )
+void Gui::Dialog::setFirstPage( Page & page )
 {
 	m_history.push_back(page.name()) ;
 	switchPage( m_history.back() ) ;
 }
 
-void GDialog::backButtonClicked()
+void Gui::Dialog::backButtonClicked()
 {
 	std::string old_page_name = m_history.back();
 	m_history.pop_back() ;
 	switchPage( m_history.back() , old_page_name , true ) ;
 }
 
-void GDialog::nextButtonClicked()
+void Gui::Dialog::nextButtonClicked()
 {
 	if( m_next_is_launch )
 	{
@@ -135,7 +137,7 @@ void GDialog::nextButtonClicked()
 	}
 }
 
-void GDialog::finishButtonClicked()
+void Gui::Dialog::finishButtonClicked()
 {
 	if( page(m_history.back()).isFinishPage() ) // ie. "close" button clicked
 	{
@@ -151,11 +153,11 @@ void GDialog::finishButtonClicked()
 	}
 }
 
-void GDialog::pageUpdated()
+void Gui::Dialog::pageUpdated()
 {
 	std::string current_page_name = m_history.back() ;
-	G_DEBUG( "GDialog::pageUpdated: \"" << current_page_name << "\" page updated" ) ;
-	GPage & current_page = page( current_page_name ) ;
+	G_DEBUG( "Gui::Dialog::pageUpdated: \"" << current_page_name << "\" page updated" ) ;
+	Page & current_page = page( current_page_name ) ;
 
 	if( current_page.isReadyToFinishPage() )
 	{
@@ -203,13 +205,13 @@ void GDialog::pageUpdated()
 	}
 }
 
-void GDialog::switchPage( const std::string & new_page_name , const std::string & old_page_name , bool back )
+void Gui::Dialog::switchPage( const std::string & new_page_name , const std::string & old_page_name , bool back )
 {
 	// hide and disconnect the old page
 	//
 	if( ! old_page_name.empty() )
 	{
-		GPage & oldPage = page(old_page_name) ;
+		Page & oldPage = page(old_page_name) ;
 		oldPage.hide();
 		m_main_layout->removeWidget(&oldPage);
 		disconnect( &oldPage , SIGNAL(pageUpdateSignal()) , this , SLOT(pageUpdated()) );
@@ -217,9 +219,9 @@ void GDialog::switchPage( const std::string & new_page_name , const std::string
 
 	// show and connect the new page
 	//
-	GPage & new_page = page( new_page_name ) ;
+	Page & new_page = page( new_page_name ) ;
 	m_main_layout->insertWidget( 0 , &new_page ) ;
-	new_page.onShow( back ) ; // GPage method
+	new_page.onShow( back ) ; // Page method
 	new_page.show() ;
 	new_page.setFocus() ;
 	connect( &new_page , SIGNAL(pageUpdateSignal()) , this , SLOT(pageUpdated()) ) ;
@@ -229,36 +231,36 @@ void GDialog::switchPage( const std::string & new_page_name , const std::string
 	pageUpdated() ;
 }
 
-bool GDialog::historyContains( const std::string & name ) const
+bool Gui::Dialog::historyContains( const std::string & name ) const
 {
 	return std::find( m_history.begin() , m_history.end() , name ) != m_history.end() ;
 }
 
-std::string GDialog::currentPageName() const
+std::string Gui::Dialog::currentPageName() const
 {
 	return m_history.empty() ? std::string() : m_history.back() ;
 }
 
-GPage & GDialog::previousPage( unsigned int distance )
+Gui::Page & Gui::Dialog::previousPage( unsigned int distance )
 {
 	if( m_history.size() < (std::size_t(distance)+1U) ) throw std::runtime_error("internal error") ;
 	auto p = m_history.rbegin() ;
 	while( distance-- ) ++p ;
-	G_DEBUG( "GDialog::previousPage: " << currentPageName() << " -> " << *p ) ;
+	G_DEBUG( "Gui::Dialog::previousPage: " << currentPageName() << " -> " << *p ) ;
 	return page(*p) ;
 }
 
-void GDialog::dumpStateVariables( std::ostream & stream ) const
+void Gui::Dialog::dumpStateVariables( std::ostream & stream ) const
 {
 	dump( stream , false ) ;
 }
 
-void GDialog::dumpInstallVariables( std::ostream & stream ) const
+void Gui::Dialog::dumpInstallVariables( std::ostream & stream ) const
 {
 	dump( stream , true ) ;
 }
 
-void GDialog::dump( std::ostream & stream , bool for_install ) const
+void Gui::Dialog::dump( std::ostream & stream , bool for_install ) const
 {
 	for( const auto & pname : m_history )
 		page(pname).dump( stream , for_install ) ;
diff --git a/src/gui/gdialog.h b/src/gui/guidialog.h
similarity index 76%
rename from src/gui/gdialog.h
rename to src/gui/guidialog.h
index 14a2846..b412d86 100644
--- a/src/gui/gdialog.h
+++ b/src/gui/guidialog.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,37 +15,42 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file gdialog.h
+/// \file guidialog.h
 ///
 
-#ifndef G_MAIN_GUI_DIALOG_H
-#define G_MAIN_GUI_DIALOG_H
+#ifndef GUI_DIALOG_H
+#define GUI_DIALOG_H
 
 #include "gdef.h"
 #include "gqt.h"
-#include "gpage.h"
+#include "guipage.h"
 #include "gpath.h"
 #include <list>
 #include <map>
 class QHBoxLayout;
 class QPushButton;
 class QVBoxLayout;
-class GPage ;
 
-//| \class GDialog
+namespace Gui
+{
+	class Dialog ;
+	class Page ;
+}
+
+//| \class Gui::Dialog
 /// The main forward-back dialog box.
 ///
-class GDialog : public QDialog
+class Gui::Dialog : public QDialog
 {Q_OBJECT
 public:
-	GDialog( const G::Path & virgin_flag_file , bool with_launch ) ;
+	Dialog( const G::Path & virgin_flag_file , bool with_launch ) ;
 		///< Constructor. Use a sequence of add()s to initialise
 		///< ending with add(void).
 
-	void add( GPage * ) ;
+	void add( Page * ) ;
 		///< Adds a page.
 
-	void add( GPage * , const std::string & conditional_page_name ) ;
+	void add( Page * , const std::string & conditional_page_name ) ;
 		///< Adds a page but only if the the page name matches
 		///< the given conditional name or if the given
 		///< conditional name is empty.
@@ -53,16 +58,16 @@ public:
 	void add() ;
 		///< To be called after other add()s.
 
-	GPage & page( const std::string & ) ;
+	Page & page( const std::string & ) ;
 		///< Finds a page by name.
 
-	const GPage & page( const std::string & ) const ;
+	const Page & page( const std::string & ) const ;
 		///< Finds a page by name.
 
 	std::string currentPageName() const ;
 		///< Returns the current page name.
 
-	GPage & previousPage( unsigned int distance = 1U ) ;
+	Page & previousPage( unsigned int distance = 1U ) ;
 		///< Returns the previous page.
 
 	bool historyContains( const std::string & ) const ;
@@ -78,8 +83,8 @@ public:
 		///< Dump the install variables from all the pages.
 
 	void setFinishing( bool ) ;
-		///< Disables all buttons. See also GPage::allFinished()
-		///< and GPage::nearlyAllFinished().
+		///< Disables all buttons. See also Page::allFinished()
+		///< and Page::nearlyAllFinished().
 
 private slots:
 	void backButtonClicked() ;
@@ -89,12 +94,12 @@ private slots:
 
 private:
 	void dump( std::ostream & , bool for_install ) const ;
-	void setFirstPage( GPage & ) ;
-	void switchPage( const std::string & new_page_name , const std::string & old_page_name = std::string() , bool back = false ) ;
+	void setFirstPage( Page & ) ;
+	void switchPage( const std::string & new_page_name , const std::string & old_page_name = {} , bool back = false ) ;
 
 private:
 	using History = std::list<std::string> ;
-	using Map = std::map<std::string,GPage*> ;
+	using Map = std::map<std::string,Page*> ;
 	Map m_map ;
 	History m_history ;
 	bool m_first ;
diff --git a/src/gui/dir.cpp b/src/gui/guidir.cpp
similarity index 73%
rename from src/gui/dir.cpp
rename to src/gui/guidir.cpp
index d1a90c1..deb8bc7 100644
--- a/src/gui/dir.cpp
+++ b/src/gui/guidir.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,58 +15,58 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file dir.cpp
+/// \file guidir.cpp
 ///
 // See also "dir_unix.cpp", "dir_mac.cpp" and "dir_win32.cpp".
 //
 
 #include "gdef.h"
-#include "dir.h"
+#include "guidir.h"
 #include "gstr.h"
 #include "gpath.h"
 #include "genvironment.h"
 
-G::Path Dir::install()
+G::Path Gui::Dir::install()
 {
 	return os_install() ;
 }
 
-G::Path Dir::desktop()
+G::Path Gui::Dir::desktop()
 {
 	return special( "desktop" ) ;
 }
 
-G::Path Dir::autostart()
+G::Path Gui::Dir::autostart()
 {
 	return special( "autostart" ) ;
 }
 
-G::Path Dir::menu()
+G::Path Gui::Dir::menu()
 {
 	return special( "menu" ) ;
 }
 
-G::Path Dir::pid( const G::Path & config )
+G::Path Gui::Dir::pid( const G::Path & config )
 {
 	return os_pid( config ) ;
 }
 
-G::Path Dir::config()
+G::Path Gui::Dir::config()
 {
 	return os_config() ;
 }
 
-G::Path Dir::spool()
+G::Path Gui::Dir::spool()
 {
 	return os_spool() ;
 }
 
-G::Path Dir::boot()
+G::Path Gui::Dir::boot()
 {
 	return os_boot() ;
 }
 
-G::Path Dir::envPath( const std::string & key , const G::Path & default_ )
+G::Path Gui::Dir::envPath( const std::string & key , const G::Path & default_ )
 {
 	return G::Path( G::Environment::get( key , default_.str() ) ) ;
 }
diff --git a/src/gui/dir.h b/src/gui/guidir.h
similarity index 89%
rename from src/gui/dir.h
rename to src/gui/guidir.h
index 9e92d1e..552189d 100644
--- a/src/gui/dir.h
+++ b/src/gui/guidir.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,7 +15,7 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file dir.h
+/// \file guidir.h
 ///
 
 #ifndef G_MAIN_GUI_DIR_H
@@ -26,11 +26,16 @@
 #include <string>
 #include <iostream>
 
-//| \class Dir
+namespace Gui
+{
+	class Dir ;
+}
+
+//| \class Gui::Dir
 /// Provides default file-system paths. The implementations
 /// of this interface are highly platform-specific.
 ///
-class Dir
+class Gui::Dir
 {
 public:
 	static G::Path install() ;
@@ -67,8 +72,8 @@ private:
 	static G::Path envPath( const std::string & , const G::Path & = G::Path() ) ;
 	static bool ok( const std::string & ) ;
 	static std::string rebase( const std::string & ) ;
-	static G::Path oneOf( std::string , std::string = std::string() , std::string = std::string() ,
-		std::string = std::string() , std::string = std::string() ) ;
+	static G::Path oneOf( std::string , std::string = {} , std::string = {} ,
+		std::string = {} , std::string = {} ) ;
 	static G::Path os_install() ;
 	static G::Path os_boot() ;
 	static G::Path os_config() ;
diff --git a/src/gui/dir_mac.cpp b/src/gui/guidir_mac.cpp
similarity index 83%
rename from src/gui/dir_mac.cpp
rename to src/gui/guidir_mac.cpp
index b19ed6c..270bf81 100644
--- a/src/gui/dir_mac.cpp
+++ b/src/gui/guidir_mac.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,11 +15,11 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file dir_mac.cpp
+/// \file guidir_mac.cpp
 ///
 
 #include "gdef.h"
-#include "dir.h"
+#include "guidir.h"
 #include "gpath.h"
 #include "gfile.h"
 #include "gdirectory.h"
@@ -50,19 +50,19 @@
 	#define G_INITDIR
 #endif
 
-std::string Dir::rebase( const std::string & dir )
+std::string Gui::Dir::rebase( const std::string & dir )
 {
 	static bool use_root = ok( "/Applications" ) ;
 	return (use_root?"":"~") + dir ;
 }
 
-G::Path Dir::os_install()
+G::Path Gui::Dir::os_install()
 {
 	// user expects to say "/Applications" or "~/Applications"
 	return rebase( "/Applications" ) ;
 }
 
-G::Path Dir::os_config()
+G::Path Gui::Dir::os_config()
 {
 	std::string sysconfdir( G_STR(G_SYSCONFDIR) ) ;
 	if( sysconfdir.empty() )
@@ -70,7 +70,7 @@ G::Path Dir::os_config()
 	return sysconfdir ;
 }
 
-G::Path Dir::os_spool()
+G::Path Gui::Dir::os_spool()
 {
 	std::string spooldir( G_STR(G_SPOOLDIR) ) ;
 	if( spooldir.empty() )
@@ -78,12 +78,12 @@ G::Path Dir::os_spool()
 	return spooldir ;
 }
 
-G::Path Dir::os_pid( const G::Path & )
+G::Path Gui::Dir::os_pid( const G::Path & )
 {
 	return ok("/var/run") ? "/var/run" : "/tmp" ;
 }
 
-G::Path Dir::special( const std::string & type )
+G::Path Gui::Dir::special( const std::string & type )
 {
 	if( type == "desktop" ) return home()+"Desktop" ;
 	if( type == "menu" ) return G::Path() ;
@@ -92,7 +92,7 @@ G::Path Dir::special( const std::string & type )
 	return G::Path() ;
 }
 
-G::Path Dir::os_boot()
+G::Path Gui::Dir::os_boot()
 {
 	std::string s( G_STR(G_INITDIR) ) ;
 	if( !s.empty() )
@@ -100,7 +100,7 @@ G::Path Dir::os_boot()
 	return "/Library/StartupItems" ;
 }
 
-bool Dir::ok( const std::string & s )
+bool Gui::Dir::ok( const std::string & s )
 {
 	return
 		!s.empty() &&
@@ -109,7 +109,7 @@ bool Dir::ok( const std::string & s )
 		G::Directory(G::Path(s)).writeable() ;
 }
 
-G::Path Dir::home()
+G::Path Gui::Dir::home()
 {
 	return envPath( "HOME" , "~" ) ;
 }
diff --git a/src/gui/dir_unix.cpp b/src/gui/guidir_unix.cpp
similarity index 59%
rename from src/gui/dir_unix.cpp
rename to src/gui/guidir_unix.cpp
index d74620c..a7f9e7e 100644
--- a/src/gui/dir_unix.cpp
+++ b/src/gui/guidir_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,11 +15,11 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file dir_unix.cpp
+/// \file guidir_unix.cpp
 ///
 
 #include "gdef.h"
-#include "dir.h"
+#include "guidir.h"
 #include "gpath.h"
 #include "gstr.h"
 #include "gdirectory.h"
@@ -59,46 +59,49 @@
 	#define G_INITDIR
 #endif
 
-namespace
+namespace Gui
 {
-	std::string run( const std::string & exe , const std::string & arg_1 = std::string() ,
-		const std::string & arg_2 = std::string() ,
-		const std::string & arg_3 = std::string() ,
-		const std::string & arg_4 = std::string() )
+	namespace DirImp
 	{
-		G::StringArray args ;
-		if( !arg_1.empty() ) args.push_back( arg_1 ) ;
-		if( !arg_2.empty() ) args.push_back( arg_2 ) ;
-		if( !arg_3.empty() ) args.push_back( arg_3 ) ;
-		if( !arg_4.empty() ) args.push_back( arg_4 ) ;
-		G::NewProcess child( exe , args ) ;
-		return child.waitable().wait().output() ;
-	}
+		std::string run( const std::string & exe , const std::string & arg_1 = std::string() ,
+			const std::string & arg_2 = std::string() ,
+			const std::string & arg_3 = std::string() ,
+			const std::string & arg_4 = std::string() )
+		{
+			G::StringArray args ;
+			if( !arg_1.empty() ) args.push_back( arg_1 ) ;
+			if( !arg_2.empty() ) args.push_back( arg_2 ) ;
+			if( !arg_3.empty() ) args.push_back( arg_3 ) ;
+			if( !arg_4.empty() ) args.push_back( arg_4 ) ;
+			G::NewProcess child( exe , args ) ;
+			return child.waitable().wait().output() ;
+		}
 
-	G::Path kde( const std::string & key , const G::Path & default_ )
-	{
-		G::Path result = run( "/usr/bin/kde4-config" , "kde4-config" , "--userpath" , key ) ;
-		return result.empty() ? default_ : result ;
-	}
+		G::Path kde( const std::string & key , const G::Path & default_ )
+		{
+			G::Path result = run( "/usr/bin/kde4-config" , "kde4-config" , "--userpath" , key ) ;
+			return result.empty() ? default_ : result ;
+		}
 
-	G::Path xdg( const std::string & key , const G::Path & default_ )
-	{
-		G::Path result = run( "/usr/dir/xdg-user-dir" , "xdg-user-dir" , key ) ;
-		return result.empty() ? default_ : result ;
-	}
+		G::Path xdg( const std::string & key , const G::Path & default_ )
+		{
+			G::Path result = run( "/usr/dir/xdg-user-dir" , "xdg-user-dir" , key ) ;
+			return result.empty() ? default_ : result ;
+		}
 
-	G::Path queryDesktop( const G::Path & default_ = G::Path() )
-	{
-		return kde( "desktop" , xdg("DESKTOP",default_) ) ;
-	}
+		G::Path queryDesktop( const G::Path & default_ = G::Path() )
+		{
+			return kde( "desktop" , xdg("DESKTOP",default_) ) ;
+		}
 
-	G::Path queryAutostart( const G::Path & default_ = G::Path() )
-	{
-		return kde( "autostart" , default_ ) ;
+		G::Path queryAutostart( const G::Path & default_ = G::Path() )
+		{
+			return kde( "autostart" , default_ ) ;
+		}
 	}
 }
 
-G::Path Dir::os_install()
+G::Path Gui::Dir::os_install()
 {
 	// this is what to present to the user as the
 	// default base of the install
@@ -106,7 +109,7 @@ G::Path Dir::os_install()
 	return "/usr" ;
 }
 
-G::Path Dir::os_config()
+G::Path Gui::Dir::os_config()
 {
 	std::string sysconfdir( G_STR(G_SYSCONFDIR) ) ;
 	if( sysconfdir.empty() )
@@ -114,7 +117,7 @@ G::Path Dir::os_config()
 	return sysconfdir ;
 }
 
-G::Path Dir::os_spool()
+G::Path Gui::Dir::os_spool()
 {
 	std::string spooldir( G_STR(G_SPOOLDIR) ) ;
 	if( spooldir.empty() )
@@ -122,18 +125,18 @@ G::Path Dir::os_spool()
 	return spooldir ;
 }
 
-G::Path Dir::os_pid( const G::Path & )
+G::Path Gui::Dir::os_pid( const G::Path & )
 {
 	return oneOf( "/run" , "/var/run" , "/tmp" ) ;
 }
 
-G::Path Dir::special( const std::string & type )
+G::Path Gui::Dir::special( const std::string & type )
 {
 	// see "http://standards.freedesktop.org"
 
-	G::Path desktop = queryDesktop( home()+"Desktop" ) ; // see also "xdg-desktop-icon install"
+	G::Path desktop = DirImp::queryDesktop( home()+"Desktop" ) ; // see also "xdg-desktop-icon install"
 	G::Path menu = envPath("XDG_DATA_HOME",home()+".local"+"share") + "applications" ; // see also "xdg-desktop-menu install"
-	G::Path autostart = queryAutostart() ; // default was envPath("XDG_CONFIG_HOME",home()+".config")+"autostart"
+	G::Path autostart = DirImp::queryAutostart() ; // default was envPath("XDG_CONFIG_HOME",home()+".config")+"autostart"
 	G::Path programs = "/usr/bin" ;
 
 	if( type == "desktop" ) return desktop ;
@@ -143,7 +146,7 @@ G::Path Dir::special( const std::string & type )
 	return G::Path() ;
 }
 
-G::Path Dir::os_boot()
+G::Path Gui::Dir::os_boot()
 {
 	std::string s( G_STR(G_INITDIR) ) ;
 	if( !s.empty() )
@@ -151,7 +154,7 @@ G::Path Dir::os_boot()
 	return "/etc/init.d" ;
 }
 
-bool Dir::ok( const std::string & s )
+bool Gui::Dir::ok( const std::string & s )
 {
 	return
 		!s.empty() &&
@@ -160,7 +163,7 @@ bool Dir::ok( const std::string & s )
 		G::Directory(G::Path(s)).writeable() ;
 }
 
-G::Path Dir::oneOf( std::string d1 , std::string d2 , std::string d3 , std::string d4 , std::string d5 )
+G::Path Gui::Dir::oneOf( std::string d1 , std::string d2 , std::string d3 , std::string d4 , std::string d5 )
 {
 	if( ok(d1) ) return G::Path(d1) ;
 	if( ok(d2) ) return G::Path(d2) ;
@@ -170,7 +173,7 @@ G::Path Dir::oneOf( std::string d1 , std::string d2 , std::string d3 , std::stri
 	return G::Path() ;
 }
 
-G::Path Dir::home()
+G::Path Gui::Dir::home()
 {
 	return envPath( "HOME" , "~" ) ;
 }
diff --git a/src/gui/dir_win32.cpp b/src/gui/guidir_win32.cpp
similarity index 60%
rename from src/gui/dir_win32.cpp
rename to src/gui/guidir_win32.cpp
index 567332b..f8f1a89 100644
--- a/src/gui/dir_win32.cpp
+++ b/src/gui/guidir_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,12 +15,12 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file dir_win32.cpp
+/// \file guidir_win32.cpp
 ///
 
 #include "gdef.h"
 #include "gconvert.h"
-#include "dir.h"
+#include "guidir.h"
 #include "gfile.h"
 #include "gpath.h"
 #include "glog.h"
@@ -39,48 +39,50 @@
 #define CSIDL_PROGRAM_FILESX86 42
 #endif
 
-G::Path Dir::os_install()
+G::Path Gui::Dir::os_install()
 {
 	return special("programs") + "E-MailRelay" ;
 }
 
-G::Path Dir::os_config()
+G::Path Gui::Dir::os_config()
 {
 	return special("data") + "E-MailRelay" ;
 }
 
-G::Path Dir::os_spool()
+G::Path Gui::Dir::os_spool()
 {
 	return special("data") + "E-MailRelay" + "spool" ;
 }
 
-G::Path Dir::os_pid( const G::Path & config_dir )
+G::Path Gui::Dir::os_pid( const G::Path & /*config_dir*/ )
 {
 	return special("data") + "E-MailRelay" ;
 }
 
-G::Path Dir::os_boot()
+G::Path Gui::Dir::os_boot()
 {
-	// empty implies no access (see call to Boot::able() in pages.cpp),
-	// so the default has to be a bogus value
+	// the default has to be any non-empty string
 	return "services" ;
 }
 
-namespace
+namespace Gui
 {
-	int special_id( const std::string & type )
+	namespace DirImp
 	{
-		if( type == "desktop" ) return CSIDL_DESKTOPDIRECTORY ; // "c:/users/<username>/desktop"
-		if( type == "menu" ) return CSIDL_PROGRAMS ; // "c:/users/<username>/appdata/roaming/microsoft/windows/start menu/programs"
-		if( type == "autostart" ) return CSIDL_STARTUP ; // "c:/users/<username>/appdata/roaming/microsoft/windows/start menu/startup/programs"
-		if( type == "programs" ) return sizeof(void*) == 4 ? CSIDL_PROGRAM_FILESX86 : CSIDL_PROGRAM_FILES ; // "c:/program files"
-		if( type == "data" ) return CSIDL_COMMON_APPDATA ; // "c:/programdata"
-		throw std::runtime_error("internal error") ;
-		return 0 ;
+		int special_id( const std::string & type )
+		{
+			if( type == "desktop" ) return CSIDL_DESKTOPDIRECTORY ; // "c:/users/<username>/desktop"
+			if( type == "menu" ) return CSIDL_PROGRAMS ; // "c:/users/<username>/appdata/roaming/microsoft/windows/start menu/programs"
+			if( type == "autostart" ) return CSIDL_STARTUP ; // "c:/users/<username>/appdata/roaming/microsoft/windows/start menu/startup/programs"
+			if( type == "programs" ) return sizeof(void*) == 4 ? CSIDL_PROGRAM_FILESX86 : CSIDL_PROGRAM_FILES ; // "c:/program files"
+			if( type == "data" ) return CSIDL_COMMON_APPDATA ; // "c:/programdata"
+			throw std::runtime_error("internal error") ;
+			return 0 ;
+		}
 	}
 }
 
-G::Path Dir::special( const std::string & type )
+G::Path Gui::Dir::special( const std::string & type )
 {
 	// this is not quite right when running with UAC administrator rights because
 	// it gets the administrator's user directories for the desktop etc links and not
@@ -88,12 +90,12 @@ G::Path Dir::special( const std::string & type )
 	std::vector<char> buffer( MAX_PATH+1U ) ;
 	buffer.at(0) = '\0' ;
 	HANDLE user_token = HNULL ; // TODO original user's paths when run-as administrator
-	bool ok = S_OK == SHGetFolderPathA( HNULL , special_id(type) , user_token , SHGFP_TYPE_CURRENT , &buffer[0] ) ;
+	bool ok = S_OK == SHGetFolderPathA( HNULL , DirImp::special_id(type) , user_token , SHGFP_TYPE_CURRENT , &buffer[0] ) ;
 	buffer.at(buffer.size()-1U) = '\0' ;
 	return ok ? G::Path(&buffer[0]) : G::Path("c:/") ;
 }
 
-G::Path Dir::home()
+G::Path Gui::Dir::home()
 {
 	return envPath( "USERPROFILE" , envPath( "HOME" , desktop() ) ) ;
 }
diff --git a/src/gui/legal.cpp b/src/gui/guilegal.cpp
similarity index 99%
rename from src/gui/legal.cpp
rename to src/gui/guilegal.cpp
index b588e65..4416241 100644
--- a/src/gui/legal.cpp
+++ b/src/gui/guilegal.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,15 +15,15 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file legal.cpp
+/// \file guilegal.cpp
 ///
 
 #include "gdef.h"
-#include "legal.h"
+#include "guilegal.h"
 
 // clang-format off
 
-const char * Legal::text()
+const char * Gui::Legal::text()
 {
 	return
 		"This program is free software: you can redistribute it and/or modify\n"
@@ -36,10 +36,10 @@ const char * Legal::text()
 		"MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n"
 		"GNU General Public License for more details.\n"
 		"\n\n"
-		"Copyright (C) 2001-2021 Graeme Walker" ;
+		"Copyright (C) 2001-2022 Graeme Walker" ;
 }
 
-std::vector<std::string> Legal::credits()
+std::vector<std::string> Gui::Legal::credits()
 {
 	return {
 	#if GCONFIG_HAVE_OPENSSL
@@ -60,7 +60,7 @@ std::vector<std::string> Legal::credits()
 	} ;
 }
 
-const char * Legal::license()
+const char * Gui::Legal::license()
 {
 	return
 		"                    GNU GENERAL PUBLIC LICENSE\n"
diff --git a/src/gui/legal.h b/src/gui/guilegal.h
similarity index 84%
rename from src/gui/legal.h
rename to src/gui/guilegal.h
index 4332ef6..6f6deb2 100644
--- a/src/gui/legal.h
+++ b/src/gui/guilegal.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,20 +15,25 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file legal.h
+/// \file guilegal.h
 ///
 
-#ifndef G_MAIN_GUI_LEGAL_H
-#define G_MAIN_GUI_LEGAL_H
+#ifndef GUI_LEGAL_H
+#define GUI_LEGAL_H
 
 #include "gdef.h"
 #include <string>
 #include <vector>
 
-//| \class Legal
+namespace Gui
+{
+	class Legal ;
+}
+
+//| \class Gui::Legal
 /// A static class providing warranty and copyright text.
 ///
-class Legal
+class Gui::Legal
 {
 public:
 	static const char * text() ;
diff --git a/src/gui/glink.h b/src/gui/guilink.h
similarity index 63%
rename from src/gui/glink.h
rename to src/gui/guilink.h
index 48c712c..b01385a 100644
--- a/src/gui/glink.h
+++ b/src/gui/guilink.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,41 +15,41 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file glink.h
+/// \file guilink.h
 ///
 
-#ifndef G_MAIN_GUI_LINK_H
-#define G_MAIN_GUI_LINK_H
+#ifndef GUI_LINK_H
+#define GUI_LINK_H
 
 #include "gdef.h"
 #include "gpath.h"
 #include "gexception.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include <string>
 
-namespace G
+namespace Gui
 {
 	class Link ;
 	class LinkImp ;
 }
 
-//| \class G::Link
+//| \class Gui::Link
 /// A class for creating desktop links (aka "shortcuts") and
 /// application menu items.
 ///
-class G::Link
+class Gui::Link
 {
 public:
-	G_EXCEPTION( SaveError , "error saving desktop or menu link" ) ;
+	G_EXCEPTION( SaveError , tx("error saving desktop or menu link") ) ;
 
 	enum class Show { Default , Hide } ;
 
-	Link( const Path & target_path , const std::string & name , const std::string & description ,
-		const Path & working_dir , const StringArray & args = StringArray() ,
-		const Path & icon_source = Path() , Show show = Show::Default ,
-		const std::string & internal_comment_1 = std::string() ,
-		const std::string & internal_comment_2 = std::string() ,
-		const std::string & internal_comment_3 = std::string() ) ;
+	Link( const G::Path & target_path , const std::string & name , const std::string & description ,
+		const G::Path & working_dir , const G::StringArray & args = G::StringArray() ,
+		const G::Path & icon_source = G::Path() , Show show = Show::Default ,
+		const std::string & internal_comment_1 = {} ,
+		const std::string & internal_comment_2 = {} ,
+		const std::string & internal_comment_3 = {} ) ;
 			///< Constructor. Note that the path of the link itself
 			///< is specified in saveAs(), not the constructor.
 			///< The "working_dir" is the current-working-directory
@@ -58,23 +58,23 @@ public:
 	static std::string filename( const std::string & name ) ;
 		///< Returns a normalised filename including an extension like ".lnk" or ".desktop".
 
-	void saveAs( const Path & link_path ) ;
+	void saveAs( const G::Path & link_path ) ;
 		///< Saves the link.
 
 	~Link() ;
 		///< Destructor.
 
-	static bool remove( const Path & link_path ) ;
+	static bool remove( const G::Path & link_path ) ;
 		///< Removes a link. Returns true if removed.
 
-	static bool exists( const Path & link_path ) ;
+	static bool exists( const G::Path & link_path ) ;
 		///< Returns true if the link exists.
 
 public:
 	Link( const Link & ) = delete ;
 	Link( Link && ) = delete ;
-	void operator=( const Link & ) = delete ;
-	void operator=( Link && ) = delete ;
+	Link & operator=( const Link & ) = delete ;
+	Link & operator=( Link && ) = delete ;
 
 private:
 	std::unique_ptr<LinkImp> m_imp ;
diff --git a/src/gui/glink_mac.cpp b/src/gui/guilink_mac.cpp
similarity index 67%
rename from src/gui/glink_mac.cpp
rename to src/gui/guilink_mac.cpp
index 6057b8a..729d000 100644
--- a/src/gui/glink_mac.cpp
+++ b/src/gui/guilink_mac.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,51 +15,51 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file glink_mac.cpp
+/// \file guilink_mac.cpp
 ///
 
 #include "gdef.h"
+#include "guilink.h"
 #include "gstr.h"
-#include "glink.h"
 #include "gfile.h"
 #include <string>
 #include <sstream>
 #include <fstream>
 #include <cstdlib> // std::system()
 
-class G::LinkImp
+class Gui::LinkImp
 {
 public:
-	LinkImp( const Path & target_path , const std::string & name , const std::string & description ,
-		const Path & working_dir , const StringArray & args , const Path & icon_source , Link::Show show ) ;
+	LinkImp( const G::Path & target_path , const std::string & name , const std::string & description ,
+		const G::Path & working_dir , const G::StringArray & args , const G::Path & icon_source , Link::Show show ) ;
 	static std::string filename( const std::string & ) ;
-	void saveAs( const Path & ) ;
+	void saveAs( const G::Path & ) ;
 
 public:
 	~LinkImp() = default ;
 	LinkImp( const LinkImp & ) = delete ;
 	LinkImp( LinkImp && ) = delete ;
-	void operator=( const LinkImp & ) = delete ;
-	void operator=( LinkImp && ) = delete ;
+	LinkImp & operator=( const LinkImp & ) = delete ;
+	LinkImp & operator=( LinkImp && ) = delete ;
 
 private:
-	Path m_target_path ;
+	G::Path m_target_path ;
 	std::string m_name ;
 } ;
 
-G::LinkImp::LinkImp( const Path & target_path , const std::string & name , const std::string & ,
-	const Path & , const StringArray & , const Path & , Link::Show ) :
+Gui::LinkImp::LinkImp( const G::Path & target_path , const std::string & name , const std::string & ,
+	const G::Path & , const G::StringArray & , const G::Path & , Link::Show ) :
 		m_target_path(target_path) ,
 		m_name(name)
 {
 }
 
-std::string G::LinkImp::filename( const std::string & )
+std::string Gui::LinkImp::filename( const std::string & )
 {
 	return std::string() ;
 }
 
-void G::LinkImp::saveAs( const Path & )
+void Gui::LinkImp::saveAs( const G::Path & )
 {
 	// TODO -- hardcoded Start.app name
 	//
@@ -68,9 +68,9 @@ void G::LinkImp::saveAs( const Path & )
 	// the installer's LinkInfo structure at this interface and add a
 	// third section to it
 	//
-	Path start_app_path( m_target_path.dirname() , "E-MailRelay-Start.app" ) ;
+	G::Path start_app_path( m_target_path.dirname() , "E-MailRelay-Start.app" ) ;
 	if( !File::exists(start_app_path) )
-		start_app_path = Path( m_target_path.dirname() , "../E-MailRelay-Start.app" ) ;
+		start_app_path = G::Path( m_target_path.dirname() , "../E-MailRelay-Start.app" ) ;
 
 	std::ostringstream ss ;
 	ss
@@ -86,32 +86,32 @@ void G::LinkImp::saveAs( const Path & )
 
 // ==
 
-G::Link::Link( const Path & target_path , const std::string & name , const std::string & description ,
-	const Path & working_dir , const StringArray & args , const Path & icon_source , Show show ,
+Gui::Link::Link( const G::Path & target_path , const std::string & name , const std::string & description ,
+	const G::Path & working_dir , const G::StringArray & args , const G::Path & icon_source , Show show ,
 	const std::string & , const std::string & , const std::string & ) :
 		m_imp( std::make_unique<LinkImp>(target_path,name,description,working_dir,args,icon_source,show) )
 {
 }
 
-G::Link::~Link()
+Gui::Link::~Link()
 = default ;
 
-std::string G::Link::filename( const std::string & name_in )
+std::string Gui::Link::filename( const std::string & name_in )
 {
 	return LinkImp::filename( name_in ) ;
 }
 
-void G::Link::saveAs( const Path & link_path )
+void Gui::Link::saveAs( const G::Path & link_path )
 {
 	m_imp->saveAs( link_path ) ;
 }
 
-bool G::Link::exists( const Path & path )
+bool Gui::Link::exists( const G::Path & path )
 {
 	return File::exists( path.dirname()+"E-MailRelay-Start.app" , std::nothrow ) ; // not tested
 }
 
-bool G::Link::remove( const Path & )
+bool Gui::Link::remove( const G::Path & )
 {
 	std::ostringstream ss ;
 	ss
diff --git a/src/gui/glink_unix.cpp b/src/gui/guilink_unix.cpp
similarity index 69%
rename from src/gui/glink_unix.cpp
rename to src/gui/guilink_unix.cpp
index e0dac17..9c6348b 100644
--- a/src/gui/glink_unix.cpp
+++ b/src/gui/guilink_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,53 +15,53 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file glink_unix.cpp
+/// \file guilink_unix.cpp
 ///
 
 #include "gdef.h"
+#include "guilink.h"
 #include "gstr.h"
-#include "glink.h"
 #include "gfile.h"
 #include <string>
 #include <sstream>
 #include <fstream>
 
-class G::LinkImp
+class Gui::LinkImp
 {
 public:
-	LinkImp( const Path & target_path , const std::string & name , const std::string & description ,
-		const Path & working_dir , const StringArray & args , const Path & icon_source , Link::Show show ,
+	LinkImp( const G::Path & target_path , const std::string & name , const std::string & description ,
+		const G::Path & working_dir , const G::StringArray & args , const G::Path & icon_source , Link::Show show ,
 		const std::string & c1 , const std::string & c2 , const std::string & c3 ) ;
 	static std::string filename( const std::string & ) ;
-	void saveAs( const Path & ) ;
+	void saveAs( const G::Path & ) ;
 
 public:
 	~LinkImp() = default ;
 	LinkImp( const LinkImp & ) = delete ;
 	LinkImp( LinkImp && ) = delete ;
-	void operator=( const LinkImp & ) = delete ;
-	void operator=( LinkImp && ) = delete ;
+	LinkImp & operator=( const LinkImp & ) = delete ;
+	LinkImp & operator=( LinkImp && ) = delete ;
 
 private:
 	static std::string quote( const std::string & ) ;
 	static std::string escape( const std::string & ) ;
-	static std::string escapeAndQuote( const StringArray & ) ;
+	static std::string escapeAndQuote( const G::StringArray & ) ;
 
 private:
-	Path m_target_path ;
+	G::Path m_target_path ;
 	std::string m_name ;
 	std::string m_description ;
-	Path m_working_dir ;
-	StringArray m_args ;
-	Path m_icon_source ;
+	G::Path m_working_dir ;
+	G::StringArray m_args ;
+	G::Path m_icon_source ;
 	bool m_terminal ;
 	std::string m_c1 ;
 	std::string m_c2 ;
 	std::string m_c3 ;
 } ;
 
-G::LinkImp::LinkImp( const Path & target_path , const std::string & name , const std::string & description ,
-	const Path & working_dir , const StringArray & args , const Path & icon_source , Link::Show show ,
+Gui::LinkImp::LinkImp( const G::Path & target_path , const std::string & name , const std::string & description ,
+	const G::Path & working_dir , const G::StringArray & args , const G::Path & icon_source , Link::Show show ,
 	const std::string & c1 , const std::string & c2 , const std::string & c3 ) :
 		m_target_path(target_path) ,
 		m_name(name) ,
@@ -76,14 +76,14 @@ G::LinkImp::LinkImp( const Path & target_path , const std::string & name , const
 {
 }
 
-std::string G::LinkImp::filename( const std::string & name )
+std::string Gui::LinkImp::filename( const std::string & name )
 {
-	std::string result = Str::lower(name) + ".desktop" ;
-	Str::replaceAll( result , "-" , "" ) ;
+	std::string result = G::Str::lower(name) + ".desktop" ;
+	G::Str::replaceAll( result , "-" , "" ) ;
 	return result ;
 }
 
-void G::LinkImp::saveAs( const Path & path )
+void Gui::LinkImp::saveAs( const G::Path & path )
 {
 	// see "http://standards.freedesktop.org"
 
@@ -91,7 +91,7 @@ void G::LinkImp::saveAs( const Path & path )
 
 	const char * eol = "\n" ;
 	std::ofstream file ;
-	File::open( file , path ) ;
+	G::File::open( file , path ) ;
 
 	if( !m_c1.empty() ) file << "# " << m_c1 << eol ;
 	if( !m_c2.empty() ) file << "# " << m_c2 << eol ;
@@ -108,7 +108,7 @@ void G::LinkImp::saveAs( const Path & path )
 	file << "Comment=" << m_description << eol ;
 	file << "Path=" << m_working_dir << eol ;
 	if( ! m_icon_source.str().empty() )
-		file << "Icon=" << m_icon_source << eol ;
+	file << "Icon=" << m_icon_source << eol ;
 	file << "Terminal=" << (m_terminal?"true":"false") << eol ;
 
 	file << "Categories=System;" << eol ;
@@ -117,10 +117,10 @@ void G::LinkImp::saveAs( const Path & path )
 	if( !file.good() )
 		throw Link::SaveError(path.str()) ;
 
-	File::chmodx( path , std::nothrow ) ;
+	G::File::chmodx( path , std::nothrow ) ;
 }
 
-std::string G::LinkImp::escape( const std::string & s_in )
+std::string Gui::LinkImp::escape( const std::string & s_in )
 {
 	// <citation version="1.0">
 	// Note that the general escape rule for values of type string states that
@@ -136,10 +136,10 @@ std::string G::LinkImp::escape( const std::string & s_in )
 	// percentage characters must be escaped as %%.
 	// </citation>
 
-	return Str::escaped( Str::escaped(s_in,'\\',"\\$","\\$") , '%' , "%" , "%" ) ;
+	return G::Str::escaped( G::Str::escaped(s_in,'\\',"\\$","\\$") , '%' , "%" , "%" ) ;
 }
 
-std::string G::LinkImp::quote( const std::string & s_in )
+std::string Gui::LinkImp::quote( const std::string & s_in )
 {
 	// <citation version="1.0">
 	// If an argument contains a reserved character the argument must be quoted.
@@ -159,7 +159,7 @@ std::string G::LinkImp::quote( const std::string & s_in )
 		// character ("\") by preceding it with an additional backslash character.
 		// </citation>
 
-		return std::string(1U,'\"') + Str::escaped(s_in,'\\',"\"`$\\","\"`$\\") + std::string(1U,'\"') ;
+		return std::string(1U,'\"') + G::Str::escaped(s_in,'\\',"\"`$\\","\"`$\\") + std::string(1U,'\"') ;
 	}
 	else
 	{
@@ -167,7 +167,7 @@ std::string G::LinkImp::quote( const std::string & s_in )
 	}
 }
 
-std::string G::LinkImp::escapeAndQuote( const StringArray & args )
+std::string Gui::LinkImp::escapeAndQuote( const G::StringArray & args )
 {
 	std::ostringstream ss ;
 	const char * sep = "" ;
@@ -181,33 +181,33 @@ std::string G::LinkImp::escapeAndQuote( const StringArray & args )
 
 // ==
 
-G::Link::Link( const Path & target_path , const std::string & name , const std::string & description ,
-	const Path & working_dir , const StringArray & args , const Path & icon_source , Show show ,
+Gui::Link::Link( const G::Path & target_path , const std::string & name , const std::string & description ,
+	const G::Path & working_dir , const G::StringArray & args , const G::Path & icon_source , Show show ,
 	const std::string & c1 , const std::string & c2 , const std::string & c3 ) :
 		m_imp(std::make_unique<LinkImp>(target_path,name,description,working_dir,args,icon_source,show,c1,c2,c3))
 {
 }
 
-G::Link::~Link()
+Gui::Link::~Link()
 = default ;
 
-std::string G::Link::filename( const std::string & name_in )
+std::string Gui::Link::filename( const std::string & name_in )
 {
 	return LinkImp::filename( name_in ) ;
 }
 
-void G::Link::saveAs( const Path & link_path )
+void Gui::Link::saveAs( const G::Path & link_path )
 {
 	m_imp->saveAs( link_path ) ;
 }
 
-bool G::Link::exists( const Path & path )
+bool Gui::Link::exists( const G::Path & path )
 {
-	return File::isLink( path , std::nothrow ) ;
+	return G::File::isLink( path , std::nothrow ) ;
 }
 
-bool G::Link::remove( const Path & link_path )
+bool Gui::Link::remove( const G::Path & link_path )
 {
-	return File::remove( link_path , std::nothrow ) ;
+	return G::File::remove( link_path , std::nothrow ) ;
 }
 
diff --git a/src/gui/glink_win32.cpp b/src/gui/guilink_win32.cpp
similarity index 60%
rename from src/gui/glink_win32.cpp
rename to src/gui/guilink_win32.cpp
index 6c00d33..8bc9370 100644
--- a/src/gui/glink_win32.cpp
+++ b/src/gui/guilink_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -14,13 +14,13 @@
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
-//
-// glink_win32.cpp
-//
+///
+/// \file guilink_win32.cpp
+///
 
 #include "gdef.h"
+#include "guilink.h"
 #include "gconvert.h"
-#include "glink.h"
 #include "gstr.h"
 #include "gfile.h"
 #include "gcominit.h"
@@ -31,7 +31,7 @@
 #include <shlobj.h>
 #include <windows.h>
 
-namespace G
+namespace Gui
 {
 	template <typename I>
 	struct ComPtr
@@ -44,36 +44,36 @@ namespace G
 		void ** vp() { return reinterpret_cast<void**>(&m_p) ; }
 		ComPtr( const ComPtr<I> & ) = delete ;
 		ComPtr( ComPtr<I> && ) = delete ;
-		void operator=( const ComPtr<I> & ) = delete ;
-		void operator=( ComPtr<I> && ) = delete ;
+		ComPtr<I> & operator=( const ComPtr<I> & ) = delete ;
+		ComPtr<I> & operator=( ComPtr<I> && ) = delete ;
 		private: I * m_p ;
 	} ;
 }
 
-class G::LinkImp
+class Gui::LinkImp
 {
 public:
-	LinkImp( const Path & target_path , const std::string & name , const std::string & description ,
-		const Path & working_dir , const StringArray & args , const Path & icon_source , Link::Show show ) ;
+	LinkImp( const G::Path & target_path , const std::string & name , const std::string & description ,
+		const G::Path & working_dir , const G::StringArray & args , const G::Path & icon_source , Link::Show show ) ;
 	static std::string filename( const std::string & ) ;
-	void saveAs( const Path & link_path ) ;
+	void saveAs( const G::Path & link_path ) ;
 
 public:
 	~LinkImp() = default ;
 	LinkImp( const LinkImp & ) = delete ;
 	LinkImp( LinkImp && ) = delete ;
-	void operator=( const LinkImp & ) = delete ;
-	void operator=( LinkImp && ) = delete ;
+	LinkImp & operator=( const LinkImp & ) = delete ;
+	LinkImp & operator=( LinkImp && ) = delete ;
 
 private:
 	static void check( HRESULT , const char * ) ;
 	void createInstance() ;
 	void qi() ;
-	void setTargetPath( const Path & ) ;
+	void setTargetPath( const G::Path & ) ;
 	void setDescription( const std::string & s ) ;
-	void setWorkingDir( const Path & ) ;
-	void setArgs( const StringArray & ) ;
-	void setIcon( const Path & ) ;
+	void setWorkingDir( const G::Path & ) ;
+	void setArgs( const G::StringArray & ) ;
+	void setIcon( const G::Path & ) ;
 	void setShow( int ) ;
 
 private:
@@ -89,33 +89,33 @@ private:
 		BSTR p() ;
 		bstr( const bstr & ) = delete ;
 		bstr( bstr && ) = delete ;
-		void operator=( const bstr & ) = delete ;
-		void operator=( bstr && ) = delete ;
+		bstr & operator=( const bstr & ) = delete ;
+		bstr & operator=( bstr && ) = delete ;
 		private: BSTR m_p ;
 	} ;
 } ;
 
-G::LinkImp::bstr::bstr( const std::string & s )
+Gui::LinkImp::bstr::bstr( const std::string & s )
 {
 	std::wstring ws ;
-	Convert::convert( ws , s ) ;
+	G::Convert::convert( ws , s ) ;
 	m_p = SysAllocString( ws.c_str() ) ;
 }
 
-G::LinkImp::bstr::~bstr()
+Gui::LinkImp::bstr::~bstr()
 {
 	SysFreeString( m_p ) ;
 }
 
-BSTR G::LinkImp::bstr::p()
+BSTR Gui::LinkImp::bstr::p()
 {
 	return m_p ;
 }
 
 // ==
 
-G::LinkImp::LinkImp( const Path & target_path , const std::string & , const std::string & description ,
-	const Path & working_dir , const StringArray & args , const Path & icon_source , Link::Show show_enum )
+Gui::LinkImp::LinkImp( const G::Path & target_path , const std::string & , const std::string & description ,
+	const G::Path & working_dir , const G::StringArray & args , const G::Path & icon_source , Link::Show show_enum )
 {
 	createInstance() ;
 	setTargetPath( target_path ) ;
@@ -127,12 +127,12 @@ G::LinkImp::LinkImp( const Path & target_path , const std::string & , const std:
 	qi() ;
 }
 
-std::string G::LinkImp::filename( const std::string & name_in )
+std::string Gui::LinkImp::filename( const std::string & name_in )
 {
 	return name_in + ".lnk" ;
 }
 
-void G::LinkImp::check( HRESULT hr , const char * op )
+void Gui::LinkImp::check( HRESULT hr , const char * op )
 {
 	if( FAILED(hr) )
 	{
@@ -143,53 +143,53 @@ void G::LinkImp::check( HRESULT hr , const char * op )
 	}
 }
 
-void G::LinkImp::createInstance()
+void Gui::LinkImp::createInstance()
 {
 	HRESULT hr = CoCreateInstance( CLSID_ShellLink , nullptr , CLSCTX_INPROC_SERVER , IID_IShellLink , m_ilink.vp() ) ;
 	check( hr , "createInstance" ) ;
 }
 
-void G::LinkImp::qi()
+void Gui::LinkImp::qi()
 {
 	HRESULT hr = m_ilink.get()->QueryInterface( IID_IPersistFile , m_ipf.vp() ) ;
 	check( hr , "qi" ) ;
 }
 
-void G::LinkImp::setTargetPath( const Path & target_path )
+void Gui::LinkImp::setTargetPath( const G::Path & target_path )
 {
 	std::basic_string<TCHAR> arg ;
-	Convert::convert( arg , target_path.str() ) ;
+	G::Convert::convert( arg , target_path.str() ) ;
 	HRESULT hr = m_ilink.get()->SetPath( arg.c_str() ) ;
 	check( hr , "SetPath" ) ;
 }
 
-void G::LinkImp::setWorkingDir( const Path & working_dir )
+void Gui::LinkImp::setWorkingDir( const G::Path & working_dir )
 {
 	std::basic_string<TCHAR> arg ;
-	Convert::convert( arg , working_dir.str() ) ;
+	G::Convert::convert( arg , working_dir.str() ) ;
 	HRESULT hr = m_ilink.get()->SetWorkingDirectory( arg.c_str() ) ;
 	check( hr , "SetWorkingDirectory" ) ;
 }
 
-void G::LinkImp::setDescription( const std::string & s )
+void Gui::LinkImp::setDescription( const std::string & s )
 {
 	std::basic_string<TCHAR> arg ;
-	Convert::convert( arg , s ) ;
+	G::Convert::convert( arg , s ) ;
 	HRESULT hr = m_ilink.get()->SetDescription( arg.c_str() ) ;
 	check( hr , "SetDescription" ) ;
 }
 
-void G::LinkImp::setArgs( const StringArray & args )
+void Gui::LinkImp::setArgs( const G::StringArray & args )
 {
 	std::ostringstream ss ;
 	const char * sep = "" ;
-	for( StringArray::const_iterator p = args.begin() ; p != args.end() ; ++p )
+	for( G::StringArray::const_iterator p = args.begin() ; p != args.end() ; ++p )
 	{
 		std::string s = *p ;
 		const char * qq = "" ;
 		if( s.find(' ') != std::string::npos )
 		{
-			Str::replaceAll( s , "\"" , "\\\"" ) ; // windows is too stupid for this to work :-<
+			G::Str::replaceAll( s , "\"" , "\\\"" ) ; // windows is too stupid for this to work :-<
 			qq = "\"" ;
 		}
 		ss << sep << qq << s << qq ;
@@ -197,26 +197,26 @@ void G::LinkImp::setArgs( const StringArray & args )
 	}
 
 	std::basic_string<TCHAR> arg ;
-	Convert::convert( arg , ss.str() ) ;
+	G::Convert::convert( arg , ss.str() ) ;
 	HRESULT hr = m_ilink.get()->SetArguments( arg.c_str() ) ;
 	check( hr , "SetArguments" ) ;
 }
 
-void G::LinkImp::setIcon( const Path & icon_source )
+void Gui::LinkImp::setIcon( const G::Path & icon_source )
 {
 	std::basic_string<TCHAR> arg ;
-	Convert::convert( arg , icon_source.str() ) ;
+	G::Convert::convert( arg , icon_source.str() ) ;
 	HRESULT hr = m_ilink.get()->SetIconLocation( arg.c_str() , 0U ) ;
 	check( hr , "SetIconLocation" ) ;
 }
 
-void G::LinkImp::setShow( int show )
+void Gui::LinkImp::setShow( int show )
 {
 	HRESULT hr = m_ilink.get()->SetShowCmd( show ) ;
 	check( hr , "SetShowCmd" ) ;
 }
 
-void G::LinkImp::saveAs( const Path & link_path )
+void Gui::LinkImp::saveAs( const G::Path & link_path )
 {
 	HRESULT hr = m_ipf.get()->Save( bstr(link_path.str()).p() , TRUE ) ;
 	check( hr , "Save" ) ;
@@ -224,34 +224,33 @@ void G::LinkImp::saveAs( const Path & link_path )
 
 // ==
 
-G::Link::Link( const Path & target_path , const std::string & name , const std::string & description ,
-	const Path & working_dir , const StringArray & args , const Path & icon_source , Show show ,
+Gui::Link::Link( const G::Path & target_path , const std::string & name , const std::string & description ,
+	const G::Path & working_dir , const G::StringArray & args , const G::Path & icon_source , Show show ,
 	const std::string & , const std::string & , const std::string & ) :
 		m_imp(std::make_unique<LinkImp>(target_path,name,description,working_dir,args,icon_source,show))
 {
 }
 
-G::Link::~Link()
+Gui::Link::~Link()
 = default ;
 
-std::string G::Link::filename( const std::string & name_in )
+std::string Gui::Link::filename( const std::string & name_in )
 {
 	return LinkImp::filename( name_in ) ;
 }
 
-void G::Link::saveAs( const Path & link_path )
+void Gui::Link::saveAs( const G::Path & link_path )
 {
 	m_imp->saveAs( link_path ) ;
 }
 
-bool G::Link::exists( const Path & path )
+bool Gui::Link::exists( const G::Path & path )
 {
-	return File::exists( path , std::nothrow ) ;
+	return G::File::exists( path , std::nothrow ) ;
 }
 
-bool G::Link::remove( const Path & link_path )
+bool Gui::Link::remove( const G::Path & link_path )
 {
-	return File::remove( link_path , std::nothrow ) ;
+	return G::File::remove( link_path , std::nothrow ) ;
 }
 
-/// \file glink_win32.cpp
diff --git a/src/gui/guimain.cpp b/src/gui/guimain.cpp
index a6f7192..c29e2b2 100644
--- a/src/gui/guimain.cpp
+++ b/src/gui/guimain.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -106,17 +106,17 @@
 
 #include "gdef.h"
 #include "gqt.h"
-#include "gdialog.h"
+#include "guidialog.h"
 #include "gfile.h"
 #include "gbatchfile.h"
 #include "gmapfile.h"
 #include "gdirectory.h"
 #include "goptionparser.h"
 #include "installer.h"
-#include "dir.h"
-#include "glink.h"
+#include "guidir.h"
+#include "guilink.h"
 #include "pages.h"
-#include "boot.h"
+#include "guiboot.h"
 #include "serverconfiguration.h"
 #include "glogoutput.h"
 #include "ggetopt.h"
@@ -124,6 +124,7 @@
 #include "gpath.h"
 #include "gstr.h"
 #include "gstringwrap.h"
+#include "gformat.h"
 #include <string>
 #include <iostream>
 #include <stdexcept>
@@ -150,18 +151,25 @@ static int height()
 	return 490 ;
 }
 
-static void error( const std::string & what )
+static void errorBox( const std::string & what )
 {
 	QString title( GQt::qstr("E-MailRelay") ) ;
+	QString qwhat = GQt::qstr( what ) ;
 	QMessageBox::critical( nullptr , title ,
-		QMessageBox::tr("Failed with the following exception: %1").arg(what.c_str()) ,
+		QMessageBox::tr("Failed with the following exception: %1").arg(qwhat) ,
 		QMessageBox::Abort , QMessageBox::NoButton , QMessageBox::NoButton ) ;
 }
 
-static void info( const std::string & text )
+static QString tr( const char * text )
+{
+	return QCoreApplication::translate( "main" , text ) ;
+}
+
+static void infoBox( const std::string & text )
 {
 	QString title( GQt::qstr("E-MailRelay") ) ;
-	QMessageBox::information( nullptr , title , QString::fromLatin1(text.c_str()) ,
+	QString qtext = GQt::qstr( text ) ;
+	QMessageBox::information( nullptr , title , qtext ,
 		QMessageBox::Ok , QMessageBox::NoButton , QMessageBox::NoButton ) ;
 }
 
@@ -202,7 +210,7 @@ bool Application::notify( QObject * p1 , QEvent * p2 )
 	catch( std::exception & e )
 	{
 		G_ERROR( "exception: " << e.what() ) ;
-		error( e.what() ) ;
+		errorBox( e.what() ) ;
 		std::string message = G::StringWrap::wrap( e.what() , "" , "" , 40U ) ;
 		qCritical( message.find(' ')==std::string::npos ? "exception: %s" : "%s" , message.c_str() ) ;
 		exit( 3 ) ;
@@ -258,7 +266,7 @@ int main( int argc , char * argv [] )
 			const char * sep = "" ;
 			for( int i = 2 ; i < argc ; i++ , sep = " " )
 				ss << sep << argv[i] ;
-			info( ss.str() ) ;
+			infoBox( ss.str() ) ;
 			return 1 ;
 		}
 		G::LogOutput log_ouptut( "" ,
@@ -288,7 +296,7 @@ int main( int argc , char * argv [] )
 				if( qmdir.empty() )
 					qmdir = argv0.dirname() + "translations" ;
 				if( !qmfile.empty() )
-					loaded = translator.load( GQt::qstr(qmfile.str()) ) ;
+					loaded = translator.load( GQt::qstr(qmfile) ) ;
 				if( !loaded )
 					loaded = translator.load( QLocale() , GQt::qstr("emailrelay") , GQt::qstr(".") ,
 						GQt::qstr(qmdir.str()) , GQt::qstr(".qm") ) ;
@@ -299,7 +307,7 @@ int main( int argc , char * argv [] )
 			}
 
 			// test-mode -- create a minimal payload, make it easier to
-			// click through and write install variables to installer.txt
+			// click through, and write install variables to installer.txt
 			if( args.contains("--test") )
 			{
 				G::Path pdir = argv0.dirname() + "payload" ;
@@ -318,7 +326,7 @@ int main( int argc , char * argv [] )
 					G::File::copyInto( "/usr/sbin/emailrelay" , pdir + "usr/sbin" , std::nothrow ) ;
 					f << "usr/sbin/=%dir-install%/sbin/" << std::endl ;
 				}
-				GPage::setTestMode() ;
+				Gui::Page::setTestMode() ;
 			}
 
 			// look for the payload (for install mode)
@@ -342,10 +350,14 @@ int main( int argc , char * argv [] )
 
 			// fail if no payload and no pointer file
 			if( configure_mode && pointer_file.empty() )
-				throw std::runtime_error( "cannot find a 'payload' directory for installation or a "
-					"'" + pointerFilename(argv0) + "' pointer file to allow reconfiguration: "
+			{
+				QString message_format = tr( "cannot find a 'payload' directory for installation or a "
+					"'%1' pointer file to allow reconfiguration: "
 					"this program has probably been moved away from its original location: "
 					"please configure the emailrelay server manually" ) ;
+				QString message = message_format.arg( GQt::qstr( pointerFilename(argv0) , GQt::Path ) ) ;
+				throw std::runtime_error( GQt::stdstr( message , GQt::Utf8 ) ) ;
+			}
 
 			// load the pointer file
 			G::MapFile pointer_map ;
@@ -371,8 +383,8 @@ int main( int argc , char * argv [] )
 			}
 
 			// load the existing server configuration
-			G::Path dir_config = pointer_map.expandedPathValue( "dir-config" , Dir::config() ) ;
-			G::Path dir_run = pointer_map.expandedPathValue( "dir-run" , Dir::pid(dir_config) ) ;
+			G::Path dir_config = pointer_map.expandedPathValue( "dir-config" , Gui::Dir::config() ) ;
+			G::Path dir_run = pointer_map.expandedPathValue( "dir-run" , Gui::Dir::pid(dir_config) ) ;
 			G::Path server_config_file = configFile( dir_config ) ; // config-file or batch-file
 			G::MapFile server_config_map ;
 			if( configure_mode )
@@ -384,7 +396,7 @@ int main( int argc , char * argv [] )
 			}
 
 			// determine the install root
-			G::Path dir_install = Dir::install() ;
+			G::Path dir_install = Gui::Dir::install() ;
 			if( configure_mode )
 			{
 				// configure-mode dir-install is relative to the server exe or this gui exe, with a pointer-file override
@@ -409,21 +421,22 @@ int main( int argc , char * argv [] )
 
 			// set up the gui pages' config map
 			G::MapFile pages_config = server_config_map ;
-			if( !pages_config.contains("spool-dir") ) pages_config.add( "spool-dir" , Dir::spool().str() ) ;
 			pages_config.add( "=dir-config" , dir_config.str() ) ;
 			pages_config.add( "=dir-install" , dir_install.str() ) ;
 			pages_config.add( "=dir-run" , dir_run.str() ) ;
-			pages_config.add( "=dir-boot" , Dir::boot().str() ) ;
-			pages_config.add( "=dir-boot-enabled" , Boot::installable(Dir::boot()) ? "y" : "n" ) ;
+			pages_config.add( "=dir-boot" , Gui::Dir::boot().str() ) ;
+			pages_config.add( "=dir-boot-enabled" , Gui::Boot::installable(Gui::Dir::boot()) ? "y" : "n" ) ;
+			if( !pages_config.contains("spool-dir") )
+				pages_config.add( "spool-dir" , Gui::Dir::spool().str() ) ;
 
 			// set widget states based on the current file-system state
 			if( configure_mode )
 			{
-				std::string fname = G::Link::filename( "E-MailRelay" ) ;
-				pages_config.add( "start-on-boot" , Boot::installed(Dir::boot(),"emailrelay") ? "y" : "n" ) ;
-				pages_config.add( "start-link-desktop" , G::Link::exists(Dir::desktop()+fname) ? "y" : "n" ) ;
-				pages_config.add( "start-link-menu" , G::Link::exists(Dir::menu()+fname) ? "y" : "n" ) ;
-				pages_config.add( "start-at-login" , G::Link::exists(Dir::autostart()+fname) ? "y" : "n" ) ;
+				std::string fname = Gui::Link::filename( "E-MailRelay" ) ;
+				pages_config.add( "start-on-boot" , Gui::Boot::installed(Gui::Dir::boot(),"emailrelay") ? "y" : "n" ) ;
+				pages_config.add( "start-link-desktop" , Gui::Link::exists(Gui::Dir::desktop()+fname) ? "y" : "n" ) ;
+				pages_config.add( "start-link-menu" , Gui::Link::exists(Gui::Dir::menu()+fname) ? "y" : "n" ) ;
+				pages_config.add( "start-at-login" , Gui::Link::exists(Gui::Dir::autostart()+fname) ? "y" : "n" ) ;
 			}
 
 			// check the config file (or windows batch file) will be writeable
@@ -431,20 +444,24 @@ int main( int argc , char * argv [] )
 			{
 				if( G::File::exists(server_config_file) )
 				{
-					std::string more_help = isWindows() ? " or run as administrator" : "" ;
 					std::ofstream f ;
 					G::File::open( f , server_config_file , G::File::Append() ) ;
 					if( !f.good() )
-						throw std::runtime_error( "cannot write [" + server_config_file.str() + "]"
-							": check file permissions" + more_help ) ;
+					{
+						QString message_format = tr( "cannot write [%1]: check file permissions%2" ) ;
+						QString more_help = isWindows() ? tr( " or run as administrator" ) : QString() ;
+						QString message = message_format.arg(GQt::qstr(server_config_file.str())).arg(more_help) ;
+						throw std::runtime_error( GQt::stdstr( message , GQt::Utf8 ) ) ;
+					}
 				}
 				else if( !G::Directory(server_config_file.dirname()).valid(true) )
 				{
-					std::string gerund_article = pointer_map.contains("dir-config") ? "changing the" : "adding a" ;
-					std::string preposition = pointer_map.contains("dir-config") ? "in" : "to" ;
-					throw std::runtime_error( "cannot create files in [" + server_config_file.dirname().str() + "]: "
-						"try " + gerund_article + " \"dir-config\" entry " + preposition + " the configuration file "
-						"[" + pointer_file.str() + "]" ) ;
+					bool exists = pointer_map.contains( "dir-config" ) ;
+					QString message_format = exists ?
+						tr( "cannot create files in [%1]: try changing the \"dir-config\" entry in the configuration file [%2]" ) :
+						tr( "cannot create files in [%1]: try adding a \"dir-config\" entry to the configuration file [%2]" ) ;
+					QString message = message_format.arg(GQt::qstr(server_config_file.dirname())).arg(GQt::qstr(pointer_file)) ;
+					throw std::runtime_error( GQt::stdstr( message , GQt::Utf8 ) ) ;
 				}
 			}
 
@@ -457,7 +474,7 @@ int main( int argc , char * argv [] )
 			// as the configure-mode flag because the first run is always in
 			// install mode -- but for a mac bundle we are always in configure
 			// mode, so we add a flag file into the distribution bundle that gets
-			// deleted by a successful first configuration (see GDialog)
+			// deleted by a successful first configuration (see Gui::Dialog)
 			bool run_before = configure_mode ;
 			G::Path virgin_flag_file ;
 			if( is_mac )
@@ -470,22 +487,21 @@ int main( int argc , char * argv [] )
 			// create the dialog and all its pages
 			const bool licence_accepted = run_before ;
 			const bool with_launch = !configure_mode ;
-			GDialog d( virgin_flag_file , with_launch ) ;
-			//d.enableHelpButton() ;
-			//d.enableLaunchButton() ;
+			const bool skip_startup_page = configure_mode && !isWindows() ;
+			Gui::Dialog d( virgin_flag_file , with_launch ) ;
 			d.add( new TitlePage(d,pages_config,"title","license","") ) ;
 			d.add( new LicensePage(d,pages_config,"license","directory","",licence_accepted) ) ;
-			d.add( new DirectoryPage(d,pages_config,"directory","dowhat","",!configure_mode,is_mac) ) ;
+			d.add( new DirectoryPage(d,pages_config,"directory","dowhat","",!configure_mode,isWindows(),is_mac) ) ;
 			d.add( new DoWhatPage(d,pages_config,"dowhat","pop","smtpserver") ) ;
 			d.add( new PopPage(d,pages_config,"pop","smtpserver","logging",configure_mode) ) ;
 			d.add( new SmtpServerPage(d,pages_config,"smtpserver","smtpclient","",configure_mode,can_generate&&!configure_mode) ) ;
 			d.add( new SmtpClientPage(d,pages_config,"smtpclient","filter","",configure_mode) ) ;
 			d.add( new FilterPage(d,pages_config,"filter","logging","",!configure_mode,isWindows()) ) ;
-			d.add( new ListeningPage(d,pages_config,"listening","startup","") ) ;
 			d.add( new LoggingPage(d,pages_config,"logging","listening","") ) ;
+			d.add( new ListeningPage(d,pages_config,"listening","startup","ready",skip_startup_page) ) ;
 			d.add( new StartupPage(d,pages_config,"startup","ready","",is_mac) ) ;
 			d.add( new ReadyPage(d,pages_config,"ready","progress","",!configure_mode) ) ;
-			d.add( new ProgressPage(d,pages_config,"progress","","",installer) ) ;
+			d.add( new ProgressPage(d,pages_config,"progress","","",installer,!configure_mode) ) ;
 			d.add() ;
 
 			// set the dialog dimensions
@@ -500,13 +516,13 @@ int main( int argc , char * argv [] )
 		}
 		catch( std::exception & e )
 		{
-			error( e.what() ) ;
+			errorBox( e.what() ) ;
 			std::string message = G::StringWrap::wrap( e.what() , "" , "" , 40 ) ;
-			qCritical( "exception: %s" , message.c_str() ) ;
+			qCritical( "%s" , message.c_str() ) ;
 		}
 		catch(...)
 		{
-			error( "unknown exception" ) ;
+			errorBox( "unknown exception" ) ;
 			qCritical( "%s" , "unknown exception" ) ;
 		}
 		return 1 ;
@@ -514,7 +530,7 @@ int main( int argc , char * argv [] )
 	catch( std::exception & e )
 	{
 		std::string message = G::StringWrap::wrap( e.what() , "" , "" , 40U ) ;
-		qCritical( "exception: %s" , message.c_str() ) ;
+		qCritical( "%s" , message.c_str() ) ;
 	}
 	catch(...)
 	{
diff --git a/src/gui/gpage.cpp b/src/gui/guipage.cpp
similarity index 61%
rename from src/gui/gpage.cpp
rename to src/gui/guipage.cpp
index fb82f7b..e232ccf 100644
--- a/src/gui/gpage.cpp
+++ b/src/gui/guipage.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,20 +15,22 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file gpage.cpp
+/// \file guipage.cpp
 ///
 
 #include "gdef.h"
 #include "gqt.h"
+#include "guipage.h"
+#include "guidialog.h"
 #include "gstr.h"
-#include "gpage.h"
-#include "gdialog.h"
 #include "gmapfile.h"
 #include "glog.h"
 
-int GPage::m_test_mode = 0 ;
+#include "moc_guipage.cpp"
 
-GPage::GPage( GDialog & dialog , const std::string & name , const std::string & next_1 ,
+int Gui::Page::m_test_mode = 0 ;
+
+Gui::Page::Page( Dialog & dialog , const std::string & name , const std::string & next_1 ,
 	const std::string & next_2 ) :
 		QWidget(&dialog) ,
 		m_dialog(dialog) ,
@@ -40,57 +42,57 @@ GPage::GPage( GDialog & dialog , const std::string & name , const std::string &
 	addHelpAction() ;
 }
 
-GDialog & GPage::dialog()
+Gui::Dialog & Gui::Page::dialog()
 {
 	return m_dialog ;
 }
 
-const GDialog & GPage::dialog() const
+const Gui::Dialog & Gui::Page::dialog() const
 {
 	return m_dialog ;
 }
 
-bool GPage::isReadyToFinishPage() const
+bool Gui::Page::isReadyToFinishPage() const
 {
 	return false ;
 }
 
-bool GPage::isFinishPage() const
+bool Gui::Page::isFinishPage() const
 {
 	return false ;
 }
 
-bool GPage::isComplete()
+bool Gui::Page::isComplete()
 {
 	return true ;
 }
 
-bool GPage::isFinishing()
+bool Gui::Page::isFinishing()
 {
 	return false ;
 }
 
-bool GPage::canLaunch()
+bool Gui::Page::canLaunch()
 {
 	return false ;
 }
 
-std::string GPage::name() const
+std::string Gui::Page::name() const
 {
 	return m_name ;
 }
 
-std::string GPage::next1() const
+std::string Gui::Page::next1() const
 {
 	return m_next_1 ;
 }
 
-std::string GPage::next2() const
+std::string Gui::Page::next2() const
 {
 	return m_next_2 ;
 }
 
-QLabel * GPage::newTitle( QString s )
+QLabel * Gui::Page::newTitle( QString s )
 {
 	QString open( "<center><font size=\"5\"><b>" ) ;
 	QString close( "</b></font></center>" ) ;
@@ -101,114 +103,114 @@ QLabel * GPage::newTitle( QString s )
 	return label ;
 }
 
-void GPage::dump( std::ostream & stream , bool ) const
+void Gui::Page::dump( std::ostream & stream , bool ) const
 {
-	G_DEBUG( "GPage::dump: page: " << name() ) ;
+	G_DEBUG( "Gui::Page::dump: page: " << name() ) ;
 	stream << "# page: " << name() << "\n" ;
 }
 
-void GPage::dumpItem( std::ostream & stream , bool for_install , const std::string & key , const G::Path & value ) const
+void Gui::Page::dumpItem( std::ostream & stream , bool for_install , const std::string & key , const G::Path & value ) const
 {
 	dumpItem( stream , for_install , key , value.str() ) ;
 }
 
-void GPage::dumpItem( std::ostream & stream , bool , const std::string & key , const std::string & value ) const
+void Gui::Page::dumpItem( std::ostream & stream , bool , const std::string & key , const std::string & value ) const
 {
 	G::MapFile::writeItem( stream , key , value ) ;
 }
 
-std::string GPage::value( bool b )
+std::string Gui::Page::value( bool b )
 {
 	return b ? "y" : "n" ;
 }
 
-std::string GPage::value( const QAbstractButton * p )
+std::string Gui::Page::value( const QAbstractButton * p )
 {
 	return p && p->isChecked() ? "y" : "n" ;
 }
 
-std::string GPage::stdstr( const QString & s )
+std::string Gui::Page::stdstr( const QString & s )
 {
 	// (config files and batch scripts are in the local 8bit code page)
 	return GQt::stdstr( s ) ;
 }
 
-std::string GPage::stdstr_utf8( const QString & s )
+std::string Gui::Page::stdstr_utf8( const QString & s )
 {
 	// (userids and passwords are in utf8 (RFC-4954) and then either xtext-ed or hashed)
-	return GQt::stdstr( s , GQt::Utf8() ) ;
+	return GQt::stdstr( s , GQt::Utf8 ) ;
 }
 
-QString GPage::qstr( const std::string & s )
+QString Gui::Page::qstr( const std::string & s )
 {
 	return GQt::qstr( s ) ;
 }
 
-std::string GPage::value_utf8( const QLineEdit * p )
+std::string Gui::Page::value_utf8( const QLineEdit * p )
 {
 	return stdstr_utf8( p->text().trimmed() ) ;
 }
 
-std::string GPage::value( const QLineEdit * p )
+std::string Gui::Page::value( const QLineEdit * p )
 {
 	return p ? stdstr( p->text().trimmed() ) : std::string() ;
 }
 
-std::string GPage::value( const QComboBox * p )
+std::string Gui::Page::value( const QComboBox * p )
 {
 	return p ? stdstr( p->currentText().trimmed() ) : std::string() ;
 }
 
-void GPage::setTestMode( int test_mode )
+void Gui::Page::setTestMode( int test_mode )
 {
 	m_test_mode = test_mode ;
 }
 
-bool GPage::testMode() const
+bool Gui::Page::testMode() const
 {
 	return m_test_mode != 0 ;
 }
 
-int GPage::testModeValue() const
+int Gui::Page::testModeValue() const
 {
 	return m_test_mode ;
 }
 
-void GPage::onShow( bool )
+void Gui::Page::onShow( bool )
 {
 	// no-op
 }
 
-void GPage::onLaunch()
+void Gui::Page::onLaunch()
 {
 	// no-op
 }
 
-void GPage::tip( QWidget * w , const QString & s )
+void Gui::Page::tip( QWidget * w , const QString & s )
 {
 	if( !s.isEmpty() )
 		w->setToolTip( s ) ; // see also QWidget::setWhatsThis()
 }
 
-void GPage::tip( QWidget * w , const char * s )
+void Gui::Page::tip( QWidget * w , const char * s )
 {
 	if( s && s[0] )
 		w->setToolTip( s ) ;
 }
 
-void GPage::tip( QWidget * w , NameTip )
+void Gui::Page::tip( QWidget * w , NameTip )
 {
 	//: used as a tool-tip for edit boxes containing an authentication username
 	w->setToolTip( tr("Username to be added to the secrets file") ) ;
 }
 
-void GPage::tip( QWidget * w , PasswordTip )
+void Gui::Page::tip( QWidget * w , PasswordTip )
 {
 	//: used as a tool-tip for edit boxes containing an authentication password
 	w->setToolTip( tr("Password to be added to the secrets file") ) ;
 }
 
-void GPage::addHelpAction()
+void Gui::Page::addHelpAction()
 {
 	auto action = new QAction( this ) ;
 	action->setShortcut( QKeySequence::HelpContents ) ;
@@ -216,14 +218,14 @@ void GPage::addHelpAction()
 	addAction( action ) ;
 }
 
-void GPage::helpKeyTriggered()
+void Gui::Page::helpKeyTriggered()
 {
 	std::string language = GQt::stdstr( QLocale().bcp47Name() ) ;
 	std::string url = helpUrl( language.empty() || language == "C" ? std::string("en") : G::Str::head(language,"-",false) ) ;
 	QDesktopServices::openUrl( QString(url.c_str()) ) ;
 }
 
-std::string GPage::helpUrl( const std::string & language ) const
+std::string Gui::Page::helpUrl( const std::string & language ) const
 {
 	return "http://emailrelay.sourceforge.net/help/" + G::Str::lower(m_name) + "#" + language ;
 }
diff --git a/src/gui/gpage.h b/src/gui/guipage.h
similarity index 90%
rename from src/gui/gpage.h
rename to src/gui/guipage.h
index dfa8ae5..fb030ef 100644
--- a/src/gui/gpage.h
+++ b/src/gui/guipage.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,39 +15,44 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // ===
 ///
-/// \file gpage.h
+/// \file guipage.h
 ///
 
-#ifndef G_MAIN_GUI_PAGE_H
-#define G_MAIN_GUI_PAGE_H
+#ifndef GUI_PAGE_H
+#define GUI_PAGE_H
 
 #include "gdef.h"
 #include "gqt.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gpath.h"
 #include "gexecutablecommand.h"
 #include <string>
 
-class GDialog ;
 class QAbstractButton ;
 class QLineEdit ;
 class QComboBox ;
 
-//| \class GPage
-/// A page widget that can be installed in a GDialog.
+namespace Gui
+{
+	class Page ;
+	class Dialog ;
+}
+
+//| \class Gui::Page
+/// A page widget that can be installed in a Gui::Dialog.
 ///
-class GPage : public QWidget
+class Gui::Page : public QWidget
 {Q_OBJECT
 protected:
-	GPage( GDialog & , const std::string & name ,
+	Page( Dialog & , const std::string & name ,
 		const std::string & next_1 , const std::string & next_2 ) ;
 			///< Constructor.
 
 public:
-	GDialog & dialog() ;
+	Dialog & dialog() ;
 		///< Returns the dialog passed in to the ctor.
 
-	const GDialog & dialog() const ;
+	const Dialog & dialog() const ;
 		///< Returns the dialog passed in to the ctor.
 
 	std::string name() const ;
@@ -137,7 +142,7 @@ private:
 	void addHelpAction() ;
 
 private:
-	GDialog & m_dialog ;
+	Dialog & m_dialog ;
 	std::string m_name ;
 	std::string m_next_1 ;
 	std::string m_next_2 ;
diff --git a/src/gui/installer.cpp b/src/gui/installer.cpp
index dd8af3b..fb02d32 100644
--- a/src/gui/installer.cpp
+++ b/src/gui/installer.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,6 +21,7 @@
 #include "gdef.h"
 #include "gcominit.h"
 #include "gstr.h"
+#include "gstringmap.h"
 #include "gpath.h"
 #include "gfile.h"
 #include "gdate.h"
@@ -28,16 +29,18 @@
 #include "gtime.h"
 #include "gdirectory.h"
 #include "gprocess.h"
-#include "glink.h"
+#include "guilink.h"
 #include "gbatchfile.h"
+#include "gxtext.h"
+#include "gbase64.h"
 #include "glog.h"
 #include "glogoutput.h"
 #include "gexception.h"
 #include "gexecutablecommand.h"
 #include "gnewprocess.h"
 #include "gmapfile.h"
-#include "boot.h"
-#include "access.h"
+#include "guiboot.h"
+#include "guiaccess.h"
 #include "serverconfiguration.h"
 #include "installer.h"
 #include <functional>
@@ -56,7 +59,7 @@
 using trstring = QString ;
 static std::string from_trstring( const trstring & qs )
 {
-	return GQt::stdstr( qs , GQt::Utf8() ) ;
+	return GQt::stdstr( qs , GQt::Utf8 ) ;
 }
 static bool empty( const trstring & s )
 {
@@ -136,10 +139,6 @@ struct TrError : std::runtime_error
 #undef CreateDirectory
 #endif
 
-#ifdef G_MAIN_GUI_DIR_H
-#error do not use dir.h from installer.cpp
-#endif
-
 struct ActionInterface
 {
 	virtual void run() = 0 ;
@@ -502,7 +501,7 @@ void CreateDirectory::run()
 		{
 			G::File::mkdirs( m_path , 10 ) ;
 		}
-		Access::modify( m_path , m_tight_permissions ) ;
+		Gui::Access::modify( m_path , m_tight_permissions ) ;
 		if( !directory.writeable() )
 			throw TrError( tr("directory exists but is not writable") ) ;
 	}
@@ -554,7 +553,7 @@ void CreatePointerFile::run()
 	if( !isWindows() )
 	{
 		G::File::chmodx( m_pointer_file ) ;
-		G::File::chmodx( m_gui_exe ) ; // hopefully redundant
+		G::File::chmodx( m_gui_exe , std::nothrow ) ; // hopefully redundant
 	}
 }
 
@@ -811,7 +810,7 @@ void CreateSecrets::run()
 		if( line_list.empty() )
 		{
 			line_list.push_back( "#" ) ;
-			line_list.push_back( std::string() + "# " + m_path.basename() ) ;
+			line_list.push_back( "# " + m_path.basename() ) ;
 			line_list.push_back( "#" ) ;
 			line_list.push_back( "# client plain <name(xtext)> <password(xtext)>" ) ;
 			line_list.push_back( "# client plain:b <name(base64)> <password(base64)>" ) ;
@@ -905,7 +904,7 @@ UpdateLink::UpdateLink( LinkType link_type , bool active , G::Path link_dir , G:
 		m_args(args) ,
 		m_icon(icon)
 {
-	std::string link_filename = G::Link::filename( "E-MailRelay" ) ;
+	std::string link_filename = Gui::Link::filename( "E-MailRelay" ) ;
 	m_link_path = G::Path( m_link_dir , link_filename ) ;
 }
 
@@ -928,8 +927,8 @@ void UpdateLink::run()
 	GDEF_UNUSED GComInit com_init ;
 	if( m_active )
 	{
-		G::Link link( m_target , "E-MailRelay" , "Starts the E-MailRelay server in the background" ,
-			m_working_dir , m_args , m_icon , G::Link::Show::Hide ,
+		Gui::Link link( m_target , "E-MailRelay" , "Starts the E-MailRelay server in the background" ,
+			m_working_dir , m_args , m_icon , Gui::Link::Show::Hide ,
 			"E-MailRelay" , "Generated by the E-MailRelay configuration GUI" ) ;
 
 		//G::Process::Umask umask( G::Process::Umask::Mode::Tightest ) ;
@@ -938,7 +937,7 @@ void UpdateLink::run()
 	}
 	else
 	{
-		m_ok = G::Link::remove( m_link_path ) ? tr("removed") : tr("nothing to do") ;
+		m_ok = Gui::Link::remove( m_link_path ) ? tr("removed") : tr("nothing to do") ;
 	}
 }
 
@@ -961,7 +960,7 @@ void InstallService::run()
 {
 	if( !m_active )
 	{
-		m_ok = tr("nothing to do") ; // see Boot::installable()
+		m_ok = tr("not possible") ; // see Gui::Boot::installable()
 	}
 	else if( m_bat.empty() || m_service_wrapper.empty() )
 	{
@@ -969,11 +968,11 @@ void InstallService::run()
 	}
 	else if( m_start_on_boot )
 	{
-		Boot::install( G::Path() , "emailrelay" , m_bat , m_service_wrapper ) ;
+		Gui::Boot::install( G::Path() , "emailrelay" , m_bat , m_service_wrapper ) ;
 	}
 	else
 	{
-		bool ok = Boot::uninstall( G::Path() , "emailrelay" , m_bat , m_service_wrapper ) ;
+		bool ok = Gui::Boot::uninstall( G::Path() , "emailrelay" , m_bat , m_service_wrapper ) ;
 		m_ok = ok ? tr("uninstalled") : tr("nothing to do") ;
 	}
 }
@@ -1019,7 +1018,7 @@ void UpdateBootLink::run()
 {
 	if( !m_active )
 	{
-		m_ok = tr("nothing to do") ; // see Boot::installable()
+		m_ok = tr("not possible") ; // see Gui::Boot::installable()
 	}
 	else if( m_dir_boot.empty() || m_startstop_src.empty() || m_exe.empty() )
 	{
@@ -1027,11 +1026,11 @@ void UpdateBootLink::run()
 	}
 	else if( m_start_on_boot )
 	{
-		Boot::install( m_dir_boot , m_name , m_startstop_src , m_exe ) ;
+		Gui::Boot::install( m_dir_boot , m_name , m_startstop_src , m_exe ) ;
 	}
 	else
 	{
-		bool removed = Boot::uninstall( m_dir_boot , m_name , m_startstop_src , m_exe ) ;
+		bool removed = Gui::Boot::uninstall( m_dir_boot , m_name , m_startstop_src , m_exe ) ;
 		m_ok = removed ? tr("removed") : tr("nothing to remove") ;
 	}
 }
@@ -1190,7 +1189,7 @@ G::Path GenerateKey::exe( bool is_windows )
 	return
 		this_exe.empty() ?
 			G::Path() :
-			G::Path(this_exe).dirname() + (is_windows?"emailrelay-test-keygen.exe":"emailrelay-test-keygen") ;
+			G::Path(this_exe).dirname() + (is_windows?"emailrelay_test_keygen.exe":"emailrelay_test_keygen") ;
 }
 
 void GenerateKey::run()
@@ -1250,7 +1249,7 @@ void Launcher::run()
 {
 	if( m_as_service )
 	{
-		Boot::launch( m_dir_boot , "emailrelay" ) ;
+		Gui::Boot::launch( m_dir_boot , "emailrelay" ) ;
 	}
 	else
 	{
@@ -1370,7 +1369,7 @@ InstallerImp::InstallerImp( bool installing , bool is_windows , bool is_mac , co
 	m_installer_config.add( "-exe" , isWindows() ? "%dir-install%/emailrelay.exe" :
 		( isMac() ? "%dir-install%/E-MailRelay.app/Contents/MacOS/emailrelay" : "%dir-install%/sbin/emailrelay" ) ) ;
 	m_installer_config.add( "-gui" , isWindows() ? "%dir-install%/emailrelay-gui.exe" : "%dir-install%/sbin/emailrelay-gui.real" ) ;
-	m_installer_config.add( "-icon" , isWindows()?"%dir-install%/emailrelay.exe":"%dir-install%/share/emailrelay/emailrelay-icon.png") ;
+	m_installer_config.add( "-icon" , isWindows()?"%dir-install%/emailrelay.exe":"%dir-install%/lib/emailrelay/emailrelay-icon.png");
 	m_installer_config.add( "-trdir" , isWindows()?"%dir-install%/translations":"%dir-install%/share/emailrelay") ;
 	m_installer_config.add( "-pointer" , isWindows() ? "%dir-install%/emailrelay-gui.cfg" : "%dir-install%/sbin/emailrelay-gui" ) ;
 	m_installer_config.add( "-startstop" , isWindows() ? "" : "%dir-install%/lib/emailrelay/emailrelay-startstop.sh" ) ;
@@ -1504,9 +1503,9 @@ void InstallerImp::addActions()
 	{
 		G::Path spool_dir( pvalue("dir-spool") ) ;
 		std::vector<std::string> names ;
-		names.push_back( pvalue("pop-account-1-name") ) ;
-		names.push_back( pvalue("pop-account-2-name") ) ;
-		names.push_back( pvalue("pop-account-3-name") ) ;
+		names.push_back( G::Xtext::encode( G::Base64::decode(pvalue("pop-account-1-name")) ) ) ;
+		names.push_back( G::Xtext::encode( G::Base64::decode(pvalue("pop-account-2-name")) ) ) ;
+		names.push_back( G::Xtext::encode( G::Base64::decode(pvalue("pop-account-3-name")) ) ) ;
 		for( const auto & name : names )
 		{
 			if( name.empty() ) continue ;
@@ -1555,6 +1554,8 @@ void InstallerImp::addActions()
 
 	// create secrets
 	//
+	// (this would be better using a separate file for the pop secrets)
+	//
 	G::Path authtemplate_src = m_installing ? ivalue( "-authtemplate" ) : std::string() ;
 	addAction( new CreateSecrets(pvalue("dir-config"),"emailrelay.auth",authtemplate_src,m_pages_output) ) ;
 
@@ -1607,29 +1608,35 @@ void InstallerImp::addActions()
 		}
 	}
 
-	// create a startup batch file
+	// update the configuration
 	//
 	if( isWindows() )
 	{
-		G::Path exe = ivalue("-exe") ;
-		G::Path bat = ivalue("-bat") ;
+		G::Path exe = ivalue( "-exe" ) ;
+		G::Path bat = ivalue( "-bat" ) ;
+		G::Path dir_install = pvalue( "dir-install" ) ;
+		G::Path working_dir = pvalue( "dir-config" ) ;
+		G::Path target = bat ;
+		G::Path icon = ivalue( "-icon" ) ;
 		G::StringArray args = ServerConfiguration::fromPages(m_pages_output).args() ;
 		addAction( new CreateBatchFile(bat,exe,args) ) ;
+		addAction( new UpdateLink(UpdateLink::LinkType::BatchFile,true,dir_install,working_dir,target,args,icon) ) ;
+	}
+	else
+	{
+		G::Path dir_config = pvalue( "dir-config" ) ;
+		G::Path conftemplate_src = m_installing ? ivalue( "-conftemplate" ) : std::string() ;
+		G::MapFile server_config = ServerConfiguration::fromPages(m_pages_output).map() ;
+		addAction( new CreateConfigFile(dir_config,"emailrelay.conf",conftemplate_src) ) ;
+		addAction( new EditConfigFile(dir_config,"emailrelay.conf",server_config,!m_installing) ) ;
 	}
 
-	// create startup links and startup config
+	// create startup links
 	//
+	if( yes(pvalue("start-page")) ) // if the startup page was presented at all -- see guimain.cpp
 	{
-		G::Path server_exe = ivalue("-exe") ;
-		G::Path working_dir = pvalue("dir-config") ;
-		G::Path dir_config = pvalue( "dir-config" ) ;
-		G::Path dir_install = pvalue( "dir-install" ) ;
-
-		bool do_desktop = yes(pvalue("start-link-desktop")) && !yes(pvalue("start-is-mac")) ;
-		bool do_menu = yes(pvalue("start-link-menu")) && !yes(pvalue("start-is-mac")) ;
-		bool do_login = yes(pvalue("start-at-login")) ;
-		bool do_boot = yes(pvalue("start-on-boot")) ;
-		bool do_boot_enabled = yes(pvalue("start-on-boot-enabled")) ; // see Boot::installable()
+		G::Path server_exe = ivalue( "-exe" ) ;
+		G::Path working_dir = pvalue( "dir-config" ) ;
 
 		G::Path dir_desktop = pvalue( "dir-desktop" ) ;
 		G::Path dir_menu = pvalue( "dir-menu" ) ;
@@ -1641,24 +1648,24 @@ void InstallerImp::addActions()
 		G::StringArray args = isWindows() ? G::StringArray() : ServerConfiguration::fromPages(m_pages_output).args() ;
 		G::Path icon = ivalue( "-icon" ) ;
 
-		addAction( new UpdateLink(UpdateLink::LinkType::Desktop,do_desktop,dir_desktop,working_dir,target,args,icon) ) ;
-		addAction( new UpdateLink(UpdateLink::LinkType::StartMenu,do_menu,dir_menu,working_dir,target,args,icon) ) ;
-		addAction( new UpdateLink(UpdateLink::LinkType::AutoStart,do_login,dir_login,working_dir,target,args,icon) ) ;
+		bool desktop_state = yes(pvalue("start-link-desktop")) && !yes(pvalue("start-is-mac")) ;
+		bool menu_state = yes(pvalue("start-link-menu")) && !yes(pvalue("start-is-mac")) ;
+		bool login_state = yes(pvalue("start-at-login")) ;
+		bool do_boot_update = yes(pvalue("start-on-boot-enabled")) ; // see Gui::Boot::installable()
+		bool boot_state = yes(pvalue("start-on-boot")) ;
+
+		addAction( new UpdateLink(UpdateLink::LinkType::Desktop,desktop_state,dir_desktop,working_dir,target,args,icon) ) ;
+		addAction( new UpdateLink(UpdateLink::LinkType::StartMenu,menu_state,dir_menu,working_dir,target,args,icon) ) ;
+		addAction( new UpdateLink(UpdateLink::LinkType::AutoStart,login_state,dir_login,working_dir,target,args,icon) ) ;
 
 		if( isWindows() )
 		{
-			addAction( new UpdateLink(UpdateLink::LinkType::BatchFile,true,dir_install,working_dir,target,args,icon) ) ;
 			G::Path service_wrapper = ivalue( "-servicewrapper" ) ;
-			addAction( new InstallService(do_boot_enabled,do_boot,bat,service_wrapper) ) ;
+			addAction( new InstallService(do_boot_update,boot_state,bat,service_wrapper) ) ;
 		}
 		else
 		{
-			// install the startstop script and its config file
-			G::Path conftemplate_src = m_installing ? ivalue( "-conftemplate" ) : std::string() ;
-			G::MapFile server_config = ServerConfiguration::fromPages(m_pages_output).map() ;
-			addAction( new UpdateBootLink(do_boot_enabled,do_boot,dir_boot,"emailrelay",ivalue("-startstop"),server_exe) ) ;
-			addAction( new CreateConfigFile(dir_config,"emailrelay.conf",conftemplate_src) ) ;
-			addAction( new EditConfigFile(dir_config,"emailrelay.conf",server_config,!m_installing) ) ;
+			addAction( new UpdateBootLink(do_boot_update,boot_state,dir_boot,"emailrelay",ivalue("-startstop"),server_exe) ) ;
 		}
 	}
 
diff --git a/src/gui/installer.h b/src/gui/installer.h
index 2f63e70..d1f59d8 100644
--- a/src/gui/installer.h
+++ b/src/gui/installer.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -109,8 +109,8 @@ public:
 public:
 	Installer( const Installer & ) = delete ;
 	Installer( Installer && ) = delete ;
-	void operator=( const Installer & ) = delete ;
-	void operator=( Installer && ) = delete ;
+	Installer & operator=( const Installer & ) = delete ;
+	Installer & operator=( Installer && ) = delete ;
 
 private:
 	bool doneImp() ;
diff --git a/src/gui/pages.cpp b/src/gui/pages.cpp
index 4033297..336483b 100644
--- a/src/gui/pages.cpp
+++ b/src/gui/pages.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,9 +21,10 @@
 #include "gdef.h"
 #include "gqt.h"
 #include "pages.h"
-#include "legal.h"
-#include "dir.h"
-#include "boot.h"
+#include "guilegal.h"
+#include "guidialog.h"
+#include "guidir.h"
+#include "guiboot.h"
 #include "gmapfile.h"
 #include "gstr.h"
 #include "gfile.h"
@@ -34,31 +35,26 @@
 #include "gbase64.h"
 #include "gxtext.h"
 #include "gstringview.h"
+#include "genvironment.h"
 #include "glog.h"
 #include <stdexcept>
 #include <fstream>
 #include <cstring>
 
-namespace
-{
-	std::string encode( const std::string & s )
-	{
-		return G::Base64::encode( s ) ;
-	}
-}
+#include "moc_pages.cpp"
 
 // ==
 
-TitlePage::TitlePage( GDialog & dialog , const G::MapFile & , const std::string & name ,
+TitlePage::TitlePage( Gui::Dialog & dialog , const G::MapFile & , const std::string & name ,
 	const std::string & next_1 , const std::string & next_2 ) :
-		GPage(dialog,name,next_1,next_2)
+		Gui::Page(dialog,name,next_1,next_2)
 {
-	m_label = new QLabel( QString(Legal::text()) ) ;
+	m_label = new QLabel( QString(Gui::Legal::text()) ) ;
 	m_label->setAlignment( Qt::AlignHCenter ) ;
 
 	{
 		std::string credit = "<small><font color=\"#888\">" ;
-		credit.append( G::Str::join( "\n\n" , Legal::credits() ) ) ;
+		credit.append( G::Str::join( "\n\n" , Gui::Legal::credits() ) ) ;
 		credit.append( "</font></small>" ) ;
 		m_credit = new QLabel( QString(credit.c_str()) ) ;
 		m_credit->setAlignment( Qt::AlignHCenter ) ;
@@ -81,21 +77,21 @@ std::string TitlePage::nextPage()
 
 void TitlePage::dump( std::ostream & stream , bool for_install ) const
 {
-	GPage::dump( stream , for_install ) ;
+	Gui::Page::dump( stream , for_install ) ;
 }
 
 // ==
 
-LicensePage::LicensePage( GDialog & dialog , const G::MapFile & , const std::string & name ,
+LicensePage::LicensePage( Gui::Dialog & dialog , const G::MapFile & , const std::string & name ,
 	const std::string & next_1 , const std::string & next_2 , bool accepted ) :
-		GPage(dialog,name,next_1,next_2)
+		Gui::Page(dialog,name,next_1,next_2)
 {
 	m_text_edit = new QTextEdit ;
 	m_text_edit->setReadOnly( true ) ;
 	m_text_edit->setWordWrapMode( QTextOption::NoWrap ) ;
 	m_text_edit->setLineWrapMode( QTextEdit::NoWrap ) ;
 	m_text_edit->setFontFamily( "courier" ) ;
-	m_text_edit->setPlainText( QString(Legal::license()) ) ;
+	m_text_edit->setPlainText( QString(Gui::Legal::license()) ) ;
 
 	m_agree_checkbox = new QCheckBox( tr("I agree to the terms and conditions of the license") );
 	setFocusProxy( m_agree_checkbox ) ;
@@ -120,7 +116,7 @@ std::string LicensePage::nextPage()
 
 void LicensePage::dump( std::ostream & stream , bool for_install ) const
 {
-	GPage::dump( stream , for_install ) ;
+	Gui::Page::dump( stream , for_install ) ;
 }
 
 bool LicensePage::isComplete()
@@ -135,10 +131,10 @@ std::string LicensePage::helpUrl( const std::string & language ) const
 
 // ==
 
-DirectoryPage::DirectoryPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+DirectoryPage::DirectoryPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 	const std::string & next_1 , const std::string & next_2 ,
-	bool installing , bool is_mac ) :
-		GPage(dialog,name,next_1,next_2) ,
+	bool installing , bool /*is_windows*/ , bool is_mac ) :
+		Gui::Page(dialog,name,next_1,next_2) ,
 		m_installing(installing) ,
 		m_is_mac(is_mac) ,
 		m_other_dir_changed(false)
@@ -358,23 +354,23 @@ G::Path DirectoryPage::normalise( const G::Path & dir ) const
 	// leave them as relative to the bundle contents on mac
 
 	G::Path result = dir ;
-	if( dir.isRelative() && !Dir::home().empty() )
+	if( dir.isRelative() && !Gui::Dir::home().empty() )
 	{
 		if( dir.str() == "~" || dir.str() == "~/" || dir.str() == "$HOME" || dir.str() == "$HOME/" )
 		{
-			result = Dir::home() ;
+			result = Gui::Dir::home() ;
 		}
 		else if( dir.str().find("~/") == 0U )
 		{
-			result = G::Path( Dir::home() , dir.str().substr(2U) ) ;
+			result = G::Path( Gui::Dir::home() , dir.str().substr(2U) ) ;
 		}
 		else if( dir.str().find("$HOME/") == 0U )
 		{
-			result = G::Path( Dir::home() , dir.str().substr(6U) ) ;
+			result = G::Path( Gui::Dir::home() , dir.str().substr(6U) ) ;
 		}
 		else if( !m_is_mac )
 		{
-			result = G::Path::join( Dir::home() , dir ) ;
+			result = G::Path::join( Gui::Dir::home() , dir ) ;
 		}
 	}
 	return result ;
@@ -382,16 +378,16 @@ G::Path DirectoryPage::normalise( const G::Path & dir ) const
 
 void DirectoryPage::dump( std::ostream & stream , bool for_install ) const
 {
-	GPage::dump( stream , for_install ) ;
+	Gui::Page::dump( stream , for_install ) ;
 	dumpItem( stream , for_install , "dir-install" , installDir() ) ;
 	dumpItem( stream , for_install , "dir-spool" , spoolDir() ) ;
 	dumpItem( stream , for_install , "dir-config" , configDir() ) ;
 	dumpItem( stream , for_install , "dir-run" , runtimeDir() ) ;
 
-	dumpItem( stream , for_install , "dir-boot" , Dir::boot() ) ;
-	dumpItem( stream , for_install , "dir-desktop" , Dir::desktop() ) ;
-	dumpItem( stream , for_install , "dir-menu" , Dir::menu() ) ;
-	dumpItem( stream , for_install , "dir-login" , Dir::autostart() ) ;
+	dumpItem( stream , for_install , "dir-boot" , Gui::Dir::boot() ) ;
+	dumpItem( stream , for_install , "dir-desktop" , Gui::Dir::desktop() ) ;
+	dumpItem( stream , for_install , "dir-menu" , Gui::Dir::menu() ) ;
+	dumpItem( stream , for_install , "dir-login" , Gui::Dir::autostart() ) ;
 }
 
 bool DirectoryPage::isComplete()
@@ -424,9 +420,9 @@ G::Path DirectoryPage::configDir() const
 
 // ==
 
-DoWhatPage::DoWhatPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+DoWhatPage::DoWhatPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 	const std::string & next_1 , const std::string & next_2 ) :
-		GPage(dialog,name,next_1,next_2)
+		Gui::Page(dialog,name,next_1,next_2)
 {
 	m_pop_checkbox = new QCheckBox( tr("POP3 server") ) ;
 	m_smtp_checkbox = new QCheckBox( tr("SMTP server") ) ;
@@ -536,7 +532,7 @@ bool DoWhatPage::pop() const
 
 void DoWhatPage::dump( std::ostream & stream , bool for_install ) const
 {
-	GPage::dump( stream , for_install ) ;
+	Gui::Page::dump( stream , for_install ) ;
 	dumpItem( stream , for_install , "do-pop" , value(m_pop_checkbox) ) ;
 	dumpItem( stream , for_install , "do-smtp" , value(m_smtp_checkbox) ) ;
 	dumpItem( stream , for_install , "forward-immediate" , value(m_immediate_checkbox) ) ;
@@ -554,10 +550,10 @@ bool DoWhatPage::isComplete()
 
 // ==
 
-PopPage::PopPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+PopPage::PopPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 	const std::string & next_1 , const std::string & next_2 ,
 	bool have_accounts ) :
-		GPage(dialog,name,next_1,next_2) ,
+		Gui::Page(dialog,name,next_1,next_2) ,
 		m_have_accounts(have_accounts)
 {
 	//: internet address, port number
@@ -698,7 +694,7 @@ std::string PopPage::nextPage()
 
 void PopPage::dump( std::ostream & stream , bool for_install ) const
 {
-	GPage::dump( stream , for_install ) ;
+	Gui::Page::dump( stream , for_install ) ;
 	dumpItem( stream , for_install , "pop-port" , value(m_port_edit_box) ) ;
 	dumpItem( stream , for_install , "pop-simple" , value(m_one) ) ;
 	dumpItem( stream , for_install , "pop-shared" , value(m_shared) ) ;
@@ -708,12 +704,12 @@ void PopPage::dump( std::ostream & stream , bool for_install ) const
 	dumpItem( stream , for_install , "pop-auth-mechanism" , std::string("plain:b") ) ;
 	if( for_install )
 	{
-		dumpItem( stream , for_install , "pop-account-1-name" , encode(value_utf8(m_name_1)) ) ;
-		dumpItem( stream , for_install , "pop-account-1-password" , encode(value_utf8(m_pwd_1)) ) ;
-		dumpItem( stream , for_install , "pop-account-2-name" , encode(value_utf8(m_name_2)) ) ;
-		dumpItem( stream , for_install , "pop-account-2-password" , encode(value_utf8(m_pwd_2)) ) ;
-		dumpItem( stream , for_install , "pop-account-3-name" , encode(value_utf8(m_name_3)) ) ;
-		dumpItem( stream , for_install , "pop-account-3-password" , encode(value_utf8(m_pwd_3)) ) ;
+		dumpItem( stream , for_install , "pop-account-1-name" , G::Base64::encode(value_utf8(m_name_1)) ) ;
+		dumpItem( stream , for_install , "pop-account-1-password" , G::Base64::encode(value_utf8(m_pwd_1)) ) ;
+		dumpItem( stream , for_install , "pop-account-2-name" , G::Base64::encode(value_utf8(m_name_2)) ) ;
+		dumpItem( stream , for_install , "pop-account-2-password" , G::Base64::encode(value_utf8(m_pwd_2)) ) ;
+		dumpItem( stream , for_install , "pop-account-3-name" , G::Base64::encode(value_utf8(m_name_3)) ) ;
+		dumpItem( stream , for_install , "pop-account-3-password" , G::Base64::encode(value_utf8(m_pwd_3)) ) ;
 	}
 }
 
@@ -740,10 +736,10 @@ bool PopPage::withFilterCopy() const
 
 // ==
 
-SmtpServerPage::SmtpServerPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+SmtpServerPage::SmtpServerPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 	const std::string & next_1 , const std::string & next_2 ,
 	bool have_account , bool can_generate ) :
-		GPage(dialog,name,next_1,next_2) ,
+		Gui::Page(dialog,name,next_1,next_2) ,
 		m_have_account(have_account) ,
 		m_can_generate(can_generate)
 {
@@ -921,14 +917,14 @@ std::string SmtpServerPage::nextPage()
 
 void SmtpServerPage::dump( std::ostream & stream , bool for_install ) const
 {
-	GPage::dump( stream , for_install ) ;
+	Gui::Page::dump( stream , for_install ) ;
 	dumpItem( stream , for_install , "smtp-server-port" , value(m_port_edit_box) ) ;
 	dumpItem( stream , for_install , "smtp-server-auth" , value(m_auth_checkbox) ) ;
 	dumpItem( stream , for_install , "smtp-server-auth-mechanism" , std::string("plain:b") ) ;
 	if( for_install )
 	{
-		dumpItem( stream , for_install , "smtp-server-account-name" , encode(value_utf8(m_account_name)) ) ;
-		dumpItem( stream , for_install , "smtp-server-account-password" , encode(value_utf8(m_account_pwd)) ) ;
+		dumpItem( stream , for_install , "smtp-server-account-name" , G::Base64::encode(value_utf8(m_account_name)) ) ;
+		dumpItem( stream , for_install , "smtp-server-account-password" , G::Base64::encode(value_utf8(m_account_pwd)) ) ;
 	}
 	dumpItem( stream , for_install , "smtp-server-trust" , value(m_trust_address) ) ;
 	dumpItem( stream , for_install , "smtp-server-tls" , value(m_tls_checkbox->isChecked() && m_tls_starttls->isChecked()) ) ;
@@ -967,10 +963,10 @@ bool SmtpServerPage::isComplete()
 
 // ==
 
-FilterPage::FilterPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+FilterPage::FilterPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 	const std::string & next_1 , const std::string & next_2 ,
 	bool installing , bool is_windows ) :
-		GPage(dialog,name,next_1,next_2) ,
+		Gui::Page(dialog,name,next_1,next_2) ,
 		m_installing(installing) ,
 		m_is_windows(is_windows) ,
 		m_dot_exe(is_windows?".exe":"") ,
@@ -1204,16 +1200,16 @@ void FilterPage::onToggle()
 
 void FilterPage::dump( std::ostream & stream , bool for_install ) const
 {
-	GPage::dump( stream , for_install ) ;
+	Gui::Page::dump( stream , for_install ) ;
 	dumpItem( stream , for_install , "filter-server" , value(m_server_filter_edit_box) ) ;
 	dumpItem( stream , for_install , "filter-client" , value(m_client_filter_edit_box) ) ;
 }
 
 // ==
 
-SmtpClientPage::SmtpClientPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+SmtpClientPage::SmtpClientPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 	const std::string & next_1 , const std::string & next_2 , bool have_account ) :
-		GPage(dialog,name,next_1,next_2) ,
+		Gui::Page(dialog,name,next_1,next_2) ,
 		m_have_account(have_account)
 {
 	//: internet address, hostname of remote smtp server
@@ -1351,7 +1347,7 @@ std::string SmtpClientPage::nextPage()
 
 void SmtpClientPage::dump( std::ostream & stream , bool for_install ) const
 {
-	GPage::dump( stream , for_install ) ;
+	Gui::Page::dump( stream , for_install ) ;
 	dumpItem( stream , for_install , "smtp-client-host" , value(m_server_edit_box) ) ;
 	dumpItem( stream , for_install , "smtp-client-port" , value(m_port_edit_box) ) ;
 	dumpItem( stream , for_install , "smtp-client-tls" , value(m_tls_checkbox->isChecked()&&!m_tls_tunnel->isChecked()) ) ;
@@ -1360,8 +1356,8 @@ void SmtpClientPage::dump( std::ostream & stream , bool for_install ) const
 	dumpItem( stream , for_install , "smtp-client-auth-mechanism" , std::string("plain:b") ) ;
 	if( for_install )
 	{
-		dumpItem( stream , for_install , "smtp-client-account-name" , encode(value_utf8(m_account_name)) ) ;
-		dumpItem( stream , for_install , "smtp-client-account-password" , encode(value_utf8(m_account_pwd)) ) ;
+		dumpItem( stream , for_install , "smtp-client-account-name" , G::Base64::encode(value_utf8(m_account_name)) ) ;
+		dumpItem( stream , for_install , "smtp-client-account-password" , G::Base64::encode(value_utf8(m_account_pwd)) ) ;
 	}
 }
 
@@ -1378,9 +1374,9 @@ bool SmtpClientPage::isComplete()
 
 // ==
 
-LoggingPage::LoggingPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+LoggingPage::LoggingPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 	const std::string & next_1 , const std::string & next_2 ) :
-		GPage(dialog,name,next_1,next_2)
+		Gui::Page(dialog,name,next_1,next_2)
 {
 	m_config_log_file = config.value( "log-file" ) ;
 
@@ -1523,7 +1519,7 @@ void LoggingPage::onToggle()
 
 void LoggingPage::dump( std::ostream & stream , bool for_install ) const
 {
-	GPage::dump( stream , for_install ) ;
+	Gui::Page::dump( stream , for_install ) ;
 	dumpItem( stream , for_install , "logging-verbose" , value(m_log_level_verbose_checkbox) ) ;
 	dumpItem( stream , for_install , "logging-debug" , value(m_log_level_debug_checkbox) ) ;
 	dumpItem( stream , for_install , "logging-syslog" , value(m_log_output_syslog_checkbox) ) ;
@@ -1534,9 +1530,10 @@ void LoggingPage::dump( std::ostream & stream , bool for_install ) const
 
 // ==
 
-ListeningPage::ListeningPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
-	const std::string & next_1 , const std::string & next_2 ) :
-		GPage(dialog,name,next_1,next_2)
+ListeningPage::ListeningPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
+	const std::string & next_1 , const std::string & next_2 , bool next_is_next2 ) :
+		Gui::Page(dialog,name,next_1,next_2) ,
+		m_next_is_next2(next_is_next2)
 {
 	//: server listening-address options...
 	m_all_checkbox = new QRadioButton( tr("Any address") ) ;
@@ -1637,7 +1634,7 @@ ListeningPage::ListeningPage( GDialog & dialog , const G::MapFile & config , con
 
 std::string ListeningPage::nextPage()
 {
-	return next1() ;
+	return m_next_is_next2 ? next2() : next1() ;
 }
 
 void ListeningPage::onTextChanged()
@@ -1680,16 +1677,16 @@ std::string ListeningPage::normalise( const std::string & s )
 
 void ListeningPage::dump( std::ostream & stream , bool for_install ) const
 {
-	GPage::dump( stream , for_install ) ;
+	Gui::Page::dump( stream , for_install ) ;
 	dumpItem( stream , for_install , "listening-interface" , normalise(value(m_listening_interface)) ) ;
 	dumpItem( stream , for_install , "listening-remote" , value(m_remote_checkbox) ) ;
 }
 
 // ==
 
-StartupPage::StartupPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+StartupPage::StartupPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 	const std::string & next_1 , const std::string & next_2 , bool is_mac ) :
-		GPage(dialog,name,next_1,next_2) ,
+		Gui::Page(dialog,name,next_1,next_2) ,
 		m_is_mac(is_mac)
 {
 	m_on_boot_checkbox = new QCheckBox( tr("At system startup") ) ;
@@ -1710,10 +1707,10 @@ StartupPage::StartupPage( GDialog & dialog , const G::MapFile & config , const s
 		m_add_menu_item_checkbox->setEnabled( false ) ;
 		m_add_desktop_item_checkbox->setEnabled( false ) ;
 	}
-	m_at_login_checkbox->setEnabled( !Dir::autostart().str().empty() ) ;
+	m_at_login_checkbox->setEnabled( !Gui::Dir::autostart().str().empty() ) ;
 	m_on_boot_checkbox->setEnabled( config.booleanValue("=dir-boot-enabled",false) ) ;
 
-	m_at_login_checkbox->setChecked( !Dir::autostart().str().empty() && config.booleanValue("start-at-login",false) ) ;
+	m_at_login_checkbox->setChecked( !Gui::Dir::autostart().str().empty() && config.booleanValue("start-at-login",false) ) ;
 	m_add_menu_item_checkbox->setChecked( !m_is_mac && config.booleanValue("start-link-menu",true) ) ;
 	m_add_desktop_item_checkbox->setChecked( !m_is_mac && config.booleanValue("start-link-desktop",false) ) ;
 	m_on_boot_checkbox->setChecked( config.booleanValue("start-on-boot",false) ) ;
@@ -1748,7 +1745,8 @@ std::string StartupPage::nextPage()
 
 void StartupPage::dump( std::ostream & stream , bool for_install ) const
 {
-	GPage::dump( stream , for_install ) ;
+	Gui::Page::dump( stream , for_install ) ;
+	dumpItem( stream , for_install , "start-page" , std::string("y") ) ; // since not necessarily used at all -- see guimain.cpp
 	dumpItem( stream , for_install , "start-on-boot-enabled" , std::string(m_on_boot_checkbox->isEnabled()?"y":"n") ) ;
 	dumpItem( stream , for_install , "start-on-boot" , value(m_on_boot_checkbox) ) ;
 	dumpItem( stream , for_install , "start-at-login" , value(m_at_login_checkbox) ) ;
@@ -1762,9 +1760,9 @@ void StartupPage::dump( std::ostream & stream , bool for_install ) const
 
 // ==
 
-ReadyPage::ReadyPage( GDialog & dialog , const G::MapFile & , const std::string & name , const std::string & next_1 ,
+ReadyPage::ReadyPage( Gui::Dialog & dialog , const G::MapFile & , const std::string & name , const std::string & next_1 ,
 	const std::string & next_2 , bool installing ) :
-		GPage(dialog,name,next_1,next_2) ,
+		Gui::Page(dialog,name,next_1,next_2) ,
 		m_installing(installing)
 {
 	m_label = new QLabel( text() ) ;
@@ -1802,7 +1800,7 @@ bool ReadyPage::isReadyToFinishPage() const
 
 void ReadyPage::dump( std::ostream & s , bool for_install ) const
 {
-	GPage::dump( s , for_install ) ;
+	Gui::Page::dump( s , for_install ) ;
 }
 
 // ==
@@ -1833,10 +1831,10 @@ void LogWatchThread::run()
 	}
 }
 
-ProgressPage::ProgressPage( GDialog & dialog , const G::MapFile & , const std::string & name ,
+ProgressPage::ProgressPage( Gui::Dialog & dialog , const G::MapFile & , const std::string & name ,
 	const std::string & next_1 , const std::string & next_2 ,
-	Installer & installer ) :
-		GPage(dialog,name,next_1,next_2) ,
+	Installer & installer , bool installing ) :
+		Gui::Page(dialog,name,next_1,next_2) ,
 		m_text_pos(0) ,
 		m_installer(installer) ,
 		m_state(0)
@@ -1848,8 +1846,8 @@ ProgressPage::ProgressPage( GDialog & dialog , const G::MapFile & , const std::s
 	//m_text_edit->setFontFamily( "courier" ) ;
 
 	auto * layout = new QVBoxLayout ;
-	//: page title of installation progress page
-	layout->addWidget( newTitle(tr("Installing")) ) ;
+	//: page title of installation-or-reconfiguration progress page
+	layout->addWidget( newTitle(installing?tr("Installing"):tr("Configuring")) ) ;
 	layout->addWidget(m_text_edit) ;
 	setLayout( layout ) ;
 }
@@ -1937,7 +1935,7 @@ void ProgressPage::onInstallTimeout()
 			if( m_installer.failed() )
 			{
 				if( m_state == 2 )
-					addLine( GQt::qstr(m_installer.failedText(),GQt::Utf8()) ) ;
+					addLine( GQt::qstr(m_installer.failedText(),GQt::Utf8) ) ;
 				else
 					m_installer.back() ;
 				m_state += 1 ;
@@ -1945,13 +1943,13 @@ void ProgressPage::onInstallTimeout()
 			else
 			{
 				if( m_state == 2 )
-					addLine( GQt::qstr(m_installer.finishedText(),GQt::Utf8()) ) ;
+					addLine( GQt::qstr(m_installer.finishedText(),GQt::Utf8) ) ;
 				m_state += 2 ;
 				if( m_logwatch_thread )
 					m_logwatch_thread->start() ;
 			}
 		}
-		emit pageUpdateSignal() ; // NOLINT
+		emit pageUpdateSignal() ;
 	}
 	catch( std::exception & e )
 	{
@@ -1978,10 +1976,10 @@ void ProgressPage::addOutput( const Installer::Output & output )
 
 QString ProgressPage::format( const Installer::Output & output )
 {
-	QString action_tr = GQt::qstr( output.action_utf8 , GQt::Utf8() ) ;
+	QString action_tr = GQt::qstr( output.action_utf8 , GQt::Utf8 ) ;
 	QString subject_native = GQt::qstr( output.subject ) ;
-	QString result_tr = GQt::qstr( output.result_utf8 , GQt::Utf8() ) ;
-	QString error_tr = GQt::qstr( output.error_utf8 , GQt::Utf8() ) ;
+	QString result_tr = GQt::qstr( output.result_utf8 , GQt::Utf8 ) ;
+	QString error_tr = GQt::qstr( output.error_utf8 , GQt::Utf8 ) ;
 	QString error_native = GQt::qstr( output.error ) ;
 
 	// use the translation mechanism to format the line because
@@ -2060,7 +2058,7 @@ std::string ProgressPage::nextPage()
 
 void ProgressPage::dump( std::ostream & s , bool for_install ) const
 {
-	GPage::dump( s , for_install ) ;
+	Gui::Page::dump( s , for_install ) ;
 }
 
 bool ProgressPage::isFinishPage() const
diff --git a/src/gui/pages.h b/src/gui/pages.h
index bd0a0fa..bf3c104 100644
--- a/src/gui/pages.h
+++ b/src/gui/pages.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,13 +22,13 @@
 #define G_MAIN_GUI_PAGES_H
 
 #include "gdef.h"
+#include "gqt.h"
+#include "guidialog.h"
+#include "guipage.h"
+#include "installer.h"
 #include "gmapfile.h"
 #include "gpath.h"
-#include "gstrings.h"
-#include "gqt.h"
-#include "gdialog.h"
-#include "gpage.h"
-#include "installer.h"
+#include "gstringarray.h"
 #include <fstream>
 
 class QCheckBox;
@@ -45,10 +45,10 @@ class FinishPage;
 class RegisterPage;
 class TitlePage;
 
-class TitlePage : public GPage
+class TitlePage : public Gui::Page
 {Q_OBJECT
 public:
-	TitlePage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+	TitlePage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 		const std::string & next_1 , const std::string & next_2 ) ;
 
 	std::string nextPage() override ;
@@ -59,10 +59,10 @@ private:
 	QLabel * m_credit ;
 };
 
-class LicensePage : public GPage
+class LicensePage : public Gui::Page
 {Q_OBJECT
 public:
-	LicensePage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+	LicensePage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 		const std::string & next_1 , const std::string & next_2 , bool accepted ) ;
 
 	std::string nextPage() override ;
@@ -75,12 +75,12 @@ private:
 	QCheckBox * m_agree_checkbox ;
 };
 
-class DirectoryPage : public GPage
+class DirectoryPage : public Gui::Page
 {Q_OBJECT
 public:
-	DirectoryPage( GDialog & dialog , const G::MapFile & , const std::string & name ,
+	DirectoryPage( Gui::Dialog & dialog , const G::MapFile & , const std::string & name ,
 		const std::string & next_1 , const std::string & next_2 ,
-		bool installing , bool is_mac ) ;
+		bool installing , bool is_windows , bool is_mac ) ;
 
 	G::Path installDir() const ;
 	G::Path spoolDir() const ;
@@ -125,10 +125,10 @@ private:
 	bool m_other_dir_changed ;
 } ;
 
-class DoWhatPage : public GPage
+class DoWhatPage : public Gui::Page
 {Q_OBJECT
 public:
-	DoWhatPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+	DoWhatPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 		const std::string & next_1 , const std::string & next_2 ) ;
 
 	std::string nextPage() override ;
@@ -150,10 +150,10 @@ private slots:
 	void onToggle() ;
 } ;
 
-class PopPage : public GPage
+class PopPage : public Gui::Page
 {Q_OBJECT
 public:
-	explicit PopPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+	explicit PopPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 		const std::string & next_1 , const std::string & next_2 ,
 		bool have_accounts ) ;
 	bool withFilterCopy() const ;
@@ -181,10 +181,10 @@ private:
 	QLineEdit * m_pwd_3 ;
 } ;
 
-class SmtpServerPage : public GPage
+class SmtpServerPage : public Gui::Page
 {Q_OBJECT
 public:
-	SmtpServerPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+	SmtpServerPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 		const std::string & next_1 , const std::string & next_2 ,
 		bool have_account , bool is_windows ) ;
 
@@ -216,10 +216,10 @@ private slots:
 	void browseCertificate() ;
 } ;
 
-class FilterPage : public GPage
+class FilterPage : public Gui::Page
 {Q_OBJECT
 public:
-	FilterPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+	FilterPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 		const std::string & next_1 , const std::string & next_2 ,
 		bool installing , bool is_windows ) ;
 
@@ -260,10 +260,10 @@ private:
 	G::Path m_client_filter_script_path_default ;
 } ;
 
-class SmtpClientPage : public GPage
+class SmtpClientPage : public Gui::Page
 {Q_OBJECT
 public:
-	SmtpClientPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+	SmtpClientPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 		const std::string & next_1 , const std::string & next_2 , bool have_account ) ;
 
 	std::string nextPage() override ;
@@ -286,11 +286,12 @@ private slots:
 	void onToggle() ;
 } ;
 
-class StartupPage : public GPage
+class StartupPage : public Gui::Page
 {Q_OBJECT
 public:
-	StartupPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
-		const std::string & next_1 , const std::string & next_2 , bool is_mac ) ;
+	StartupPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
+		const std::string & next_1 , const std::string & next_2 ,
+		bool is_mac ) ;
 
 	std::string nextPage() override ;
 	void dump( std::ostream & , bool ) const override ;
@@ -304,10 +305,10 @@ private:
 	QCheckBox * m_add_desktop_item_checkbox ;
 } ;
 
-class LoggingPage : public GPage
+class LoggingPage : public Gui::Page
 {Q_OBJECT
 public:
-	LoggingPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
+	LoggingPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
 		const std::string & next_1 , const std::string & next_2 ) ;
 
 	std::string nextPage() override ;
@@ -335,11 +336,11 @@ private:
 	QCheckBox * m_log_fields_address_checkbox ;
 } ;
 
-class ListeningPage : public GPage
+class ListeningPage : public Gui::Page
 {Q_OBJECT
 public:
-	ListeningPage( GDialog & dialog , const G::MapFile & config , const std::string & name ,
-		const std::string & next_1 , const std::string & next_2 ) ;
+	ListeningPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name ,
+		const std::string & next_1 , const std::string & next_2 , bool next_is_next2 ) ;
 
 	std::string nextPage() override ;
 	void dump( std::ostream & , bool ) const override ;
@@ -351,6 +352,7 @@ private slots:
 	void onTextChanged() ;
 
 private:
+	bool m_next_is_next2 ;
 	QCheckBox * m_remote_checkbox ;
 	QRadioButton * m_all_checkbox ;
 	QRadioButton * m_ipv4_checkbox ;
@@ -361,10 +363,10 @@ private:
 	std::string m_value ;
 } ;
 
-class ReadyPage : public GPage
+class ReadyPage : public Gui::Page
 {Q_OBJECT
 public:
-	ReadyPage( GDialog & dialog , const G::MapFile & config , const std::string & name , const std::string & next_1 ,
+	ReadyPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name , const std::string & next_1 ,
 		const std::string & next_2 , bool installing ) ;
 
 	std::string nextPage() override ;
@@ -395,11 +397,11 @@ signals:
 	void newLine( QString ) ;
 } ;
 
-class ProgressPage : public GPage
+class ProgressPage : public Gui::Page
 {Q_OBJECT
 public:
-	ProgressPage( GDialog & dialog , const G::MapFile & config , const std::string & name , const std::string & next_1 ,
-		const std::string & next_2 , Installer & ) ;
+	ProgressPage( Gui::Dialog & dialog , const G::MapFile & config , const std::string & name , const std::string & next_1 ,
+		const std::string & next_2 , Installer & , bool installing ) ;
 
 	std::string nextPage() override ;
 	void dump( std::ostream & , bool ) const override ;
diff --git a/src/gui/serverconfiguration.cpp b/src/gui/serverconfiguration.cpp
index 5c5f70d..7672823 100644
--- a/src/gui/serverconfiguration.cpp
+++ b/src/gui/serverconfiguration.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -23,6 +23,8 @@
 #include "options.h"
 #include "gbatchfile.h"
 #include "gfile.h"
+#include "gstringarray.h"
+#include "gstringmap.h"
 #include "goptionparser.h"
 #include "glog.h"
 
diff --git a/src/gui/serverconfiguration.h b/src/gui/serverconfiguration.h
index 5584e1a..8acbe7a 100644
--- a/src/gui/serverconfiguration.h
+++ b/src/gui/serverconfiguration.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,7 +22,7 @@
 #define G_MAIN_GUI_SERVER_CONFIGURATION_H
 
 #include "gdef.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gmapfile.h"
 #include "gpath.h"
 
diff --git a/src/main/Makefile.am b/src/main/Makefile.am
index f894fcb..2bb1367 100644
--- a/src/main/Makefile.am
+++ b/src/main/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -88,7 +88,9 @@ MISC_EXTRA_DIST = \
 	emailrelay-service.exe.manifest \
 	fakemc.c \
 	messages.mc \
-	resource.h
+	resource.h \
+	testrun.cpp \
+	testrun.h
 
 if GCONFIG_MAC
  MAC_PROGS = emailrelay-start
@@ -206,6 +208,7 @@ else
 	$(top_builddir)/src/gsmtp/libgsmtp.a \
 	$(top_builddir)/src/gauth/libgauth.a \
 	$(top_builddir)/src/gnet/libgnet.a \
+	$(top_builddir)/src/gssl/libgssl.a \
 	$(top_builddir)/src/glib/libglib.a
 endif
 
@@ -268,3 +271,7 @@ fakemc.exe: $(top_srcdir)/src/main/fakemc.c
 strip:
 	$(STRIP) $(sbin_PROGRAMS) $(e_libexec_PROGRAMS)
 
+.PHONY: map
+map:
+	$(CXXLD) -Xlinker -Map=emailrelay.map $(AM_CXXFLAGS) $(CXXFLAGS) $(emailrelay_LDFLAGS) $(LDFLAGS) -o /tmp/emailrelay.tmp $(emailrelay_OBJECTS) $(emailrelay_LDADD) $(LIBS)
+
diff --git a/src/main/Makefile.in b/src/main/Makefile.in
index 6832e52..9ccbf5d 100644
--- a/src/main/Makefile.in
+++ b/src/main/Makefile.in
@@ -210,6 +210,7 @@ emailrelay_submit_OBJECTS = $(am_emailrelay_submit_OBJECTS)
 @GCONFIG_WINDOWS_FALSE@	$(top_builddir)/src/gsmtp/libgsmtp.a \
 @GCONFIG_WINDOWS_FALSE@	$(top_builddir)/src/gauth/libgauth.a \
 @GCONFIG_WINDOWS_FALSE@	$(top_builddir)/src/gnet/libgnet.a \
+@GCONFIG_WINDOWS_FALSE@	$(top_builddir)/src/gssl/libgssl.a \
 @GCONFIG_WINDOWS_FALSE@	$(top_builddir)/src/glib/libglib.a
 @GCONFIG_WINDOWS_TRUE@emailrelay_submit_DEPENDENCIES =  \
 @GCONFIG_WINDOWS_TRUE@	$(top_builddir)/src/gsmtp/libgsmtp.a \
@@ -592,7 +593,9 @@ MISC_EXTRA_DIST = \
 	emailrelay-service.exe.manifest \
 	fakemc.c \
 	messages.mc \
-	resource.h
+	resource.h \
+	testrun.cpp \
+	testrun.h
 
 @GCONFIG_MAC_FALSE@MAC_PROGS = 
 @GCONFIG_MAC_TRUE@MAC_PROGS = emailrelay-start
@@ -679,6 +682,7 @@ emailrelay_submit_SOURCES = submit.cpp legal.cpp legal.h
 @GCONFIG_WINDOWS_FALSE@	$(top_builddir)/src/gsmtp/libgsmtp.a \
 @GCONFIG_WINDOWS_FALSE@	$(top_builddir)/src/gauth/libgauth.a \
 @GCONFIG_WINDOWS_FALSE@	$(top_builddir)/src/gnet/libgnet.a \
+@GCONFIG_WINDOWS_FALSE@	$(top_builddir)/src/gssl/libgssl.a \
 @GCONFIG_WINDOWS_FALSE@	$(top_builddir)/src/glib/libglib.a
 
 @GCONFIG_WINDOWS_TRUE@emailrelay_submit_LDADD = \
@@ -1300,6 +1304,10 @@ fakemc.exe: $(top_srcdir)/src/main/fakemc.c
 strip:
 	$(STRIP) $(sbin_PROGRAMS) $(e_libexec_PROGRAMS)
 
+.PHONY: map
+map:
+	$(CXXLD) -Xlinker -Map=emailrelay.map $(AM_CXXFLAGS) $(CXXFLAGS) $(emailrelay_LDFLAGS) $(LDFLAGS) -o /tmp/emailrelay.tmp $(emailrelay_OBJECTS) $(emailrelay_LDADD) $(LIBS)
+
 # Tell versions [3.59,3.63) of GNU make to not export all variables.
 # Otherwise a system limit (for SysV at least) may be exceeded.
 .NOEXPORT:
diff --git a/src/main/commandline.cpp b/src/main/commandline.cpp
index 87c8e0c..fb16e12 100644
--- a/src/main/commandline.cpp
+++ b/src/main/commandline.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -20,12 +20,14 @@
 
 #include "gdef.h"
 #include "gssl.h"
-#include "goptions.h"
 #include "legal.h"
 #include "configuration.h"
 #include "commandline.h"
+#include "options.h"
 #include "gmessagestore.h"
 #include "ggetopt.h"
+#include "goptionsusage.h"
+#include "gaddress.h"
 #include "gprocess.h"
 #include "gpath.h"
 #include "gfile.h"
@@ -54,8 +56,8 @@ public:
 public:
 	Show( const Show & ) = delete ;
 	Show( Show && ) = delete ;
-	void operator=( const Show & ) = delete ;
-	void operator=( Show && ) = delete ;
+	Show & operator=( const Show & ) = delete ;
+	Show & operator=( Show && ) = delete ;
 
 private:
 	static Show * m_this ;
@@ -67,7 +69,8 @@ private:
 
 // ==
 
-Main::CommandLine::CommandLine( Output & output , const G::Arg & arg , const G::Options & spec ,
+Main::CommandLine::CommandLine( Output & output , const G::Arg & arg ,
+	const G::Options & spec ,
 	const std::string & version ) :
 		m_output(output) ,
 		m_version(version) ,
@@ -77,9 +80,7 @@ Main::CommandLine::CommandLine( Output & output , const G::Arg & arg , const G::
 {
 	if( !m_getopt.hasErrors() && m_getopt.args().c() == 2U )
 	{
-		std::string config_file = m_getopt.args().v(1U) ;
-		if( sanityCheck( config_file ) )
-			m_getopt.addOptionsFromFile( 1U , "@app" , G::Path(G::Process::exe()).dirname().str() ) ;
+		m_getopt.addOptionsFromFile( 1U , "@app" , G::Path(G::Process::exe()).dirname().str() ) ;
 	}
 }
 
@@ -91,7 +92,7 @@ const G::OptionMap & Main::CommandLine::map() const
 	return m_getopt.map() ;
 }
 
-const G::Options & Main::CommandLine::options() const
+const std::vector<G::Option> & Main::CommandLine::options() const
 {
 	return m_getopt.options() ;
 }
@@ -101,67 +102,71 @@ std::size_t Main::CommandLine::argc() const
 	return m_getopt.args().c() ;
 }
 
-bool Main::CommandLine::sanityCheck( const G::Path & path )
+G::StringArray Main::CommandLine::usageErrors() const
 {
-	// a simple check to reject pem files since 'server-tls' no longer takes a value
-	using G::format ;
-	using G::gettext ;
-	std::ifstream file ;
-	if( path.extension() == "pem" )
-		m_insanity = str( format(gettext("invalid filename extension for config file: [%1%]")) % path.str() ) ;
-	G::File::open( file , path ) ;
-	if( file.good() && G::Str::readLineFrom(file).find("---") == 0U )
-		m_insanity = str( format(gettext("invalid file format for config file: [%1%]")) % path.str() ) ;
-	return m_insanity.empty() ;
+	return m_getopt.errorList() ;
 }
 
 bool Main::CommandLine::hasUsageErrors() const
 {
-	return !m_insanity.empty() || m_getopt.hasErrors() ;
+	return m_getopt.hasErrors() ;
 }
 
-void Main::CommandLine::showUsage( bool e ) const
+void Main::CommandLine::showUsage( bool is_error ) const
 {
-	G::OptionsLayout layout = m_output.outputLayout( m_verbose ) ;
-	layout.set_column( m_verbose ? 38U : 30U ) ;
+	std::string args = " [<config-file>]" ;
+	auto layout = m_output.outputLayout( m_verbose ) ;
+	layout.set_column( m_verbose ? 42U : 30U ) ;
 	layout.set_extra( m_verbose ) ;
 	layout.set_alt_usage( !m_verbose ) ;
-	if( !m_verbose )
-		layout.set_level( 2U ) ;
+	layout.set_level_max( m_verbose ? 99U : 20U ) ;
 
-	Show show( m_output , e , m_verbose ) ;
-
-	m_getopt.options().showUsage( layout ,
-		show.s() , m_arg.prefix() , " [<config-file>]" ) ;
+	G::OptionsUsage usage( m_getopt.options() ) ;
+	if( m_verbose )
+	{
+		// show help in sections...
+		bool help_state = false ;
+		usage.help( layout , &help_state ) ;
+		Show show( m_output , is_error , m_verbose ) ;
+		show.s() << usage.summary(layout,m_arg.prefix(),args) << "\n" ;
+		auto tags = Options::tags() ;
+		for( const auto & tag : tags )
+		{
+			layout.set_main_tag( tag.first ) ;
+			show.s() << "\n" << tag.second << "\n" << usage.help(layout,&help_state) ;
+		}
+	}
+	else
+	{
+		Show show( m_output , is_error , m_verbose ) ;
+		usage.output( layout , show.s() , m_arg.prefix() , args ) ;
+	}
 }
 
 void Main::CommandLine::showUsageErrors( bool e ) const
 {
 	Show show( m_output , e , m_verbose ) ;
-	if( !m_insanity.empty() )
-		show.s() << m_arg.prefix() << ": error: " << m_insanity << std::endl ;
-	else
-		m_getopt.showErrors( show.s() ) ;
+	m_getopt.showErrors( show.s() ) ;
 	showShortHelp( e ) ;
 }
 
 void Main::CommandLine::showArgcError( bool e ) const
 {
-	using G::gettext ;
+	using G::txt ;
 	Show show( m_output , e , m_verbose ) ;
-	show.s() << m_arg.prefix() << ": " << gettext("usage error: too many non-option arguments") << std::endl ;
+	show.s() << m_arg.prefix() << ": " << txt("usage error: too many non-option arguments") << std::endl ;
 	showShortHelp( e ) ;
 }
 
 void Main::CommandLine::showShortHelp( bool e ) const
 {
 	using G::format ;
-	using G::gettext ;
+	using G::txt ;
 	Show show( m_output , e , m_verbose ) ;
 	const std::string & exe = m_arg.prefix() ;
 	show.s()
 		<< std::string(exe.length()+2U,' ')
-		<< str(format(gettext("try \"%1%\" for more information"))%(exe+" --help --verbose")) << std::endl ;
+		<< str(format(txt("try \"%1%\" for more information"))%(exe+" --help --verbose")) << std::endl ;
 }
 
 void Main::CommandLine::showHelp( bool e ) const
@@ -177,56 +182,51 @@ void Main::CommandLine::showHelp( bool e ) const
 void Main::CommandLine::showExtraHelp( bool e ) const
 {
 	using G::format ;
-	using G::gettext ;
+	using G::txt ;
 	Show show( m_output , e , m_verbose ) ;
 	const std::string & exe = m_arg.prefix() ;
 
-	show.s() << std::endl ;
-
+	show.s() << "\n" ;
 	if( m_verbose )
 	{
 		show.s()
-			<< gettext("To start a 'storage' daemon in background...") << std::endl
-			<< "   " << exe << " --as-server" << std::endl
-			<< std::endl ;
-
-		show.s()
-			<< gettext("To forward stored mail to \"mail.myisp.net\"...") << std::endl
-			<< "   " << exe << " --as-client mail.myisp.net:smtp" << std::endl
-			<< std::endl ;
-
-		show.s()
-			<< gettext("To run as a proxy (on port 10025) to a local server (on port 25)...") << std::endl
-			<< "   " << exe << " --port 10025 --as-proxy localhost:25" << std::endl
+			<< txt("To start a 'storage' daemon in background...") << "\n"
+			<< "   " << exe << " --as-server\n\n"
+			//
+			<< txt("To forward stored mail to \"mail.myisp.net\"...") << "\n"
+			<< "   " << exe << " --as-client mail.myisp.net:smtp\n\n"
+			//
+			<< txt("To run as a proxy (on port 10025) to a local server (on port 25)...") << "\n"
+			<< "   " << exe << " --port 10025 --as-proxy localhost:25\n"
 			<< std::endl ;
 	}
 	else
 	{
 		show.s()
-			<< format(gettext("For complete usage information run \"%1%\"")) % (exe+" --help --verbose") << std::endl
+			<< format(txt("For complete usage information run \"%1%\"")) % (exe+" --help --verbose") << "\n"
 			<< std::endl ;
 	}
 }
 
 void Main::CommandLine::showNothingToSend( bool e ) const
 {
-	using G::gettext ;
+	using G::txt ;
 	Show show( m_output , e , m_verbose ) ;
-	show.s() << m_arg.prefix() << ": " << gettext("no messages to send") << std::endl ;
+	show.s() << m_arg.prefix() << ": " << txt("no messages to send") << std::endl ;
 }
 
 void Main::CommandLine::showNothingToDo( bool e ) const
 {
-	using G::gettext ;
+	using G::txt ;
 	Show show( m_output , e , m_verbose ) ;
-	show.s() << m_arg.prefix() << ": " << gettext("nothing to do") << std::endl ;
+	show.s() << m_arg.prefix() << ": " << txt("nothing to do") << std::endl ;
 }
 
 void Main::CommandLine::showFinished( bool e ) const
 {
-	using G::gettext ;
+	using G::txt ;
 	Show show( m_output , e , m_verbose ) ;
-	show.s() << m_arg.prefix() << ": " << gettext("finished") << std::endl ;
+	show.s() << m_arg.prefix() << ": " << txt("finished") << std::endl ;
 }
 
 void Main::CommandLine::showError( const std::string & reason , bool e ) const
@@ -269,7 +269,17 @@ void Main::CommandLine::showSslVersion( bool e , const std::string & eot ) const
 void Main::CommandLine::showThreading( bool e , const std::string & eot ) const
 {
 	Show show( m_output , e , m_verbose ) ;
-	show.s() << "Multi-threading: " << (G::threading::works()?"enabled":"disabled") << std::endl << eot ;
+	show.s() << "Multi-threading: " << (G::threading::works()?"enabled":"disabled") << eot ;
+}
+
+void Main::CommandLine::showUds( bool e , const std::string & eot ) const
+{
+	if( !G::is_windows() || G::is_wine() )
+	{
+		bool enabled = GNet::Address::supports( GNet::Address::Family::local ) ;
+		Show show( m_output , e , m_verbose ) ;
+		show.s() << "Unix domain sockets: " << (enabled?"enabled":"disabled") << eot ;
+	}
 }
 
 void Main::CommandLine::showVersion( bool e ) const
@@ -280,6 +290,7 @@ void Main::CommandLine::showVersion( bool e ) const
 	if( m_verbose )
 	{
 		showThreading( e , "\n" ) ;
+		showUds( e , "\n" ) ;
 		showSslVersion( e , "\n" ) ;
 	}
 	showSslCredit( e , "\n" ) ;
@@ -288,19 +299,21 @@ void Main::CommandLine::showVersion( bool e ) const
 
 void Main::CommandLine::showSemanticError( const std::string & error ) const
 {
-	using G::gettext ;
+	using G::txt ;
 	Show show( m_output , true , m_verbose ) ;
-	show.s() << m_arg.prefix() << ": " << gettext("usage error: ") << error << std::endl ;
+	show.s() << m_arg.prefix() << ": " << txt("usage error: ") << error << std::endl ;
 }
 
 void Main::CommandLine::showSemanticWarnings( const G::StringArray & warnings ) const
 {
-	using G::gettext ;
+	using G::txt ;
 	if( !warnings.empty() )
 	{
 		Show show( m_output , true , m_verbose ) ;
-		const char * warning = gettext( "warning" ) ;
-		show.s() << m_arg.prefix() << ": " << warning << ": " << G::Str::join("\n"+m_arg.prefix()+": "+warning+": ",warnings) << std::endl ;
+		const char * warning = txt( "warning" ) ;
+		std::string sep = std::string(1U,'\n').append(m_arg.prefix()).append(": ",2U).append(warning).append(": ",2U) ;
+		show.s() << m_arg.prefix() << ": " << warning << ": "
+			<< G::Str::join(sep,warnings) << std::endl ;
 	}
 }
 
diff --git a/src/main/commandline.h b/src/main/commandline.h
index 659c20d..324585e 100644
--- a/src/main/commandline.h
+++ b/src/main/commandline.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,11 +24,11 @@
 #include "gdef.h"
 #include "garg.h"
 #include "ggetopt.h"
-#include "goptions.h"
+#include "goption.h"
 #include "output.h"
 #include "configuration.h"
 #include "output.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include <string>
 
 namespace Main
@@ -40,7 +40,7 @@ namespace Main
 /// A class which deals with the command-line interface to the process, both
 /// input from command-line parameters and feedback to (eg.) stdout.
 ///
-/// Higher-level access to command-line options is provided by the Configuration class.
+/// Higher-level access to command-line options is provided by Main::Configuration.
 ///
 class Main::CommandLine
 {
@@ -55,8 +55,11 @@ public:
 	const G::OptionMap & map() const ;
 		///< Exposes the option-map sub-object.
 
-	const G::Options & options() const ;
-		///< Exposes the options sub-object.
+	const std::vector<G::Option> & options() const ;
+		///< Exposes the command-line options.
+
+	G::StringArray usageErrors() const ;
+		///< Returns the usage error list.
 
 	std::size_t argc() const ;
 		///< Returns the number of non-option arguments on the command line.
@@ -88,10 +91,10 @@ public:
 	void showVersion( bool error_stream = false ) const ;
 		///< Writes the version number.
 
-	void showBanner( bool error_stream = false , const std::string & = std::string() ) const ;
+	void showBanner( bool error_stream = false , const std::string & = {} ) const ;
 		///< Writes a startup banner.
 
-	void showCopyright( bool error_stream = false , const std::string & = std::string() ) const ;
+	void showCopyright( bool error_stream = false , const std::string & = {} ) const ;
 		///< Writes a copyright message.
 
 	void showSemanticError( const std::string & semantic_error ) const ;
@@ -106,18 +109,18 @@ public:
 public:
 	CommandLine( const CommandLine & ) = delete ;
 	CommandLine( CommandLine && ) = delete ;
-	void operator=( const CommandLine & ) = delete ;
-	void operator=( CommandLine && ) = delete ;
+	CommandLine & operator=( const CommandLine & ) = delete ;
+	CommandLine & operator=( CommandLine && ) = delete ;
 
 private:
 	void showUsage( bool e ) const ;
 	void showShortHelp( bool e ) const ;
 	void showExtraHelp( bool e ) const ;
-	void showWarranty( bool e = false , const std::string & eot = std::string() ) const ;
-	void showSslCredit( bool e = false , const std::string & eot = std::string() ) const ;
-	void showSslVersion( bool e = false , const std::string & eot = std::string() ) const ;
-	void showThreading( bool e = false , const std::string & eot = std::string() ) const ;
-	bool sanityCheck( const G::Path & ) ;
+	void showWarranty( bool e = false , const std::string & eot = {} ) const ;
+	void showSslCredit( bool e = false , const std::string & eot = {} ) const ;
+	void showSslVersion( bool e = false , const std::string & eot = {} ) const ;
+	void showThreading( bool e = false , const std::string & eot = {} ) const ;
+	void showUds( bool e = false , const std::string & eod = {} ) const ;
 
 private:
 	Output & m_output ;
@@ -125,7 +128,6 @@ private:
 	G::Arg m_arg ;
 	G::GetOpt m_getopt ;
 	bool m_verbose ;
-	std::string m_insanity ;
 } ;
 
 #endif
diff --git a/src/main/configuration.cpp b/src/main/configuration.cpp
index 01c62c8..21502df 100644
--- a/src/main/configuration.cpp
+++ b/src/main/configuration.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -20,9 +20,11 @@
 
 #include "gdef.h"
 #include "gstr.h"
+#include "gstringfield.h"
 #include "configuration.h"
 #include "commandline.h"
 #include "gmessagestore.h"
+#include "gfactoryparser.h"
 #include "gaddress.h"
 #include "gprocess.h"
 #include "gformat.h"
@@ -30,7 +32,7 @@
 #include "glog.h"
 #include <array>
 
-Main::Configuration::Configuration( const G::Options & options , const G::OptionMap & map ,
+Main::Configuration::Configuration( const std::vector<G::Option> & options , const G::OptionMap & map ,
 	const G::Path & app_dir , const G::Path & base_dir ) :
 		m_options(options) ,
 		m_map(map) ,
@@ -115,12 +117,17 @@ unsigned int Main::Configuration::port() const
 	return G::Str::toUInt( m_map.value( "port" , "25" ) ) ;
 }
 
-G::StringArray Main::Configuration::listeningAddresses( const std::string & protocol ) const
+bool Main::Configuration::closeFiles() const
 {
-	// allow eg. "127.0.0.1,smtp=192.168.1.1,admin=10.0.0.1"
+	return daemon() && m_map.value("interface").find("fd#") == std::string::npos ;
+}
+
+G::StringArray Main::Configuration::listeningNames( const std::string & protocol ) const
+{
+	// allow eg. "127.0.0.1,smtp=192.168.1.1,admin=10.0.0.1,pop=fd#4"
 
 	// prepare the naive result by splitting the user's string by commas
-	G::StringArray result = G::Str::splitIntoFields( m_map.value("interface") , "," ) ;
+	G::StringArray result = G::Str::splitIntoFields( m_map.value("interface") , ',' ) ;
 
 	// then weed out the ones that have an explicit protocol name that doesnt match the
 	// required protocol, removing the "protocol=" prefix at the same time to leave just
@@ -143,7 +150,6 @@ G::StringArray Main::Configuration::listeningAddresses( const std::string & prot
 
 std::string Main::Configuration::clientBindAddress() const
 {
-	// "--interface client=..." no longer supported, just "--client-interface"
 	return m_map.value( "client-interface" ) ;
 }
 
@@ -232,18 +238,22 @@ bool Main::Configuration::immediate() const
 
 bool Main::Configuration::doPolling() const
 {
-	return m_map.contains( "poll" ) && pollingTimeout() > 0U ;
+	return m_map.contains( "poll" ) ;
 }
 
-unsigned int Main::Configuration::pollingTimeout() const
+G::TimeInterval Main::Configuration::pollingTimeout() const
 {
-	return G::Str::toUInt( m_map.value( "poll" , "0" ) ) ;
+	std::string value = m_map.value( "poll" , "0" ) ;
+	if( G::Str::tailMatch(value,"ms"_sv) )
+		return G::TimeInterval( 0U , 1000U * G::Str::toUInt( G::Str::head(value,"ms"_sv) ) ) ;
+	else
+		return G::TimeInterval( G::Str::toUInt( value ) ) ;
 }
 
 bool Main::Configuration::pollingLog() const
 {
 	// dont log if polling very frequently
-	return doPolling() && pollingTimeout() > 60U ;
+	return doPolling() && pollingTimeout() > G::TimeInterval(60U) ;
 }
 
 bool Main::Configuration::forwardOnDisconnect() const
@@ -308,14 +318,14 @@ bool Main::Configuration::useFilter() const
 	return m_map.contains( "filter" ) ;
 }
 
-G::Path Main::Configuration::filter() const
+GSmtp::FactoryParser::Result Main::Configuration::filter() const
 {
-	return m_map.contains("filter") ? pathValue("filter") : G::Path() ;
+	return specValue( "filter" , true ) ;
 }
 
-G::Path Main::Configuration::clientFilter() const
+GSmtp::FactoryParser::Result Main::Configuration::clientFilter() const
 {
-	return m_map.contains("client-filter") ? pathValue("client-filter") : G::Path() ;
+	return specValue( "client-filter" , true ) ;
 }
 
 G::Path Main::Configuration::clientSecretsFile() const
@@ -465,9 +475,9 @@ std::string Main::Configuration::user() const
 	return m_map.value( "user" , "daemon" ) ;
 }
 
-G::Path Main::Configuration::verifier() const
+GSmtp::FactoryParser::Result Main::Configuration::verifier() const
 {
-	return m_map.contains("address-verifier") ? pathValue("address-verifier") : G::Path() ;
+	return specValue( "address-verifier" , false ) ;
 }
 
 bool Main::Configuration::withTerminate() const
@@ -500,9 +510,41 @@ unsigned int Main::Configuration::scannerResponseTimeout() const
 	return 90U ; // for now
 }
 
-bool Main::Configuration::anonymous() const
+bool Main::Configuration::anonymous( G::string_view type ) const
 {
-	return m_map.contains( "anonymous" ) ;
+	if( !m_map.contains("anonymous") )
+		return false ;
+
+	std::string value = m_map.value( "anonymous" ) ;
+	if( value.empty() )
+		return true ;
+
+	for( G::StringField f(value,",",1U) ; f ; ++f )
+	{
+		if( f() == type )
+			return true ;
+	}
+	return false ;
+}
+
+bool Main::Configuration::anonymousServerVrfy() const
+{
+	return anonymous( "vrfy" ) ;
+}
+
+bool Main::Configuration::anonymousServerSmtp() const
+{
+	return anonymous( "server" ) ;
+}
+
+bool Main::Configuration::anonymousContent() const
+{
+	return anonymous( "content" ) ;
+}
+
+bool Main::Configuration::anonymousClientSmtp() const
+{
+	return anonymous( "client" ) ;
 }
 
 bool Main::Configuration::smtpPipelining() const
@@ -516,34 +558,28 @@ unsigned int Main::Configuration::filterTimeout() const
 	return G::Str::toUInt( m_map.value( "filter-timeout" , "300" ) ) ;
 }
 
-G::StringArray Main::Configuration::semanticWarnings() const
-{
-	return semantics( false ) ;
-}
-
 std::string Main::Configuration::semanticError() const
 {
-	G::StringArray errors = semantics( true ) ;
-	return errors.empty() ? std::string() : errors.at(0U) ;
+	// (code size optimisation)
+	std::string s ;
+	const char * p = semanticErrorImp( s ) ;
+	return (p && *p) ? std::string(p) : ( p ? s : std::string() ) ;
 }
 
-G::StringArray Main::Configuration::semantics( bool want_errors ) const
+const char * Main::Configuration::semanticErrorImp( std::string & s ) const
 {
+	using G::txt ;
 	using G::format ;
-	using G::gettext ;
-	G::StringArray errors ;
-	G::StringArray warnings ;
 
 	if( m_map.contains("syslog") && !validSyslogFacility() )
 	{
-		errors.push_back( str(
-			format(gettext("invalid --syslog facility [%1%]: use %2%")) %
-				m_map.value("syslog") % validSyslogFacilities() ) ) ;
+		s.assign( str( format(txt("invalid --syslog facility [%1%]: use %2%")) % m_map.value("syslog") % validSyslogFacilities() ) ) ;
+		return "" ;
 	}
 
-	if( m_map.contains("poll") && G::Str::toUInt(m_map.value("poll","0")) == 0U )
+	if( m_map.contains("poll") && pollingTimeout() == G::TimeInterval(0U) )
 	{
-		errors.push_back( gettext("invalid --poll period: try --forward-on-disconnect") ) ;
+		return txt("invalid --poll period: try --forward-on-disconnect") ;
 	}
 
 	if( ! m_map.contains("pop") && (
@@ -552,23 +588,23 @@ G::StringArray Main::Configuration::semantics( bool want_errors ) const
 		m_map.contains("pop-by-name") ||
 		m_map.contains("pop-no-delete") ) )
 	{
-		errors.push_back( gettext("pop options require --pop") ) ;
+		return txt("pop options require --pop") ;
 	}
 
 	if( m_map.contains("pop") && !m_map.contains("pop-auth") )
 	{
-		errors.push_back( gettext("the --pop option requires --pop-auth") ) ;
+		return txt("the --pop option requires --pop-auth") ;
 	}
 
 	if( m_map.contains("admin-terminate") && !m_map.contains("admin") )
 	{
-		errors.push_back( gettext("the --admin-terminate option requires --admin") ) ;
+		return txt("the --admin-terminate option requires --admin") ;
 	}
 
 	if( daemon() && spoolDir().isRelative() )
 	{
 		// (in case m_base_dir is relative)
-		errors.push_back( gettext("in daemon mode the spool-dir must be an absolute path") ) ;
+		return txt("in daemon mode the spool-dir must be an absolute path") ;
 	}
 
 	if( daemon() && (
@@ -577,12 +613,12 @@ G::StringArray Main::Configuration::semantics( bool want_errors ) const
 		( m_map.contains("pop-auth") && ( popSecretsFile().empty() || popSecretsFile().isRelative() ) ) ) )
 	{
 		// (in case m_base_dir is relative)
-		errors.push_back( gettext("in daemon mode the authorisation secrets file(s) must be absolute paths") ) ;
+		return txt("in daemon mode the authorisation secrets file(s) must be absolute paths") ;
 	}
 
 	if( m_map.contains("forward-to") && ( m_map.contains("as-proxy") || m_map.contains("as-client") ) )
 	{
-		errors.push_back( gettext("--forward-to cannot be used with --as-client or --as-proxy") ) ;
+		return txt("--forward-to cannot be used with --as-client or --as-proxy") ;
 	}
 
 	const bool have_forward_to =
@@ -601,7 +637,10 @@ G::StringArray Main::Configuration::semantics( bool want_errors ) const
 		for( const char * p : need_forward_to )
 		{
 			if( m_map.contains(p) && !have_forward_to )
-				errors.push_back( str( format(gettext("%1% requires --forward-to")) % ("--"+std::string(p)) ) ) ;
+			{
+				s.assign( str( format(txt("%1% requires --forward-to")) % ("--"+std::string(p)) ) ) ;
+				return "" ;
+			}
 		}
 	}
 
@@ -624,34 +663,44 @@ G::StringArray Main::Configuration::semantics( bool want_errors ) const
 	if( not_serving ) // ie. if not serving admin, smtp or pop
 	{
 		if( m_map.contains("filter") )
-			errors.push_back( gettext("the --filter option cannot be used with --as-client or --dont-serve") ) ;
+			return txt("the --filter option cannot be used with --as-client or --dont-serve") ;
 
 		if( m_map.contains("port") )
-			errors.push_back( gettext("the --port option cannot be used with --as-client or --dont-serve") ) ;
+			return txt("the --port option cannot be used with --as-client or --dont-serve") ;
 
 		if( m_map.contains("server-auth") )
-			errors.push_back( gettext("the --server-auth option cannot be used with --as-client or --dont-serve") ) ;
+			return txt("the --server-auth option cannot be used with --as-client or --dont-serve") ;
 
 		if( m_map.contains("pop") )
-			errors.push_back( gettext("the --pop option cannot be used with --as-client or --dont-serve") ) ;
+			return txt("the --pop option cannot be used with --as-client or --dont-serve") ;
 
 		if( m_map.contains("admin") )
-			errors.push_back( gettext("the --admin option cannot be used with --as-client or --dont-serve") ) ;
+			return txt("the --admin option cannot be used with --as-client or --dont-serve") ;
 
 		if( m_map.contains("poll") )
-			errors.push_back( gettext("the --poll option cannot be used with --as-client or --dont-serve") ) ;
+			return txt("the --poll option cannot be used with --as-client or --dont-serve") ;
 	}
 
 	if( m_map.contains("no-smtp") ) // ie. if not serving smtp
 	{
 		if( m_map.contains("filter") )
-			errors.push_back( gettext("the --filter option cannot be used with --no-smtp") ) ;
+			return txt("the --filter option cannot be used with --no-smtp") ;
 
 		if( m_map.contains("port") )
-			errors.push_back( gettext("the --port option cannot be used with --no-smtp") ) ;
+			return txt("the --port option cannot be used with --no-smtp") ;
 
 		if( m_map.contains("server-auth") )
-			errors.push_back( gettext("the --server-auth option cannot be used with --no-smtp") ) ;
+			return txt("the --server-auth option cannot be used with --no-smtp") ;
+	}
+
+	if( m_map.contains("server-auth-config") && !m_map.contains("server-auth") )
+	{
+		return txt("--server-auth-config requires --server-auth") ;
+	}
+
+	if( m_map.contains("client-auth-config") && !m_map.contains("client-auth") )
+	{
+		return txt("--client-auth-config requires --client-auth") ;
 	}
 
 	const bool contains_log =
@@ -662,117 +711,113 @@ G::StringArray Main::Configuration::semantics( bool want_errors ) const
 
 	if( m_map.contains("verbose") && ! ( m_map.contains("help") || contains_log ) )
 	{
-		errors.push_back(
-			gettext("the --verbose option must be used with --log, --help, --as-client, --as-server or --as-proxy") ) ;
+		return txt("the --verbose option must be used with --log, --help, --as-client, --as-server or --as-proxy") ;
 	}
 
 	if( m_map.contains("debug") && !contains_log )
 	{
-		errors.push_back(
-			gettext("the --debug option requires --log, --as-client, --as-server or --as-proxy") ) ;
+		return txt("the --debug option requires --log, --as-client, --as-server or --as-proxy") ;
 	}
 
-	const bool no_daemon =
-		m_map.contains("as-client") || // => no-daemon
-		m_map.contains("no-daemon") ;
-
 	if( m_map.contains("client-tls") && m_map.contains("client-tls-connection") )
 	{
-		errors.push_back(
-			gettext("the --client-tls and --client-tls-connection options cannot be used together") ) ;
+		return txt("the --client-tls and --client-tls-connection options cannot be used together") ;
 	}
 
 	if( m_map.contains("server-tls") && m_map.contains("server-tls-connection") )
 	{
-		errors.push_back(
-			gettext("the --server-tls and --server-tls-connection options cannot be used together") ) ;
+		return txt("the --server-tls and --server-tls-connection options cannot be used together") ;
 	}
 
 	if( m_map.contains("server-tls") && !m_map.contains("server-tls-certificate") )
 	{
-		errors.push_back(
-			gettext("the --server-tls option requires --server-tls-certificate") ) ;
+		return txt("the --server-tls option requires --server-tls-certificate") ;
 	}
 
 	if( m_map.contains("server-tls-connection") && !m_map.contains("server-tls-certificate") )
 	{
-		errors.push_back(
-			gettext("the --server-tls-connection option requires --server-tls-certificate") ) ;
+		return txt("the --server-tls-connection option requires --server-tls-certificate") ;
 	}
 
 	if( ( m_map.contains("server-tls-certificate") || m_map.contains("server-tls-verify") ) &&
 		!( m_map.contains("server-tls") || m_map.contains("server-tls-connection") ) )
 	{
-		errors.push_back(
-			gettext("the --server-tls options require either --server-tls or --server-tls-connection") ) ;
+		return txt("the --server-tls options require either --server-tls or --server-tls-connection") ;
 	}
 
 	if( ( m_map.contains("client-tls-certificate") || m_map.contains("client-tls-verify") ||
 		m_map.contains("client-tls-required") ) &&
 		!( m_map.contains("client-tls") || m_map.contains("client-tls-connection") ) )
 	{
-		errors.push_back(
-			gettext("the --client-tls- options require --client-tls or --client-tls-connection") ) ;
+		return txt("the --client-tls- options require --client-tls or --client-tls-connection") ;
 	}
 
 	if( m_map.count("server-tls-certificate") > 2U )
 	{
-		errors.push_back(
-			gettext("the --server-tls-certificate option cannot be used more than twice") ) ;
+		return txt("the --server-tls-certificate option cannot be used more than twice") ;
 	}
 
 	if( m_map.count("client-tls-certificate") > 2U )
 	{
-		errors.push_back(
-			gettext("the --client-tls-certificate option cannot be used more than twice") ) ;
+		return txt("the --client-tls-certificate option cannot be used more than twice") ;
 	}
 
 	if( m_map.contains("client-tls-verify-name") && !m_map.contains("client-tls-verify") )
 	{
-		errors.push_back(
-			gettext("the --client-tls-verify-name options requires --client-tls-verify") ) ;
-	}
-
-	if( m_map.contains("server-auth") && m_map.value("server-auth") == "/pam" &&
-		!( m_map.contains("server-tls" ) || m_map.contains("server-tls-connection") ) )
-	{
-		errors.push_back(
-			gettext("--server-auth using pam requires --server-tls or --server-tls-connection") ) ;
+		return txt("the --client-tls-verify-name options requires --client-tls-verify") ;
 	}
 
 	if( m_map.contains("server-tls-required") &&
 		!( m_map.contains("server-tls" ) || m_map.contains("server-tls-connection") ) )
 	{
-		errors.push_back(
-			gettext("--server-tls-required requires --server-tls or --server-tls-connection") ) ;
-	}
-
-	if( m_map.contains("pop-auth") && m_map.value("pop-auth") == "/pam" &&
-		!( m_map.contains("server-tls" ) || m_map.contains("server-tls-connection") ) )
-	{
-		errors.push_back(
-			gettext("--pop-auth using pam requires --server-tls or --server-tls-connection") ) ;
+		return txt("--server-tls-required requires --server-tls or --server-tls-connection") ;
 	}
 
 	if( m_map.contains("interface") && m_map.value("interface").find("client=") != std::string::npos )
 	{
-		errors.push_back(
-			gettext("using --interface with client= is no longer supported: use --client-interface instead") ) ;
+		return txt("using --interface with client= is no longer supported: use --client-interface instead") ;
 	}
 
 	if( m_map.contains("dnsbl") && !m_map.contains("remote-clients") )
 	{
-		errors.push_back( gettext("--dnsbl requires --remote-clients or -r") ) ;
+		return txt("--dnsbl requires --remote-clients or -r") ;
 	}
 
 	std::string forward_to = serverAddress() ;
 
 	if( m_map.contains("client-interface") && GNet::Address::isFamilyLocal(forward_to) )
 	{
-		errors.push_back( "cannot use --client-interface with a unix-domain forwarding address" ) ;
+		return txt("cannot use --client-interface with a unix-domain forwarding address") ;
 	}
 
-	// warnings...
+	{
+		GSmtp::FactoryParser::Result r ;
+		if( (r=filter()).first.empty() )
+		{
+			s.assign( str( format(txt("invalid filter specification: %1%")) % r.second ) ) ;
+			return "" ;
+		}
+		if( (r=clientFilter()).first.empty() )
+		{
+			s.assign( str( format(txt("invalid client filter specification: %1%")) % r.second ) ) ;
+			return "" ;
+		}
+		if( (r=verifier()).first.empty() )
+		{
+			s.assign( str( format(txt("invalid address verifier specification: %1%")) % r.second ) ) ;
+			return "" ;
+		}
+	}
+
+	return nullptr ;
+}
+
+G::StringArray Main::Configuration::semanticWarnings() const
+{
+	using G::txt ;
+	using G::format ;
+
+	G::StringArray warnings ;
 
 	const bool no_syslog =
 		m_map.contains("no-syslog") ||
@@ -786,6 +831,12 @@ G::StringArray Main::Configuration::semantics( bool want_errors ) const
 		m_map.contains("as-server") ||
 		m_map.contains("as-proxy") ;
 
+	const bool contains_log =
+		m_map.contains("log") ||
+		m_map.contains("as-server") || // => log
+		m_map.contains("as-client") || // => log
+		m_map.contains("as-proxy") ; // => log
+
 	if( contains_log && close_stderr && !m_map.contains("log-file") && !syslog ) // ie. logging to nowhere
 	{
 		std::string close_stderr_option =
@@ -794,79 +845,53 @@ G::StringArray Main::Configuration::semantics( bool want_errors ) const
 			"--as-proxy" ) ) ;
 
 		warnings.push_back( str( format(
-			gettext("logging will stop because %1% closes the standard error stream soon after startup")) %
+			txt("logging will stop because %1% closes the standard error stream soon after startup")) %
 				close_stderr_option ) ) ;
 	}
 
+	const bool no_daemon =
+		m_map.contains("as-client") || // => no-daemon
+		m_map.contains("no-daemon") ;
+
 	if( m_map.contains("show") && ( no_daemon || m_map.contains("hidden") ) ) // (windows)
 	{
 		warnings.push_back(
-			gettext("the --show option is ignored when using --no-daemon, --as-client or --hidden") ) ;
+			txt("the --show option is ignored when using --no-daemon, --as-client or --hidden") ) ;
 	}
 
-	return want_errors ? errors : warnings ;
+	specValue( "filter" , true , &warnings ) ;
+	specValue( "client-filter" , true , &warnings ) ;
+	specValue( "address-verifier" , false , &warnings ) ;
+
+	return warnings ;
+}
+
+GSmtp::FactoryParser::Result Main::Configuration::specValue( const std::string & option_name , bool is_filter ,
+	G::StringArray * warnings_p ) const
+{
+	std::string value = m_map.value( option_name ) ;
+	return GSmtp::FactoryParser::parse( value , is_filter ,
+		m_base_dir.str() , m_app_dir.str() , warnings_p ) ;
 }
 
 G::Path Main::Configuration::pathValue( const std::string & option_name ) const
 {
-	std::string value = m_map.value( option_name ) ;
-	if( filterType(option_name) && specialFilterValue(value) ) // dont mess with eg. "--filter=net:localhost:999"
-	{
+ 	std::string value = m_map.value( option_name ) ;
+	if( verifyType(option_name) && specialVerifyValue(value) ) // dont mess "<none>" etc. in "--tls-client-verify=<none>"
 		return value ;
-	}
-	else if( verifyType(option_name) && specialVerifyValue(value) ) // dont mess with eg. "--tls-client-verify=<none>"
-	{
-		return value ;
-	}
 	else
-	{
 		return pathValueImp( value ) ;
-	}
 }
 
 G::Path Main::Configuration::pathValueImp( const std::string & value_in ) const
 {
+	// (see also GSmtp::FactoryParser::parse())
 	std::string value = value_in ;
 	if( value.find("@app") == 0U && !m_app_dir.empty() )
 		G::Str::replace( value , "@app" , m_app_dir.str() ) ;
-
 	return G::Path(value).isAbsolute() ? G::Path(value) : ( daemon() ? (m_base_dir+value) : value ) ;
 }
 
-bool Main::Configuration::pathlike( const std::string & option_name )
-{
-	return
-		option_name == "log-file" ||
-		option_name == "spool-dir" ||
-		option_name == "pid-file" ||
-		option_name == "filter" || // filterType()
-		option_name == "client-filter" || // filterType()
-		option_name == "client-auth" ||
-		option_name == "server-tls-certificate" ||
-		option_name == "server-tls-verify" || // verifyType()
-		option_name == "client-tls-certificate" ||
-		option_name == "client-tls-verify" || // verifyType()
-		option_name == "pop-auth" ||
-		option_name == "server-auth" ||
-		option_name == "address-verifier" || // filterType()
-		false ;
-}
-
-bool Main::Configuration::filterType( const std::string & option_name )
-{
-	return
-		option_name == "filter" ||
-		option_name == "client-filter" ||
-		option_name == "address-verifier" ;
-}
-
-bool Main::Configuration::specialFilterValue( const std::string & value )
-{
-	return
-		value.find(':') != std::string::npos &&
-		value.find(':') >= 3U ;
-}
-
 bool Main::Configuration::verifyType( const std::string & option_name )
 {
 	return
@@ -879,55 +904,74 @@ bool Main::Configuration::specialVerifyValue( const std::string & value )
 	return !value.empty() && value.at(0U) == '<' && value.at(value.length()-1U) == '>' ;
 }
 
+#ifdef G_WINDOWS
+bool Main::Configuration::pathlike( const std::string & option_name )
+{
+	return
+		option_name == "log-file" ||
+		option_name == "spool-dir" ||
+		option_name == "pid-file" ||
+		option_name == "client-auth" ||
+		option_name == "server-tls-certificate" ||
+		option_name == "server-tls-verify" || // verifyType()
+		option_name == "client-tls-certificate" ||
+		option_name == "client-tls-verify" || // verifyType()
+		option_name == "pop-auth" ||
+		option_name == "server-auth" ||
+		false ;
+}
+#endif
+
+#ifdef G_WINDOWS
 G::StringArray Main::Configuration::display() const
 {
 	const std::string yes = "yes" ;
 	const std::string no = "no" ;
 	G::StringArray result ;
 	result.reserve( 70U ) ;
-	G::StringArray names = m_options.names() ;
-	for( const auto & name : names )
+	for( const auto & option : m_options )
 	{
-		if( m_options.visible(name) &&
-			name != "version" &&
-			name != "help" &&
-			name != "no-syslog" &&
-			name.find("as-") != 0U &&
+		if( option.visible() &&
+			option.name != "version" &&
+			option.name != "help" &&
+			option.name != "no-syslog" &&
+			option.name.find("as-") != 0U &&
 			true )
 		{
-			result.push_back( name ) ;
-			if( name == "log" )
+			result.push_back( option.name ) ;
+			if( option.name == "log" )
 				result.push_back( log()?yes:no ) ;
-			else if( name == "syslog" )
+			else if( option.name == "syslog" )
 				result.push_back( useSyslog()?yes:no ) ;
-			else if( name == "spool-dir" )
+			else if( option.name == "spool-dir" )
 				result.push_back( spoolDir().str() ) ;
-			else if( name == "close-stderr" )
+			else if( option.name == "close-stderr" )
 				result.push_back( closeStderr()?yes:no ) ;
-			else if( name == "no-daemon" )
+			else if( option.name == "no-daemon" )
 				result.back() = "daemon" , result.push_back( daemon()?yes:no ) ;
-			else if( name == "dont-serve" )
+			else if( option.name == "dont-serve" )
 				result.back() = "serve" , result.push_back( doServing()?yes:no ) ;
-			else if( name == "forward" )
+			else if( option.name == "forward" )
 				result.push_back( forwardOnStartup()?yes:no ) ;
-			else if( name == "forward-on-disconnect" )
+			else if( option.name == "forward-on-disconnect" )
 				result.push_back( forwardOnDisconnect()?yes:no ) ;
-			else if( name == "forward-to" )
+			else if( option.name == "forward-to" )
 				result.push_back( serverAddress() ) ;
-			else if( name == "port" )
+			else if( option.name == "port" )
 				result.push_back( (doSmtp()&&doServing()) ? G::Str::fromUInt(port()) : std::string() ) ;
-			else if( name == "pop-port" )
+			else if( option.name == "pop-port" )
 				result.push_back( (doPop()&&doServing()) ? G::Str::fromUInt(popPort()) : std::string() ) ;
-			else if( m_options.multivalued(name) )
-				result.push_back( m_map.value(name) ) ;
-			else if( m_options.valued(name) && pathlike(name) )
-				result.push_back( m_map.contains(name) ? pathValue(name).str() : std::string() ) ;
-			else if( m_options.valued(name) )
-				result.push_back( m_map.value(name) ) ;
+			else if( option.multivalued() )
+				result.push_back( m_map.value(option.name) ) ;
+			else if( option.valued() && pathlike(option.name) )
+				result.push_back( m_map.contains(option.name) ? pathValue(option.name).str() : std::string() ) ;
+			else if( option.valued() )
+				result.push_back( m_map.value(option.name) ) ;
 			else
-				result.push_back( m_map.contains(name) ? yes : no ) ;
+				result.push_back( m_map.contains(option.name) ? yes : no ) ;
 		}
 	}
 	return result ;
 }
+#endif
 
diff --git a/src/main/configuration.h b/src/main/configuration.h
index 4c64198..61c016e 100644
--- a/src/main/configuration.h
+++ b/src/main/configuration.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -25,9 +25,12 @@
 #include "garg.h"
 #include "goptions.h"
 #include "goptionmap.h"
+#include "gfactoryparser.h"
+#include "gdatetime.h"
 #include "gpath.h"
 #include "gstrings.h"
 #include "glogoutput.h"
+#include <vector>
 #include <string>
 
 namespace Main
@@ -44,7 +47,7 @@ namespace Main
 class Main::Configuration
 {
 public:
-	Configuration( const G::Options & , const G::OptionMap & , const G::Path & app_dir , const G::Path & base_dir ) ;
+	Configuration( const std::vector<G::Option> & , const G::OptionMap & , const G::Path & app_dir , const G::Path & base_dir ) ;
 		///< Constructor. The app-dir path is used as a substitution
 		///< value, and the base-dir path is used to turn relative paths
 		///< into absolute ones when daemon() is true.
@@ -64,8 +67,11 @@ public:
 	unsigned int port() const ;
 		///< Returns the main listening port number.
 
-	G::StringArray listeningAddresses( const std::string & protocol = std::string() ) const ;
-		///< Returns the listening addresses.
+	bool closeFiles() const ;
+		///< Returns true if the server should start by closing file descriptors.
+
+	G::StringArray listeningNames( const std::string & protocol = std::string() ) const ;
+		///< Returns the listening addresses, interfaces and file descriptors.
 
 	std::string clientBindAddress() const ;
 		///< Returns the sending address.
@@ -161,11 +167,11 @@ public:
 	bool useFilter() const ;
 		///< Returns true if pre-processing.
 
-	G::Path filter() const ;
-		///< Returns the path to a server-side pre-processor.
+	GSmtp::FactoryParser::Result filter() const ;
+		///< Returns the spec for the server-side pre-processor(s).
 
-	G::Path clientFilter() const ;
-		///< Returns the path to a client-side pre-processor.
+	GSmtp::FactoryParser::Result clientFilter() const ;
+		///< Returns the spec for the client-side pre-processor(s).
 
 	unsigned int filterTimeout() const ;
 		///< Returns the timeout for executing an ansynchronous
@@ -219,8 +225,8 @@ public:
 		///< Returns the name of an unprivileged user. This is only
 		///< used if running with a real user-id of root.
 
-	G::Path verifier() const ;
-		///< Returns the path of an external address verifier program.
+	GSmtp::FactoryParser::Result verifier() const ;
+		///< Returns the spec of an address verifier.
 
 	bool doPolling() const ;
 		///< Returns true if doing poll-based forwarding.
@@ -228,7 +234,7 @@ public:
 	bool pollingLog() const ;
 		///< Returns true if polling activity should be logged.
 
-	unsigned int pollingTimeout() const ;
+	G::TimeInterval pollingTimeout() const ;
 		///< Returns the timeout for periodic polling.
 
 	bool immediate() const ;
@@ -253,10 +259,22 @@ public:
 	unsigned int scannerResponseTimeout() const ;
 		///< Returns a timeout for talking to the scanner process.
 
-	bool anonymous() const ;
+	bool anonymousServerVrfy() const ;
+		///< Returns true if the server protocol should not
+		///< allow VRFY.
+
+	bool anonymousServerSmtp() const ;
 		///< Returns true if the server protocol should be
 		///< slightly more anonymous.
 
+	bool anonymousContent() const ;
+		///< Returns true if the server should not add a
+		///< received line.
+
+	bool anonymousClientSmtp() const ;
+		///< Returns true if the client protocol should be
+		///< slightly more anonymous.
+
 	bool clientTls() const ;
 		///< Returns true if the client protocol should take
 		///< account of the server's TLS capability.
@@ -327,19 +345,20 @@ public:
 private:
 	G::Path pathValue( const std::string & option ) const ;
 	G::Path pathValueImp( const std::string & value ) const ;
+	GSmtp::FactoryParser::Result specValue( const std::string & , bool is_filter , G::StringArray * = nullptr ) const ;
 	G::Path keyFile( const std::string & option ) const ;
 	G::Path certificateFile( const std::string & option ) const ;
-	std::string semanticError( bool & ) const ;
 	static bool pathlike( const std::string & ) ;
 	static bool filterType( const std::string & ) ;
-	static bool specialFilterValue( const std::string & ) ;
 	static bool verifyType( const std::string & ) ;
 	static bool specialVerifyValue( const std::string & ) ;
 	G::StringArray semantics( bool ) const ;
 	bool validSyslogFacility() const ;
+	bool anonymous( G::string_view ) const ;
+	const char * semanticErrorImp( std::string & ) const ;
 
 private:
-	G::Options m_options ;
+	std::vector<G::Option> m_options ;
 	G::OptionMap m_map ;
 	G::Path m_app_dir ;
 	G::Path m_base_dir ;
diff --git a/src/main/doxygen.h b/src/main/doxygen.h
index 3ac005a..67ef84a 100644
--- a/src/main/doxygen.h
+++ b/src/main/doxygen.h
@@ -1,5 +1,5 @@
 /*
-   Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+   Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
diff --git a/src/main/emailrelay.rc b/src/main/emailrelay.rc
index a7df416..4020899 100644
--- a/src/main/emailrelay.rc
+++ b/src/main/emailrelay.rc
@@ -1,78 +1,78 @@
-
-#include <windows.h>
-#include "resource.h"
-
-LANGUAGE 0x9,0x1
-1 11 "MSG00001.bin"
-
-IDD_PROPPAGE_1 DIALOGEX 0, 0, 259, 178
-STYLE DS_SETFONT | DS_FIXEDSYS | WS_CHILD | WS_DISABLED | WS_CAPTION
-CAPTION "Property Page"
-FONT 8, "MS Shell Dlg", 400, 0, 0x0
-BEGIN
-    CONTROL         "",IDC_LIST1,"SysListView32",LVS_REPORT | LVS_ALIGNLEFT | WS_BORDER | WS_TABSTOP,7,7,245,164
-END
-
-IDD_DIALOG1 DIALOG 0, 0, 259, 190
-STYLE DS_SETFONT | WS_CHILD
-FONT 8, "MS Sans Serif"
-BEGIN
-    DEFPUSHBUTTON   "OK",IDOK,105,169,50,14
-    EDITTEXT        IDC_EDIT1,7,7,245,153,ES_MULTILINE | ES_READONLY | WS_VSCROLL
-END
-
-IDD_DIALOG2 DIALOGEX 0, 0, 311, 194
-STYLE DS_SETFONT | DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
-CAPTION "Dialog"
-FONT 8, "MS Sans Serif", 0, 0, 0x0
-BEGIN
-    DEFPUSHBUTTON   "OK",IDOK,130,174,50,14
-    EDITTEXT        IDC_EDIT1,7,7,297,163,ES_MULTILINE | ES_AUTOVSCROLL | ES_AUTOHSCROLL | ES_READONLY | WS_VSCROLL | WS_HSCROLL
-END
-
-IDI_ICON1               ICON                    "emailrelay-icon.ico"
-
-IDR_MENU1 MENU
-BEGIN
-    POPUP "popup"
-    BEGIN
-        MENUITEM "&Open",                       IDM_OPEN
-        MENUITEM "&Close",                      IDM_CLOSE
-        MENUITEM "&Quit",                       IDM_QUIT
-    END
-END
-
-VS_VERSION_INFO VERSIONINFO
- FILEVERSION 2, 3, 0, 0
- PRODUCTVERSION 2, 3, 0, 0
- FILEFLAGSMASK 0x3fL
-#ifdef _DEBUG
- FILEFLAGS 0x1L
-#else
- FILEFLAGS 0x0L
-#endif
- FILEOS 0x10004L
- FILETYPE 0x1L
- FILESUBTYPE 0x0L
-BEGIN
-    BLOCK "StringFileInfo"
-    BEGIN
-        BLOCK "080904b0"
-        BEGIN
-            VALUE "Comments", "GPL v3 license"
-            VALUE "CompanyName", " "
-            VALUE "FileDescription", "E-MailRelay Application"
-            VALUE "FileVersion", "2, 3, 0, 0"
-            VALUE "InternalName", "emailrelay"
-            VALUE "LegalCopyright", "Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>"
-            VALUE "OriginalFilename", "emailrelay.exe"
-            VALUE "ProductName", "E-MailRelay"
-            VALUE "ProductVersion", "2, 3, 0, 0"
-        END
-    END
-    BLOCK "VarFileInfo"
-    BEGIN
-        VALUE "Translation", 0x809, 1200
-    END
-END
-
+
+#include <windows.h>
+#include "resource.h"
+
+LANGUAGE 0x9,0x1
+1 11 "MSG00001.bin"
+
+IDD_PROPPAGE_1 DIALOGEX 0, 0, 259, 178
+STYLE DS_SETFONT | DS_FIXEDSYS | WS_CHILD | WS_DISABLED | WS_CAPTION
+CAPTION "Property Page"
+FONT 8, "MS Shell Dlg", 400, 0, 0x0
+BEGIN
+    CONTROL         "",IDC_LIST1,"SysListView32",LVS_REPORT | LVS_ALIGNLEFT | WS_BORDER | WS_TABSTOP,7,7,245,164
+END
+
+IDD_DIALOG1 DIALOG 0, 0, 259, 190
+STYLE DS_SETFONT | WS_CHILD
+FONT 8, "MS Sans Serif"
+BEGIN
+    DEFPUSHBUTTON   "OK",IDOK,105,169,50,14
+    EDITTEXT        IDC_EDIT1,7,7,245,153,ES_MULTILINE | ES_READONLY | WS_VSCROLL
+END
+
+IDD_DIALOG2 DIALOGEX 0, 0, 311, 194
+STYLE DS_SETFONT | DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
+CAPTION "Dialog"
+FONT 8, "MS Sans Serif", 0, 0, 0x0
+BEGIN
+    DEFPUSHBUTTON   "OK",IDOK,130,174,50,14
+    EDITTEXT        IDC_EDIT1,7,7,297,163,ES_MULTILINE | ES_AUTOVSCROLL | ES_AUTOHSCROLL | ES_READONLY | WS_VSCROLL | WS_HSCROLL
+END
+
+IDI_ICON1               ICON                    "emailrelay-icon.ico"
+
+IDR_MENU1 MENU
+BEGIN
+    POPUP "popup"
+    BEGIN
+        MENUITEM "&Open",                       IDM_OPEN
+        MENUITEM "&Close",                      IDM_CLOSE
+        MENUITEM "&Quit",                       IDM_QUIT
+    END
+END
+
+VS_VERSION_INFO VERSIONINFO
+ FILEVERSION 2, 4, 0, 0
+ PRODUCTVERSION 2, 4, 0, 0
+ FILEFLAGSMASK 0x3fL
+#ifdef _DEBUG
+ FILEFLAGS 0x1L
+#else
+ FILEFLAGS 0x0L
+#endif
+ FILEOS 0x10004L
+ FILETYPE 0x1L
+ FILESUBTYPE 0x0L
+BEGIN
+    BLOCK "StringFileInfo"
+    BEGIN
+        BLOCK "080904b0"
+        BEGIN
+            VALUE "Comments", "GPL v3 license"
+            VALUE "CompanyName", " "
+            VALUE "FileDescription", "E-MailRelay Application"
+            VALUE "FileVersion", "2, 4, 0, 0"
+            VALUE "InternalName", "emailrelay"
+            VALUE "LegalCopyright", "Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>"
+            VALUE "OriginalFilename", "emailrelay.exe"
+            VALUE "ProductName", "E-MailRelay"
+            VALUE "ProductVersion", "2, 4, 0, 0"
+        END
+    END
+    BLOCK "VarFileInfo"
+    BEGIN
+        VALUE "Translation", 0x809, 1200
+    END
+END
+
diff --git a/src/main/fakemc.c b/src/main/fakemc.c
index 6915853..3f40812 100644
--- a/src/main/fakemc.c
+++ b/src/main/fakemc.c
@@ -1,5 +1,5 @@
 /*
-   Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+   Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
    
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
diff --git a/src/main/filter.cpp b/src/main/filter.cpp
index 10815db..298a5a2 100644
--- a/src/main/filter.cpp
+++ b/src/main/filter.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -43,7 +43,7 @@
 #include <set>
 #include <string>
 
-G_EXCEPTION_CLASS( FilterError , "filter error" ) ;
+G_EXCEPTION_CLASS( FilterError , tx("filter error") ) ;
 
 static void help( const std::string & prefix )
 {
diff --git a/src/main/icon/Makefile.am b/src/main/icon/Makefile.am
index d2cedca..95676aa 100644
--- a/src/main/icon/Makefile.am
+++ b/src/main/icon/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
diff --git a/src/main/legal.cpp b/src/main/legal.cpp
index 95de8a9..ae76966 100644
--- a/src/main/legal.cpp
+++ b/src/main/legal.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/main/legal.h b/src/main/legal.h
index 1782d16..072e81f 100644
--- a/src/main/legal.h
+++ b/src/main/legal.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/main/licence.cpp b/src/main/licence.cpp
index ea04b37..7b68ece 100644
--- a/src/main/licence.cpp
+++ b/src/main/licence.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/main/licence.h b/src/main/licence.h
index 6d8d390..a208694 100644
--- a/src/main/licence.h
+++ b/src/main/licence.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/main/main.cpp b/src/main/main.cpp
index 547e73f..dd046ba 100644
--- a/src/main/main.cpp
+++ b/src/main/main.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -35,7 +35,7 @@ class Main::App : public Main::Output
 {
 private: // overrides
 	void output( const std::string & text , bool e , bool ) override ;
-	G::Options::Layout outputLayout( bool verbose ) const override ;
+	G::OptionsUsage::Config outputLayout( bool verbose ) const override ;
 	bool outputSimple() const override ;
 } ;
 
@@ -45,7 +45,7 @@ void Main::App::output( const std::string & text , bool e , bool )
 	s << text << std::flush ;
 }
 
-G::Options::Layout Main::App::outputLayout( bool ) const
+G::OptionsUsage::Config Main::App::outputLayout( bool ) const
 {
 	return {} ;
 }
@@ -70,6 +70,11 @@ int main( int argc , char * argv [] )
 			ok = true ;
 		}
 	}
+	catch( GNet::SocketBase::SocketBindError & e )
+	{
+		std::cerr << G::Arg::prefix(argv) << ": error: " << e.what() << std::endl ;
+		return 2 ;
+	}
 	catch( std::exception & e )
 	{
 		std::cerr << G::Arg::prefix(argv) << ": error: " << e.what() << std::endl ;
diff --git a/src/main/messages.mc b/src/main/messages.mc
index 2174f2d..2927af8 100644
--- a/src/main/messages.mc
+++ b/src/main/messages.mc
@@ -1,65 +1,65 @@
-
-SeverityNames=(Success=0x0:STATUS_SEVERITY_SUCCESS
- Informational=0x1:STATUS_SEVERITY_INFORMATIONAL
- Warning=0x2:STATUS_SEVERITY_WARNING
- Error=0x3:STATUS_SEVERITY_ERROR
-)
-
-FacilityNames=(Application=0x0:FACILITY_APPLICATION
-)
-
-MessageId=0x1
-SymbolicName=CATEGORY_1
-Language=English
-General
-.
-
-MessageIdTypedef=DWORD
-
-MessageId=1001
-Severity=Informational
-Facility=Application
-SymbolicName=MSG_INFO
-Language=English
-%1!S!
-.
-
-MessageId=1002
-Severity=Warning
-Facility=Application
-SymbolicName=MSG_WARNING
-Language=English
-%1!S!
-.
-
-MessageId=1003
-Severity=Error
-Facility=Application
-SymbolicName=MSG_ERROR
-Language=English
-%1!S!
-.
-
-MessageId=1011
-Severity=Informational
-Facility=Application
-SymbolicName=MSG_INFO
-Language=English
-%1
-.
-
-MessageId=1012
-Severity=Warning
-Facility=Application
-SymbolicName=MSG_WARNING
-Language=English
-%1
-.
-
-MessageId=1013
-Severity=Error
-Facility=Application
-SymbolicName=MSG_ERROR
-Language=English
-%1
-.
+
+SeverityNames=(Success=0x0:STATUS_SEVERITY_SUCCESS
+ Informational=0x1:STATUS_SEVERITY_INFORMATIONAL
+ Warning=0x2:STATUS_SEVERITY_WARNING
+ Error=0x3:STATUS_SEVERITY_ERROR
+)
+
+FacilityNames=(Application=0x0:FACILITY_APPLICATION
+)
+
+MessageId=0x1
+SymbolicName=CATEGORY_1
+Language=English
+General
+.
+
+MessageIdTypedef=DWORD
+
+MessageId=1001
+Severity=Informational
+Facility=Application
+SymbolicName=MSG_INFO
+Language=English
+%1!S!
+.
+
+MessageId=1002
+Severity=Warning
+Facility=Application
+SymbolicName=MSG_WARNING
+Language=English
+%1!S!
+.
+
+MessageId=1003
+Severity=Error
+Facility=Application
+SymbolicName=MSG_ERROR
+Language=English
+%1!S!
+.
+
+MessageId=1011
+Severity=Informational
+Facility=Application
+SymbolicName=MSG_INFO
+Language=English
+%1
+.
+
+MessageId=1012
+Severity=Warning
+Facility=Application
+SymbolicName=MSG_WARNING
+Language=English
+%1
+.
+
+MessageId=1013
+Severity=Error
+Facility=Application
+SymbolicName=MSG_ERROR
+Language=English
+%1
+.
diff --git a/src/main/news.cpp b/src/main/news.cpp
index b4e4999..99352c2 100644
--- a/src/main/news.cpp
+++ b/src/main/news.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/main/news.h b/src/main/news.h
index 4e60f8d..b3de4b9 100644
--- a/src/main/news.h
+++ b/src/main/news.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/main/options.cpp b/src/main/options.cpp
index 1a4c736..7277a6e 100644
--- a/src/main/options.cpp
+++ b/src/main/options.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,62 +22,113 @@
 #include "options.h"
 #include "ggettext.h"
 
+namespace Main
+{
+	namespace OptionsImp
+	{
+		constexpr unsigned int t_logging = 1U<<0 ;
+		constexpr unsigned int t_process = 1U<<1 ;
+		constexpr unsigned int t_tls = 1U<<2 ;
+		//constexpr unsigned int t_xxx = 1U<<3 ;
+		constexpr unsigned int t_smtpclient = 1U<<4 ;
+		constexpr unsigned int t_smtpserver = 1U<<5 ;
+		constexpr unsigned int t_pop = 1U<<6 ;
+		constexpr unsigned int t_info = 1U<<7 ;
+		constexpr unsigned int t_auth = 1U<<8 ;
+		constexpr unsigned int t_admin = 1U<<9 ;
+		constexpr unsigned int t_filter = 1U<<10 ;
+		constexpr unsigned int t_basic = 1U<<11 ;
+	}
+}
+
+std::vector<Main::Options::Tag> Main::Options::tags()
+{
+	using namespace Main::OptionsImp ;
+	using G::tx ;
+	return {
+		{ t_basic , tx("Basic options") } ,
+		{ t_smtpclient , tx("SMTP client options") } ,
+		{ t_smtpserver , tx("SMTP server options") } ,
+		{ t_pop , tx("POP server options") } ,
+		{ t_admin , tx("Admin server options") } ,
+		{ t_auth , tx("Authentication options") } ,
+		{ t_tls , tx("TLS options") } ,
+		{ t_process , tx("Process options") } ,
+		{ t_logging , tx("Logging options") } ,
+	} ;
+}
+
 // clang-format off
 
 G::Options Main::Options::spec( bool is_windows )
 {
-	using G::gettext ;
+	using G::tx ;
+	using M = G::Option::Multiplicity ;
+	using namespace Main::OptionsImp ;
+
 	G::Options opt ;
 
 	if( is_windows )
 	{
-		opt.add( { "l" , "log" ,
-			gettext("log information on stderr and to the event log! "
-				"(but see --close-stderr and --no-syslog)") ,
-			"0" , "" , "2" } , '!' ) ;
+		#ifdef G_WINDOWS
 
-		opt.add( { "t" , "no-daemon" ,
-			gettext("uses an ordinary window, not the system tray!, equivalent to --show=window") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'l' , "log" ,
+			tx("log information on stderr and to the event log! "
+				"(but see --close-stderr and --no-syslog)") , "" ,
+			M::zero , "" , 20 ,
+			t_logging ) ;
 
-		opt.add( { "k" , "syslog" ,
-			gettext("forces system event log output if logging is enabled (overrides --no-syslog)") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 't' , "no-daemon" ,
+			tx("uses an ordinary window, not the system tray!, equivalent to --show=window") , "" ,
+			M::zero , "" , 30 ,
+			t_process ) ;
 
-		opt.add( { "n" , "no-syslog" ,
-			gettext("disables use of the system event log") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'k' , "syslog" ,
+			tx("forces system event log output if logging is enabled (overrides --no-syslog)") , "" ,
+			M::zero , "" , 30 ,
+			t_logging ) ;
 
-		opt.add( { "H" , "hidden" ,
-			gettext("hides the application window and suppresses message boxes (requires --no-daemon)") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'n' , "no-syslog" ,
+			tx("disables use of the system event log") , "" ,
+			M::zero , "" , 30 ,
+			t_logging ) ;
+
+		G::Options::add( opt , 'H' , "hidden" ,
+			tx("hides the application window and suppresses message boxes (requires --no-daemon)") , "" ,
+			M::zero , "" , 30 ,
+			t_process ) ;
 				// Windows only. Hides the application window and disables all message
 				// boxes, overriding any --show option. This is useful when running
 				// as a windows service.
 
-		opt.add( { "" , "show" ,
-			gettext("start the application window in the given style") ,
-			"1" , "style" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "show" ,
+			tx("start the application window in the given style") , "" ,
+			M::one , "style" , 30 ,
+			t_process ) ;
 				// Windows only. Starts the application window in the given style: "hidden",
 				// "popup", "window", "window,tray", or "tray". Ignored if also using
 				// --no-daemon or --hidden. If none of --window, --no-daemon and
 				// --hidden are used then the default style is "tray".
+
+		#endif
 	}
 	else
 	{
-		opt.add( { "l" , "log" ,
-			gettext("writes log information on standard error and syslog! "
-				"(but see --close-stderr and --no-syslog)") ,
-			 "0" , "" , "2" } , '!' ) ;
+		G::Options::add( opt , 'l' , "log" ,
+			tx("writes log information on standard error and syslog! "
+				"(but see --close-stderr and --no-syslog)") , "" ,
+			M::zero , "" , 20 ,
+			t_logging ) ;
 				// Enables logging to the standard error stream and to the syslog. The
 				// --close-stderr and --no-syslog options can be used to disable output to
 				// standard error stream and the syslog separately. Note that --as-server,
 				// --as-client and --as-proxy imply --log, and --as-server and --as-proxy
 				// also imply --close-stderr.
 
-		opt.add( { "t" , "no-daemon" ,
-			gettext("does not detach from the terminal") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 't' , "no-daemon" ,
+			tx("does not detach from the terminal") , "" ,
+			M::zero , "" , 30 ,
+			t_process ) ;
 				// Disables the normal backgrounding at startup so that the program
 				// runs in the foreground, without forking or detaching from the
 				// terminal.
@@ -86,9 +137,10 @@ G::Options Main::Options::spec( bool is_windows )
 				// uses a normal window; when the window is closed the program
 				// terminates.
 
-		opt.add( { "u" , "user" ,
-			gettext("names the effective user to switch to if started as root (default is \"daemon\")") ,
-			"1" , "username" , "3" } , '!' ) ;
+		G::Options::add( opt , 'u' , "user" ,
+			tx("names the effective user to switch to if started as root (default is \"daemon\")") , "" ,
+			M::one , "username" , 30 ,
+			t_process ) ;
 				//default: daemon
 				//example: nobody
 				// When started as root the program switches to a non-privileged effective
@@ -96,22 +148,25 @@ G::Options Main::Options::spec( bool is_windows )
 				// also the group ownership of new files and sockets. Specify "root" to
 				// disable all user-id switching. Ignored on Windows.
 
-		opt.add( { "k" , "syslog" ,
-			gettext("forces syslog output if logging is enabled (overrides --no-syslog)") ,
-			"01" , "facility" , "3" } , '!' ) ;
+		G::Options::add( opt , 'k' , "syslog" ,
+			tx("forces syslog output if logging is enabled (overrides --no-syslog)") , "" ,
+			M::zero_or_one , "facility" , 30 ,
+			t_logging ) ;
 				// When used with --log this option enables logging to the syslog even
 				// if the --no-syslog option is also used. This is typically used as
 				// a convenient override when using --as-client.
 
-		opt.add( { "n" , "no-syslog" ,
-			gettext("disables syslog output (always overridden by --syslog)") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'n' , "no-syslog" ,
+			tx("disables syslog output (always overridden by --syslog)") , "" ,
+			M::zero , "" , 30 ,
+			t_logging ) ;
 				// Disables logging to the syslog. Note that
 				// --as-client implies --no-syslog.
 
-		opt.add( { "" , "localedir" ,
-			gettext("enables text localisation using the given locale base directory") ,
-				"1" , "dir" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "localedir" ,
+			tx("enables text localisation using the given locale base directory") , "" ,
+				M::one , "dir" , 30 ,
+				t_process ) ;
 					//example: /opt/share/locale
 					// Enables localisation and specifies the locale base directory where
 					// message catalogues can be found. An empty directory can be used
@@ -119,104 +174,117 @@ G::Options Main::Options::spec( bool is_windows )
 	}
 
 	{
-		opt.add( { "q" , "as-client" ,
-			gettext("runs as a client, forwarding all spooled mail to <host>!: "
-				"equivalent to \"--log --no-syslog --no-daemon --dont-serve --forward --forward-to\"") ,
-			"1" , "host:port" , "1" } , '!' ) ;
+		G::Options::add( opt , 'q' , "as-client" ,
+			tx("runs as a client, forwarding all spooled mail to <host>!: "
+				"equivalent to \"--log --no-syslog --no-daemon --dont-serve --forward --forward-to\"") , "" ,
+			M::one , "host:port" , 10 ,
+			t_basic , t_smtpclient ) ;
 				//example: smtp.example.com:25
 				// This is equivalent to --log, --no-syslog, --no-daemon, --dont-serve,
 				// --forward and --forward-to. It is a convenient way of running a
 				// forwarding agent that forwards spooled mail messages and then
 				// terminates.
 
-		opt.add( { "d" , "as-server" ,
-			gettext("runs as a server, storing mail in the spool directory!: "
-				"equivalent to \"--log --close-stderr\"") ,
-			"0" , "" , "1" } , '!' ) ;
+		G::Options::add( opt , 'd' , "as-server" ,
+			tx("runs as a server, storing mail in the spool directory!: "
+				"equivalent to \"--log --close-stderr\"") , "" ,
+			M::zero , "" , 10 ,
+			t_basic , t_smtpserver ) ;
 				// This is equivalent to --log and --close-stderr. It is a convenient way
 				// of running a background storage daemon that accepts mail messages and
 				// spools them. Use --log instead of --as-server to keep standard error
 				// stream open.
 
-		opt.add( { "y" , "as-proxy" ,
-			gettext("runs as a proxy server, forwarding each mail immediately to <host>!: "
-				"equivalent to \"--log --close-stderr --forward-on-disconnect --forward-to\"") ,
-			"1" , "host:port" , "1" } , '!' ) ;
+		G::Options::add( opt , 'y' , "as-proxy" ,
+			tx("runs as a proxy server, forwarding each mail immediately to <host>!: "
+				"equivalent to \"--log --close-stderr --forward-on-disconnect --forward-to\"") , "" ,
+			M::one , "host:port" , 10 ,
+			t_basic ) ;
 				//example: smtp.example.com:25
 				// This is equivalent to --log, --close-stderr, --forward-on-disconnect and
 				// --forward-to. It is a convenient way of running a store-and-forward
 				// daemon. Use --log, --forward-on-disconnect and --forward-to instead
 				// of --as-proxy to keep the standard error stream open.
 
-		opt.add( { "v" , "verbose" ,
-			gettext("generates more verbose output! "
-				"(works with --help and --log)") ,
-			"0" , "" , "1" } , '!' ) ;
+		G::Options::add( opt , 'v' , "verbose" ,
+			tx("generates more verbose output! "
+				"(works with --help and --log)") , "" ,
+			M::zero , "" , 10 ,
+			t_logging , t_basic ) ;
 				// Enables more verbose logging when used with --log, and more verbose
 				// help when used with --help.
 
-		opt.add( { "h" , "help" ,
-			gettext("displays help text and exits") ,
-			"0" , "" , "1" } , '!' ) ;
+		G::Options::add( opt , 'h' , "help" ,
+			tx("displays help text and exits") , "" ,
+			M::zero , "" , 11 ,
+			t_basic , t_info ) ;
 				// Displays help text and then exits. Use with --verbose for more complete
 				// output.
 
-		opt.add( { "p" , "port" ,
-			gettext("specifies the SMTP listening port number (default is 25)") ,
-			"1" , "port" , "2" } , '!' ) ;
+		G::Options::add( opt , 'p' , "port" ,
+			tx("specifies the SMTP listening port number (default is 25)") , "" ,
+			M::one , "port" , 20 ,
+			t_smtpserver ) ;
 				//default: 25
 				//example: 587
 				// Sets the port number used for listening for incoming SMTP connections.
 
-		opt.add( { "r" , "remote-clients" ,
-			gettext("allows remote clients to connect") ,
-			"0" , "" , "2" } , '!' ) ;
+		G::Options::add( opt , 'r' , "remote-clients" ,
+			tx("allows remote clients to connect") , "" ,
+			M::zero , "" , 20 ,
+			t_smtpserver ) ;
 				// Allows incoming connections from addresses that are not local. The
 				// default behaviour is to reject connections that are not local in
 				// order to prevent accidental exposure to the public internet,
 				// although a firewall should also be used. Local address ranges are
 				// defined in RFC-1918, RFC-6890 etc.
 
-		opt.add( { "s" , "spool-dir" ,
-			gettext("specifies the spool directory") ,
-			"1" , "dir" , "2" } , '!' ) ;
+		G::Options::add( opt , 's' , "spool-dir" ,
+			tx("specifies the spool directory") , "" ,
+			M::one , "dir" , 10 ,
+			t_basic ) ;
 				//example: /var/spool/emailrelay
 				//example: C:/ProgramData/E-MailRelay/spool
 				// Specifies the directory used for holding mail messages that have been
 				// received but not yet forwarded.
 
-		opt.add( { "V" , "version" ,
-			gettext("displays version information and exits") ,
-			"0" , "" , "2" } , '!' ) ;
+		G::Options::add( opt , 'V' , "version" ,
+			tx("displays version information and exits") , "" ,
+			M::zero , "" , 20 ,
+			t_basic , t_info|t_logging ) ;
 				// Displays version information and then exits.
 
-		opt.add( { "K" , "server-tls" ,
-			gettext("enables negotiated TLS when acting as an SMTP server! "
-				"(ie. STARTTLS) (requires --server-tls-certificate)") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'K' , "server-tls" ,
+			tx("enables negotiated TLS when acting as an SMTP server! "
+				"(ie. STARTTLS) (requires --server-tls-certificate)") , "" ,
+			M::zero , "" , 30 ,
+			t_tls , t_smtpserver ) ;
 				// Enables TLS for incoming SMTP and POP connections. SMTP clients can
 				// then request TLS encryption by issuing the STARTTLS command. The
 				// --server-tls-certificate option must be used to define the server
 				// certificate.
 
-		opt.add( { "" , "server-tls-connection" ,
-			gettext("enables implicit TLS when acting as an SMTP server! "
-				"(ie. SMTPS) (requires --server-tls-certificate)") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "server-tls-connection" ,
+			tx("enables implicit TLS when acting as an SMTP server! "
+				"(ie. SMTPS) (requires --server-tls-certificate)") , "" ,
+			M::zero , "" , 30 ,
+			t_tls , t_smtpserver ) ;
 				// Enables SMTP over TLS when acting as an SMTP server. This is for SMTP
 				// over TLS (SMTPS), not TLS negotiated within SMTP using STARTTLS.
 
-		opt.add( { "" , "server-tls-required" ,
-			gettext("mandatory use of TLS before SMTP server authentication or mail-to") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "server-tls-required" ,
+			tx("mandatory use of TLS before SMTP server authentication or mail-to") , "" ,
+			M::zero , "" , 30 ,
+			t_tls , t_smtpserver ) ;
 				// Makes the use of TLS mandatory for any incoming SMTP and POP connections.
 				// SMTP clients must use the STARTTLS command to establish a TLS session
 				// before they can issue SMTP AUTH or SMTP MAIL-TO commands.
 
-		opt.add( { "" , "server-tls-certificate" ,
-			gettext("specifies a private TLS key+certificate file for --server-tls! "
-				"or --server-tls-connection") ,
-			"2" , "pem-file" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "server-tls-certificate" ,
+			tx("specifies a private TLS key+certificate file for --server-tls! "
+				"or --server-tls-connection") , "" ,
+			M::many , "pem-file" , 30 ,
+			t_tls , t_smtpserver ) ;
 				//example: /etc/ssl/certs/emailrelay.pem
 				//example: C:/ProgramData/E-MailRelay/emailrelay.pem
 				// Defines the TLS certificate file when acting as a SMTP or POP server.
@@ -226,83 +294,94 @@ G::Options Main::Options::spec( bool is_windows )
 				// certificate file. Keep the file permissions tight to avoid
 				// accidental exposure of the private key.
 
-		opt.add( { "" , "server-tls-verify" ,
-			gettext("enables verification of remote client's certificate! "
-				"against CA certificates in the given file or directory") ,
-			"1" , "ca-list" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "server-tls-verify" ,
+			tx("enables verification of remote client's certificate! "
+				"against CA certificates in the given file or directory") , "" ,
+			M::one , "ca-list" , 30 ,
+			t_tls , t_smtpserver ) ;
 				//example: /etc/ssl/certs/ca-certificates.crt
 				//example: C:/ProgramData/E-MailRelay/ca-certificates.crt
 				// Enables verification of remote SMTP and POP clients' certificates
 				// against any of the trusted CA certificates in the specified file
 				// or directory. In many use cases this should be a file containing
-				// just your self-signed root certificate.
+				// just your self-signed root certificate. Specify "<default>" for
+				// the TLS library's default set of trusted CAs.
 
-		opt.add( { "j" , "client-tls" ,
-			gettext("enables negotiated TLS when acting as an SMTP client! "
-				"(ie. STARTTLS)") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'j' , "client-tls" ,
+			tx("enables negotiated TLS when acting as an SMTP client! "
+				"(ie. STARTTLS)") , "" ,
+			M::zero , "" , 30 ,
+			t_tls , t_smtpclient ) ;
 				// Enables negotiated TLS for outgoing SMTP connections; the SMTP
 				// STARTTLS command will be issued if the remote server supports it.
 
-		opt.add( { "b" , "client-tls-connection" ,
-			gettext("enables SMTP over TLS for SMTP client connections") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'b' , "client-tls-connection" ,
+			tx("enables SMTP over TLS for SMTP client connections") , "" ,
+			M::zero , "" , 30 ,
+			t_tls , t_smtpclient ) ;
 				// Enables the use of a TLS tunnel for outgoing SMTP connections.
 				// This is for SMTP over TLS (SMTPS), not TLS negotiated within SMTP
 				// using STARTTLS.
 
-		opt.add( { "" , "client-tls-certificate" ,
-			gettext("specifies a private TLS key+certificate file for --client-tls") ,
-			"2" , "pem-file" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "client-tls-certificate" ,
+			tx("specifies a private TLS key+certificate file for --client-tls") , "" ,
+			M::many , "pem-file" , 30 ,
+			t_tls , t_smtpclient ) ;
 				//example: /etc/ssl/certs/emailrelay.pem
 				//example: C:/ProgramData/E-MailRelay/emailrelay.pem
 				// Defines the TLS certificate file when acting as a SMTP client. This file
 				// must contain the client's private key and certificate chain using the
 				// PEM file format. Alternatively, use this option twice with the first
 				// one specifying the key file and the second the certificate file.
-				// Keep the file permissions tight to avoid accidental exposure of the
-				// private key.
+				// Keep the file permissions tight to avoid accidental exposure of
+				// the private key.
 
-		opt.add( { "" , "client-tls-verify" ,
-			gettext("enables verification of remote server's certificate! "
-				"against CA certificates in the given file or directory") ,
-			"1" , "ca-list" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "client-tls-verify" ,
+			tx("enables verification of remote server's certificate! "
+				"against CA certificates in the given file or directory") , "" ,
+			M::one , "ca-list" , 30 ,
+			t_tls , t_smtpclient ) ;
 				//example: /etc/ssl/certs/ca-certificates.crt
 				//example: C:/ProgramData/E-MailRelay/ca-certificates.crt
 				// Enables verification of the remote SMTP server's certificate against
 				// any of the trusted CA certificates in the specified file or directory.
 				// In many use cases this should be a file containing just your self-signed
-				// root certificate.
+				// root certificate. Specify "<default>" for the TLS library's default
+				// set of trusted CAs.
 
-		opt.add( { "" , "client-tls-verify-name" ,
-			gettext("enables verification of the cname in the remote server's certificate! "
-				"(requires --client-tls-verify)") ,
-			"1" , "cname" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "client-tls-verify-name" ,
+			tx("enables verification of the cname in the remote server's certificate! "
+				"(requires --client-tls-verify)") , "" ,
+			M::one , "cname" , 30 ,
+			t_tls , t_smtpclient ) ;
 				//example: smtp.example.com
 				// Enables verification of the CNAME within the remote SMTP server's certificate.
 
-		opt.add( { "" , "client-tls-server-name" ,
-			gettext("includes the server hostname in the tls handshake! "
-				"(ie. server name identification)") ,
-			"1" , "hostname" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "client-tls-server-name" ,
+			tx("includes the server hostname in the tls handshake! "
+				"(ie. server name identification)") , "" ,
+			M::one , "hostname" , 30 ,
+			t_tls , t_smtpclient ) ;
 				//example: smtp.example.com
 				// Defines the target server hostname in the TLS handshake. With
 				// --client-tls-connection this can be used for SNI, allowing the remote
 				// server to adopt an appropriate identity.
 
-		opt.add( { "" , "client-tls-required" ,
-			gettext("mandatory use of TLS for SMTP client connections! "
-				"(requires --client-tls)") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "client-tls-required" ,
+			tx("mandatory use of TLS for SMTP client connections! "
+				"(requires --client-tls)") , "" ,
+			M::zero , "" , 30 ,
+			t_tls , t_smtpclient ) ;
 				// Makes the use of TLS mandatory for outgoing SMTP connections. The SMTP
 				// STARTTLS command will be used before mail messages are sent out.
 				// If the remote server does not allow STARTTLS then the SMTP connection
 				// will fail.
 
-		opt.add( { "9" , "tls-config" ,
-			gettext("sets low-level TLS configuration options! "
-				"(eg. tlsv1.2)") ,
-			"2" , "options" , "3" } , '!' ) ;
+		G::Options::add( opt , '9' , "tls-config" ,
+			tx("sets low-level TLS configuration options! "
+				"(eg. tlsv1.2)") , "" ,
+			M::many , "options" , 30 ,
+			t_tls ) ;
 				//example: mbedtls,tlsv1.2
 				// Selects and configures the low-level TLS library, using a comma-separated
 				// list of keywords. If OpenSSL and mbedTLS are both built in then keywords
@@ -310,16 +389,18 @@ G::Options Main::Options::spec( bool is_windows )
 				// "tlsv1.0" can be used to set a minimum TLS protocol version, or
 				// "-tlsv1.2" to set a maximum version.
 
-		opt.add( { "g" , "debug" ,
-			gettext("generates debug-level logging if built in") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'g' , "debug" ,
+			tx("generates debug-level logging if built in") , "" ,
+			M::zero , "" , 30 ,
+			t_logging ) ;
 				// Enables debug level logging, if built in. Debug messages are usually
 				// only useful when cross-referenced with the source code and they may
 				// expose plaintext passwords and mail message content.
 
-		opt.add( { "C" , "client-auth" ,
-			gettext("enables SMTP authentication with the remote server, using the given client secrets file") ,
-			"1" , "file" , "3" } , '!' ) ;
+		G::Options::add( opt , 'C' , "client-auth" ,
+			tx("enables SMTP authentication with the remote server, using the given client secrets file") , "" ,
+			M::one , "file" , 30 ,
+			t_auth , t_smtpclient ) ;
 				//example: /etc/emailrelay.auth
 				//example: C:/ProgramData/E-MailRelay/emailrelay.auth
 				// Enables SMTP client authentication with the remote server, using the
@@ -332,31 +413,38 @@ G::Options Main::Options::spec( bool is_windows )
 				// or generated by "emailrelay-passwd". If the remote server does not
 				// support SMTP authentication then the SMTP connection will fail.
 
-		opt.add( { "" , "client-auth-config" ,
-			gettext("configures the client authentication module") ,
-			"1" , "config" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "client-auth-config" ,
+			tx("configures the client authentication module") , "" ,
+			M::one , "config" , 30 ,
+			t_auth , t_smtpclient ) ;
 				//example: m:cram-sha1,cram-md5
 				//example: x:plain,login
+				//example: m:;a:plain
 				// Configures the SMTP client authentication module using a
 				// semicolon-separated list of configuration items. Each item is a
 				// single-character key, followed by a colon and then a comma-separated
-				// list. A 'm' character introduces an ordered list of authentication
-				// mechanisms, and an 'x' is used for blocklisted mechanisms.
+				// list. A 'm' character introduces an ordered list of preferred
+				// authentication mechanisms and an 'x' introduces a list of mechanisms
+				// to avoid. An 'a' list and a 'd' list can be used similarly to prefer
+				// and avoid certain mechanisms once the session is encrypted with TLS.
 
-		opt.add( { "L" , "log-time" ,
-			gettext("adds a timestamp to the logging output") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'L' , "log-time" ,
+			tx("adds a timestamp to the logging output") , "" ,
+			M::zero , "" , 30 ,
+			t_logging ) ;
 				// Adds a timestamp to the logging output using the local timezone.
 
-		opt.add( { "" , "log-address" ,
-			gettext("adds the network address of remote clients to the logging output") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "log-address" ,
+			tx("adds the network address of remote clients to the logging output") , "" ,
+			M::zero , "" , 30 ,
+			t_logging ) ;
 				// Adds the network address of remote clients to the logging output.
 
-		opt.add( { "N" , "log-file" ,
-			gettext("log to file instead of stderr! "
-				"(with '%d' replaced by the current date)") ,
-			"1" , "file" , "3" } , '!' ) ;
+		G::Options::add( opt , 'N' , "log-file" ,
+			tx("log to file instead of stderr! "
+				"(with '%d' replaced by the current date)") , "" ,
+			M::one , "file" , 30 ,
+			t_logging ) ;
 				//example: /var/log/emailrelay-%d
 				//example: C:/ProgramData/E-MailRelay/log-%d.txt
 				// Redirects standard-error logging to the specified file. Logging to
@@ -364,9 +452,10 @@ G::Options Main::Options::spec( bool is_windows )
 				// include "%d" to get daily log files; the "%d" is replaced by the
 				// current date in the local timezone using a "YYYYMMDD" format.
 
-		opt.add( { "S" , "server-auth" ,
-			gettext("enables authentication of remote SMTP clients, using the given server secrets file") ,
-			"1" , "file" , "3" } , '!' ) ;
+		G::Options::add( opt , 'S' , "server-auth" ,
+			tx("enables authentication of remote SMTP clients, using the given server secrets file") , "" ,
+			M::one , "file" , 30 ,
+			t_auth , t_smtpserver ) ;
 				//example: /etc/private/emailrelay.auth
 				//example: C:/ProgramData/E-MailRelay/emailrelay.auth
 				//example: /pam
@@ -380,51 +469,62 @@ G::Options Main::Options::spec( bool is_windows )
 				// "emailrelay-passwd". A special value of "/pam" can be used for
 				// authentication using linux PAM.
 
-		opt.add( { "" , "server-auth-config" ,
-			gettext("configures the server authentication module") ,
-			"1" , "config" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "server-auth-config" ,
+			tx("configures the server authentication module") , "" ,
+			M::one , "config" , 30 ,
+			t_auth , t_smtpserver ) ;
 				//example: m:cram-sha256,cram-sha1
 				//example: x:plain,login
+				//example: m:;a:plain
 				// Configures the SMTP server authentication module using a
 				// semicolon-separated list of configuration items. Each item is a
 				// single-character key, followed by a colon and then a comma-separated
-				// list. A 'm' character introduces a preferred sub-set of the built-in
-				// authentication mechanisms, and an 'x' is used for blocklisted
-				// mechanisms.
+				// list. A 'm' character introduces an ordered list of allowed
+				// authentication mechanisms and an 'x' introduces a list of
+				// mechanisms to deny. An 'a' list and a 'd' list can be used similarly
+				// to allow and deny mechanisms once the session is encrypted with
+				// TLS. In typical usage you might have an empty allow list for an
+				// unencrypted session and a single preferred mechanism once
+				// encrypted, "m:;a:plain".
 
-		opt.add( { "e" , "close-stderr" ,
-			gettext("closes the standard error stream soon after start-up") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'e' , "close-stderr" ,
+			tx("closes the standard error stream soon after start-up") , "" ,
+			M::zero , "" , 31 ,
+			t_logging , t_process ) ;
 				// Causes the standard error stream to be closed soon after start-up.
-				// This is useful when operating as a backgroud daemon and it is
+				// This is useful when operating as a background daemon and it is
 				// therefore implied by --as-server and --as-proxy.
 
-		opt.add( { "a" , "admin" ,
-			gettext("enables the administration interface and specifies its listening port number") ,
-			"1" , "admin-port" , "3" } , '!' ) ;
+		G::Options::add( opt , 'a' , "admin" ,
+			tx("enables the administration interface and specifies its listening port number") , "" ,
+			M::one , "port" , 30 ,
+			t_admin ) ;
 				//example: 587
 				// Enables an administration interface on the specified listening port
 				// number. Use telnet or something similar to connect. The administration
 				// interface can be used to trigger forwarding of spooled mail messages
 				// if the --forward-to option is used.
 
-		opt.add( { "x" , "dont-serve" ,
-			gettext("disables acting as a server on any port! "
-				"(part of --as-client and usually used with --forward)") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'x' , "dont-serve" ,
+			tx("disables acting as a server on any port! "
+				"(part of --as-client and usually used with --forward)") , "" ,
+			M::zero , "" , 30 ,
+			t_process ) ;
 				// Disables all network serving, including SMTP, POP and administration
 				// interfaces. The program will terminate as soon as any initial
 				// forwarding is complete.
 
-		opt.add( { "X" , "no-smtp" ,
-			gettext("disables listening for SMTP connections! "
-				"(usually used with --admin or --pop)") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'X' , "no-smtp" ,
+			tx("disables listening for SMTP connections! "
+				"(usually used with --admin or --pop)") , "" ,
+			M::zero , "" , 30 ,
+			t_process ) ;
 				// Disables listening for incoming SMTP connections.
 
-		opt.add( { "z" , "filter" ,
-			gettext("specifies an external program to process messages as they are stored") ,
-			"1" , "program" , "3" } , '!' ) ;
+		G::Options::add( opt , 'z' , "filter" ,
+			tx("specifies an external program to process messages as they are stored") , "" ,
+			M::many , "program" , 30 ,
+			t_smtpserver , t_filter ) ;
 				//example: /usr/local/sbin/emailrelay-filter
 				//example: C:/Program\ Files/E-MailRelay/filter.bat
 				//example: net:127.0.0.1:1111
@@ -435,106 +535,118 @@ G::Options Main::Options::spec( bool is_windows )
 				// stored. The filter is passed the name of the message file in the
 				// spool directory so that it can edit it as required. The mail message
 				// is rejected if the filter program terminates with an exit code between
-				// 1 and 99. Use "net:<transport-address>" to communicate with a filter
-				// daemon over the network, or "spam:<transport-address>" for a
+				// 1 and 99. Use "net:<tcp-address>" to communicate with a filter
+				// daemon over the network, or "spam:<tcp-address>" for a
 				// spamassassin spamd daemon to accept or reject mail messages, or
-				// "spam-edit:<transport-address>" to have spamassassin edit the message
+				// "spam-edit:<tcp-address>" to have spamassassin edit the message
 				// content without rejecting it, or "exit:<number>" to emulate a filter
 				// program that just exits.
 
-		opt.add( { "W" , "filter-timeout" ,
-			gettext("sets the timeout (in seconds) for running the --filter (default is 300)") ,
-			"1" , "time" , "3" } , '!' ) ;
-				//default: 300
+		G::Options::add( opt , 'W' , "filter-timeout" ,
+			tx("sets the timeout (in seconds) for running the --filter (default is 60)") , "" ,
+			M::one , "time" , 30 ,
+			t_smtpserver , t_filter ) ;
+				//default: 60
 				//example: 10
 				// Specifies a timeout (in seconds) for running a --filter program. The
-				// default is 300 seconds.
+				// default is 60 seconds.
 
-		opt.add( { "w" , "prompt-timeout" ,
-			gettext("sets the timeout (in seconds) for getting an initial prompt from the server (default is 20)") ,
-			"1" , "time" , "3" } , '!' ) ;
+		G::Options::add( opt , 'w' , "prompt-timeout" ,
+			tx("sets the timeout (in seconds) for getting an initial prompt from the server (default is 20)") , "" ,
+			M::one , "time" , 30 ,
+			t_smtpserver ) ;
 				//default: 20
 				//example: 3
 				// Specifies a timeout (in seconds) for getting the initial prompt from
 				// a remote SMTP server. If no prompt is received after this time then
 				// the SMTP dialog goes ahead without it.
 
-		opt.add( { "D" , "domain" ,
-			gettext("sets an override for the host's fully qualified network name") ,
-			"1" , "fqdn" , "3" } , '!' ) ;
+		G::Options::add( opt , 'D' , "domain" ,
+			tx("sets an override for the host's fully qualified network name") , "" ,
+			M::one , "fqdn" , 30 ,
+			t_smtpserver ) ;
 				//example: smtp.example.com
 				// Specifies the network name that is used in SMTP EHLO commands,
 				// "Received" lines, and for generating authentication challenges.
 				// The default is derived from a DNS lookup of the local hostname.
 
-		opt.add( { "f" , "forward" ,
-			gettext("forwards stored mail on startup! "
-				"(requires --forward-to)") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'f' , "forward" ,
+			tx("forwards stored mail on startup! "
+				"(requires --forward-to)") , "" ,
+			M::zero , "" , 30 ,
+			t_smtpclient ) ;
 				// Causes spooled mail messages to be forwarded when the program first
 				// starts.
 
-		opt.add( { "1" , "forward-on-disconnect" ,
-			gettext("forwards stored mail once the SMTP client disconnects! "
-				"(requires --forward-to)") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , '1' , "forward-on-disconnect" ,
+			tx("forwards stored mail once the SMTP client disconnects! "
+				"(requires --forward-to)") , "" ,
+			M::zero , "" , 30 ,
+			t_smtpclient ) ;
 				// Causes spooled mail messages to be forwarded whenever a SMTP client
 				// connection disconnects.
 
-		opt.add( { "o" , "forward-to" ,
-			gettext("specifies the address of the remote SMTP server! "
-				"(required by --forward, --forward-on-disconnect and --immediate)") ,
-			"1" , "host:port" , "3" } , '!' ) ;
+		G::Options::add( opt , 'o' , "forward-to" ,
+			tx("specifies the address of the remote SMTP server! "
+				"(required by --forward, --forward-on-disconnect and --immediate)") , "" ,
+			M::one , "host:port" , 30 ,
+			t_smtpclient ) ;
 				//example: smtp.example.com:25
-				// Specifies the transport address of the remote SMTP server that is
-				// use for mail message forwarding.
+				// Specifies the transport address of the remote SMTP server that
+				// spooled mail messages are forwarded to.
 
-		opt.add( { "" , "forward-to-some" ,
-			gettext("allows forwarding to some addressees! "
-				"even if others are rejected") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "forward-to-some" ,
+			tx("allows forwarding to some addressees even if others are rejected") , "" ,
+			M::zero , "" , 32 ,
+			t_smtpclient ) ;
 				// Allow forwarding to continue even if some recipient addresses on an
 				// e-mail envelope are rejected by the remote server.
 
-		opt.add( { "T" , "response-timeout" ,
-			gettext("sets the response timeout (in seconds) when talking to a remote server (default is 1800)") ,
-			"1" , "time" , "3" } , '!' ) ;
-				//default: 1800
+		G::Options::add( opt , 'T' , "response-timeout" ,
+			tx("sets the response timeout (in seconds) when talking to a remote server (default is 60)") , "" ,
+			M::one , "time" , 31 ,
+			t_smtpclient ) ;
+				//default: 60
 				//example: 2
 				// Specifies a timeout (in seconds) for getting responses from remote
-				// SMTP servers. The default is 1800 seconds.
+				// SMTP servers. The default is 60 seconds.
 
-		opt.add( { "" , "idle-timeout" ,
-			gettext("sets the idle timeout (in seconds) when talking to a remote client (default is 1800)") ,
-			"1" , "time" , "3" } , '!' ) ;
-				//default: 1800
+		G::Options::add( opt , '\0' , "idle-timeout" ,
+			tx("sets the connection idle timeout (in seconds) (default is 60)") , "" ,
+			M::one , "time" , 31 ,
+			t_smtpclient ) ;
+				//default: 60
 				//example: 2
 				// Specifies a timeout (in seconds) for receiving network traffic from
-				// remote SMTP and POP clients. The default is 1800 seconds.
+				// remote SMTP and POP clients. The default is 60 seconds.
 
-		opt.add( { "U" , "connection-timeout" ,
-			gettext("sets the timeout (in seconds) when connecting to a remote server (default is 40)") ,
-			"1" , "time" , "3" } , '!' ) ;
+		G::Options::add( opt , 'U' , "connection-timeout" ,
+			tx("sets the timeout (in seconds) when connecting to a remote server (default is 40)") , "" ,
+			M::one , "time" , 31 ,
+			t_smtpclient ) ;
 				//default: 40
 				//example: 10
 				// Specifies a timeout (in seconds) for establishing a TCP connection
 				// to remote SMTP servers. The default is 40 seconds.
 
-		opt.add( { "m" , "immediate" ,
-			gettext("enables immediate forwarding of messages as they are received! "
-				"from the submitting client and before their receipt is acknowledged (requires --forward-to)") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'm' , "immediate" ,
+			tx("enables immediate forwarding of messages as they are received! "
+				"from the submitting client and before their receipt is acknowledged (requires --forward-to)") , "" ,
+			M::zero , "" , 32 ,
+			t_smtpclient , t_smtpserver ) ;
 				// Causes mail messages to be forwarded as they are received, even before
 				// they have been accepted. This can be used to do proxying without
 				// store-and-forward, but in practice clients tend to to time out
 				// while waiting for their mail message to be accepted.
 
-		opt.add( { "I" , "interface" ,
-			gettext("defines the listening network addresses used for incoming connections! "
-				"(comma-separated list with optional smtp=,pop=,admin= qualifiers)") ,
-			"2" , "ip-address-list" , "3" } , '!' ) ;
+		G::Options::add( opt , 'I' , "interface" ,
+			tx("defines the listening network addresses used for incoming connections! "
+				"(comma-separated list with optional smtp=,pop=,admin= qualifiers)") , "" ,
+			M::many , "ip-address-list" , 30 ,
+			t_smtpserver ) ;
 				//example: 127.0.0.1,smtp=eth0
 				//example: fe80::1%1,smtp=::,admin=lo-ipv4,pop=10.0.0.1
+				//example: smtp=fd#3,smtp=fd#4,pop=fd#5
 				//example: lo
 				//example: 10.0.0.1
 				// Specifies the IP network addresses or interface names used to bind
@@ -551,10 +663,14 @@ G::Options Main::Options::spec( bool is_windows )
 				// for listening. When an interface name is decorated with a "-ipv4"
 				// or "-ipv6" suffix only their IPv4 or IPv6 addresses will be used
 				// (eg. "ppp0-ipv4").
+				//
+				// To inherit listening file descriptors from the parent process on
+				// unix use a syntax like this: --interface=smtp=fd#3,smtp=fd#4,pop=fd#5.
 
-		opt.add( { "6" , "client-interface" ,
-			gettext("defines the local network address used for outgoing connections") ,
-			"1" , "ip-address" , "3" } , '!' ) ;
+		G::Options::add( opt , '6' , "client-interface" ,
+			tx("defines the local network address used for outgoing connections") , "" ,
+			M::one , "ip-address" , 31 ,
+			t_smtpclient ) ;
 				//example: 10.0.0.2
 				// Specifies the IP network address to be used to bind the local end of
 				// outgoing SMTP connections. By default the address will depend on the
@@ -562,74 +678,88 @@ G::Options Main::Options::spec( bool is_windows )
 				// addresses returned from DNS lookups of the --forward-to address,
 				// or "::" for IPv6.
 
-		opt.add( { "i" , "pid-file" ,
-			gettext("defines a file for storing the daemon process-id") ,
-			"1" , "pid-file" , "3" } , '!' ) ;
+		G::Options::add( opt , 'i' , "pid-file" ,
+			tx("defines a file for storing the daemon process-id") , "" ,
+			M::one , "path" , 30 ,
+			t_process ) ;
 				//example: /run/emailrelay/emailrelay.pid
 				//example: C:/ProgramData/E-MailRelay/pid.txt
 				// Causes the process-id to be written into the specified file when the
-				// program starts up, typically after it has become a backgroud daemon.
+				// program starts up, typically after it has become a background daemon.
+				// The immediate parent directory is created if necessary.
 
-		opt.add( { "O" , "poll" ,
-			gettext("enables polling of the spool directory for messages to be forwarded with the specified period! "
-				"(requires --forward-to)") ,
-			"1" , "period" , "3" } , '!' ) ;
+		G::Options::add( opt , 'O' , "poll" ,
+			tx("enables polling of the spool directory for messages to be forwarded with the specified period! "
+				"(requires --forward-to)") , "" ,
+			M::one , "period" , 30 ,
+			t_smtpclient ) ;
 				//example: 60
 				// Causes forwarding of spooled mail messages to happen at regular intervals
 				// (with the time given in seconds).
 
-		opt.add( { "" , "address-verifier" ,
-			gettext("specifies an external program for address verification") ,
-			"1" , "program" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "address-verifier" ,
+			tx("specifies an external program for address verification") , "" ,
+			M::one , "program" , 30 ,
+			t_smtpserver ) ;
 				//example: /usr/local/sbin/emailrelay-verifier.sh
 				//example: C:/ProgramData/E-MailRelay/verifier.js
 				// Runs the specified external program to verify a message recipent's e-mail
-				// address. A network verifier can be specified as "net:<transport-address>".
+				// address. A network verifier can be specified as "net:<tcp-address>".
 
-		opt.add( { "Y" , "client-filter" ,
-			gettext("specifies an external program to process messages when they are forwarded") ,
-			"1" , "program" , "3" } , '!' ) ;
+		G::Options::add( opt , 'Y' , "client-filter" ,
+			tx("specifies an external program to process messages when they are forwarded") , "" ,
+			M::many , "program" , 31 ,
+			t_smtpclient , t_filter ) ;
 				//example: /usr/local/sbin/emailrelay-client-filter
 				//example: C:/ProgramData/E-MailRelay/client-filter.js
 				// Runs the specified external filter program whenever a mail message is
 				// forwarded. The filter is passed the name of the message file in the spool
 				// directory so that it can edit it as required. A network filter can be
-				// specified as "net:<transport-address>" and prefixes of "spam:", "spam-edit:"
+				// specified as "net:<tcp-address>" and prefixes of "spam:", "spam-edit:"
 				// and "exit:" are also allowed. The "spam:" and "spam-edit:" prefixes
 				// require a SpamAssassin daemon to be running. For store-and-forward
 				// applications the --filter option is normally more useful than
 				// --client-filter.
 
-		opt.add( { "Q" , "admin-terminate" ,
-			gettext("enables the terminate command on the admin interface") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'Q' , "admin-terminate" ,
+			tx("enables the terminate command on the admin interface") , "" ,
+			M::zero , "" , 30 ,
+			t_admin , t_process ) ;
 				// Enables the "terminate" command in the administration interface.
 
-		opt.add( { "A" , "anonymous" ,
-			gettext("disables the SMTP VRFY command and sends less verbose SMTP responses") ,
-			"0" , "" , "3" } , '!' ) ;
-				// Disables the server's SMTP VRFY command, sends less verbose SMTP
-				// responses and SMTP greeting, and stops "Received" lines being
-				// added to mail message content files.
+		G::Options::add( opt , 'A' , "anonymous" ,
+			tx("disables the SMTP VRFY command and sends less verbose SMTP responses") , "" ,
+			M::zero_or_one , "scope" , 30 ,
+			t_smtpserver ) ;
+				// Disables the server's SMTP VRFY command, sends less verbose
+				// SMTP greeting and responses, stops "Received" lines being
+				// added to mail message content files, and stops the SMTP
+				// client protocol adding "AUTH=" to the "MAIL" command.
+				// For finer control use a comma-separated list of things
+				// to anonymise: "vrfy", "server", "content" and/or "client",
+				// eg. --anonymous=server,content.
 
-		opt.add( { "B" , "pop" ,
-			gettext("enables the pop server") ,
-			"0" , "" , "3" } , '!' ) ;
-				// Enables the POP server listening, by default on port 110, providing
+		G::Options::add( opt , 'B' , "pop" ,
+			tx("enables the pop server") , "" ,
+			M::zero , "" , 30 ,
+			t_pop , t_smtpserver ) ;
+				// Enables the POP server, listening by default on port 110, providing
 				// access to spooled mail messages. Negotiated TLS using the POP "STLS"
 				// command will be enabled if the --server-tls option is also given.
 
-		opt.add( { "E" , "pop-port" ,
-			gettext("specifies the pop listening port number (default is 110)! "
-				"(requires --pop)") ,
-			"1" , "port" , "3" } , '!' ) ;
+		G::Options::add( opt , 'E' , "pop-port" ,
+			tx("specifies the pop listening port number (default is 110)! "
+				"(requires --pop)") , "" ,
+			M::one , "port" , 30 ,
+			t_pop , t_smtpserver ) ;
 				//default: 110
 				//example: 995
 				// Sets the POP server's listening port number.
 
-		opt.add( { "F" , "pop-auth" ,
-			gettext("defines the pop server secrets file") ,
-			"1" , "file" , "3" } , '!' ) ;
+		G::Options::add( opt , 'F' , "pop-auth" ,
+			tx("defines the pop server secrets file") , "" ,
+			M::one , "file" , 31 ,
+			t_auth , t_pop|t_smtpserver ) ;
 				//example: /etc/private/emailrelay-pop.auth
 				//example: C:/ProgramData/E-MailRelay/pop.auth
 				//example: /pam
@@ -639,35 +769,39 @@ G::Options Main::Options::spec( bool is_windows )
 				// and fourth fields. A special value of "/pam" can be used for
 				// authentication using linux PAM.
 
-		opt.add( { "G" , "pop-no-delete" ,
-			gettext("disables message deletion via pop! "
-				"(requires --pop)") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'G' , "pop-no-delete" ,
+			tx("disables message deletion via pop! "
+				"(requires --pop)") , "" ,
+			M::zero , "" , 30 ,
+			t_pop , t_smtpserver ) ;
 				// Disables the POP DELE command so that the command appears to succeed
 				// but mail messages are not deleted from the spool directory.
 
-		opt.add( { "J" , "pop-by-name" ,
-			gettext("modifies the pop spool directory according to the pop user name! "
-				"(requires --pop)") ,
-			"0" , "" , "3" } , '!' ) ;
+		G::Options::add( opt , 'J' , "pop-by-name" ,
+			tx("modifies the pop spool directory according to the pop user name! "
+				"(requires --pop)") , "" ,
+			M::zero , "" , 30 ,
+			t_pop , t_smtpserver ) ;
 				// Modifies the spool directory used by the POP server to be a
 				// sub-directory with the same name as the POP authentication user-id.
-				// This allows multiple POP clients to read the spooled messages
+				// This allows multiple POP clients to read the spooled mail messages
 				// without interfering with each other, particularly when also
 				// using --pop-no-delete. Content files can stay in the main spool
 				// directory with only the envelope files copied into user-specific
 				// sub-directories. The "emailrelay-filter-copy" program is a
 				// convenient way of doing this when run via --filter.
 
-		opt.add( { "M" , "size" ,
-			gettext("limits the size of submitted messages") ,
-			"1" , "bytes" , "3" } , '!' ) ;
+		G::Options::add( opt , 'M' , "size" ,
+			tx("limits the size of submitted messages") , "" ,
+			M::one , "bytes" , 30 ,
+			t_smtpserver ) ;
 				//example: 10000000
 				// Limits the size of mail messages that can be submitted over SMTP.
 
-		opt.add( { "" , "dnsbl" ,
-			gettext("configuration for DNSBL blocking of smtp client addresses") ,
-			"2" , "config" , "3" } , '!' ) ;
+		G::Options::add( opt , '\0' , "dnsbl" ,
+			tx("configuration for DNSBL blocking of SMTP client addresses") , "" ,
+			M::many , "config" , 30 ,
+			t_smtpserver ) ;
 				//example: 1.1.1.1:53,1000,1,spam.dnsbl.example.com,block.dnsbl.example.com
 				// Specifies a list of DNSBL servers that are used to reject SMTP
 				// connections from blocked addresses. The configuration string
@@ -675,7 +809,7 @@ G::Options Main::Options::spec( bool is_windows )
 				// transport address, a timeout in milliseconds, a rejection
 				// threshold, and then the list of DNSBL servers.
 
-		opt.add( { "" , "test" , "testing" , "1" , "x" , "0" } , '!' ) ;
+		G::Options::add( opt , '\0' , "test" , "testing" , "" , M::one , "x" , 0 , 0 ) ;
 	}
 	return opt ;
 }
diff --git a/src/main/options.h b/src/main/options.h
index 94ff7ee..d9d70ee 100644
--- a/src/main/options.h
+++ b/src/main/options.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,6 +24,8 @@
 #include "gdef.h"
 #include "goptions.h"
 #include <string>
+#include <vector>
+#include <utility>
 
 namespace Main
 {
@@ -40,6 +42,12 @@ public:
 	static G::Options spec( bool is_windows ) ;
 		///< Returns an o/s-specific G::OptionParser specification.
 
+	using Tag = std::pair<unsigned,std::string> ;
+
+	static std::vector<Tag> tags() ;
+		///< Returns an ordered list of tags to be matched
+		///< against each option's 'main_tag'.
+
 public:
 	Options() = delete ;
 } ;
diff --git a/src/main/output.cpp b/src/main/output.cpp
index 9f91688..63d2031 100644
--- a/src/main/output.cpp
+++ b/src/main/output.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/main/output.h b/src/main/output.h
index 7823d7f..e746378 100644
--- a/src/main/output.h
+++ b/src/main/output.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,7 +22,7 @@
 #define G_MAIN_OUTPUT_H
 
 #include "gdef.h"
-#include "goptions.h"
+#include "goptionsusage.h"
 #include <string>
 
 namespace Main
@@ -41,7 +41,7 @@ public:
 	virtual void output( const std::string & , bool error , bool ) = 0 ;
 		///< Outputs the given string.
 
-	virtual G::Options::Layout outputLayout( bool verbose ) const = 0 ;
+	virtual G::OptionsUsage::Config outputLayout( bool verbose ) const = 0 ;
 		///< Returns a layout definition for G::Options.
 
 	virtual bool outputSimple() const = 0 ;
diff --git a/src/main/passwd.cpp b/src/main/passwd.cpp
index a3f25e1..26a32fa 100644
--- a/src/main/passwd.cpp
+++ b/src/main/passwd.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -32,8 +32,11 @@
 #include "gmd5.h"
 #include "ghash.h"
 #include "ggetopt.h"
+#include "goptions.h"
+#include "goptionsusage.h"
 #include "gbase64.h"
 #include "gxtext.h"
+#include "ggettext.h"
 #include "gssl.h"
 #include "legal.h"
 #include <iostream>
@@ -65,43 +68,63 @@ namespace PasswdImp
 	}
 }
 
+static G::Options options()
+{
+	using G::tx ;
+	using M = G::Option::Multiplicity ;
+	G::Options opt ;
+	unsigned int t_undef = 0U ;
+
+	G::Options::add( opt , 'h' , "help" ,
+		tx("show usage help") , "" ,
+		M::zero , "" , 1 , t_undef ) ;
+			// Shows help text and exits.
+
+	G::Options::add( opt , 'H' , "hash" ,
+		tx("use the named hash function! such as MD5") , "" ,
+		M::one , "function" , 1 , t_undef ) ;
+			// Specifies the hash function, such as MD5 or SHA1.
+			// MD5 is the default, and a hash function of NONE does
+			// simple xtext encoding. Other hash function may or may
+			// not be available, depending on the build.
+
+	G::Options::add( opt , 'p' , "password" ,
+		tx("defines the password! on the command-line") , "" ,
+		M::one , "pwd" , 2 , t_undef ) ;
+			// Specifies the password to be hashed. Beware of leaking
+			// sensitive passwords via command-line history or the
+			// process-table when using this option.
+
+	G::Options::add( opt , 'b' , "base64" ,
+		tx("interpret the password as base64-encoded") , "" ,
+		M::zero , "" , 2 , t_undef ) ;
+			// The input password is interpreted as being base-64 encoded.
+
+	G::Options::add( opt , 'd' , "dotted" ,
+		tx("use a dotted decimal format! for backwards compatibility") , "" ,
+		M::zero , "" , 2 , t_undef ) ;
+			// Generates a dotted decimal format, for backwards compatibility.
+
+	G::Options::add( opt , 'v' , "verbose" , "verbose" , "" , M::zero , "" , 0 , t_undef ) ;
+		// Verbose logging. (undocumented)
+
+	G::Options::add( opt , 't' , "tls" , "tls" , "" , M::zero , "" , 0 , t_undef ) ;
+		// Enables the TLS library even if using a hash function of
+		// MD5 or NONE. (undocumented)
+
+	G::Options::add( opt , 'T' , "tls-config" , "tls-config" , "" , M::one , "config" , 0 , t_undef ) ;
+		// Configures the TLS library with the given configuration
+		// string. (undocumented)
+
+	return opt ;
+}
+
 int main( int argc , char * argv [] )
 {
 	G::Arg arg( argc , argv ) ;
 	try
 	{
-		G::GetOpt opt( arg ,
-
-			"h!help!show usage help!!0!!1" "|"
-				// Shows help and exits.
-
-			"H!hash!use the named hash function! (eg. MD5)!1!function!1" "|"
-				// Specifies the hash function, such as MD5 or SHA1.
-				// MD5 is the default, and a hash function of NONE does
-				// simple xtext encoding. Other hash function may or may
-				// not be available, depending on the build.
-
-			"p!password!defines the password! on the command-line (beware command-line history)!2!pwd!2" "|"
-				// Specifies the password to be hashed. Beware of leaking
-				// sensitive passwords via command-line history or the
-				// process-table when using this option.
-
-			"b!base64!interpret the password as base64-encoded!!0!!2" "|"
-				// Interpret the input password as base64 encoded.
-
-			"v!verbose!!!0!!0" "|"
-				// Verbose logging.
-
-			"d!dotted!use a dotted decimal format! for backwards compatibility!0!!2" "|"
-				// Generate a dotted decimal format, for backwards compatibility.
-
-			"t!tls!!!0!!0" "|"
-				// Enable the TLS library even if using a hash function of MD5 or NONE.
-
-			"T!tls-config!!!1!config!0" "|"
-				// Configure the TLS library with the given configuration string.
-
-		) ;
+		G::GetOpt opt( arg , options() ) ;
 		if( opt.hasErrors() )
 		{
 			opt.showErrors( std::cerr ) ;
@@ -109,11 +132,11 @@ int main( int argc , char * argv [] )
 		}
 		if( opt.contains("help") )
 		{
-			G::OptionsLayout layout ;
+			G::OptionsUsage::Config layout ;
 			if( !opt.contains("verbose") )
-				layout.set_level( 1U ) ;
+				layout.set_level_max( 1U ) ;
 
-			opt.options().showUsage( layout , std::cout , arg.prefix() ) ;
+			G::OptionsUsage(opt.options()).output( layout , std::cout , arg.prefix() ) ;
 
 			std::cout
 				<< "\n"
diff --git a/src/main/resource.h b/src/main/resource.h
index 3d006d6..732e2e9 100644
--- a/src/main/resource.h
+++ b/src/main/resource.h
@@ -1,15 +1,15 @@
-
-#define IDI_ICON1                       101
-#define IDD_DIALOG1                     101
-#define IDR_MENU1                       102
-#define IDD_DIALOG2                     103
-#define IDD_PROPPAGE_1                  106
-#define IDC_EDIT1                       1000
-#define IDC_LIST1                       1000
-#define IDS_EVENTLOG_INFORMATION        1001
-#define IDS_EVENTLOG_WARNING            1002
-#define IDS_EVENTLOG_ERROR              1003
-#define IDM_OPEN                        40001
-#define IDM_QUIT                        40002
-#define IDM_CLOSE                       40005
-
+
+#define IDI_ICON1                       101
+#define IDD_DIALOG1                     101
+#define IDR_MENU1                       102
+#define IDD_DIALOG2                     103
+#define IDD_PROPPAGE_1                  106
+#define IDC_EDIT1                       1000
+#define IDC_LIST1                       1000
+#define IDS_EVENTLOG_INFORMATION        1001
+#define IDS_EVENTLOG_WARNING            1002
+#define IDS_EVENTLOG_ERROR              1003
+#define IDM_OPEN                        40001
+#define IDM_QUIT                        40002
+#define IDM_CLOSE                       40005
+
diff --git a/src/main/run.cpp b/src/main/run.cpp
index e538d14..1a1591e 100644
--- a/src/main/run.cpp
+++ b/src/main/run.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -37,7 +37,7 @@
 #include "gfilterfactory.h"
 #include "gfactoryparser.h"
 #include "gverifierfactory.h"
-#include "gdnsblock.h"
+#include "gdnsbl.h"
 #include "gslot.h"
 #include "gmonitor.h"
 #include "glocal.h"
@@ -68,13 +68,11 @@ namespace { std::string localedir() { return std::string() ; } }
 
 std::string Main::Run::versionNumber()
 {
-	return "2.3.1" ;
+	return "2.4" ;
 }
 
 Main::Run::Run( Main::Output & output , const G::Arg & arg , bool is_windows , bool has_gui ) :
 	m_output(output) ,
-	m_es_rethrow(GNet::ExceptionSink::Type::Rethrow,nullptr) ,
-	m_es_nothrow(GNet::ExceptionSink::Type::Log,nullptr) ,
 	m_is_windows(is_windows) ,
 	m_arg(arg) ,
 	m_forwarding_pending(false) ,
@@ -162,7 +160,7 @@ bool Main::Run::runnable()
 void Main::Run::run()
 {
 	using G::format ;
-	using G::gettext ;
+	using G::txt ;
 
 	if( commandline().map().contains("help") || commandline().map().contains("version") )
 		return ;
@@ -181,7 +179,7 @@ void Main::Run::run()
 	// when running as a daemon -- this has to be done early, before
 	// opening any sockets or message-store streams
 	//
-	if( configuration().daemon() )
+	if( configuration().closeFiles() )
 	{
 		closeFiles() ;
 	}
@@ -201,10 +199,10 @@ void Main::Run::run()
 			.set_strip(!configuration().debug())
 			.set_use_syslog(configuration().useSyslog())
 			.set_allow_bad_syslog(!(m_has_gui&&configuration().logFile().empty()))
+			.set_umask( G::Process::Umask::Mode::Tighter )
 			.set_facility(configuration().syslogFacility()) ,
 		configuration().logFile().str() // stderr-replacement
 	) ;
-	G::LogOutput::translate( gettext("info: ") , gettext("warning: ") , gettext("error: ") , gettext("fatal: ") ) ;
 
 	// if we are going to close stderr soon then make stderr logging
 	// less verbose so that startup scripts are cleaner, but without
@@ -233,17 +231,10 @@ void Main::Run::run()
 	// hook up the timer callbacks now we have a timer list
 	//
 	using Timer = GNet::Timer<Run> ;
-	m_forwarding_timer = std::make_unique<Timer>( *this , &Run::onRequestForwardingTimeout , m_es_nothrow ) ;
-	m_poll_timer = std::make_unique<Timer>( *this , &Run::onPollTimeout , m_es_nothrow ) ;
-	m_queue_timer = std::make_unique<Timer>( *this , &Run::onQueueTimeout , m_es_nothrow ) ;
-
-	// early check on socket bindability
-	//
-	checkPorts() ;
-
-	// early check on script executablity
-	//
-	checkScripts() ;
+	GNet::ExceptionSink es_log_only = GNet::ExceptionSink::logOnly() ;
+	m_forwarding_timer = std::make_unique<Timer>( *this , &Run::onRequestForwardingTimeout , es_log_only ) ;
+	m_poll_timer = std::make_unique<Timer>( *this , &Run::onPollTimeout , es_log_only ) ;
+	m_queue_timer = std::make_unique<Timer>( *this , &Run::onQueueTimeout , es_log_only ) ;
 
 	// early check on multi-threading behaviour
 	//
@@ -280,7 +271,7 @@ void Main::Run::run()
 			configuration().clientTlsPeerHostName() ) ;
 
 	if( need_tls && !m_tls_library->enabled() )
-		throw G::Exception( gettext("cannot do tls/ssl: tls library not built in: "
+		throw G::Exception( txt("cannot do tls/ssl: tls library not built in: "
 			"remove tls options from the command-line or "
 			"rebuild the emailrelay executable with a supported tls library") ) ;
 
@@ -297,15 +288,15 @@ void Main::Run::run()
 		GNet::Location location( configuration().serverAddress() , resolverFamily() ) ;
 		std::string error = GNet::Resolver::resolve( location ) ;
 		if( !error.empty() )
-			G_WARNING( "Main::Run::run: " << format(gettext("dns lookup of forward-to address failed: %1%")) % error ) ;
+			G_WARNING( "Main::Run::run: " << format(txt("dns lookup of forward-to address failed: %1%")) % error ) ;
 		else
-			G_LOG( "Main::Run::run: " << format(gettext("forwarding address %1%")) % location.displayString() ) ;
+			G_LOG( "Main::Run::run: " << format(txt("forwarding address %1%")) % location.displayString() ) ;
 	}
 
 	// early check on the DNSBL configuration string
 	//
 	if( !configuration().dnsbl().empty() )
-		GNet::DnsBlock::checkConfig( configuration().dnsbl() ) ;
+		GNet::Dnsbl::checkConfig( configuration().dnsbl() ) ;
 
 	// figure out what we're doing
 	//
@@ -343,18 +334,22 @@ void Main::Run::run()
 	if( configuration().doPop() )
 		m_pop_secrets = std::make_unique<GAuth::Secrets>( configuration().popSecretsFile().str() , "pop-server" ) ;
 
-	// daemonise
+	// prepare the pid file
 	//
-	G::PidFile pid_file ;
-	if( configuration().usePidFile() ) pid_file.init( G::Path(configuration().pidFile()) ) ;
-	if( configuration().daemon() ) G::Daemon::detach( pid_file ) ;
+	G::Path pid_file_path = configuration().usePidFile() ? G::Path(configuration().pidFile()) : G::Path() ;
+	G::PidFile pid_file( pid_file_path ) ;
+	{
+		G::Root claim_root ;
+		G::Process::Umask _( G::Process::Umask::Mode::GroupOpen ) ;
+		pid_file.mkdir() ;
+	}
 
 	// create the smtp server
 	//
 	if( do_smtp )
 	{
 		if( configuration().immediate() )
-			G_WARNING( "Run::doServing: " << gettext("using --immediate can result in client timeout errors: "
+			G_WARNING( "Run::doServing: " << txt("using --immediate can result in client timeout errors: "
 				"try --forward-on-disconnect instead") ) ;
 
 		G_ASSERT( m_store != nullptr ) ;
@@ -368,6 +363,7 @@ void Main::Run::run()
 			*m_server_secrets ,
 			smtpServerConfig() ,
 			configuration().immediate() ? configuration().serverAddress() : std::string() ,
+			resolverFamily() ,
 			clientConfig() ) ;
 
 		m_smtp_server->eventSignal().connect( G::Slot::slot(*this,&Run::onServerEvent) ) ;
@@ -398,7 +394,7 @@ void Main::Run::run()
 			*m_store ,
 			*m_filter_factory ,
 			m_forward_request_signal ,
-			GNet::ServerPeerConfig(0U) ,
+			GNet::ServerPeer::Config().set_idle_timeout(0U) ,
 			netServerConfig() ,
 			clientConfig() ,
 			*m_client_secrets ,
@@ -417,6 +413,13 @@ void Main::Run::run()
 	}
 	else
 	{
+		// daemonise etc
+		if( configuration().daemon() )
+			G::Daemon::detach( pid_file.path() ) ;
+		commit( pid_file ) ;
+		if( configuration().closeStderr() )
+			G::Process::closeStderr() ;
+
 		// kick off some forwarding
 		//
 		if( configuration().forwardOnStartup() )
@@ -435,8 +438,6 @@ void Main::Run::run()
 
 		// run the event loop
 		//
-		commit( pid_file ) ;
-		closeMoreFiles() ;
 		std::string quit_reason = m_event_loop->run() ;
 		if( !quit_reason.empty() )
 			throw std::runtime_error( quit_reason ) ;
@@ -466,67 +467,11 @@ void Main::Run::closeFiles() const
 	}
 }
 
-void Main::Run::closeMoreFiles() const
-{
-	if( configuration().closeStderr() )
-		G::Process::closeStderr() ;
-}
-
 bool Main::Run::hidden() const
 {
 	return configuration().hidden() || configuration().show("hidden") ;
 }
 
-void Main::Run::checkPort( bool check , const std::string & ip , unsigned int port )
-{
-	if( check )
-	{
-		const bool do_throw = true ;
-		if( ip.empty() )
-		{
-			if( GNet::Address::supports( GNet::Address::Family::ipv6 ) &&
-				GNet::StreamSocket::supports( GNet::Address::Family::ipv6 ) )
-			{
-				GNet::Address address( GNet::Address::Family::ipv6 , port ) ;
-				GNet::Server::canBind( address , do_throw ) ;
-			}
-			if( GNet::Address::supports( GNet::Address::Family::ipv4 ) )
-			{
-				GNet::Address address( GNet::Address::Family::ipv4 , port ) ;
-				GNet::Server::canBind( address , do_throw ) ;
-			}
-		}
-		else if( GNet::Address::validStrings(ip,"0") )
-		{
-			GNet::Address address = GNet::Address::parse( ip , port ) ;
-			GNet::Server::canBind( address , do_throw ) ;
-		}
-	}
-}
-
-void Main::Run::checkPorts() const
-{
-	if( configuration().doServing() )
-	{
-		G::StringArray smtp_addresses = configuration().listeningAddresses("smtp") ;
-		checkPort( configuration().doSmtp() && smtp_addresses.empty() , std::string() , configuration().port() ) ;
-		for( const auto & a : smtp_addresses )
-			checkPort( configuration().doSmtp() , a , configuration().port() ) ;
-
-		G::StringArray pop_addresses = configuration().listeningAddresses("pop") ;
-		checkPort( configuration().doPop() && pop_addresses.empty() , std::string() , configuration().popPort() ) ;
-		for( const auto & a : pop_addresses )
-			checkPort( configuration().doPop() , a , configuration().popPort() ) ;
-
-		G::StringArray admin_addresses = configuration().listeningAddresses("admin") ;
-		checkPort( configuration().doAdmin() && admin_addresses.empty() ,
-			std::string() , configuration().adminPort() ) ;
-
-		for( const auto & a : admin_addresses )
-			checkPort( configuration().doAdmin() , a , configuration().adminPort() ) ;
-	}
-}
-
 void Main::Run::commit( G::PidFile & pid_file )
 {
 	if( !pid_file.committed() )
@@ -541,24 +486,38 @@ void Main::Run::commit( G::PidFile & pid_file )
 	}
 }
 
+GNet::StreamSocket::Config Main::Run::netSocketConfig( bool /*server*/ ) const
+{
+	std::pair<int,int> linger = { -1 , 0 } ;
+	return
+		GNet::StreamSocket::Config()
+			.set_create_linger( linger )
+			.set_accept_linger( linger )
+			.set_bind_reuse( !G::is_windows() || G::is_wine() )
+			.set_bind_exclusive( G::is_windows() && !G::is_wine() )
+			.set_last<GNet::StreamSocket::Config>() ;
+}
+
 GSmtp::ServerProtocol::Config Main::Run::serverProtocolConfig() const
 {
 	return
 		GSmtp::ServerProtocol::Config()
-			.set_with_vrfy( !configuration().anonymous() )
+			.set_with_vrfy( !configuration().anonymousServerVrfy() )
 			.set_filter_timeout( configuration().filterTimeout() )
 			.set_max_size( configuration().maxSize() )
 			.set_authentication_requires_encryption( configuration().serverTlsRequired() )
+			.set_mail_requires_authentication( !configuration().serverSecretsFile().empty() )
 			.set_mail_requires_encryption( configuration().serverTlsRequired() )
 			.set_tls_starttls( configuration().serverTls() )
 			.set_tls_connection( configuration().serverTlsConnection() )
 			.set_allow_pipelining( configuration().smtpPipelining() ) ;
 }
 
-GNet::ServerConfig Main::Run::netServerConfig() const
+GNet::Server::Config Main::Run::netServerConfig() const
 {
 	bool open = configuration().user().empty() || configuration().user() == "root" ;
-	return GNet::ServerConfig()
+	return GNet::Server::Config()
+		.set_stream_socket_config( netSocketConfig() )
 		.set_uds_open_permissions( open ) ;
 }
 
@@ -567,15 +526,16 @@ GSmtp::Server::Config Main::Run::smtpServerConfig() const
 	return
 		GSmtp::Server::Config()
 			.set_allow_remote( configuration().allowRemoteClients() )
-			.set_interfaces( configuration().listeningAddresses("smtp") )
+			.set_interfaces( configuration().listeningNames("smtp") )
 			.set_port( configuration().port() )
 			.set_ident( smtpIdent() )
-			.set_anonymous( configuration().anonymous() )
-			.set_filter_address( configuration().filter().str() )
+			.set_anonymous_smtp( configuration().anonymousServerSmtp() )
+			.set_anonymous_content( configuration().anonymousContent() )
+			.set_filter_spec( configuration().filter() )
 			.set_filter_timeout( configuration().filterTimeout() )
-			.set_verifier_address( configuration().verifier().str() )
+			.set_verifier_spec( configuration().verifier() )
 			.set_verifier_timeout( configuration().filterTimeout() )
-			.set_server_peer_config( GNet::ServerPeerConfig(configuration().idleTimeout()) )
+			.set_server_peer_config( GNet::ServerPeer::Config().set_idle_timeout(configuration().idleTimeout()) )
 			.set_server_config( netServerConfig() )
 			.set_protocol_config( serverProtocolConfig() )
 			.set_sasl_server_config( configuration().smtpSaslServerConfig() )
@@ -588,9 +548,9 @@ GPop::Server::Config Main::Run::popConfig() const
 		GPop::Server::Config()
 			.set_allow_remote( configuration().allowRemoteClients() )
 			.set_port( configuration().popPort() )
-			.set_addresses( configuration().listeningAddresses("pop") )
+			.set_addresses( configuration().listeningNames("pop") )
 			.set_server_peer_config(
-				GNet::ServerPeerConfig()
+				GNet::ServerPeer::Config()
 					.set_idle_timeout( configuration().idleTimeout()) )
 			.set_server_config( netServerConfig() )
 			.set_sasl_server_config( configuration().popSaslServerConfig() ) ;
@@ -600,10 +560,7 @@ GSmtp::Client::Config Main::Run::clientConfig() const
 {
 	return
 		GSmtp::Client::Config()
-			.set_filter_address( configuration().clientFilter().str() )
-			.set_filter_timeout( configuration().filterTimeout() )
-			.set_bind_local_address( !configuration().clientBindAddress().empty() )
-			.set_local_address( asAddress(configuration().clientBindAddress()) )
+			.set_stream_socket_config( netSocketConfig(false) )
 			.set_client_protocol_config(
 				GSmtp::ClientProtocol::Config()
 					.set_thishost_name( GNet::Local::canonicalName() )
@@ -613,9 +570,13 @@ GSmtp::Client::Config Main::Run::clientConfig() const
 					.set_use_starttls_if_possible( configuration().clientTls() && !configuration().clientOverTls() )
 					.set_must_use_tls( configuration().clientTlsRequired() && !configuration().clientOverTls() )
 					.set_must_authenticate( true )
-					.set_anonymous( configuration().anonymous() )
+					.set_anonymous( configuration().anonymousClientSmtp() )
 					.set_must_accept_all_recipients( !configuration().forwardToSome() )
 					.set_eight_bit_strict( false ) )
+			.set_filter_spec( configuration().clientFilter() )
+			.set_filter_timeout( configuration().filterTimeout() )
+			.set_bind_local_address( !configuration().clientBindAddress().empty() )
+			.set_local_address( asAddress(configuration().clientBindAddress()) )
 			.set_connection_timeout( configuration().connectionTimeout() )
 			.set_secure_connection_timeout( configuration().secureConnectionTimeout() )
 			.set_secure_tunnel( configuration().clientOverTls() )
@@ -653,11 +614,11 @@ void Main::Run::requestForwarding( const std::string & reason )
 void Main::Run::onRequestForwardingTimeout()
 {
 	using G::format ;
-	using G::gettext ;
+	using G::txt ;
 	if( m_client_ptr.busy() )
 	{
 		G_LOG( "Main::Run::onRequestForwardingTimeout: "
-			<< format(gettext("forwarding: [%1%]: still busy from last time")) % m_forwarding_reason ) ;
+			<< format(txt("forwarding: [%1%]: still busy from last time")) % m_forwarding_reason ) ;
 		m_forwarding_pending = true ;
 	}
 	else
@@ -665,7 +626,7 @@ void Main::Run::onRequestForwardingTimeout()
 		if( logForwarding() )
 		{
 			G_LOG( "Main::Run::onRequestForwardingTimeout: "
-				<< format(gettext("forwarding: [%1%]")) % m_forwarding_reason ) ;
+				<< format(txt("forwarding: [%1%]")) % m_forwarding_reason ) ;
 		}
 
 		emit( "forward" , "start" ) ;
@@ -678,18 +639,18 @@ void Main::Run::onRequestForwardingTimeout()
 bool Main::Run::logForwarding() const
 {
 	return m_forwarding_reason != "poll" || configuration().pollingLog() ||
-		( G::LogOutput::instance() && G::LogOutput::instance()->at( G::Log::Severity::s_Debug ) ) ;
+		( G::LogOutput::instance() && G::LogOutput::instance()->at( G::Log::Severity::Debug ) ) ;
 }
 
 std::string Main::Run::startForwarding()
 {
-	using G::gettext ;
+	using G::txt ;
 	try
 	{
 		if( m_store->empty() )
 		{
 			if( logForwarding() )
-				G_LOG( "Main::Run::startForwarding: " << gettext("forwarding: no messages to send") ) ;
+				G_LOG( "Main::Run::startForwarding: " << txt("forwarding: no messages to send") ) ;
 			return "no messages" ;
 		}
 		else
@@ -709,7 +670,7 @@ std::string Main::Run::startForwarding()
 	}
 	catch( std::exception & e )
 	{
-		G_ERROR( "Main::Run::startForwarding: " << gettext("forwarding failure") << ": " << e.what() ) ;
+		G_ERROR( "Main::Run::startForwarding: " << txt("forwarding failure") << ": " << e.what() ) ;
 		return e.what() ;
 	}
 }
@@ -717,7 +678,7 @@ std::string Main::Run::startForwarding()
 void Main::Run::onClientDone( const std::string & reason )
 {
 	using G::format ;
-	using G::gettext ;
+	using G::txt ;
 	G_DEBUG( "Main::Run::onClientDone: reason=[" << reason << "]" ) ;
 	if( m_quit_when_sent )
 	{
@@ -728,14 +689,14 @@ void Main::Run::onClientDone( const std::string & reason )
 	else
 	{
 		if( ! reason.empty() )
-			G_ERROR( "Main::Run::onClientDone: " << format(gettext("forwarding: %1%")) % reason ) ;
+			G_ERROR( "Main::Run::onClientDone: " << format(txt("forwarding: %1%")) % reason ) ;
 
 		// go round again if necessary
 		if( m_forwarding_pending )
 		{
 			m_forwarding_pending = false ;
 			G_LOG( "Main::Run::onClientDone: "
-				<< format(gettext("forwarding: queued request [%1%]")) % m_forwarding_reason ) ;
+				<< format(txt("forwarding: queued request [%1%]")) % m_forwarding_reason ) ;
 			requestForwarding() ;
 		}
 	}
@@ -767,7 +728,7 @@ void Main::Run::emit( const std::string & s0 , const std::string & s1 ,
 	const std::string & s2 , const std::string & s3 )
 {
 	// use an asynchronous queue to avoid side-effects from callbacks
-	using G::gettext ;
+	using G::txt ;
 	bool notifying = m_admin_server && m_admin_server->notifying() ;
 	if( notifying || m_has_gui )
 	{
@@ -777,7 +738,7 @@ void Main::Run::emit( const std::string & s0 , const std::string & s1 ,
 
 		while( m_queue.size() > 100U )
 		{
-			G_WARNING_ONCE( "Main::Run::emit: " << gettext("too many notification events: discarding old ones") ) ;
+			G_WARNING_ONCE( "Main::Run::emit: " << txt("too many notification events: discarding old ones") ) ;
 			m_queue.pop_front() ;
 		}
 
@@ -819,41 +780,9 @@ int Main::Run::resolverFamily() const
 	return ( address.af() == AF_INET || address.af() == AF_INET6 ) ? address.af() : AF_UNSPEC ;
 }
 
-void Main::Run::checkScripts() const
-{
-	checkFilterScript( configuration().filter().str() ) ;
-	checkFilterScript( configuration().clientFilter().str() ) ;
-	checkVerifierScript( configuration().verifier().str() ) ;
-}
-
-void Main::Run::checkVerifierScript( const std::string & script ) const
-{
-	using G::format ;
-	using G::gettext ;
-	std::string reason = GSmtp::VerifierFactory::check( script ) ;
-	if( !reason.empty() )
-	{
-		G_WARNING( "Main::Run::checkVerifierScript: " << format(gettext("invalid verifier \"%1%\": %2%"))%script%reason ) ;
-	}
-}
-
-void Main::Run::checkFilterScript( const std::string & script ) const
-{
-	using G::format ;
-	using G::gettext ;
-	std::string reason = GSmtp::FilterFactory::check( script ) ;
-	if( !reason.empty() )
-	{
-		G_WARNING( "Main::Run::checkFilterScript: " << format(gettext("invalid filter \"%1%\": %2%"))%script%reason ) ;
-	}
-}
-
 void Main::Run::checkThreading() const
 {
-	if( G::threading::using_std_thread && (
-		GSmtp::FactoryParser::parse(configuration().filter().str(),true).first == "file" ||
-		GSmtp::FactoryParser::parse(configuration().clientFilter().str(),true).first == "file" ||
-		GSmtp::FactoryParser::parse(configuration().clientFilter().str(),true).first == "file" ) )
+	if( G::threading::using_std_thread )
 	{
 		// ignore the result here -- we are just trying to provoke an early weak-symbol linking failure
 		G::threading::works() ;
@@ -874,7 +803,7 @@ G::Path Main::Run::appDir() const
 std::unique_ptr<GSmtp::AdminServer> Main::Run::newAdminServer( GNet::ExceptionSink es ,
 	const Configuration & cfg , GSmtp::MessageStore & store , GSmtp::FilterFactory & ff ,
 	G::Slot::Signal<const std::string&> & forward_request_signal ,
-	const GNet::ServerPeerConfig & server_peer_config , const GNet::ServerConfig & net_server_config ,
+	const GNet::ServerPeer::Config & server_peer_config , const GNet::Server::Config & net_server_config ,
 	const GSmtp::Client::Config & client_config , const GAuth::Secrets & client_secrets ,
 	const std::string & version_number )
 {
@@ -897,7 +826,7 @@ std::unique_ptr<GSmtp::AdminServer> Main::Run::newAdminServer( GNet::ExceptionSi
 			net_server_config ,
 			client_config ,
 			client_secrets ,
-			cfg.listeningAddresses("admin") ,
+			cfg.listeningNames("admin") ,
 			cfg.adminPort() ,
 			cfg.allowRemoteClients() ,
 			cfg.serverAddress() ,
diff --git a/src/main/run.h b/src/main/run.h
index cdff031..2b02179 100644
--- a/src/main/run.h
+++ b/src/main/run.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -124,13 +124,12 @@ private:
 public:
 	Run( const Run & ) = delete ;
 	Run( Run && ) = delete ;
-	void operator=( const Run & ) = delete ;
-	void operator=( Run && ) = delete ;
+	Run & operator=( const Run & ) = delete ;
+	Run & operator=( Run && ) = delete ;
 
 private:
 	void doForwardingOnStartup( G::PidFile & ) ;
 	void closeFiles() const ;
-	void closeMoreFiles() const ;
 	void commit( G::PidFile & ) ;
 	std::string smtpIdent() const ;
 	void recordPid() ;
@@ -149,18 +148,14 @@ private:
 	void onQueueTimeout() ;
 	std::string startForwarding() ;
 	bool logForwarding() const ;
-	void checkPorts() const ;
-	static void checkPort( bool , const std::string & , unsigned int ) ;
+	GNet::StreamSocket::Config netSocketConfig( bool server = true ) const ;
 	GSmtp::Client::Config clientConfig() const ;
 	GSmtp::ServerProtocol::Config serverProtocolConfig() const ;
 	GSmtp::Server::Config smtpServerConfig() const ;
-	GNet::ServerConfig netServerConfig() const ;
+	GNet::Server::Config netServerConfig() const ;
 	int resolverFamily() const ;
 	static GNet::Address asAddress( const std::string & ) ;
 	GPop::Server::Config popConfig() const ;
-	void checkScripts() const ;
-	void checkVerifierScript( const std::string & ) const ;
-	void checkFilterScript( const std::string & ) const ;
 	void checkThreading() const ;
 	std::string versionString() const ;
 	static std::string buildConfiguration() ;
@@ -168,8 +163,8 @@ private:
 	std::unique_ptr<GSmtp::AdminServer> newAdminServer( GNet::ExceptionSink ,
 		const Configuration & , GSmtp::MessageStore & , GSmtp::FilterFactory & ,
 		G::Slot::Signal<const std::string&> & ,
-		const GNet::ServerPeerConfig & ,
-		const GNet::ServerConfig & , const GSmtp::Client::Config & ,
+		const GNet::ServerPeer::Config & ,
+		const GNet::Server::Config & , const GSmtp::Client::Config & ,
 		const GAuth::Secrets & , const std::string & ) ;
 
 private:
diff --git a/src/main/servicecontrol.h b/src/main/servicecontrol.h
index 402245b..e075c93 100644
--- a/src/main/servicecontrol.h
+++ b/src/main/servicecontrol.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/main/servicecontrol_unix.cpp b/src/main/servicecontrol_unix.cpp
index 1e23a8c..6800b78 100644
--- a/src/main/servicecontrol_unix.cpp
+++ b/src/main/servicecontrol_unix.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/main/servicecontrol_win32.cpp b/src/main/servicecontrol_win32.cpp
index 325e195..452be8a 100644
--- a/src/main/servicecontrol_win32.cpp
+++ b/src/main/servicecontrol_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -45,8 +45,8 @@ struct ServiceControl::ScopeExitCloser
 	~ScopeExitCloser() { CloseServiceHandle( m_h ) ; }
 	ScopeExitCloser( const ScopeExitCloser & ) = delete ;
 	ScopeExitCloser( ScopeExitCloser && ) = delete ;
-	void operator=( const ScopeExitCloser & ) = delete ;
-	void operator=( ScopeExitCloser && ) = delete ;
+	ScopeExitCloser & operator=( const ScopeExitCloser & ) = delete ;
+	ScopeExitCloser & operator=( ScopeExitCloser && ) = delete ;
 	SC_HANDLE m_h ;
 } ;
 
@@ -60,8 +60,8 @@ public:
 public:
 	Manager( const Manager & ) = delete ;
 	Manager( Manager && ) = delete ;
-	void operator=( const Manager & ) = delete ;
-	void operator=( Manager && ) = delete ;
+	Manager & operator=( const Manager & ) = delete ;
+	Manager & operator=( Manager && ) = delete ;
 
 private:
 	SC_HANDLE m_h ;
@@ -84,8 +84,8 @@ public:
 public:
 	Service( const Service & ) = delete ;
 	Service( Service && ) = delete ;
-	void operator=( const Service & ) = delete ;
-	void operator=( Service && ) = delete ;
+	Service & operator=( const Service & ) = delete ;
+	Service & operator=( Service && ) = delete ;
 
 private:
 	SC_HANDLE open( SC_HANDLE , const std::string & ) ;
diff --git a/src/main/serviceimp.h b/src/main/serviceimp.h
index d6b1413..2583690 100644
--- a/src/main/serviceimp.h
+++ b/src/main/serviceimp.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/main/serviceimp_none.cpp b/src/main/serviceimp_none.cpp
index b8e30c4..0fd6258 100644
--- a/src/main/serviceimp_none.cpp
+++ b/src/main/serviceimp_none.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/main/serviceimp_win32.cpp b/src/main/serviceimp_win32.cpp
index 718d0cc..cb83fb1 100644
--- a/src/main/serviceimp_win32.cpp
+++ b/src/main/serviceimp_win32.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/main/servicewrapper.cpp b/src/main/servicewrapper.cpp
index 7a2eb17..dc35233 100644
--- a/src/main/servicewrapper.cpp
+++ b/src/main/servicewrapper.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -154,7 +154,6 @@ struct ServiceEvent
 	}
 	void create()
 	{
-		const DWORD access = DELETE | SYNCHRONIZE | EVENT_MODIFY_STATE | PROCESS_DUP_HANDLE ;
 		m_h = CreateEvent( nullptr , FALSE , FALSE , nullptr ) ;
 		if( m_h == 0 )
 		{
@@ -218,8 +217,8 @@ public:
 public:
 	Service( const Service & ) = delete ;
 	Service( Service && ) = delete ;
-	void operator=( const Service & ) = delete ;
-	void operator=( Service && ) = delete ;
+	Service & operator=( const Service & ) = delete ;
+	Service & operator=( Service && ) = delete ;
 
 private:
 	void setStatus( DWORD ) ;
diff --git a/src/main/start.cpp b/src/main/start.cpp
index 98df28f..702fea7 100644
--- a/src/main/start.cpp
+++ b/src/main/start.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/main/submit.cpp b/src/main/submit.cpp
index 038d5ae..f08e6fd 100644
--- a/src/main/submit.cpp
+++ b/src/main/submit.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -42,6 +42,7 @@
 #include "gstr.h"
 #include "gxtext.h"
 #include "ggetopt.h"
+#include "goptionsusage.h"
 #include "gpath.h"
 #include "gverifier.h"
 #include "gfilestore.h"
@@ -60,11 +61,9 @@
 #include <memory>
 #include <cstdlib>
 
-G_EXCEPTION_CLASS( NoBody , "no body text" ) ;
-
 std::string versionNumber()
 {
-	return "2.3.1" ;
+	return "2.4" ;
 }
 
 static std::string writeFiles( const G::Path & spool_dir ,
@@ -153,29 +152,97 @@ static std::string appDir()
 		return this_exe.dirname().str() ;
 }
 
+static G::Options options()
+{
+	using G::tx ;
+	using M = G::Option::Multiplicity ;
+	G::Options opt ;
+	unsigned int t_undef = 0U ;
+
+	G::Options::add( opt , 'h' , "help" ,
+		tx("show usage help") , "" ,
+		M::zero , "" , 1 , t_undef ) ;
+			// Shows help text and exits.
+
+	G::Options::add( opt , 'v' , "verbose" ,
+		tx("prints the path of the created content file") , "" ,
+		M::zero , "" , 1 , t_undef ) ;
+			// Prints the full path of the content file.
+
+	G::Options::add( opt , 's' , "spool-dir" ,
+		tx("specifies the spool directory") , "" ,
+		M::one , "dir" , 1 , t_undef ) ;
+			// Specifies the spool directory.
+
+	G::Options::add( opt , 'f' , "from" ,
+		tx("sets the envelope sender") , "" ,
+		M::one , "name" , 1 , t_undef ) ;
+			// Sets the envelope 'from' address.
+
+	G::Options::add( opt , 't' , "content-to" ,
+		tx("add recipients as content headers") , "" ,
+		M::zero , "" , 2 , t_undef ) ;
+			// Adds the envelope 'to' addresses as "To:" content headers.
+
+	G::Options::add( opt , 'F' , "content-from" ,
+		tx("add sender as content header") , "" ,
+		M::zero , "" , 2 , t_undef ) ;
+			// Adds the envelope 'from' addresses as a "From:" content header.
+
+	G::Options::add( opt , 'd' , "content-date" ,
+		tx("add a date content header") , "" ,
+		M::zero , "" , 2 , t_undef ) ;
+			// Adds a "Date:" content header if there is none.
+
+	G::Options::add( opt , 'c' , "copy" ,
+		tx("copy into spool sub-directories") , "" ,
+		M::zero , "" , 2 , t_undef ) ;
+			// Copies the envelope file into all sub-directories of the
+			// main spool directory.
+
+	G::Options::add( opt , 'n' , "filename" ,
+		tx("prints the name of the created content file") , "" ,
+		M::zero , "" , 2 , t_undef ) ;
+			// Prints the name of the content file.
+
+	G::Options::add( opt , 'C' , "content" ,
+		tx("sets a line of content") , "" ,
+		M::many , "base64" , 3 , t_undef ) ;
+			// Sets a line of content. This can be a header line, a blank line
+			// or a line of the body text. The first blank line separates headers
+			// from the body. The option value should be base64 encoded.
+
+	G::Options::add( opt , 'N' , "no-stdin" ,
+		tx("ignores the standard input stream") , "" ,
+		M::zero , "" , 3 , t_undef ) ;
+			// Ignores the standard-input. Typically used with "--content".
+
+	G::Options::add( opt , 'a' , "auth" ,
+		tx("sets the envelope authentication value") , "" ,
+		M::one , "name" , 3 , t_undef ) ;
+			// Sets the authentication value in the envelope file.
+
+	G::Options::add( opt , 'i' , "from-auth-in" ,
+		tx("sets the envelope from-auth-in value") , "" ,
+		M::one , "name" , 3 , t_undef ) ;
+			// Sets the 'from-auth-in' value in the envelope file.
+
+	G::Options::add( opt , 'o' , "from-auth-out" ,
+		tx("sets the envelope from-auth-out value") , "" ,
+		M::one , "name" , 3 , t_undef ) ;
+			// Sets the 'from-auth-out' value in the envelope file.
+
+	G::Options::add( opt , 'V' , "version" ,
+		tx("prints the version and exits") , "" ,
+		M::zero , "" , 2 , t_undef ) ;
+			// Prints the version number and exits.
+
+	return opt ;
+}
+
 static void run( const G::Arg & arg )
 {
-	G::GetOpt opt( arg ,
-
-		"v!verbose!prints the path of the created content file!!0!!1|"
-		"s!spool-dir!specifies the spool directory!!1!dir!1|"
-		"f!from!sets the envelope sender!!1!name!1|"
-
-		"t!content-to!add recipients as content headers!!0!!2|"
-		"F!content-from!add sender as content header!!0!!2|"
-		"d!content-date!add a date content header!!0!!2|"
-		"c!copy!copy into spool sub-directories!!0!!2|"
-		"n!filename!prints the name of the created content file!!0!!2|"
-
-		"C!content!sets a line of content! and ignores stdin!2!base64!3|"
-		"a!auth!sets the envelope authentication value!!1!name!3|"
-		"i!from-auth-in!sets the envelope from-auth-in value!!1!name!3|"
-		"o!from-auth-out!sets the envelope from-auth-out value!!1!name!3|"
-
-		"h!help!shows this help!!0!!2|"
-		"V!version!prints the version and exits!!0!!2|"
-	) ;
-
+	G::GetOpt opt( arg , options() ) ;
 	if( opt.hasErrors() )
 	{
 		opt.showErrors( std::cerr ) ;
@@ -183,18 +250,25 @@ static void run( const G::Arg & arg )
 	else if( opt.contains("help") )
 	{
 		std::ostream & stream = std::cerr ;
-		G::OptionsLayout layout ;
+		G::OptionsUsage::Config layout ;
 		if( opt.contains("verbose") )
-			layout.set_level( 3U ) ;
+			layout.set_level_max( 3U ) ;
 		else
-			layout.set_level(1U).set_alt_usage() ;
-		opt.options().showUsage( layout , stream , arg.prefix() , " <to-address> [<to-address> ...]" ) ;
+			layout.set_level_max(1U).set_alt_usage() ;
+
+		G::OptionsUsage(opt.options()).output( layout , stream , arg.prefix() , " <to-address> [<to-address> ...]" ) ;
+		stream << "\n" ;
+
+		stream << "If message content is read from the terminal then use ^" << (G::is_windows()?"Z":"D") << " to finish.\n" ;
+
 		if( !opt.contains("verbose") )
-			stream << "\nFor complete usage information run \"emailrelay-submit --help --verbose\"" << std::endl ;
+		{
+			stream << "\n" "For more options use \"--help -v\".\n" ;
+		}
 		stream
-			<< std::endl
+			<< "\n"
 			<< Main::Legal::warranty("","\n")
-			<< std::endl
+			<< "\n"
 			<< Main::Legal::copyright()
 			<< std::endl ;
 	}
@@ -205,16 +279,17 @@ static void run( const G::Arg & arg )
 	else if( opt.args().c() == 1U )
 	{
 		std::cerr
-			<< opt.options().usageSummary( {} , arg.prefix() , " <to-address> [<to-address> ...]" )
+			<< G::OptionsUsage(opt.options()).summary( {} , arg.prefix() , " <to-address> [<to-address> ...]" )
 			<< std::endl ;
 	}
 	else
 	{
 		// parse the command-line options
 		bool opt_copy = opt.contains( "copy" ) ;
+		bool opt_no_stdin = opt.contains( "no-stdin" ) ;
 		std::string opt_spool_dir = opt.value( "spool-dir" , GSmtp::MessageStore::defaultDirectory().str() ) ;
 		std::string opt_from = opt.value( "from" ) ;
-		G::StringArray opt_content = G::Str::splitIntoTokens( opt.value("content") , "," ) ;
+		G::StringArray opt_content = G::Str::splitIntoFields( opt.value("content") , ',' ) ;
 		bool opt_content_date = opt.contains( "content-date" ) ;
 		bool opt_content_from = opt.contains( "content-from" ) ;
 		bool opt_content_to = opt.contains( "content-to" ) ;
@@ -242,15 +317,13 @@ static void run( const G::Arg & arg )
 			for( const auto & part : opt_content )
 				content.push_back( part.size() <= 1U ? std::string() : G::Base64::decode(part,true) ) ;
 		}
-		else
+		if( !opt_no_stdin )
 		{
 			std::istream & stream = std::cin ;
 			while( stream.good() )
 			{
 				std::string line = G::Str::readLineFrom( stream ) ;
 				G::Str::trimRight( line , {"\r",1U} , 1U ) ;
-				if( line == "." )
-					throw NoBody() ;
 				if( !stream || line.empty() )
 					break ;
 				content.push_back( line ) ;
@@ -312,7 +385,7 @@ static void run( const G::Arg & arg )
 		std::stringstream empty ;
 		std::string new_path = writeFiles( opt_spool_dir , envelope_to_list , from ,
 			opt_from_auth_in , opt_from_auth_out , content ,
-			opt.contains("content") ? empty : std::cin ) ;
+			opt_no_stdin ? empty : std::cin ) ;
 
 		// copy into spool-dir subdirectories (cf. emailrelay-filter-copy)
 		if( opt_copy )
diff --git a/src/main/testrun.cpp b/src/main/testrun.cpp
new file mode 100644
index 0000000..d801f04
--- /dev/null
+++ b/src/main/testrun.cpp
@@ -0,0 +1,998 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file testrun.cpp
+///
+// A drop-in replacement for run.cpp that allows for soak testing
+// if the config file on the command-line contains "%x".
+//
+// The %x is replaced by 1,2,3 etc and as long as there is a
+// config file with that name it is used to add additional
+// active components surrounding a spool directory. If the
+// spool directory does not exist it is created, and if it is
+// empty it is populated with a dummy message.
+//
+// The optional "0" file can be used for confuring singletons,
+// such as logging.
+//
+// Eg:
+//    $ ( echo log ; echo log-file log ; echo no-daemon ) > config-0
+//    $ ( echo spool-dir spool-1 ; echo port 10001 ; echo forward-to localhost:10002 ; echo poll 1 ) > config-1
+//    $ ( echo spool-dir spool-2 ; echo port 10002 ; echo forward-to localhost:10001 ; echo poll 1 ) > config-2
+//    $ ./emailrelay config-%x
+//
+
+#include "gdef.h"
+#include "gssl.h"
+#include "testrun.h"
+#include "options.h"
+#include "gsmtpserver.h"
+#include "gsmtpclient.h"
+#include "gnewfile.h"
+#include "gsecrets.h"
+#include "geventloop.h"
+#include "garg.h"
+#include "gdaemon.h"
+#include "gpidfile.h"
+#include "gfilestore.h"
+#include "gmultiserver.h"
+#include "gadminserver.h"
+#include "gpopserver.h"
+#include "gsocket.h"
+#include "gfilterfactory.h"
+#include "gfactoryparser.h"
+#include "gverifierfactory.h"
+#include "gdnsbl.h"
+#include "gslot.h"
+#include "gmonitor.h"
+#include "glocal.h"
+#include "gfile.h"
+#include "gpath.h"
+#include "groot.h"
+#include "gexception.h"
+#include "gprocess.h"
+#include "ggettext.h"
+#include "gstrmacros.h"
+#include "gformat.h"
+#include "gtest.h"
+#include "glogoutput.h"
+#include "glog.h"
+#include "gassert.h"
+#include "legal.h"
+#include <vector>
+#include <iostream>
+#include <exception>
+#include <memory>
+#include <utility>
+
+#ifdef G_LOCALEDIR
+namespace { std::string localedir() { return G_STR(G_LOCALEDIR) ; } }
+#else
+namespace { std::string localedir() { return std::string() ; } }
+#endif
+
+std::string Main::Run::versionNumber()
+{
+	return "2.4" ;
+}
+
+Main::Run::Unit::Unit( std::size_t unit_id , Run * run , const Configuration & config , int resolver_family ) :
+	m_unit_id(unit_id) ,
+	m_run(run) ,
+	m_config(config) ,
+	m_resolver_family(resolver_family)
+{
+	G_LOG( "Main::Run::Unit::ctor: unit " << m_unit_id << ": port=" << config.port() ) ;
+	G_LOG( "Main::Run::Unit::ctor: unit " << m_unit_id << ": spool-dir=" << config.spoolDir() ) ;
+	G_LOG( "Main::Run::Unit::ctor: unit " << m_unit_id << ": server-tls=" << config.serverTls() ) ;
+	G_LOG( "Main::Run::Unit::ctor: unit " << m_unit_id << ": server-tls-certificate=" << config.serverTlsCertificate() ) ;
+	G_LOG( "Main::Run::Unit::ctor: unit " << m_unit_id << ": server-tls-private-key=" << config.serverTlsPrivateKey() ) ;
+	m_client_ptr = std::make_unique<GNet::ClientPtr<GSmtp::Client>>() ;
+	G_ASSERT( !(*m_client_ptr).busy() ) ;
+}
+
+void Main::Run::Unit::create( GSsl::Library * tls_library ,
+	GNet::Server::Config net_server_config ,
+	GSmtp::Server::Config smtp_server_config , GSmtp::Client::Config smtp_client_config ,
+	GPop::Server::Config pop_server_config )
+{
+	(*m_client_ptr).deletedSignal().connect( G::Slot::slot(*this,&Unit::onClientDone) ) ;
+	(*m_client_ptr).eventSignal().connect( G::Slot::slot(*this,&Unit::onClientEvent) ) ;
+	m_forward_request_signal.connect( G::Slot::slot(*this,&Unit::onForwardRequest) ) ;
+
+	auto es_log_only = GNet::ExceptionSink::logOnly() ;
+	m_forwarding_timer = std::make_unique<GNet::Timer<Unit>>( *this , &Unit::onRequestForwardingTimeout , es_log_only ) ;
+	m_poll_timer = std::make_unique<GNet::Timer<Unit>>( *this , &Unit::onPollTimeout , es_log_only ) ;
+
+	bool do_smtp = m_config.doServing() && m_config.doSmtp() ;
+	bool do_pop = m_config.doServing() && m_config.doPop() ;
+	bool do_admin = m_config.doServing() && m_config.doAdmin() ;
+
+	std::string server_tls_profile = std::string("server-").append(std::to_string(m_unit_id)) ;
+	std::string client_tls_profile = std::string("client-").append(std::to_string(m_unit_id)) ;
+
+	smtp_server_config.server_peer_config.socket_protocol_config.set_server_tls_profile( server_tls_profile ) ;
+	pop_server_config.server_peer_config.socket_protocol_config.set_server_tls_profile( server_tls_profile ) ;
+	smtp_client_config.set_client_tls_profile( client_tls_profile ) ;
+
+	if( m_config.serverTls() || m_config.serverTlsConnection() )
+	{
+		G_ASSERT( tls_library != nullptr ) ;
+		G_LOG( "Main::Run::Unit::create: unit " << m_unit_id << ": server tls profile: " << server_tls_profile ) ;
+		tls_library->addProfile( server_tls_profile , true ,
+			m_config.serverTlsPrivateKey().str() ,
+			m_config.serverTlsCertificate().str() ,
+			m_config.serverTlsCaList().str() ) ;
+	}
+	else
+	{
+		G_LOG( "Main::Run::Unit::create: unit " << m_unit_id << ": no server tls" ) ;
+	}
+
+	if( m_config.clientTls() || m_config.clientOverTls() )
+	{
+		G_ASSERT( tls_library != nullptr ) ;
+		G_LOG( "Main::Run::Unit::create: unit " << m_unit_id << ": client tls profile: " << client_tls_profile ) ;
+		tls_library->addProfile( client_tls_profile , false ,
+			m_config.clientTlsPrivateKey().str() ,
+			m_config.clientTlsCertificate().str() ,
+			m_config.clientTlsCaList().str() ,
+			m_config.clientTlsPeerCertificateName() ,
+			m_config.clientTlsPeerHostName() ) ;
+	}
+	else
+	{
+		G_LOG( "Main::Run::Unit::create: unit " << m_unit_id << ": no client tls" ) ;
+	}
+
+	using G::format ;
+	using G::txt ;
+	auto es_rethrow = GNet::ExceptionSink() ;
+
+	m_smtp_client_config = std::make_unique<GSmtp::Client::Config>( smtp_client_config ) ;
+
+	G::File::mkdir( m_config.spoolDir() , std::nothrow ) ;
+
+	m_store = std::make_unique<GSmtp::FileStore>( m_config.spoolDir() ,
+		m_config.maxSize() , m_config.eightBitTest() ) ;
+
+	if( m_unit_id && m_store->empty() )
+	{
+		std::string from = m_config.spoolDir().basename() ;
+		GSmtp::NewFile new_file( *m_store , from , {} , {} , 0U , false ) ;
+		GSmtp::NewMessage & new_message = new_file ;
+		new_message.addTo( "you" , false ) ;
+		new_message.addTextLine( "Subject: test" ) ;
+		new_message.addTextLine( {} ) ;
+		new_message.addTextLine( "created by testrun.cpp" ) ;
+		new_message.prepare( {} , "127.0.0.1" , {} ) ;
+		new_message.commit( true ) ;
+	}
+
+	m_filter_factory = std::make_unique<GSmtp::FilterFactoryFileStore>( *m_store ) ;
+	m_store->messageStoreRescanSignal().connect( G::Slot::slot(*this,&Unit::onStoreRescanEvent) ) ;
+	if( do_pop )
+	{
+		m_pop_store = std::make_unique<GPop::Store>( m_config.spoolDir() ,
+			m_config.popByName() , ! m_config.popNoDelete() ) ;
+	}
+
+	// authentication secrets
+	//
+	GAuth::Secrets::check( m_config.clientSecretsFile().str() , m_config.serverSecretsFile().str() ,
+		m_config.doPop() ? m_config.popSecretsFile().str() : std::string() ) ;
+	m_client_secrets = std::make_unique<GAuth::Secrets>( m_config.clientSecretsFile().str() , "client" ) ;
+	m_server_secrets = std::make_unique<GAuth::Secrets>( m_config.serverSecretsFile().str() , "server" ) ;
+	if( m_config.doPop() )
+		m_pop_secrets = std::make_unique<GAuth::Secrets>( m_config.popSecretsFile().str() , "pop-server" ) ;
+
+	// create the smtp server
+	//
+	if( do_smtp )
+	{
+		if( m_config.immediate() )
+			G_WARNING( "Run::doServing: " << txt("using --immediate can result in client timeout errors: "
+				"try --forward-on-disconnect instead") ) ;
+
+		G_ASSERT( m_store != nullptr ) ;
+		G_ASSERT( m_client_secrets != nullptr ) ;
+		G_ASSERT( m_server_secrets != nullptr ) ;
+		m_smtp_server = std::make_unique<GSmtp::Server>(
+			es_rethrow ,
+			*m_store ,
+			*m_filter_factory ,
+			*m_client_secrets ,
+			*m_server_secrets ,
+			smtp_server_config ,
+			m_config.immediate() ? m_config.serverAddress() : std::string() ,
+			m_resolver_family ,
+			*m_smtp_client_config ) ;
+
+		m_smtp_server->eventSignal().connect( G::Slot::slot(*this,&Unit::onServerEvent) ) ;
+	}
+
+	// create the pop server
+	//
+	if( do_pop )
+	{
+		G_ASSERT( m_pop_store != nullptr ) ;
+		G_ASSERT( m_pop_secrets != nullptr ) ;
+		m_pop_server = std::make_unique<GPop::Server>(
+			es_rethrow ,
+			*m_pop_store ,
+			*m_pop_secrets ,
+			pop_server_config ) ;
+	}
+
+	// create the admin server
+	//
+	if( do_admin )
+	{
+		G_ASSERT( m_store != nullptr ) ;
+		G_ASSERT( m_client_secrets != nullptr ) ;
+		m_admin_server = newAdminServer(
+			es_rethrow ,
+			m_config ,
+			*m_store ,
+			*m_filter_factory ,
+			m_forward_request_signal ,
+			GNet::ServerPeer::Config().set_idle_timeout(0U) ,
+			net_server_config ,
+			smtp_client_config ,
+			*m_client_secrets ,
+			versionNumber() ) ;
+	}
+}
+
+void Main::Run::Unit::start()
+{
+	// kick off some forwarding
+	//
+	if( m_config.forwardOnStartup() )
+		requestForwarding( "startup" ) ;
+
+	// kick off the polling cycle
+	//
+	if( m_config.doPolling() )
+		m_poll_timer->startTimer( m_config.pollingTimeout() ) ;
+
+	// report stuff
+	//
+	if( m_smtp_server ) m_smtp_server->report() ;
+	if( m_admin_server ) m_admin_server->report() ;
+	if( m_pop_server ) m_pop_server->report() ;
+}
+
+std::string Main::Run::Unit::exceptionSourceId() const
+{
+	return m_config.spoolDir().basename() ;
+}
+
+bool Main::Run::needTls( const Configuration & config ) const
+{
+	return
+		config.clientTls() ||
+		config.clientOverTls() ||
+		config.serverTls() ||
+		config.serverTlsConnection() ;
+}
+
+bool Main::Run::preferTls( const Configuration & config ) const
+{
+	// secrets might need hash functions from tls library
+	return
+		!config.clientSecretsFile().empty() ||
+		!config.serverSecretsFile().empty() ||
+		!config.popSecretsFile().empty() ;
+}
+
+Main::Run::Run( Main::Output & output , const G::Arg & arg , bool is_windows , bool has_gui ) :
+	m_output(output) ,
+	m_is_windows(is_windows) ,
+	m_arg(arg) ,
+	m_quit_when_sent(false) ,
+	m_has_gui(has_gui)
+{
+	// initialise gettext() early iff "--localedir" is used
+	{
+		std::string ldir = localedir() ;
+		std::size_t pos = m_arg.index( "--localedir" , 1U ) ;
+		std::size_t mpos = m_arg.match( "--localedir=" ) ;
+		if( pos )
+			ldir = m_arg.removeAt( pos , 1U ) ;
+		else if( mpos )
+			ldir = G::Str::tail( m_arg.removeAt(mpos) , "=" ) ;
+		if( pos || mpos ) // moot, but avoid surprising regressions
+			G::gettext_init( ldir , "emailrelay" ) ;
+	}
+
+	// initialise the base configuration
+	//
+	bool multi = m_arg.c() > 1U && m_arg.v(m_arg.c()-1U).find("%x") != std::string::npos ;
+	if( multi )
+	{
+		std::string config_file = m_arg.v(m_arg.c()-1U) ;
+		G::Str::replace( config_file , "%x" , "0" ) ;
+		G::StringArray parts = m_arg.array() ;
+		parts.pop_back() ;
+		if( G::File::exists(config_file) ) parts.push_back( config_file ) ; // "0" file is optional
+		m_commandline = std::make_unique<CommandLine>( m_output , G::Arg(parts) , Main::Options::spec(m_is_windows) , versionNumber() ) ;
+		m_configuration = std::make_unique<Configuration>( m_commandline->options() , m_commandline->map() , appDir() , G::Process::cwd() ) ;
+	}
+	else
+	{
+		m_commandline = std::make_unique<CommandLine>( m_output , m_arg , Main::Options::spec(m_is_windows) , versionNumber() ) ;
+		m_configuration = std::make_unique<Configuration>( m_commandline->options() , m_commandline->map() , appDir() , G::Process::cwd() ) ;
+	}
+}
+
+void Main::Run::configure()
+{
+}
+
+bool Main::Run::runnable()
+{
+	if( commandline().map().contains("help") )
+	{
+		commandline().showHelp( false ) ;
+		return true ;
+	}
+	else if( commandline().hasUsageErrors() )
+	{
+		commandline().showUsageErrors( true ) ;
+		return false ;
+	}
+	else if( commandline().map().contains("version") )
+	{
+		commandline().showVersion( false ) ;
+		return true ;
+	}
+	else if( commandline().argc() > 1U )
+	{
+		commandline().showArgcError( true ) ;
+		return false ;
+	}
+
+	if( !configuration().semanticError().empty() )
+	{
+		commandline().showSemanticError( configuration().semanticError() ) ;
+		return false ;
+	}
+
+	if( m_output.outputSimple() && !configuration().semanticWarnings().empty() )
+	{
+		commandline().showSemanticWarnings( configuration().semanticWarnings() ) ;
+	}
+
+	if( commandline().map().contains("test") )
+	{
+		G::Test::set( commandline().map().value("test") ) ;
+	}
+
+	return true ;
+}
+
+void Main::Run::run()
+{
+	using G::format ;
+	using G::txt ;
+
+	if( commandline().map().contains("help") || commandline().map().contains("version") )
+		return ;
+
+	// override for local host's canonical network name
+	//
+	bool network_name_defined = configuration().networkName(std::string(1U,'\0')) != std::string(1U,'\0') ;
+	if( network_name_defined )
+		GNet::Local::canonicalName( configuration().networkName() ) ; // set the override
+
+	// close inherited file descriptors to avoid locking file systems
+	// when running as a daemon -- this has to be done early, before
+	// opening any sockets or message-store streams
+	//
+	if( configuration().closeFiles() )
+	{
+		closeFiles() ;
+	}
+
+	// open log file and/or syslog after closeFiles()
+	//
+	m_log_output = std::make_unique<G::LogOutput>(
+		m_arg.prefix() ,
+		G::LogOutput::Config()
+			.set_output_enabled(configuration().log())
+			.set_summary_info(configuration().log())
+			.set_verbose_info(configuration().verbose())
+			.set_debug(configuration().debug())
+			.set_with_level(true)
+			.set_with_timestamp(configuration().logTimestamp())
+			.set_with_context(configuration().logAddress())
+			.set_strip(!configuration().debug())
+			.set_use_syslog(configuration().useSyslog())
+			.set_allow_bad_syslog(!(m_has_gui&&configuration().logFile().empty()))
+			.set_umask( G::Process::Umask::Mode::Tighter )
+			.set_facility(configuration().syslogFacility()) ,
+		configuration().logFile().str() // stderr-replacement
+	) ;
+
+	// tighten the umask
+	//
+	G::Process::Umask::set( G::Process::Umask::Mode::Tightest ) ;
+
+	// log command-line warnings
+	//
+	if( !m_output.outputSimple() )
+	{
+		commandline().logSemanticWarnings( configuration().semanticWarnings() ) ;
+	}
+
+	// if we are going to close stderr soon then make stderr logging
+	// less verbose so that startup scripts are cleaner, but without
+	// affecting syslog output
+	if( configuration().useSyslog() && configuration().daemon() &&
+		configuration().closeStderr() && configuration().logFile().empty() )
+			m_log_output->configure( m_log_output->config().set_quiet_stderr() ) ;
+
+	// release root privileges and extra group memberships
+	//
+	if( configuration().user() != "root" )
+		G::Root::init( configuration().user() ) ;
+
+	// create event loop singletons
+	//
+	m_event_loop = GNet::EventLoop::create() ;
+	m_timer_list = std::make_unique<GNet::TimerList>() ;
+
+	// early check on multi-threading behaviour
+	//
+	checkThreading() ;
+
+	// network monitor singleton
+	//
+	m_monitor = std::make_unique<GNet::Monitor>() ;
+	m_monitor->signal().connect( G::Slot::slot(*this,&Run::onNetworkEvent) ) ;
+
+	// early check that the forward-to address can be resolved
+	//
+	if( configuration().log() && !configuration().serverAddress().empty() && !configuration().forwardOnStartup() &&
+		!GNet::Address::isFamilyLocal( configuration().serverAddress() ) )
+	{
+		GNet::Location location( configuration().serverAddress() , resolverFamily(configuration()) ) ;
+		std::string error = GNet::Resolver::resolve( location ) ;
+		if( !error.empty() )
+			G_WARNING( "Main::Run::run: " << format(txt("dns lookup of forward-to address failed: %1%")) % error ) ;
+		else
+			G_LOG( "Main::Run::run: " << format(txt("forwarding address %1%")) % location.displayString() ) ;
+	}
+
+	// early check on the DNSBL configuration string
+	//
+	if( !configuration().dnsbl().empty() )
+		GNet::Dnsbl::checkConfig( configuration().dnsbl() ) ;
+
+	// prepare the pid file
+	//
+	G::Path pid_file_path = configuration().usePidFile() ? G::Path(configuration().pidFile()) : G::Path() ;
+	G::PidFile pid_file( pid_file_path ) ;
+	{
+		G::Root claim_root ;
+		G::Process::Umask _( G::Process::Umask::Mode::GroupOpen ) ;
+		pid_file.mkdir() ;
+	}
+
+	// read the config files
+	//
+	std::vector<G::Arg> args_list ;
+	bool need_tls = false ;
+	bool prefer_tls = false ;
+	std::string tls_config ;
+	bool multi = m_arg.c() > 1U && m_arg.v(m_arg.c()-1U).find("%x") != std::string::npos ;
+	if( multi )
+	{
+		for( int i = 1 ; i < 100 ; i++ )
+		{
+			std::string config_file = m_arg.v(m_arg.c()-1U) ;
+			G::Str::replace( config_file , "%x" , G::Str::fromInt(i) ) ;
+			if( !G::File::exists(config_file) ) break ;
+			G_LOG( "Unit::ctor: reading config file: " << config_file ) ;
+			G::StringArray arg_parts = m_arg.array() ;
+			arg_parts.back() = config_file ;
+			CommandLine cl( m_output , G::Arg(arg_parts) , Main::Options::spec(m_is_windows) , versionNumber() ) ;
+			if( cl.hasUsageErrors() )
+				throw G::Exception( "unit configuration file error" , config_file , G::Str::join("|",cl.usageErrors()) ) ;
+			Configuration cfg( cl.options() , cl.map() , appDir() , G::Process::cwd() ) ;
+			if( !cfg.semanticError().empty() )
+				throw G::Exception( "unit configuration file error" , config_file , cfg.semanticError() ) ;
+			if( !cfg.tlsConfig().empty() )
+				throw G::Exception( "invalid tls configuration string in unit configuration" ) ;
+			args_list.push_back( G::Arg(arg_parts) ) ;
+			if( needTls(cfg) ) need_tls = true ;
+			if( preferTls(cfg) ) prefer_tls = true ;
+		}
+	}
+	else
+	{
+		need_tls = needTls( configuration() ) ;
+		prefer_tls = preferTls( configuration() ) ;
+		tls_config = configuration().tlsConfig() ;
+	}
+
+	// tls library setup
+	//
+	G_LOG( "Run::ctor: need tls: " << need_tls ) ;
+	G_LOG( "Run::ctor: prefer tls: " << prefer_tls ) ;
+	m_tls_library = std::make_unique<GSsl::Library>( need_tls || prefer_tls ,
+		tls_config , GSsl::Library::log , configuration().debug() ) ;
+	if( need_tls && !m_tls_library->enabled() )
+		throw G::Exception( txt("cannot do tls/ssl: tls library not built in: "
+			"remove tls options from the command-line or "
+			"rebuild the emailrelay executable with a supported tls library") ) ;
+
+	// create the units
+	//
+	if( multi )
+	{
+		for( std::size_t i = 0U ; i < args_list.size() ; i++ )
+		{
+			G::Arg args = args_list.at( i ) ;
+			G_LOG( "Unit::ctor: args: " << G::Str::join("|",args.array(1U)) ) ;
+			CommandLine cl( m_output , G::Arg(args) , Main::Options::spec(m_is_windows) , versionNumber() ) ;
+			Configuration cfg( cl.options() , cl.map() , appDir() , G::Process::cwd() ) ;
+			m_unit.emplace_back( i+1U , this , cfg , resolverFamily(cfg) ) ;
+		}
+	}
+	else
+	{
+		m_unit.emplace_back( 0U , this , configuration() , resolverFamily(configuration()) ) ;
+	}
+	if( m_unit.empty() )
+		throw G::Exception( "no units" ) ;
+
+	// figure out what we're doing
+	//
+	bool do_smtp = configuration().doServing() && configuration().doSmtp() ;
+	bool do_pop = configuration().doServing() && configuration().doPop() ;
+	bool do_admin = configuration().doServing() && configuration().doAdmin() ;
+	bool serving = do_smtp || do_pop || do_admin ;
+	bool admin_forwarding = do_admin && !configuration().serverAddress().empty() ;
+	bool forwarding = configuration().forwardOnStartup() || configuration().doPolling() || admin_forwarding ;
+	m_quit_when_sent =
+		!serving &&
+		configuration().forwardOnStartup() &&
+		!configuration().doPolling() &&
+		!admin_forwarding ;
+
+	// activate the units
+	//
+	for( auto & unit : m_unit )
+	{
+		std::string name = unit.m_config.spoolDir().basename() ;
+		unit.create( m_tls_library.get() ,
+			netServerConfig(unit.m_config) ,
+			smtpServerConfig(unit.m_config) ,
+			clientConfig(unit.m_config,name) ,
+			popConfig(unit.m_config) ) ;
+	}
+
+	// do serving and/or forwarding
+	//
+	if( !serving && !forwarding )
+	{
+		commandline().showNothingToDo( true ) ;
+	}
+	else if( m_quit_when_sent &&
+		std::all_of( m_unit.begin() , m_unit.end() ,
+			[](Unit &unit){return unit.m_store && unit.m_store->empty();} ) )
+	{
+		commandline().showNothingToSend( true ) ;
+	}
+	else
+	{
+		// daemonise etc
+		if( configuration().daemon() )
+			G::Daemon::detach( pid_file.path() ) ;
+		commit( pid_file ) ;
+		if( configuration().closeStderr() )
+			G::Process::closeStderr() ;
+
+		for( auto & unit : m_unit )
+		{
+			unit.start() ;
+		}
+
+		// run the event loop
+		//
+		std::string quit_reason = m_event_loop->run() ;
+		if( !quit_reason.empty() )
+			throw std::runtime_error( quit_reason ) ;
+	}
+}
+
+const Main::CommandLine & Main::Run::commandline() const
+{
+	G_ASSERT( m_commandline != nullptr ) ;
+	return *m_commandline ;
+}
+
+std::string Main::Run::smtpIdent() const
+{
+	return std::string("E-MailRelay V") + versionNumber() ;
+}
+
+void Main::Run::closeFiles() const
+{
+	if( configuration().daemon() )
+	{
+		const bool keep_stderr = true ;
+		G::Process::closeFiles( keep_stderr ) ;
+	}
+}
+
+bool Main::Run::hidden() const
+{
+	return configuration().hidden() || configuration().show("hidden") ;
+}
+
+void Main::Run::commit( G::PidFile & pid_file )
+{
+	if( !pid_file.committed() )
+	{
+		// change user id so that we can write to /var/run or wherever -- but dont
+		// change the effective group id -- as a result we create the pid file with
+		// unprivileged group ownership, which is easier to clean up -- also use
+		// a world-readable umask so that different users can play nice together
+		G::Root claim_root( false ) ;
+		G::Process::Umask umask( G::Process::Umask::Mode::Readable ) ;
+		pid_file.commit() ;
+	}
+}
+
+GNet::StreamSocket::Config Main::Run::netSocketConfig( bool /*server*/ ) const
+{
+	std::pair<int,int> linger = { -1 , 0 } ;
+	return
+		GNet::StreamSocket::Config()
+			.set_create_linger( linger )
+			.set_accept_linger( linger )
+			.set_bind_reuse( !G::is_windows() || G::is_wine() )
+			.set_bind_exclusive( G::is_windows() && !G::is_wine() )
+			.set_last<GNet::StreamSocket::Config>() ;
+}
+
+GSmtp::ServerProtocol::Config Main::Run::serverProtocolConfig( const Configuration & config ) const
+{
+	return
+		GSmtp::ServerProtocol::Config()
+			.set_with_vrfy( !config.anonymousServerVrfy() )
+			.set_filter_timeout( config.filterTimeout() )
+			.set_max_size( config.maxSize() )
+			.set_authentication_requires_encryption( config.serverTlsRequired() )
+			.set_mail_requires_authentication( !config.serverSecretsFile().empty() )
+			.set_mail_requires_encryption( config.serverTlsRequired() )
+			.set_tls_starttls( config.serverTls() )
+			.set_tls_connection( config.serverTlsConnection() )
+			.set_allow_pipelining( config.smtpPipelining() ) ;
+}
+
+GNet::Server::Config Main::Run::netServerConfig( const Configuration & config ) const
+{
+	bool open = config.user().empty() || config.user() == "root" ;
+	return GNet::Server::Config()
+		.set_stream_socket_config( netSocketConfig() )
+		.set_uds_open_permissions( open ) ;
+}
+
+GSmtp::Server::Config Main::Run::smtpServerConfig( const Configuration & config ) const
+{
+	return
+		GSmtp::Server::Config()
+			.set_allow_remote( config.allowRemoteClients() )
+			.set_interfaces( config.listeningNames("smtp") )
+			.set_port( config.port() )
+			.set_ident( smtpIdent() )
+			.set_anonymous_smtp( config.anonymousServerSmtp() )
+			.set_anonymous_content( config.anonymousContent() )
+			.set_filter_spec( config.filter() )
+			.set_filter_timeout( config.filterTimeout() )
+			.set_verifier_spec( config.verifier() )
+			.set_verifier_timeout( config.filterTimeout() )
+			.set_server_peer_config( GNet::ServerPeer::Config().set_idle_timeout(config.idleTimeout()) )
+			.set_server_config( netServerConfig(config) )
+			.set_protocol_config( serverProtocolConfig(config) )
+			.set_sasl_server_config( config.smtpSaslServerConfig() )
+			.set_dnsbl_config( config.dnsbl() ) ;
+}
+
+GPop::Server::Config Main::Run::popConfig( const Configuration & config ) const
+{
+	return
+		GPop::Server::Config()
+			.set_allow_remote( config.allowRemoteClients() )
+			.set_port( config.popPort() )
+			.set_addresses( config.listeningNames("pop") )
+			.set_server_peer_config(
+				GNet::ServerPeer::Config()
+					.set_idle_timeout( config.idleTimeout()) )
+			.set_server_config( netServerConfig(config) )
+			.set_sasl_server_config( config.popSaslServerConfig() ) ;
+}
+
+GSmtp::Client::Config Main::Run::clientConfig( const Configuration & config , const std::string & name ) const
+{
+	return
+		GSmtp::Client::Config()
+			.set_stream_socket_config( netSocketConfig(false) )
+			.set_client_protocol_config(
+				GSmtp::ClientProtocol::Config()
+					.set_thishost_name( name )
+					.set_response_timeout( config.responseTimeout() )
+					.set_ready_timeout( config.promptTimeout() )
+					.set_filter_timeout( config.filterTimeout() )
+					.set_use_starttls_if_possible( config.clientTls() && !config.clientOverTls() )
+					.set_must_use_tls( config.clientTlsRequired() && !config.clientOverTls() )
+					.set_must_authenticate( true )
+					.set_anonymous( config.anonymousClientSmtp() )
+					.set_must_accept_all_recipients( !config.forwardToSome() )
+					.set_eight_bit_strict( false ) )
+			.set_filter_spec( config.clientFilter() )
+			.set_filter_timeout( config.filterTimeout() )
+			.set_bind_local_address( !config.clientBindAddress().empty() )
+			.set_local_address( asAddress(config.clientBindAddress()) )
+			.set_connection_timeout( config.connectionTimeout() )
+			.set_secure_connection_timeout( config.secureConnectionTimeout() )
+			.set_secure_tunnel( config.clientOverTls() )
+			.set_sasl_client_config( config.smtpSaslClientConfig() ) ;
+}
+
+GNet::Address Main::Run::asAddress( const std::string & s )
+{
+	// (port number is optional)
+	return s.empty() ?
+		GNet::Address::defaultAddress() :
+		( GNet::Address::validString(s,GNet::Address::NotLocal()) ? GNet::Address::parse(s,GNet::Address::NotLocal()) : GNet::Address::parse(s,0U) ) ;
+}
+
+void Main::Run::Unit::onPollTimeout()
+{
+	G_DEBUG( "Main::Run::onPollTimeout" ) ;
+	m_poll_timer->startTimer( m_config.pollingTimeout() ) ;
+	requestForwarding( "poll" ) ;
+}
+
+void Main::Run::Unit::onForwardRequest( const std::string & reason )
+{
+	requestForwarding( reason ) ;
+}
+
+void Main::Run::Unit::requestForwarding( const std::string & reason )
+{
+	G_ASSERT( m_forwarding_timer != nullptr ) ;
+	G_LOG( "Main::Run::Unit::requestForwarding: " << m_config.spoolDir().basename() << ": forwarding request [" << reason << "]" ) ;
+	if( !reason.empty() )
+		m_forwarding_reason = reason ;
+	m_forwarding_timer->startTimer( 0U ) ;
+}
+
+void Main::Run::Unit::onRequestForwardingTimeout()
+{
+	using G::format ;
+	using G::txt ;
+	if( (*m_client_ptr).busy() )
+	{
+		G_LOG( "Main::Run::onRequestForwardingTimeout: " << m_config.spoolDir().basename() << ": "
+			<< format(txt("forwarding: [%1%]: still busy from last time")) % m_forwarding_reason ) ;
+		m_forwarding_pending = true ;
+	}
+	else
+	{
+		if( logForwarding() )
+		{
+			G_LOG( "Main::Run::onRequestForwardingTimeout: " << m_config.spoolDir().basename() << ": "
+				<< format(txt("forwarding: [%1%]")) % m_forwarding_reason ) ;
+		}
+
+		emit( "forward" , "start" ) ;
+		std::string error = startForwarding() ;
+		if( !error.empty() )
+			emit( "forward" , "end" , error ) ;
+	}
+}
+
+bool Main::Run::Unit::logForwarding() const
+{
+	return m_forwarding_reason != "poll" || m_config.pollingLog() ||
+		( G::LogOutput::instance() && G::LogOutput::instance()->at( G::Log::Severity::Debug ) ) ;
+}
+
+std::string Main::Run::Unit::startForwarding()
+{
+	using G::txt ;
+	try
+	{
+		if( m_store->empty() )
+		{
+			if( logForwarding() )
+				G_LOG( "Main::Run::startForwarding: " << txt("forwarding: no messages to send") ) ;
+			return "no messages" ;
+		}
+		else
+		{
+			G_LOG( "Main::Run::startForwarding: " << m_config.spoolDir().basename() << ": "
+				<< "now forwarding to " << m_config.serverAddress() << " "
+				<< "(resolver family " << m_resolver_family << ")" ) ;
+			G_ASSERT( m_client_secrets != nullptr ) ;
+			(*m_client_ptr).reset( std::make_unique<GSmtp::Client>(
+				GNet::ExceptionSink(*m_client_ptr,this) ,
+				*m_filter_factory ,
+				GNet::Location(m_config.serverAddress(),m_resolver_family) ,
+				*m_client_secrets ,
+				*m_smtp_client_config ) ) ;
+
+			G_ASSERT( m_store != nullptr ) ;
+			(*m_client_ptr)->sendMessagesFrom( *m_store ) ; // once connected
+			return std::string() ;
+		}
+	}
+	catch( std::exception & e )
+	{
+		G_ERROR( "Main::Run::startForwarding: " << txt("forwarding failure") << ": " << e.what() ) ;
+		return e.what() ;
+	}
+}
+
+void Main::Run::Unit::onClientDone( const std::string & reason )
+{
+	using G::format ;
+	using G::txt ;
+	G_DEBUG( "Main::Run::onClientDone: reason=[" << reason << "]" ) ;
+	bool quit = m_run->onClientDone( reason ) ;
+	if( !quit )
+	{
+		if( ! reason.empty() )
+			G_ERROR( "Main::Run::onClientDone: " << format(txt("forwarding: %1%")) % reason ) ;
+
+		// go round again if necessary
+		if( m_forwarding_pending )
+		{
+			m_forwarding_pending = false ;
+			G_LOG( "Main::Run::onClientDone: "
+				<< format(txt("forwarding: queued request [%1%]")) % m_forwarding_reason ) ;
+			requestForwarding() ;
+		}
+	}
+	emit( "forward" , "end" , reason ) ;
+}
+
+bool Main::Run::onClientDone( const std::string & reason )
+{
+	if( m_quit_when_sent )
+	{
+		// quit the event loop
+		if( m_event_loop )
+			m_event_loop->quit( reason ) ;
+		return true ;
+	}
+	else
+	{
+		return false ;
+	}
+}
+
+void Main::Run::Unit::onClientEvent( const std::string & s1 , const std::string & s2 , const std::string & s3 )
+{
+	emit( "client" , s1 , s2 , s3 ) ;
+}
+
+void Main::Run::Unit::onServerEvent( const std::string & s1 , const std::string & )
+{
+	if( s1 == "done" && m_config.forwardOnDisconnect() )
+		requestForwarding( "client disconnect" ) ;
+}
+
+void Main::Run::Unit::onStoreRescanEvent()
+{
+	requestForwarding( "rescan" ) ;
+}
+
+void Main::Run::onNetworkEvent( const std::string & s1 , const std::string & s2 )
+{
+	emit( "network" , s1 , s2 ) ;
+}
+
+void Main::Run::Unit::emit( const std::string & s0 , const std::string & s1 ,
+	const std::string & s2 , const std::string & s3 )
+{
+	m_run->emit( s0 , s1 , s2 , s3 ) ;
+}
+
+void Main::Run::emit( std::string s0 , std::string s1 , std::string s2 , std::string s3 )
+{
+	// (now gutted)
+}
+
+G::Slot::Signal<std::string,std::string,std::string,std::string> & Main::Run::signal()
+{
+	return m_signal ;
+}
+
+int Main::Run::resolverFamily( const Configuration & config ) const
+{
+	// choose an address family for the DNS lookup based on the "--client-interface" address
+	std::string client_bind_address = config.clientBindAddress() ;
+	if( client_bind_address.empty() )
+		return AF_UNSPEC ;
+
+	GNet::Address address = asAddress( client_bind_address ) ;
+	return ( address.af() == AF_INET || address.af() == AF_INET6 ) ? address.af() : AF_UNSPEC ;
+}
+
+void Main::Run::checkThreading() const
+{
+	if( G::threading::using_std_thread )
+	{
+		// ignore the result here -- we are just trying to provoke an early weak-symbol linking failure
+		G::threading::works() ;
+	}
+}
+
+G::Path Main::Run::appDir() const
+{
+	G::Path this_exe = G::Arg::exe() ;
+	if( this_exe.empty() ) // eg. linux with no procfs
+		return G::Path(m_arg.v(0U)).dirname() ; // may be relative and/or bogus
+	else if( this_exe.dirname().basename() == "MacOS" && this_exe.dirname().dirname().basename() == "Contents" )
+		return this_exe.dirname().dirname().dirname() ; // .app
+	else
+		return this_exe.dirname() ;
+}
+
+std::unique_ptr<GSmtp::AdminServer> Main::Run::Unit::newAdminServer( GNet::ExceptionSink es ,
+	const Configuration & cfg , GSmtp::MessageStore & store , GSmtp::FilterFactory & ff ,
+	G::Slot::Signal<const std::string&> & forward_request_signal ,
+	const GNet::ServerPeer::Config & server_peer_config , const GNet::Server::Config & net_server_config ,
+	const GSmtp::Client::Config & client_config , const GAuth::Secrets & client_secrets ,
+	const std::string & version_number )
+{
+	G::StringMap info_map ;
+	info_map["version"] = version_number ;
+	info_map["warranty"] = Legal::warranty("","\n") ;
+	info_map["credit"] = GSsl::Library::credit("","\n","") ;
+	info_map["copyright"] = Legal::copyright() ;
+
+	G::StringMap config_map ;
+	//config_map["forward-to"] = cfg.serverAddress() ;
+	//config_map["spool-dir"] = cfg.spoolDir().str() ;
+
+	return std::make_unique<GSmtp::AdminServer>(
+			es ,
+			store ,
+			ff ,
+			forward_request_signal ,
+			server_peer_config ,
+			net_server_config ,
+			client_config ,
+			client_secrets ,
+			cfg.listeningNames("admin") ,
+			cfg.adminPort() ,
+			cfg.allowRemoteClients() ,
+			cfg.serverAddress() ,
+			cfg.connectionTimeout() ,
+			info_map ,
+			config_map ,
+			cfg.withTerminate() ) ;
+}
+
diff --git a/src/main/testrun.h b/src/main/testrun.h
new file mode 100644
index 0000000..bc81980
--- /dev/null
+++ b/src/main/testrun.h
@@ -0,0 +1,233 @@
+//
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// ===
+///
+/// \file testrun.h
+///
+
+#ifndef G_MAIN_TESTRUN_H
+#define G_MAIN_TESTRUN_H
+
+#include "gdef.h"
+#include "gssl.h"
+#include "configuration.h"
+#include "commandline.h"
+#include "output.h"
+#include "geventloop.h"
+#include "gtimerlist.h"
+#include "gclientptr.h"
+#include "glogoutput.h"
+#include "gmonitor.h"
+#include "gdaemon.h"
+#include "gpidfile.h"
+#include "gslot.h"
+#include "garg.h"
+#include "gsecrets.h"
+#include "gmessagestore.h"
+#include "gfilestore.h"
+#include "gsmtpclient.h"
+#include "gsmtpserver.h"
+#include "gadminserver.h"
+#include "gpopserver.h"
+#include "gpopstore.h"
+#include <iostream>
+#include <exception>
+#include <memory>
+#include <deque>
+
+namespace Main
+{
+	class Run ;
+}
+
+//| \class Main::Run
+/// A top-level class for the process.
+/// Usage:
+/// \code
+/// int main( int argc , char ** argv )
+/// {
+///   G::Arg arg( argc , argv ) ;
+///   Output output ;
+///   Main::Run run( output , arg ) ;
+///   run.configure() ;
+///   if( run.runnable() )
+///      run.run() ;
+///   return 0 ;
+/// }
+/// \endcode
+///
+class Main::Run : private GNet::EventHandler
+{
+public:
+	Run( Output & output , const G::Arg & arg , bool is_windows = false , bool has_gui = false ) ;
+		///< Constructor. Tries not to throw.
+
+	void configure() ;
+		///< Prepares to run() typically by parsing the commandline.
+
+	bool hidden() const ;
+		///< Returns true if the program should run in hidden mode.
+		///< Precondition: configure()d
+
+	bool runnable() ;
+		///< Returns true if run() should be called.
+		///< Precondition: configure()d
+
+	void run() ;
+		///< Runs the application. Error messages are sent to the Output
+		///< interface.
+		///< Precondition: runnable()
+
+	const Configuration & configuration() const ;
+		///< Returns a configuration object.
+
+	static std::string versionNumber() ;
+		///< Returns the application version number string.
+
+	G::Slot::Signal<std::string,std::string,std::string,std::string> & signal() ;
+		///< Provides a signal which is activated when something changes.
+
+private:
+	struct QueueItem
+	{
+		int target ;
+		std::string s0 ;
+		std::string s1 ;
+		std::string s2 ;
+		std::string s3 ;
+		QueueItem( int target_ , const std::string & s0_ , const std::string & s1_ , const std::string & s2_ , const std::string & s3_ ) :
+			target(target_) ,
+			s0(s0_) ,
+			s1(s1_) ,
+			s2(s2_) ,
+			s3(s3_)
+		{
+		}
+	} ;
+
+public:
+	Run( const Run & ) = delete ;
+	Run( Run && ) = delete ;
+	Run & operator=( const Run & ) = delete ;
+	Run & operator=( Run && ) = delete ;
+
+public:
+	// for Unit...
+	bool onClientDone( const std::string & ) ;
+	void emit( std::string , std::string , std::string = {} , std::string = {} ) ;
+
+private:
+	void doForwardingOnStartup( G::PidFile & ) ;
+	void closeFiles() const ;
+	void commit( G::PidFile & ) ;
+	std::string smtpIdent() const ;
+	void recordPid() ;
+	const CommandLine & commandline() const ;
+	void onServerEvent( const std::string & , const std::string & ) ; // Server::eventSignal()
+	void onStoreUpdateEvent() ;
+	void onNetworkEvent( const std::string & , const std::string & ) ;
+	void onQueueTimeout() ;
+	GNet::StreamSocket::Config netSocketConfig( bool server = true ) const ;
+	GSmtp::Client::Config clientConfig( const Configuration & , const std::string & ) const ;
+	GSmtp::ServerProtocol::Config serverProtocolConfig( const Configuration & ) const ;
+	GSmtp::Server::Config smtpServerConfig( const Configuration & ) const ;
+	GNet::Server::Config netServerConfig( const Configuration & ) const ;
+	int resolverFamily( const Configuration & ) const ;
+	static GNet::Address asAddress( const std::string & ) ;
+	GPop::Server::Config popConfig( const Configuration & ) const ;
+	void checkThreading() const ;
+	std::string versionString() const ;
+	static std::string buildConfiguration() ;
+	G::Path appDir() const ;
+	bool needTls( const Configuration & ) const ;
+	bool preferTls( const Configuration & ) const ;
+
+private:
+	Output & m_output ;
+	GNet::ExceptionSink m_es_rethrow ;
+	GNet::ExceptionSink m_es_nothrow ;
+	bool m_is_windows ;
+	G::Arg m_arg ;
+	G::Slot::Signal<std::string,std::string,std::string,std::string> m_signal ;
+	std::unique_ptr<CommandLine> m_commandline ;
+	std::unique_ptr<Configuration> m_configuration ;
+	std::unique_ptr<G::LogOutput> m_log_output ;
+	std::unique_ptr<GNet::EventLoop> m_event_loop ;
+	std::unique_ptr<GNet::TimerList> m_timer_list ;
+	std::unique_ptr<GNet::Monitor> m_monitor ;
+	std::unique_ptr<GSsl::Library> m_tls_library ;
+	std::deque<QueueItem> m_queue ;
+	bool m_quit_when_sent ;
+	bool m_has_gui ;
+	struct Unit : private GNet::ExceptionSource
+	{
+		Unit( std::size_t , Run * , const Configuration & , int resolver_family ) ;
+		void create( GSsl::Library * , GNet::Server::Config net_server_config ,
+			GSmtp::Server::Config smtp_server_config , GSmtp::Client::Config smtp_client_config ,
+			GPop::Server::Config pop_server_config ) ;
+		void start() ;
+		//
+		std::unique_ptr<GSmtp::AdminServer> newAdminServer( GNet::ExceptionSink ,
+			const Configuration & , GSmtp::MessageStore & , GSmtp::FilterFactory & ,
+			G::Slot::Signal<const std::string&> & ,
+			const GNet::ServerPeer::Config & ,
+			const GNet::Server::Config & , const GSmtp::Client::Config & ,
+			const GAuth::Secrets & , const std::string & ) ;
+		void onForwardRequest( const std::string & ) ;
+		void onClientDone( const std::string & ) ;
+		void onClientEvent( const std::string & , const std::string & , const std::string & ) ;
+		void onRequestForwardingTimeout() ;
+		void onPollTimeout() ;
+		void onStoreRescanEvent() ;
+		void onServerEvent( const std::string & s1 , const std::string & ) ;
+		void requestForwarding( const std::string & = std::string() ) ;
+		std::string startForwarding() ;
+		bool logForwarding() const ;
+		void emit( const std::string & s0 , const std::string & s1 , const std::string & s2 = {} , const std::string & s3 = {} ) ;
+		//
+		std::string exceptionSourceId() const override ;
+		//
+		std::size_t m_unit_id ;
+		Run * m_run ;
+		Configuration m_config ;
+		int m_resolver_family ;
+		std::unique_ptr<GSmtp::Client::Config> m_smtp_client_config ;
+		G::Slot::Signal<const std::string&> m_forward_request_signal ;
+		std::unique_ptr<GNet::Timer<Unit>> m_forwarding_timer ;
+		std::unique_ptr<GNet::Timer<Unit>> m_poll_timer ;
+		std::unique_ptr<GSmtp::FileStore> m_store ;
+		std::unique_ptr<GSmtp::FilterFactory> m_filter_factory ;
+		std::unique_ptr<GAuth::Secrets> m_client_secrets ;
+		std::unique_ptr<GAuth::Secrets> m_server_secrets ;
+		std::unique_ptr<GAuth::Secrets> m_pop_secrets ;
+		std::unique_ptr<GSmtp::Server> m_smtp_server ;
+		std::unique_ptr<GPop::Store> m_pop_store ;
+		std::unique_ptr<GPop::Server> m_pop_server ;
+		std::unique_ptr<GSmtp::AdminServer> m_admin_server ;
+		std::unique_ptr<GNet::ClientPtr<GSmtp::Client>> m_client_ptr ;
+		std::string m_forwarding_reason ;
+		bool m_forwarding_pending {false} ;
+	} ;
+	std::vector<Unit> m_unit ;
+} ;
+
+inline
+const Main::Configuration & Main::Run::configuration() const
+{
+	return *m_configuration ;
+}
+
+#endif
diff --git a/src/main/winapp.cpp b/src/main/winapp.cpp
index 255259c..df712c7 100644
--- a/src/main/winapp.cpp
+++ b/src/main/winapp.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -27,6 +27,7 @@
 #include "gtest.h"
 #include "gcontrol.h"
 #include "gdialog.h"
+#include "ggettext.h"
 #include "resource.h"
 
 namespace Main
@@ -45,22 +46,13 @@ namespace Main
 		unsigned int m_width ;
 		unsigned int m_width2 ;
 	} ;
-} ;
+}
 
 Main::PixelLayout::PixelLayout( bool verbose )
 {
-	if( isWine() )
-	{
-		m_tabstop = verbose ? 37 : 28 ;
-		m_width = verbose ? 60U : 85U ;
-		m_width2 = verbose ? 48U : 65U ;
-	}
-	else
-	{
-		m_tabstop = verbose ? 120 : 90 ;
-		m_width = verbose ? 60U : 80U ;
-		m_width2 = verbose ? 48U : 80U ;
-	}
+    m_tabstop = verbose ? 122 : 90 ;
+    m_width = verbose ? 60U : 80U ;
+    m_width2 = verbose ? 48U : 80U ;
 }
 
 bool Main::PixelLayout::isWine()
@@ -146,7 +138,8 @@ bool Main::WinApp::onCreate()
 		}
 		catch( std::exception & e )
 		{
-			throw G::Exception( e.what() , "try using the --no-daemon option" ) ;
+			using G::txt ;
+			throw G::Exception( e.what() , txt("try using the --no-daemon option") ) ;
 		}
 	}
 	if( m_cfg.open_on_create )
@@ -190,9 +183,9 @@ void Main::WinApp::onTrayDoubleClick()
 	PostMessage( handle() , wm_user() , 2 , static_cast<LPARAM>(IDM_OPEN) ) ;
 }
 
-LRESULT Main::WinApp::onUser( WPARAM wparam , LPARAM lparam )
+LRESULT Main::WinApp::onUser( WPARAM /*wparam*/ , LPARAM lparam )
 {
-	G_DEBUG( "Main::WinApp::onUser: wparam=" << wparam << " lparam=" << lparam ) ;
+	G_DEBUG( "Main::WinApp::onUser: lparam=" << lparam ) ;
 	int id = static_cast<int>(lparam) ;
 	if( id == IDM_OPEN ) doOpen() ;
 	if( id == IDM_CLOSE ) doClose() ;
@@ -329,17 +322,13 @@ void Main::WinApp::onWindowException( std::exception & e )
 	GGui::Window::onWindowException( e ) ;
 }
 
-G::Options::Layout Main::WinApp::outputLayout( bool verbose ) const
+G::OptionsUsage::Config Main::WinApp::outputLayout( bool verbose ) const
 {
-	G::Options::Layout layout ;
+	G::OptionsUsage::Config layout ;
 	layout.separator = "\t" ;
-	//layout.column
 	layout.width = PixelLayout(verbose).width() ;
 	layout.width2 = PixelLayout(verbose).width2() ;
 	layout.margin = 0U ;
-	//layout.level
-	//layout.extra
-	//layout.usage_other
 	return layout ;
 }
 
@@ -353,7 +342,7 @@ void Main::WinApp::output( const std::string & text , bool , bool verbose )
 	if( !m_disable_output )
 	{
 		G::StringArray text_lines ;
-		G::Str::splitIntoFields( text , text_lines , "\r\n" ) ;
+		G::Str::splitIntoFields( G::Str::removedAll(text,'\r') , text_lines , '\n' ) ;
 		if( text_lines.size() > 10U ) // eg. "--help"
 		{
 			Box box( *this , text_lines , PixelLayout(verbose).tabstop() ) ;
@@ -367,11 +356,11 @@ void Main::WinApp::output( const std::string & text , bool , bool verbose )
 	}
 }
 
-void Main::WinApp::onError( const std::string & text )
+void Main::WinApp::onError( const std::string & text , int exit_code )
 {
 	// called from WinMain(), possibly before init()
 	output( text , true , false ) ; // override implemented above
-	m_exit_code = 1 ;
+	m_exit_code = exit_code ;
 }
 
 // ==
diff --git a/src/main/winapp.h b/src/main/winapp.h
index db12038..ee56c7a 100644
--- a/src/main/winapp.h
+++ b/src/main/winapp.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,6 +24,7 @@
 #include "gdef.h"
 #include "gappbase.h"
 #include "gexception.h"
+#include "goptionsusage.h"
 #include "gtray.h"
 #include "winform.h"
 #include "winmenu.h"
@@ -61,7 +62,7 @@ namespace Main
 class Main::WinApp : public GGui::ApplicationBase , public Main::Output
 {
 public:
-	G_EXCEPTION( Error , "application error" ) ;
+	G_EXCEPTION( Error , tx("application error") ) ;
 
 	WinApp( HINSTANCE h , HINSTANCE p , const std::string & name ) ;
 		///< Constructor. Initialise with init().
@@ -78,7 +79,7 @@ public:
 	void disableOutput() ;
 		///< Disables subsequent calls to output().
 
-	void onError( const std::string & message ) ;
+	void onError( const std::string & message , int exit_code = 1 ) ;
 		///< To be called when WinMain() catches an exception.
 
 	unsigned int columns() ;
@@ -91,7 +92,7 @@ public:
 
 private: // overrides
 	void output( const std::string & message , bool error , bool ) override ; // Override from Main::Output.
-	G::Options::Layout outputLayout( bool verbose ) const override ; // Override from Main::Output.
+	G::OptionsUsage::Config outputLayout( bool verbose ) const override ; // Override from Main::Output.
 	bool outputSimple() const override ; // Override from Main::Output.
 	void onWindowException( std::exception & e ) override ; // Override from GGui::Window.
 	DWORD classStyle() const override ; // Override from GGui::ApplicationBase.
@@ -130,8 +131,8 @@ private:
 public:
 	WinApp( const WinApp & ) = delete ;
 	WinApp( WinApp && ) = delete ;
-	void operator=( const WinApp & ) = delete ;
-	void operator=( WinApp && ) = delete ;
+	WinApp & operator=( const WinApp & ) = delete ;
+	WinApp & operator=( WinApp && ) = delete ;
 
 private:
 	void doOpen() ;
diff --git a/src/main/winform.cpp b/src/main/winform.cpp
index 39912ca..a955fed 100644
--- a/src/main/winform.cpp
+++ b/src/main/winform.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,12 +24,15 @@
 #include "gstringwrap.h"
 #include "gmonitor.h"
 #include "gtime.h"
+#include "ggettext.h"
+#include "gconvert.h"
 #include "run.h"
 #include "winform.h"
 #include "news.h"
 #include "licence.h"
 #include "legal.h"
 #include "resource.h"
+#include <cstring>
 
 Main::WinForm::WinForm( HINSTANCE hinstance , const Main::Configuration & cfg ,
 	HWND parent , HWND hnotify , std::pair<DWORD,DWORD> style ,
@@ -40,16 +43,18 @@ Main::WinForm::WinForm( HINSTANCE hinstance , const Main::Configuration & cfg ,
 		m_closed(false) ,
 		m_cfg(cfg)
 {
-  	addPage( "Configuration" , IDD_PROPPAGE_1 ) ;
-  	addPage( "Licence" , IDD_PROPPAGE_1 ) ;
-  	addPage( "Version" , IDD_PROPPAGE_1 ) ;
-  	addPage( "Status" , IDD_PROPPAGE_1 ) ;
+	using G::txt ;
+
+  	addPage( txt("Configuration") , IDD_PROPPAGE_1 ) ;
+  	addPage( txt("Licence") , IDD_PROPPAGE_1 ) ;
+  	addPage( txt("Version") , IDD_PROPPAGE_1 ) ;
+  	addPage( txt("Status") , IDD_PROPPAGE_1 ) ;
 
 	// create the stack
   	create( parent , "E-MailRelay" , with_icon?IDI_ICON1:0 , hnotify , GGui::Cracker::wm_user_other() ) ;
 
 	if( with_system_menu_quit )
-		addSystemMenuItem( "Quit" , 0x10 ) ;
+		addSystemMenuItem( txt("Quit") , 0x10 ) ;
 }
 
 void Main::WinForm::addSystemMenuItem( const char * name , unsigned int id )
@@ -60,7 +65,7 @@ void Main::WinForm::addSystemMenuItem( const char * name , unsigned int id )
 	{
 		MENUITEMINFOA item{} ;
 		item.cbSize = sizeof( item ) ;
-		item.fMask = MIIM_STRING | MIIM_ID ; // setting dwTypeData and wID
+		item.fMask = MIIM_STRING | MIIM_ID ; // setting dwTypeData & wID
 		item.fType = MFT_STRING ;
 		item.wID = id ;
 		item.dwTypeData = const_cast<LPSTR>(name) ;
@@ -253,7 +258,7 @@ G::StringArray Main::WinForm::statusData() const
 G::StringArray Main::WinForm::split( const std::string & s )
 {
 	G::StringArray list ;
-	G::Str::splitIntoFields( s , list , "\n" ) ;
+	G::Str::splitIntoFields( s , list , '\n' ) ;
 	return list ;
 }
 
diff --git a/src/main/winform.h b/src/main/winform.h
index bd09d42..940d073 100644
--- a/src/main/winform.h
+++ b/src/main/winform.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,7 +22,7 @@
 #define G_MAIN_WIN_FORM_H
 
 #include "gdef.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "gdialog.h"
 #include "gstack.h"
 #include "gcontrol.h"
@@ -80,8 +80,8 @@ public:
 	~WinForm() = default ;
 	WinForm( const WinForm & ) = delete ;
 	WinForm( WinForm && ) = delete ;
-	void operator=( const WinForm & ) = delete ;
-	void operator=( WinForm && ) = delete ;
+	WinForm & operator=( const WinForm & ) = delete ;
+	WinForm & operator=( WinForm && ) = delete ;
 
 private:
 	static void add( G::StringArray & s , const std::string & key , const std::string & value ) ;
diff --git a/src/main/winmain.cpp b/src/main/winmain.cpp
index c643497..e47b761 100644
--- a/src/main/winmain.cpp
+++ b/src/main/winmain.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -22,6 +22,7 @@
 #include "garg.h"
 #include "gslot.h"
 #include "gexception.h"
+#include "gsocket.h"
 #include "winapp.h"
 #include "commandline.h"
 #include "options.h"
@@ -56,12 +57,14 @@ int WINAPI WinMain( HINSTANCE hinstance , HINSTANCE previous , LPSTR command_lin
 				run.run() ;
 			}
 		}
+		catch( GNet::SocketBase::SocketBindError & e )
+		{
+			app.onError( e.what() , 2 ) ;
+		}
 		catch( std::exception & e )
 		{
-			app.onError( e.what() ) ;
-			return 1 ;
+			app.onError( e.what() , 1 ) ;
 		}
-
 		return app.exitCode() ;
 	}
 	catch(...)
diff --git a/src/main/winmenu.cpp b/src/main/winmenu.cpp
index 3042210..0c12797 100644
--- a/src/main/winmenu.cpp
+++ b/src/main/winmenu.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/main/winmenu.h b/src/main/winmenu.h
index 40cc6a2..a487730 100644
--- a/src/main/winmenu.h
+++ b/src/main/winmenu.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -36,7 +36,7 @@ namespace Main
 class Main::WinMenu
 {
 public:
-	G_EXCEPTION( Error , "menu error" ) ;
+	G_EXCEPTION( Error , tx("menu error") ) ;
 
 	explicit WinMenu( unsigned int resource_id ) ;
 		///< Constructor.
@@ -56,8 +56,8 @@ public:
 public:
 	WinMenu( const WinMenu & ) = delete ;
 	WinMenu( WinMenu && ) = delete ;
-	void operator=( const WinMenu & ) = delete ;
-	void operator=( WinMenu && ) = delete ;
+	WinMenu & operator=( const WinMenu & ) = delete ;
+	WinMenu & operator=( WinMenu && ) = delete ;
 
 private:
 	HMENU m_hmenu ;
diff --git a/src/win32/Makefile.am b/src/win32/Makefile.am
index 8fba0ab..81f22da 100644
--- a/src/win32/Makefile.am
+++ b/src/win32/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
diff --git a/src/win32/empty.cpp b/src/win32/empty.cpp
index 6084e16..0d6a273 100644
--- a/src/win32/empty.cpp
+++ b/src/win32/empty.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/win32/gappbase.cpp b/src/win32/gappbase.cpp
index d89f2f5..9f95db7 100644
--- a/src/win32/gappbase.cpp
+++ b/src/win32/gappbase.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/win32/gappbase.h b/src/win32/gappbase.h
index 3d1c549..4c565db 100644
--- a/src/win32/gappbase.h
+++ b/src/win32/gappbase.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -62,8 +62,8 @@ namespace GGui
 class GGui::ApplicationBase : public ApplicationInstance , public Window
 {
 public:
-	G_EXCEPTION( RegisterError, "cannot register application's window class" ) ;
-	G_EXCEPTION( CreateError , "cannot create application window" ) ;
+	G_EXCEPTION( RegisterError, tx("cannot register application's window class") ) ;
+	G_EXCEPTION( CreateError , tx("cannot create application window") ) ;
 
 	ApplicationBase( HINSTANCE current, HINSTANCE previous, const std::string & name );
 		///< Constructor. Applications should instantiate a ApplicationBase-derived
@@ -146,8 +146,8 @@ protected:
 public:
 	ApplicationBase( const ApplicationBase & ) = delete ;
 	ApplicationBase( ApplicationBase && ) = delete ;
-	void operator=( const ApplicationBase & ) = delete ;
-	void operator=( ApplicationBase && ) = delete ;
+	ApplicationBase & operator=( const ApplicationBase & ) = delete ;
+	ApplicationBase & operator=( ApplicationBase && ) = delete ;
 
 private:
 	static bool messageBoxCore( HWND , unsigned int , const std::string & , const std::string & ) ;
diff --git a/src/win32/gappinst.cpp b/src/win32/gappinst.cpp
index 0541966..f096469 100644
--- a/src/win32/gappinst.cpp
+++ b/src/win32/gappinst.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/win32/gappinst.h b/src/win32/gappinst.h
index bdd5daf..f0b6657 100644
--- a/src/win32/gappinst.h
+++ b/src/win32/gappinst.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/win32/gcontrol.cpp b/src/win32/gcontrol.cpp
index 5a16b5f..e0c30bd 100644
--- a/src/win32/gcontrol.cpp
+++ b/src/win32/gcontrol.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/win32/gcontrol.h b/src/win32/gcontrol.h
index 52bd6b8..f65cc84 100644
--- a/src/win32/gcontrol.h
+++ b/src/win32/gcontrol.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -65,7 +65,7 @@ public:
 		private: Control & m_control ;
 		public: NoRedraw(Control&) ;
 		public: ~NoRedraw() ;
-		private: void operator=( const NoRedraw & ) ;
+		private: NoRedraw & operator=( const NoRedraw & ) ;
 		private: NoRedraw( const NoRedraw & ) ;
 	} ;
 
@@ -139,8 +139,8 @@ protected:
 public:
 	Control( const Control & ) = delete ;
 	Control( Control && ) = delete ;
-	void operator=( const Control & ) = delete ;
-	void operator=( Control && ) = delete ;
+	Control & operator=( const Control & ) = delete ;
+	Control & operator=( Control && ) = delete ;
 
 private:
 	static void load() ;
@@ -187,8 +187,8 @@ public:
 public:
 	ListBox( const ListBox & ) = delete ;
 	ListBox( ListBox && ) = delete ;
-	void operator=( const ListBox & ) = delete ;
-	void operator=( ListBox && ) = delete ;
+	ListBox & operator=( const ListBox & ) = delete ;
+	ListBox & operator=( ListBox && ) = delete ;
 } ;
 
 //| \class GGui::ListView
@@ -220,8 +220,8 @@ public:
 public:
 	ListView( const ListView & ) = delete ;
 	ListView( ListView && ) = delete ;
-	void operator=( const ListView & ) = delete ;
-	void operator=( ListView && ) = delete ;
+	ListView & operator=( const ListView & ) = delete ;
+	ListView & operator=( ListView && ) = delete ;
 
 private:
 	static LPTSTR ptext( const std::string & s ) ;
@@ -286,8 +286,8 @@ public:
 public:
 	EditBox( const EditBox & ) = delete ;
 	EditBox( EditBox && ) = delete ;
-	void operator=( const EditBox & ) = delete ;
-	void operator=( EditBox && ) = delete ;
+	EditBox & operator=( const EditBox & ) = delete ;
+	EditBox & operator=( EditBox && ) = delete ;
 
 private:
 	unsigned windowHeight() ; // not const
@@ -318,8 +318,8 @@ public:
 public:
 	CheckBox( const CheckBox & ) = delete ;
 	CheckBox( CheckBox && ) = delete ;
-	void operator=( const CheckBox & ) = delete ;
-	void operator=( CheckBox && ) = delete ;
+	CheckBox & operator=( const CheckBox & ) = delete ;
+	CheckBox & operator=( CheckBox && ) = delete ;
 } ;
 
 //| \class GGui::Button
@@ -347,8 +347,8 @@ public:
 public:
 	Button( const Button & ) = delete ;
 	Button( Button && ) = delete ;
-	void operator=( const Button & ) = delete ;
-	void operator=( Button && ) = delete ;
+	Button & operator=( const Button & ) = delete ;
+	Button & operator=( Button && ) = delete ;
 } ;
 
 #endif
diff --git a/src/win32/gcracker.cpp b/src/win32/gcracker.cpp
index 04779f9..085dfd5 100644
--- a/src/win32/gcracker.cpp
+++ b/src/win32/gcracker.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -20,7 +20,7 @@
 
 #include "gdef.h"
 #include "gcracker.h"
-#include "gstrings.h"
+#include "gstringarray.h"
 #include "glog.h"
 #include "gassert.h"
 #include <windowsx.h>
@@ -225,9 +225,9 @@ LRESULT GGui::Cracker::crack( UINT message , WPARAM wparam , LPARAM lparam , boo
 			{
 				HWND window = GET_WM_COMMAND_HWND( wparam , lparam ) ;
 				UINT id = GET_WM_COMMAND_ID( wparam , lparam ) ;
-				UINT message = type ;
+				UINT command_message = type ;
 				G_DEBUG( "Cracker::onControlCommand" ) ;
-				onControlCommand( window , message , id ) ;
+				onControlCommand( window , command_message , id ) ;
 			}
 
 			return 0 ;
@@ -247,7 +247,7 @@ LRESULT GGui::Cracker::crack( UINT message , WPARAM wparam , LPARAM lparam , boo
 				processed = onDeactivate( window ) ;
 			}
 			if( !processed )
-				call_default ;
+				call_default = true ;
 			return 0 ;
 		}
 
@@ -592,10 +592,10 @@ bool GGui::Cracker::onEraseBackground( HDC hdc )
 	return !! DefWindowProc( handle() , WM_ERASEBKGND , wparam , 0L ) ;
 }
 
-void GGui::Cracker::onMouseMove( unsigned int x , unsigned int y ,
-	bool shift_key_down , bool control_key_down ,
-	bool left_button_down , bool middle_button_down ,
-	bool right_button_down )
+void GGui::Cracker::onMouseMove( unsigned int /*x*/ , unsigned int /*y*/ ,
+	bool /*shift_key_down*/ , bool /*control_key_down*/ ,
+	bool /*left_button_down*/ , bool /*middle_button_down*/ ,
+	bool /*right_button_down*/ )
 {
 }
 
@@ -604,33 +604,33 @@ void GGui::Cracker::onMouseButton( MouseButton , MouseButtonDirection ,
 {
 }
 
-void GGui::Cracker::onLeftMouseButtonDown( int x , int y ,
-	bool shift_key_down , bool control_key_down )
+void GGui::Cracker::onLeftMouseButtonDown( int /*x*/ , int /*y*/ ,
+	bool /*shift_key_down*/ , bool /*control_key_down*/ )
 {
 }
 
-void GGui::Cracker::onLeftMouseButtonUp( int x , int y ,
-	bool shift_key_down , bool control_key_down )
+void GGui::Cracker::onLeftMouseButtonUp( int /*x*/ , int /*y*/ ,
+	bool /*shift_key_down*/ , bool /*control_key_down*/ )
 {
 }
 
-void GGui::Cracker::onMiddleMouseButtonDown( int x , int y ,
-	bool shift_key_down , bool control_key_down )
+void GGui::Cracker::onMiddleMouseButtonDown( int /*x*/ , int /*y*/ ,
+	bool /*shift_key_down*/ , bool /*control_key_down*/ )
 {
 }
 
-void GGui::Cracker::onMiddleMouseButtonUp( int x , int y ,
-	bool shift_key_down , bool control_key_down )
+void GGui::Cracker::onMiddleMouseButtonUp( int /*x*/ , int /*y*/ ,
+	bool /*shift_key_down*/ , bool /*control_key_down*/ )
 {
 }
 
-void GGui::Cracker::onRightMouseButtonDown( int x , int y ,
-	bool shift_key_down , bool control_key_down )
+void GGui::Cracker::onRightMouseButtonDown( int /*x*/ , int /*y*/ ,
+	bool /*shift_key_down*/ , bool /*control_key_down*/ )
 {
 }
 
-void GGui::Cracker::onRightMouseButtonUp( int x , int y ,
-	bool shift_key_down , bool control_key_down )
+void GGui::Cracker::onRightMouseButtonUp( int /*x*/ , int /*y*/ ,
+	bool /*shift_key_down*/ , bool /*control_key_down*/ )
 {
 }
 
diff --git a/src/win32/gcracker.h b/src/win32/gcracker.h
index 0f68e3d..71bdbb7 100644
--- a/src/win32/gcracker.h
+++ b/src/win32/gcracker.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -292,8 +292,8 @@ protected:
 public:
 	Cracker( const Cracker & ) = delete ;
 	Cracker( Cracker && ) = delete ;
-	void operator=( const Cracker & ) = delete ;
-	void operator=( Cracker && ) = delete ;
+	Cracker & operator=( const Cracker & ) = delete ;
+	Cracker & operator=( Cracker && ) = delete ;
 
 private:
 	using Fn = void (Cracker::*)(int,int,bool,bool) ;
diff --git a/src/win32/gdc.cpp b/src/win32/gdc.cpp
index 6d5fe7b..b99e0a8 100644
--- a/src/win32/gdc.cpp
+++ b/src/win32/gdc.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/win32/gdc.h b/src/win32/gdc.h
index f48291c..b7e3342 100644
--- a/src/win32/gdc.h
+++ b/src/win32/gdc.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -74,8 +74,8 @@ public:
 public:
 	DeviceContext( const DeviceContext & ) = delete ;
 	DeviceContext( DeviceContext && ) = delete ;
-	void operator=( const DeviceContext & ) = delete ;
-	void operator=( DeviceContext && ) = delete ;
+	DeviceContext & operator=( const DeviceContext & ) = delete ;
+	DeviceContext & operator=( DeviceContext && ) = delete ;
 
 private:
 	HDC m_hdc ;
@@ -121,8 +121,8 @@ public:
 public:
 	ScreenDeviceContext( const ScreenDeviceContext & ) = delete ;
 	ScreenDeviceContext( ScreenDeviceContext && ) = delete ;
-	void operator=( const ScreenDeviceContext & ) = delete ;
-	void operator=( ScreenDeviceContext && ) = delete ;
+	ScreenDeviceContext & operator=( const ScreenDeviceContext & ) = delete ;
+	ScreenDeviceContext & operator=( ScreenDeviceContext && ) = delete ;
 
 private:
 	HDC m_dc ;
diff --git a/src/win32/gdialog.cpp b/src/win32/gdialog.cpp
index 82f6d04..051303f 100644
--- a/src/win32/gdialog.cpp
+++ b/src/win32/gdialog.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,7 +24,7 @@
 #include "gassert.h"
 #include <algorithm> // find
 
-BOOL CALLBACK gdialog_export( HWND hwnd , UINT message , WPARAM wparam , LPARAM lparam )
+INT_PTR CALLBACK gdialog_export( HWND hwnd , UINT message , WPARAM wparam , LPARAM lparam )
 {
 	try
 	{
@@ -115,7 +115,7 @@ LRESULT GGui::Dialog::sendMessage( int control , unsigned int message , WPARAM w
 	return SendMessage( hwnd_control , message , wparam , lparam ) ;
 }
 
-BOOL GGui::Dialog::dlgProc( HWND hwnd , UINT message , WPARAM wparam , LPARAM lparam )
+INT_PTR GGui::Dialog::dlgProc( HWND hwnd , UINT message , WPARAM wparam , LPARAM lparam )
 {
 	if( message == WM_INITDIALOG )
 	{
@@ -149,7 +149,7 @@ BOOL GGui::Dialog::dlgProc( HWND hwnd , UINT message , WPARAM wparam , LPARAM lp
 	}
 }
 
-BOOL GGui::Dialog::dlgProcImp( UINT message , WPARAM wparam , LPARAM lparam )
+INT_PTR GGui::Dialog::dlgProcImp( UINT message , WPARAM wparam , LPARAM lparam )
 {
 	switch( message )
 	{
@@ -334,8 +334,7 @@ bool GGui::Dialog::runEnd( int rc )
 {
 	if( rc == -1 )
 	{
-		DWORD error = GetLastError() ;
-		G_DEBUG( "GGui::Dialog::run: cannot create dialog box: " << error ) ;
+		G_DEBUG( "GGui::Dialog::run: cannot create dialog box" ) ;
 		return false ;
 	}
 	else if( rc == 0 )
@@ -450,7 +449,7 @@ bool GGui::Dialog::isValid()
 	return m_magic == Magic ;
 }
 
-BOOL GGui::Dialog::onControlColour_( WPARAM wparam , LPARAM lparam , WORD type )
+INT_PTR GGui::Dialog::onControlColour_( WPARAM wparam , LPARAM lparam , WORD type )
 {
 	return 0 != onControlColour( reinterpret_cast<HDC>(wparam) , reinterpret_cast<HWND>(lparam) , type ) ;
 }
diff --git a/src/win32/gdialog.h b/src/win32/gdialog.h
index 55525a9..515e4f2 100644
--- a/src/win32/gdialog.h
+++ b/src/win32/gdialog.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -88,7 +88,7 @@ public:
 		///< An override taking a resource name rather than a
 		///< resource id.
 
-	static BOOL dlgProc( HWND hwnd , UINT message , WPARAM wparam , LPARAM lparam ) ;
+	static INT_PTR dlgProc( HWND hwnd , UINT message , WPARAM wparam , LPARAM lparam ) ;
 		///< Called directly from the exported dialog procedure.
 
 	void setFocus( int control ) ;
@@ -163,18 +163,18 @@ protected:
 public:
 	Dialog( const Dialog & ) = delete ;
 	Dialog( Dialog && ) = delete ;
-	void operator=( const Dialog & ) = delete ;
-	void operator=( Dialog && ) = delete ;
+	Dialog & operator=( const Dialog & ) = delete ;
+	Dialog & operator=( Dialog && ) = delete ;
 
 private:
 	using DialogList = std::list<HWND> ;
-	BOOL dlgProcImp( UINT message , WPARAM wparam , LPARAM lparam ) ;
+	INT_PTR dlgProcImp( UINT message , WPARAM wparam , LPARAM lparam ) ;
 	void privateInit( HWND hwnd ) ;
 	void privateEnd( int n ) ;
 	bool privateFocusSet() const ;
 	void cleanup() ;
 	DialogList::iterator find( HWND h ) ;
-	BOOL onControlColour_( WPARAM wparam , LPARAM lparam , WORD type ) ;
+	INT_PTR onControlColour_( WPARAM wparam , LPARAM lparam , WORD type ) ;
 	bool runStart() ;
 	bool runCore( const char * ) ;
 	bool runCore( const wchar_t * ) ;
@@ -205,7 +205,7 @@ namespace GGui
 	template <typename T>
 	DLGPROC Dialog::toDlgProc( T export_fn )
 	{
-		return reinterpret_cast<DLGPROC>(export_fn) ;
+		return reinterpret_cast<DLGPROC>( export_fn ) ;
 	}
 }
 
diff --git a/src/win32/gpump.cpp b/src/win32/gpump.cpp
index 3d60d81..70ac16b 100644
--- a/src/win32/gpump.cpp
+++ b/src/win32/gpump.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/win32/gpump.h b/src/win32/gpump.h
index 3be09ab..1693766 100644
--- a/src/win32/gpump.h
+++ b/src/win32/gpump.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/win32/gscmap.cpp b/src/win32/gscmap.cpp
index 1a5b994..0e714af 100644
--- a/src/win32/gscmap.cpp
+++ b/src/win32/gscmap.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/win32/gscmap.h b/src/win32/gscmap.h
index 01e2eb2..b42be99 100644
--- a/src/win32/gscmap.h
+++ b/src/win32/gscmap.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -60,8 +60,8 @@ public:
 public:
 	SubClassMap( const SubClassMap & ) = delete ;
 	SubClassMap( SubClassMap && ) = delete ;
-	void operator=( const SubClassMap & ) = delete ;
-	void operator=( SubClassMap && ) = delete ;
+	SubClassMap & operator=( const SubClassMap & ) = delete ;
+	SubClassMap & operator=( SubClassMap && ) = delete ;
 
 private:
 	struct Slot
diff --git a/src/win32/gsize.h b/src/win32/gsize.h
index 4425b28..4fe9efe 100644
--- a/src/win32/gsize.h
+++ b/src/win32/gsize.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/win32/gstack.cpp b/src/win32/gstack.cpp
index 9a23b1a..8558e36 100644
--- a/src/win32/gstack.cpp
+++ b/src/win32/gstack.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -313,7 +313,7 @@ LRESULT GGui::Stack::wndProc( UINT message , WPARAM wparam , LPARAM lparam , boo
 	return 0 ;
 }
 
-int GGui::Stack::sheetProc( HWND hsheet , UINT message , LPARAM lparam )
+int GGui::Stack::sheetProc( HWND hsheet , UINT message , LPARAM /*lparam*/ )
 {
 	if( message == PSCB_INITIALIZED )
 	{
@@ -324,7 +324,7 @@ int GGui::Stack::sheetProc( HWND hsheet , UINT message , LPARAM lparam )
 	return 0 ;
 }
 
-unsigned int GGui::Stack::pageProc( HWND , UINT message , PROPSHEETPAGE * page_p )
+unsigned int GGui::Stack::pageProc( HWND , UINT message , PROPSHEETPAGE * /*page_p*/ )
 {
 	unsigned int result = 0U ;
 	if( message == PSPCB_CREATE )
@@ -332,7 +332,7 @@ unsigned int GGui::Stack::pageProc( HWND , UINT message , PROPSHEETPAGE * page_p
 	return result ;
 }
 
-bool GGui::Stack::dlgProc( HWND hpage , UINT message , WPARAM wparam , LPARAM lparam )
+bool GGui::Stack::dlgProc( HWND hpage , UINT message , WPARAM /*wparam*/ , LPARAM lparam )
 {
 	if( message == WM_INITDIALOG )
 	{
@@ -413,7 +413,7 @@ bool GGui::StackPageCallback::onApply()
 	return true ;
 }
 
-void GGui::StackPageCallback::onSysCommand( unsigned int id )
+void GGui::StackPageCallback::onSysCommand( unsigned int /*id*/ )
 {
 }
 
diff --git a/src/win32/gstack.h b/src/win32/gstack.h
index 8648a8a..2343cb6 100644
--- a/src/win32/gstack.h
+++ b/src/win32/gstack.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -94,9 +94,9 @@ public:
 		///< Destructor.
 
 	static bool stackMessage( MSG & msg ) ;
-		///< Used by the GGui::Pump message pump to bypass DispatchMessage(),
-		///< similarly to GGui::Dialog::dialogMessage(). Returns true
-		///< if a stack message.
+		///< Used by the GGui::Pump message pump to bypass DispatchMessage() if
+		///< a stack message, in the same way as GGui::Dialog::dialogMessage().
+		///< Returns true if a stack message.
 
 	static int sheetProc( HWND hwnd , UINT message , LPARAM lparam ) ;
 		///< Implementation window procedure.
@@ -121,8 +121,8 @@ private:
 public:
 	Stack( const Stack & ) = delete ;
 	Stack( Stack && ) = delete ;
-	void operator=( const Stack & ) = delete ;
-	void operator=( Stack && ) = delete ;
+	Stack & operator=( const Stack & ) = delete ;
+	Stack & operator=( Stack && ) = delete ;
 
 private:
 	using PageInfo = std::pair<Stack*,int> ;
diff --git a/src/win32/gtray.cpp b/src/win32/gtray.cpp
index 188852c..f72f4fb 100644
--- a/src/win32/gtray.cpp
+++ b/src/win32/gtray.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/src/win32/gtray.h b/src/win32/gtray.h
index 9fe8daf..3368835 100644
--- a/src/win32/gtray.h
+++ b/src/win32/gtray.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -29,7 +29,7 @@
 namespace GGui
 {
 	class Tray ;
-} ;
+}
 
 //| \class GGui::Tray
 /// Manages an icon within the system tray.
@@ -37,8 +37,8 @@ namespace GGui
 class GGui::Tray
 {
 public:
-	G_EXCEPTION( IconError , "no icon resource built-in" ) ;
-	G_EXCEPTION( Error , "system-tray error" ) ;
+	G_EXCEPTION( IconError , tx("no icon resource built-in") ) ;
+	G_EXCEPTION( Error , tx("system-tray error") ) ;
 
 	Tray( unsigned int icon_resource_id , const WindowBase & window ,
 		const std::string & tip , unsigned int message = Cracker::wm_tray() ) ;
@@ -53,8 +53,8 @@ public:
 		///< Destructor. Removes the icon from the system tray.
 
 public:
-	void operator=( const Tray & ) = delete ;
-	void operator=( Tray && ) = delete ;
+	Tray & operator=( const Tray & ) = delete ;
+	Tray & operator=( Tray && ) = delete ;
 	Tray( const Tray & ) = delete ;
 	Tray( Tray && ) = delete ;
 
diff --git a/src/win32/gwinbase.cpp b/src/win32/gwinbase.cpp
index 7dd0b8c..471bb44 100644
--- a/src/win32/gwinbase.cpp
+++ b/src/win32/gwinbase.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -81,7 +81,7 @@ std::string GGui::WindowBase::windowClass() const
 	if( (std::strlen(&buffer[0])+1U) == buffer.size() )
 	{
 		G_WARNING( "GGui::WindowBase::windowClass: possible truncation: "
-			<< "\"" << G::Str::printable(&buffer[0]) << "\"" ) ;
+			<< "\"" << G::Str::printable(std::string(&buffer[0])) << "\"" ) ;
 	}
 
 	return std::string( &buffer[0] ) ;
diff --git a/src/win32/gwinbase.h b/src/win32/gwinbase.h
index f666414..2147795 100644
--- a/src/win32/gwinbase.h
+++ b/src/win32/gwinbase.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -68,8 +68,8 @@ protected:
 public:
 	WindowBase( const WindowBase & ) = delete ;
 	WindowBase( WindowBase && ) = delete ;
-	void operator=( const WindowBase & ) = delete ;
-	void operator=( WindowBase && ) = delete ;
+	WindowBase & operator=( const WindowBase & ) = delete ;
+	WindowBase & operator=( WindowBase && ) = delete ;
 
 private:
 	HWND m_hwnd ;
diff --git a/src/win32/gwindow.cpp b/src/win32/gwindow.cpp
index 7748406..a8d860c 100644
--- a/src/win32/gwindow.cpp
+++ b/src/win32/gwindow.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -168,10 +168,10 @@ LRESULT GGui::Window::wndProc( HWND hwnd , UINT msg , WPARAM wparam , LPARAM lpa
 			{
 				window->onWindowException( e ) ; // overridable - posts wm_quit by default
 			}
-			catch( std::exception & e )
+			catch( std::exception & ee )
 			{
 				// exception from exception handler - save it for wndProcException()
-				window->m_reason = e.what() ;
+				window->m_reason = ee.what() ;
 			}
 		}
 	}
@@ -236,7 +236,7 @@ namespace GGui
 	{
 		std::pair<DWORD,DWORD> make_style( DWORD first , DWORD second = 0 )
 		{
-			return std::make_pair( first , second ) ;
+			return { first , second } ;
 		}
 	}
 }
diff --git a/src/win32/gwindow.h b/src/win32/gwindow.h
index 98d90c4..81b5e67 100644
--- a/src/win32/gwindow.h
+++ b/src/win32/gwindow.h
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -222,8 +222,8 @@ protected:
 public:
 	Window( const Window & ) = delete ;
 	Window( Window && ) = delete ;
-	void operator=( const Window & ) = delete ;
-	void operator=( Window && ) = delete ;
+	Window & operator=( const Window & ) = delete ;
+	Window & operator=( Window && ) = delete ;
 
 private:
 	static LRESULT wndProcCore( Window * , HWND , UINT , WPARAM , LPARAM ) ;
diff --git a/test/AdminClient.pm b/test/AdminClient.pm
index f0e85cf..f390f9a 100644
--- a/test/AdminClient.pm
+++ b/test/AdminClient.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/test/Check.pm b/test/Check.pm
index dfe4240..70ede27 100644
--- a/test/Check.pm
+++ b/test/Check.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -193,11 +193,11 @@ sub fileLineCountLessThan
 
 sub allFilesContain
 {
-	my ( $glob , $string , $more ) = @_ ;
+	my ( $glob , $re , $more ) = @_ ;
 	my @files = System::glob_( $glob ) ;
 	for my $file ( @files )
 	{
-		fileContains( $file , $string , $more ) ;
+		fileContains( $file , $re , $more ) ;
 	}
 }
 
@@ -213,16 +213,17 @@ sub noFileContains
 
 sub fileContains
 {
-	my ( $path , $string , $more ) = @_ ;
+	my ( $path , $re , $more , $count ) = @_ ;
 	my $fh = new FileHandle( $path ) ;
 	my $n = 0 ;
 	while(<$fh>)
 	{
 		my $line = $_ ;
 		chomp $line ;
-		if( !defined($string) || $line =~ m/$string/ ) { $n++ }
+		if( !defined($re) || $line =~ m/$re/ ) { $n++ }
 	}
-	Check::that( $n > 0 , "file does not contain expected string" , $path , "[$string]" , $more ) ;
+	my $ok = defined($count) ? ($n == $count) : ($n > 0) ;
+	Check::that( $ok , "file does not contain expected string" , $path , "[$re]" , $more ) ;
 }
 
 sub fileContainsEither
diff --git a/test/Filter.pm b/test/Filter.pm
index 316e178..9d01408 100644
--- a/test/Filter.pm
+++ b/test/Filter.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -25,7 +25,7 @@
 #	use Filter ;
 #	Filter::create( $path ,
 #		{
-#			edit => 1 ,
+#			edit => 1 , # add a snippet to edit the envelope-from
 #		} ,
 #		{
 #			unix => [
diff --git a/test/Helper.pm b/test/Helper.pm
index 0d5e397..d422fb5 100644
--- a/test/Helper.pm
+++ b/test/Helper.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -19,12 +19,14 @@
 # Helper.pm
 #
 # A wrapper for running test helper programs such as
-# "emailrelay-test-scanner".
+# "emailrelay_test_scanner" that use command-line options
+# such as "--port", "--log-file", "--debug", "--pid-file"
+# etc.
 #
 # Synopsis:
 #
 #	$Helper::bin_dir = "." ;
-#	my $helper = new Helper( "emailrelay-test-scanner" ) ;
+#	my $helper = new Helper( "emailrelay_test_scanner" ) ;
 #	$helper->run() ;
 #	$helper->kill() ;
 #	open $helper->logfile() ;
@@ -48,7 +50,7 @@ sub new
 	die if !defined($exe) ;
 	$port ||= 10010 ;
 
-	( my $short_name = $exe ) =~ s/emailrelay-test-// ;
+	( my $short_name = $exe ) =~ s/emailrelay_test_// ;
 	$short_name =~ s/\.[a-z]*$// ;
 
 	my $exe_path = System::exe( $bin_dir , $exe ) ;
diff --git a/test/Makefile.am b/test/Makefile.am
index f60b6ee..5962239 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -20,31 +20,31 @@
 # Use "make check" to run tests.
 #
 # Or, for example:
-#  $ make programs ; ./emailrelay-test.sh
-#  $ ./emailrelay-test.sh -q -v -t testStartsAndStops
+#  $ make programs ; ./emailrelay_test.sh
+#  $ ./emailrelay_test.sh -q -v -t testStartsAndStops
 #  $ sudo -v ; make check
 #  $ su -c 'make check'
 #  $ make -j 40 check TEST_LOG_FLAGS="-t -u someuser"
 #
 # Automake uses the TESTS variable for its list of tests, and runs a
 # "compiler" according to each test's filename extension -- in practice
-# "sh" for ".sh" tests and "emailrelay-test.sh" for ".test" tests.
+# "sh" for ".sh" tests and "emailrelay_test.sh" for ".test" tests.
 #
 # A ".test" file is created for each of the test routines defined within
-# "emailrelay-test.pl".
+# "emailrelay_test.pl".
 #
 # If "make check" fails then examine the relevant ".log" files and
-# re-run individual tests with "emailrelay-test.sh -q -v -t <test-name>".
+# re-run individual tests with "emailrelay_test.sh -q -v -t <test-name>".
 #
 
 utility_programs = \
-	emailrelay-test-keygen
+	emailrelay_test_keygen
 
 helper_programs = \
-	emailrelay-test-scanner \
-	emailrelay-test-client \
-	emailrelay-test-server \
-	emailrelay-test-verifier
+	emailrelay_test_scanner \
+	emailrelay_test_client \
+	emailrelay_test_server \
+	emailrelay_test_verifier
 
 helper_sources = \
 	emailrelay_test_keygen.cpp \
@@ -54,13 +54,13 @@ helper_sources = \
 	emailrelay_test_verifier.cpp
 
 other_scripts = \
-	emailrelay-test.sh \
-	emailrelay-test.pl \
-	emailrelay-soak-test.sh \
-	emailrelay-loop-test.sh
+	emailrelay_test.sh \
+	emailrelay_test.pl
 
 test_scripts = \
-	emailrelay-chain-test.sh
+	emailrelay_chain_test.sh
+
+test_programs =
 
 test_names = \
 	testServerShowsHelp.test \
@@ -89,6 +89,7 @@ test_names = \
 	testFilter.test \
 	testFilterIdentity.test \
 	testFilterFailure.test \
+	testFilterTimeout.test \
 	testFilterWithBadFileDeletion.test \
 	testFilterWithGoodFileDeletion.test \
 	testFilterRescan.test \
@@ -102,6 +103,7 @@ test_names = \
 	testProxyConnectsOnce.test \
 	testClientFilterPass.test \
 	testClientFilterBlock.test \
+	testClientNetworkFilter.test \
 	testClientGivenUnknownMechanisms.test \
 	testClientAuthenticationFailure.test \
 	testClientMessageFailure.test \
@@ -146,7 +148,7 @@ modules = \
 if GCONFIG_TESTING
 TESTING_EXTRA_DIST = $(test_scripts)
 TESTING_TESTS = $(test_names) $(test_scripts)
-TESTING_HELPERS = $(helper_programs)
+TESTING_HELPERS = $(helper_programs) $(test_programs)
 else
 TESTING_EXTRA_DIST = $(test_scripts) $(helper_sources)
 TESTING_TESTS =
@@ -167,18 +169,20 @@ CLEANFILES = $(test_names) .tmp.port
 
 TESTS = $(TESTING_TESTS)
 
-# tell automake how to run .sh and .test tests...
+# tell automake how to run tests...
 TEST_EXTENSIONS = .sh .test
-TEST_LOG_COMPILER = $(top_srcdir)/test/emailrelay-test.sh
+TEST_LOG_COMPILER = $(top_srcdir)/test/emailrelay_test.sh
 AM_TEST_LOG_FLAGS = -q -v -c $(top_srcdir)/test/certificates
-SH_LOG_COMPILER = sh
-AM_SH_LOG_FLAGS =
+SH_LOG_COMPILER = $(top_srcdir)/test/emailrelay_test.sh
+AM_SH_LOG_FLAGS = --sh
 
 AM_CPPFLAGS = \
 	-I$(top_srcdir)/src \
 	-I$(top_srcdir)/src/glib \
 	-I$(top_srcdir)/src/gssl \
 	-I$(top_srcdir)/src/gnet \
+	-I$(top_srcdir)/src/gauth \
+	-I$(top_srcdir)/src/gsmtp \
 	-D "G_SPOOLDIR=$(e_spooldir)"
 
 COMMON_LDADD = \
@@ -245,13 +249,13 @@ emailrelay_test_verifier_LDADD = \
 
 .PHONY: programs
 if GCONFIG_WINDOWS
-programs: emailrelay-test-keygen.exe emailrelay-test-scanner.exe emailrelay-test-client.exe emailrelay-test-server.exe emailrelay-test-verifier.exe
+programs: emailrelay_test_keygen.exe emailrelay_test_scanner.exe emailrelay_test_client.exe emailrelay_test_server.exe emailrelay_test_verifier.exe
 else
-programs: $(utility_programs) $(helper_programs)
+programs: $(utility_programs) $(helper_programs) $(test_programs)
 endif
 
-# the .test files are empty files passed to emailrelay-test.sh
+# the .test files are empty files passed to emailrelay_test.sh
 $(test_names):
-	-@chmod +x $(top_srcdir)/test/emailrelay-test.sh || true
+	-@chmod +x $(top_srcdir)/test/emailrelay_test.sh || true
 	@touch $(test_names)
 
diff --git a/test/Makefile.in b/test/Makefile.in
index f74247b..44c88df 100644
--- a/test/Makefile.in
+++ b/test/Makefile.in
@@ -22,21 +22,21 @@
 # Use "make check" to run tests.
 #
 # Or, for example:
-#  $ make programs ; ./emailrelay-test.sh
-#  $ ./emailrelay-test.sh -q -v -t testStartsAndStops
+#  $ make programs ; ./emailrelay_test.sh
+#  $ ./emailrelay_test.sh -q -v -t testStartsAndStops
 #  $ sudo -v ; make check
 #  $ su -c 'make check'
 #  $ make -j 40 check TEST_LOG_FLAGS="-t -u someuser"
 #
 # Automake uses the TESTS variable for its list of tests, and runs a
 # "compiler" according to each test's filename extension -- in practice
-# "sh" for ".sh" tests and "emailrelay-test.sh" for ".test" tests.
+# "sh" for ".sh" tests and "emailrelay_test.sh" for ".test" tests.
 #
 # A ".test" file is created for each of the test routines defined within
-# "emailrelay-test.pl".
+# "emailrelay_test.pl".
 #
 # If "make check" fails then examine the relevant ".log" files and
-# re-run individual tests with "emailrelay-test.sh -q -v -t <test-name>".
+# re-run individual tests with "emailrelay_test.sh -q -v -t <test-name>".
 #
 
 VPATH = @srcdir@
@@ -111,9 +111,9 @@ POST_INSTALL = :
 NORMAL_UNINSTALL = :
 PRE_UNINSTALL = :
 POST_UNINSTALL = :
-noinst_PROGRAMS = $(am__EXEEXT_3)
-check_PROGRAMS = $(am__EXEEXT_2)
-TESTS = $(am__EXEEXT_4)
+noinst_PROGRAMS = $(am__EXEEXT_4)
+check_PROGRAMS = $(am__EXEEXT_3)
+TESTS = $(am__EXEEXT_5)
 subdir = test
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps = $(top_srcdir)/m4/acinclude.m4 \
@@ -127,12 +127,13 @@ mkinstalldirs = $(install_sh) -d
 CONFIG_HEADER = $(top_builddir)/src/gconfig_defs.h
 CONFIG_CLEAN_FILES =
 CONFIG_CLEAN_VPATH_FILES =
-am__EXEEXT_1 = emailrelay-test-scanner$(EXEEXT) \
-	emailrelay-test-client$(EXEEXT) \
-	emailrelay-test-server$(EXEEXT) \
-	emailrelay-test-verifier$(EXEEXT)
-@GCONFIG_TESTING_TRUE@am__EXEEXT_2 = $(am__EXEEXT_1)
-am__EXEEXT_3 = emailrelay-test-keygen$(EXEEXT)
+am__EXEEXT_1 = emailrelay_test_scanner$(EXEEXT) \
+	emailrelay_test_client$(EXEEXT) \
+	emailrelay_test_server$(EXEEXT) \
+	emailrelay_test_verifier$(EXEEXT)
+am__EXEEXT_2 =
+@GCONFIG_TESTING_TRUE@am__EXEEXT_3 = $(am__EXEEXT_1) $(am__EXEEXT_2)
+am__EXEEXT_4 = emailrelay_test_keygen$(EXEEXT)
 PROGRAMS = $(noinst_PROGRAMS)
 am_emailrelay_test_client_OBJECTS = emailrelay_test_client.$(OBJEXT)
 emailrelay_test_client_OBJECTS = $(am_emailrelay_test_client_OBJECTS)
@@ -445,7 +446,7 @@ am__set_TESTS_bases = \
   bases=`for i in $$bases; do echo $$i; done | sed 's/\.log$$//'`; \
   bases=`echo $$bases`
 RECHECK_LOGS = $(TEST_LOGS)
-@GCONFIG_TESTING_TRUE@am__EXEEXT_4 = $(test_names) $(test_scripts)
+@GCONFIG_TESTING_TRUE@am__EXEEXT_5 = $(test_names) $(test_scripts)
 TEST_SUITE_LOG = test-suite.log
 am__test_logs1 = $(TESTS:=.log)
 am__test_logs2 = $(am__test_logs1:@EXEEXT@.log=.log)
@@ -622,13 +623,13 @@ top_build_prefix = @top_build_prefix@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 utility_programs = \
-	emailrelay-test-keygen
+	emailrelay_test_keygen
 
 helper_programs = \
-	emailrelay-test-scanner \
-	emailrelay-test-client \
-	emailrelay-test-server \
-	emailrelay-test-verifier
+	emailrelay_test_scanner \
+	emailrelay_test_client \
+	emailrelay_test_server \
+	emailrelay_test_verifier
 
 helper_sources = \
 	emailrelay_test_keygen.cpp \
@@ -638,14 +639,13 @@ helper_sources = \
 	emailrelay_test_verifier.cpp
 
 other_scripts = \
-	emailrelay-test.sh \
-	emailrelay-test.pl \
-	emailrelay-soak-test.sh \
-	emailrelay-loop-test.sh
+	emailrelay_test.sh \
+	emailrelay_test.pl
 
 test_scripts = \
-	emailrelay-chain-test.sh
+	emailrelay_chain_test.sh
 
+test_programs = 
 test_names = \
 	testServerShowsHelp.test \
 	testServerStartsAndStops.test \
@@ -673,6 +673,7 @@ test_names = \
 	testFilter.test \
 	testFilterIdentity.test \
 	testFilterFailure.test \
+	testFilterTimeout.test \
 	testFilterWithBadFileDeletion.test \
 	testFilterWithGoodFileDeletion.test \
 	testFilterRescan.test \
@@ -686,6 +687,7 @@ test_names = \
 	testProxyConnectsOnce.test \
 	testClientFilterPass.test \
 	testClientFilterBlock.test \
+	testClientNetworkFilter.test \
 	testClientGivenUnknownMechanisms.test \
 	testClientAuthenticationFailure.test \
 	testClientMessageFailure.test \
@@ -732,7 +734,7 @@ modules = \
 @GCONFIG_TESTING_FALSE@TESTING_TESTS = 
 @GCONFIG_TESTING_TRUE@TESTING_TESTS = $(test_names) $(test_scripts)
 @GCONFIG_TESTING_FALSE@TESTING_HELPERS = 
-@GCONFIG_TESTING_TRUE@TESTING_HELPERS = $(helper_programs)
+@GCONFIG_TESTING_TRUE@TESTING_HELPERS = $(helper_programs) $(test_programs)
 EXTRA_DIST = \
 	$(TESTING_EXTRA_DIST) \
 	$(other_scripts) \
@@ -742,17 +744,19 @@ SUBDIRS = certificates
 check_SCRIPTS = $(TESTING_TESTS)
 CLEANFILES = $(test_names) .tmp.port
 
-# tell automake how to run .sh and .test tests...
+# tell automake how to run tests...
 TEST_EXTENSIONS = .sh .test
-TEST_LOG_COMPILER = $(top_srcdir)/test/emailrelay-test.sh
+TEST_LOG_COMPILER = $(top_srcdir)/test/emailrelay_test.sh
 AM_TEST_LOG_FLAGS = -q -v -c $(top_srcdir)/test/certificates
-SH_LOG_COMPILER = sh
-AM_SH_LOG_FLAGS = 
+SH_LOG_COMPILER = $(top_srcdir)/test/emailrelay_test.sh
+AM_SH_LOG_FLAGS = --sh
 AM_CPPFLAGS = \
 	-I$(top_srcdir)/src \
 	-I$(top_srcdir)/src/glib \
 	-I$(top_srcdir)/src/gssl \
 	-I$(top_srcdir)/src/gnet \
+	-I$(top_srcdir)/src/gauth \
+	-I$(top_srcdir)/src/gsmtp \
 	-D "G_SPOOLDIR=$(e_spooldir)"
 
 COMMON_LDADD = \
@@ -843,24 +847,24 @@ clean-checkPROGRAMS:
 clean-noinstPROGRAMS:
 	-test -z "$(noinst_PROGRAMS)" || rm -f $(noinst_PROGRAMS)
 
-emailrelay-test-client$(EXEEXT): $(emailrelay_test_client_OBJECTS) $(emailrelay_test_client_DEPENDENCIES) $(EXTRA_emailrelay_test_client_DEPENDENCIES) 
-	@rm -f emailrelay-test-client$(EXEEXT)
+emailrelay_test_client$(EXEEXT): $(emailrelay_test_client_OBJECTS) $(emailrelay_test_client_DEPENDENCIES) $(EXTRA_emailrelay_test_client_DEPENDENCIES) 
+	@rm -f emailrelay_test_client$(EXEEXT)
 	$(AM_V_CXXLD)$(emailrelay_test_client_LINK) $(emailrelay_test_client_OBJECTS) $(emailrelay_test_client_LDADD) $(LIBS)
 
-emailrelay-test-keygen$(EXEEXT): $(emailrelay_test_keygen_OBJECTS) $(emailrelay_test_keygen_DEPENDENCIES) $(EXTRA_emailrelay_test_keygen_DEPENDENCIES) 
-	@rm -f emailrelay-test-keygen$(EXEEXT)
+emailrelay_test_keygen$(EXEEXT): $(emailrelay_test_keygen_OBJECTS) $(emailrelay_test_keygen_DEPENDENCIES) $(EXTRA_emailrelay_test_keygen_DEPENDENCIES) 
+	@rm -f emailrelay_test_keygen$(EXEEXT)
 	$(AM_V_CXXLD)$(emailrelay_test_keygen_LINK) $(emailrelay_test_keygen_OBJECTS) $(emailrelay_test_keygen_LDADD) $(LIBS)
 
-emailrelay-test-scanner$(EXEEXT): $(emailrelay_test_scanner_OBJECTS) $(emailrelay_test_scanner_DEPENDENCIES) $(EXTRA_emailrelay_test_scanner_DEPENDENCIES) 
-	@rm -f emailrelay-test-scanner$(EXEEXT)
+emailrelay_test_scanner$(EXEEXT): $(emailrelay_test_scanner_OBJECTS) $(emailrelay_test_scanner_DEPENDENCIES) $(EXTRA_emailrelay_test_scanner_DEPENDENCIES) 
+	@rm -f emailrelay_test_scanner$(EXEEXT)
 	$(AM_V_CXXLD)$(emailrelay_test_scanner_LINK) $(emailrelay_test_scanner_OBJECTS) $(emailrelay_test_scanner_LDADD) $(LIBS)
 
-emailrelay-test-server$(EXEEXT): $(emailrelay_test_server_OBJECTS) $(emailrelay_test_server_DEPENDENCIES) $(EXTRA_emailrelay_test_server_DEPENDENCIES) 
-	@rm -f emailrelay-test-server$(EXEEXT)
+emailrelay_test_server$(EXEEXT): $(emailrelay_test_server_OBJECTS) $(emailrelay_test_server_DEPENDENCIES) $(EXTRA_emailrelay_test_server_DEPENDENCIES) 
+	@rm -f emailrelay_test_server$(EXEEXT)
 	$(AM_V_CXXLD)$(emailrelay_test_server_LINK) $(emailrelay_test_server_OBJECTS) $(emailrelay_test_server_LDADD) $(LIBS)
 
-emailrelay-test-verifier$(EXEEXT): $(emailrelay_test_verifier_OBJECTS) $(emailrelay_test_verifier_DEPENDENCIES) $(EXTRA_emailrelay_test_verifier_DEPENDENCIES) 
-	@rm -f emailrelay-test-verifier$(EXEEXT)
+emailrelay_test_verifier$(EXEEXT): $(emailrelay_test_verifier_OBJECTS) $(emailrelay_test_verifier_DEPENDENCIES) $(EXTRA_emailrelay_test_verifier_DEPENDENCIES) 
+	@rm -f emailrelay_test_verifier$(EXEEXT)
 	$(AM_V_CXXLD)$(emailrelay_test_verifier_LINK) $(emailrelay_test_verifier_OBJECTS) $(emailrelay_test_verifier_LDADD) $(LIBS)
 
 mostlyclean-compile:
@@ -1362,12 +1366,12 @@ uninstall-am:
 
 
 .PHONY: programs
-@GCONFIG_WINDOWS_TRUE@programs: emailrelay-test-keygen.exe emailrelay-test-scanner.exe emailrelay-test-client.exe emailrelay-test-server.exe emailrelay-test-verifier.exe
-@GCONFIG_WINDOWS_FALSE@programs: $(utility_programs) $(helper_programs)
+@GCONFIG_WINDOWS_TRUE@programs: emailrelay_test_keygen.exe emailrelay_test_scanner.exe emailrelay_test_client.exe emailrelay_test_server.exe emailrelay_test_verifier.exe
+@GCONFIG_WINDOWS_FALSE@programs: $(utility_programs) $(helper_programs) $(test_programs)
 
-# the .test files are empty files passed to emailrelay-test.sh
+# the .test files are empty files passed to emailrelay_test.sh
 $(test_names):
-	-@chmod +x $(top_srcdir)/test/emailrelay-test.sh || true
+	-@chmod +x $(top_srcdir)/test/emailrelay_test.sh || true
 	@touch $(test_names)
 
 # Tell versions [3.59,3.63) of GNU make to not export all variables.
diff --git a/test/NetClient.pm b/test/NetClient.pm
index 4e4c108..6081d04 100644
--- a/test/NetClient.pm
+++ b/test/NetClient.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -58,7 +58,7 @@ sub send
 	my $nsent = $this->{m_s}->send( $tx ) ;
 	if( !defined($nsent) or $nsent != length($tx) )
 	{
-		die "send: socket send error" ;
+		die "send: socket send error: $$this{m_server} $$this{m_port}" ;
 	}
 }
 
diff --git a/test/Openssl.pm b/test/Openssl.pm
index c05b444..cbe0514 100644
--- a/test/Openssl.pm
+++ b/test/Openssl.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/test/OpensslCast.pm b/test/OpensslCast.pm
index 5ffab27..fffc5fe 100644
--- a/test/OpensslCast.pm
+++ b/test/OpensslCast.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/test/OpensslFileStore.pm b/test/OpensslFileStore.pm
index 80b4c19..6d24228 100644
--- a/test/OpensslFileStore.pm
+++ b/test/OpensslFileStore.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/test/OpensslRun.pm b/test/OpensslRun.pm
index 997736f..df3abb8 100644
--- a/test/OpensslRun.pm
+++ b/test/OpensslRun.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/test/PopClient.pm b/test/PopClient.pm
index 7dc5dc0..6679729 100644
--- a/test/PopClient.pm
+++ b/test/PopClient.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/test/Scanner.pm b/test/Scanner.pm
index 0462006..6fc7d21 100644
--- a/test/Scanner.pm
+++ b/test/Scanner.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -18,7 +18,7 @@
 #
 # Scanner.pm
 #
-# A wrapper for running the "emailrelay-test-scanner" program.
+# A wrapper for running the "emailrelay_test_scanner" program.
 #
 # See also: Helper
 #
@@ -31,7 +31,7 @@ package Scanner ;
 sub new
 {
 	my ( $classname , $address ) = @_ ;
-	return bless { h => new Helper( "emailrelay-test-scanner" , $address ) } , $classname ; # "--port <address>"
+	return bless { h => new Helper( "emailrelay_test_scanner" , $address ) } , $classname ; # "--port <address>"
 }
 
 sub port { return shift->{h}->port(@_) }
diff --git a/test/Server.pm b/test/Server.pm
index 8a3c56a..3f2322b 100644
--- a/test/Server.pm
+++ b/test/Server.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -25,7 +25,7 @@
 #	$Server::bin_dir = "." ;
 #	my $server = new Server( 10025 , 10101 , 10026 , "/var/tmp" ) ;
 #	$server->run( { AsServer => 1 , ForwardTo => "localhost:10020" ... } ) ;
-#	open $server->logFile() ... ;
+#	open $server->log() ... ;
 #	$server->kill() ;
 #	$server->cleanup() ;
 #	kill 15 , @Server::pid_list ;
@@ -46,13 +46,23 @@ my $exe_name = "emailrelay" ;
 
 sub new
 {
-	my ( $classname , $smtp_port , $pop_port , $admin_port , $spool_dir , $tls_certificate , $tls_verify ) = @_ ;
+	my ( $classname , $smtp_port , $pop_port , $admin_port , $spool_dir , $tls_certificate_in , $tls_verify ) = @_ ;
 
-	my $exe = System::exe( $bin_dir , $exe_name ) ;
-	if( !-x $exe ) { die "invalid server executable [$exe]" }
+	my ( $tls_private_key , $tls_certificate ) ;
+	if( ref($tls_certificate_in) )
+	{
+		($tls_private_key,$tls_certificate) = @$tls_certificate_in ;
+	}
+	else
+	{
+		($tls_private_key,$tls_certificate) = (undef,$tls_certificate_in) ;
+	}
 
 	$spool_dir ||= System::createSpoolDir() ;
 	$smtp_port ||= System::nextPort() ;
+	my $exe = System::exe( $bin_dir , $exe_name ) ;
+	if( !-x $exe ) { die "invalid server executable [$exe]" }
+
 	$pop_port ||= System::nextPort() ;
 	$admin_port ||= System::nextPort() ;
 
@@ -60,6 +70,7 @@ sub new
 	my $verifier_port = System::nextPort() ;
 	my $stdout = System::tempfile( "stdout" ) ;
 	my $stderr = System::tempfile( "stderr" ) ;
+	my $logfile = System::tempfile( "log" ) ;
 	my $piddir = System::createPidDir( System::tempfile("piddir") ) ;
 	my $pidfile = "$piddir/pid" ;
 
@@ -77,13 +88,14 @@ sub new
 		m_rc => undef ,
 		m_stdout => $stdout ,
 		m_stderr => $stderr ,
-		m_log_file => (System::unix()?undef:$stderr) ,
+		m_log_file => $logfile ,
 		m_piddir => $piddir ,
 		m_pidfile => $pidfile ,
 		m_pid => undef ,
 		m_pop_secrets => System::tempfile("pop.auth") ,
 		m_client_secrets => System::tempfile("client.auth") ,
 		m_server_secrets => System::tempfile("server.auth") ,
+		m_tls_private_key => $tls_private_key ,
 		m_tls_certificate => $tls_certificate ,
 		m_tls_verify => $tls_verify ,
 		m_tls_config => $tls_config ,
@@ -107,11 +119,12 @@ sub adminPort { return shift->{m_admin_port} }
 sub scannerAddress { return shift->{m_scanner_address} }
 sub set_scannerAddress { $_[0]->{m_scanner_address} = $_[1] }
 sub verifierPort { return shift->{m_verifier_port} }
-sub verifierAddress { return "net:$System::localhost:" . shift->{m_verifier_port} }
+sub verifierAddress { return "net:${System::localhost}:" . shift->{m_verifier_port} }
 sub popPort { return shift->{m_pop_port} }
 sub popSecrets { return shift->{m_pop_secrets} }
 sub clientSecrets { return shift->{m_client_secrets} }
 sub serverSecrets { return shift->{m_server_secrets} }
+sub tlsPrivateKey { return shift->{m_tls_private_key} }
 sub tlsCertificate { return shift->{m_tls_certificate} }
 sub tlsVerify { return shift->{m_tls_verify} }
 sub tlsConfig { return shift->{m_tls_config} }
@@ -131,7 +144,7 @@ sub filter { return shift->{m_filter} }
 sub clientFilter { return shift->{m_client_filter} }
 sub maxSize { return shift->{m_max_size} }
 sub rc { return shift->{m_rc} }
-sub logFile { return shift->{m_log_file} }
+sub log { return shift->{m_log_file} }
 
 sub _pid
 {
@@ -146,6 +159,7 @@ sub _pid
 sub _set
 {
 	my ( $s , $var , $value ) = @_ ;
+	$value = "" if !defined($value) ;
 	$s =~ s/$var/$value/g ;
 	return $s ;
 }
@@ -157,7 +171,8 @@ sub _switches
 	return
 		"" .
 		( exists($sw{AsServer}) ? "--as-server " : "" ) .
-		( exists($sw{Log}) ? "--log --log-time --log-address " : "" ) .
+		( exists($sw{Log}) ? "--log --log-time --log-address --no-syslog " : "" ) .
+		( exists($sw{LogFile}) ? "--log-file __LOG_FILE__ " : "" ) .
 		( exists($sw{Port}) ? "--port __SMTP_PORT__ " : "" ) .
 		( exists($sw{Admin}) ? "--admin __ADMIN_PORT__ " : "" ) .
 		( exists($sw{Pop}) ? "--pop " : "" ) .
@@ -174,12 +189,11 @@ sub _switches
 		( exists($sw{ForwardToSome}) ? "--forward-to-some " : "" ) .
 		( exists($sw{User}) ? "--user __USER__ " : "" ) .
 		( exists($sw{Debug}) ? "--debug " : "" ) .
-		( !System::unix() && exists($sw{Log}) ? "--log-file __LOG_FILE__ " : "" ) .
 		( exists($sw{NoDaemon}) ? "--no-daemon " : "" ) .
 		( exists($sw{Hidden}) && !System::unix() ? "--hidden " : "" ) .
 		( exists($sw{NoSmtp}) ? "--no-smtp " : "" ) .
 		( exists($sw{Poll}) ? "--poll __POLL_TIMEOUT__ " : "" ) .
-		( exists($sw{Filter}) ? "--filter __FILTER__ " : "" ) .
+		( exists($sw{Filter}) ? "--filter=exit:0 --filter __FILTER__ " : "" ) .
 		( exists($sw{FilterTimeout}) ? "--filter-timeout 1 " : "" ) .
 		( exists($sw{ConnectionTimeout}) ? "--connection-timeout 1 " : "" ) .
 		( exists($sw{Immediate}) ? "--immediate " : "" ) .
@@ -196,8 +210,10 @@ sub _switches
 		( exists($sw{ServerTlsRequired}) ? "--server-tls-required " : "" ) .
 		( exists($sw{ClientTls}) ? "--client-tls " : "" ) .
 		( exists($sw{ClientTlsConnection}) ? "--client-tls-connection " : "" ) .
+		( exists($sw{ServerTlsPrivateKey}) ? "--server-tls-certificate __TLS_PRIVATE_KEY__ " : "" ) .
 		( exists($sw{ServerTlsCertificate}) ? "--server-tls-certificate __TLS_CERTIFICATE__ " : "" ) .
 		( (exists($sw{ServerTlsVerify}) && $sw{ServerTlsVerify}) ? "--server-tls-verify __TLS_VERIFY__ " : "" ) .
+		( exists($sw{ClientTlsPrivateKey}) ? "--client-tls-certificate __TLS_PRIVATE_KEY__ " : "" ) .
 		( exists($sw{ClientTlsCertificate}) ? "--client-tls-certificate __TLS_CERTIFICATE__ " : "" ) .
 		( (exists($sw{ClientTlsVerify}) && $sw{ClientTlsVerify}) ? "--client-tls-verify __TLS_VERIFY__ " : "" ) .
 		( exists($sw{TlsConfig}) ? "--tls-config=__TLS_CONFIG__ " : "" ) .
@@ -216,7 +232,7 @@ sub _set_all
 	$command_tail = _set( $command_tail , "__POP_SECRETS__" , $this->popSecrets() ) ;
 	$command_tail = _set( $command_tail , "__PID_FILE__" , $this->pidFile() ) ;
 	$command_tail = _set( $command_tail , "__FORWARD_TO__" , $this->dst() ) ;
-	$command_tail = _set( $command_tail , "__LOG_FILE__" , $this->logFile() ) ;
+	$command_tail = _set( $command_tail , "__LOG_FILE__" , $this->log() ) ;
 	$command_tail = _set( $command_tail , "__SPOOL_DIR__" , $this->spoolDir() ) ;
 	$command_tail = _set( $command_tail , "__USER__" , $this->user() ) ;
 	$command_tail = _set( $command_tail , "__POLL_TIMEOUT__" , $this->pollTimeout() ) ;
@@ -227,6 +243,7 @@ sub _set_all
 	$command_tail = _set( $command_tail , "__CLIENT_SECRETS__" , $this->clientSecrets() ) ;
 	$command_tail = _set( $command_tail , "__MAX_SIZE__" , $this->maxSize() ) ;
 	$command_tail = _set( $command_tail , "__SERVER_SECRETS__" , $this->serverSecrets() ) ;
+	$command_tail = _set( $command_tail , "__TLS_PRIVATE_KEY__" , $this->tlsPrivateKey() ) ;
 	$command_tail = _set( $command_tail , "__TLS_CERTIFICATE__" , $this->tlsCertificate() ) ;
 	$command_tail = _set( $command_tail , "__TLS_VERIFY__" , $this->tlsVerify() ) ;
 	$command_tail = _set( $command_tail , "__TLS_CONFIG__" , $this->tlsConfig() ) ;
@@ -390,6 +407,20 @@ sub hasThreads
 	}
 }
 
+sub hasUnixDomainSockets
+{
+	my ( $this ) = @_ ;
+	return undef if !System::unix() ;
+	my $exe = $this->exe() ;
+	my $fh = new FileHandle( "$exe --version --verbose |" ) ;
+	while(<$fh>)
+	{
+		chomp( my $line = $_ ) ;
+		return 1 if( $line =~ m/Unix domain sockets: enabled/i ) ;
+	}
+	return undef ;
+}
+
 sub hasTls
 {
 	# Returns true if the executable has tls support.
diff --git a/test/SmtpClient.pm b/test/SmtpClient.pm
index 61e5166..2a23893 100644
--- a/test/SmtpClient.pm
+++ b/test/SmtpClient.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -37,6 +37,7 @@
 use strict ;
 use FileHandle ;
 use NetClient ;
+use System ;
 
 package SmtpClient ;
 
diff --git a/test/System.pm b/test/System.pm
index 7e781b1..c1e0199 100644
--- a/test/System.pm
+++ b/test/System.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -226,7 +226,7 @@ sub commandline
 		return
 			$args{prefix} . $command . " " .
 			( $args{stdout} ? ">$args{stdout} " : "" ) .
-			( $args{stderr} && System::unix() ? "2>$stderr " : "" ) .
+			( $args{stderr} ? "2>$stderr " : "" ) .
 			( ( $args{prefix} =~ m/"$/ ) ? "\" " : "" ) .
 			( $args{background} ? "&" : "" ) ;
 	}
@@ -249,7 +249,7 @@ sub _tempdir
 		# using Cwd::cwd() here can be awkward because permissioning tests
 		# typically need some unprivileged access to spool directories etc.
 		# (consider filter tests where the filter scripts run as "daemon",
-		# or submit tests where the submit tool is run from an unprivileted
+		# or submit tests where the submit tool is run from an unprivileged
 		# test account) -- when using absolute paths under the cwd every
 		# directory on the path requires "--------x" (see stat(2) and
 		# open(2)), but we might be running under a home directory with
@@ -483,14 +483,14 @@ sub matchOne
 
 sub submitSmallMessage
 {
-	# Submits a small message using emailrelay-submit.
+	# Submits a small message using the "emailrelay-submit" utility.
 	my ( $spool_dir , @to ) = @_ ;
 	submitMessage( $spool_dir , 10 , @to ) ;
 }
 
 sub submitMessage
 {
-	# Submits a message of 'n' lines.
+    # Submits a message of 'n' lines using the "emailrelay-submit" utility.
 	my ( $spool_dir , $n , @to ) = @_ ;
 	push @to , "me\@there.localnet" if( scalar(@to) == 0 ) ;
 	my $path = _createMessageFile( tempfile("message") , $n ) ;
@@ -500,28 +500,42 @@ sub submitMessage
 	System::unlink( $path ) ;
 }
 
+{
+our $seq = 1 ;
 sub submitMessageText
 {
-    # Submits a message using emailrelay-submit.
+    # Submits a message using the "emailrelay-submit" utility.
 	my ( $spool_dir , @lines ) = @_ ;
 	my $to = "me\@there.localnet" ;
-	my $path = tempfile( "message" ) ;
-	my $fh = new FileHandle( $path , "w" ) or die ;
+	my $tmp_path = tempfile( "message" ) ;
+	my $fh = new FileHandle( $tmp_path , "w" ) or die ;
 	print $fh "Subject: test\r\n\r\n" ;
 	for my $line ( @lines )
 	{
 		print $fh $line , "\r\n" ;
 	}
 	$fh->close() or die ;
-	my $rc = system( sanepath(exe($bin_dir,"emailrelay-submit")) . " --from me\@here.localnet " .
-		"--spool-dir $spool_dir $to < $path" ) ;
-	Check::that( $rc == 0 , "failed to submit" ) ;
-	System::unlink( $path ) ;
+	my $cmd = sanepath(exe($bin_dir,"emailrelay-submit")) .
+		" --verbose --from me\@here.localnet --spool-dir $spool_dir $to" ;
+	my $fh_out = new FileHandle( "$cmd < $tmp_path |" ) ;
+	chomp( my $content_path = <$fh_out> ) ;
+	$fh_out->close() ;
+	( my $envelope_path = $content_path ) =~ s/\.content$/.envelope/ ;
+	Check::that( -e $content_path && -e $envelope_path , "failed to submit" , $content_path ) ;
+	System::unlink( $tmp_path ) ;
+
+	# impose an ordering
+	my $n = $seq++ ;
+	( my $new_content_path = $content_path ) =~ s:emailrelay\.(\d+)\.(\d+)\.(\d+)\.content$:emailrelay.$n.content: ;
+	( my $new_envelope_path = $envelope_path ) =~ s:emailrelay\.(\d+)\.(\d+)\.(\d+)\.envelope$:emailrelay.$n.envelope: ;
+	rename( $content_path , $new_content_path ) or die ;
+	rename( $envelope_path , $new_envelope_path ) or die ;
+}
 }
 
 sub submitMessages
 {
-	# Submits 'n' message of 'm' lines using the "emailrelay-submit" utility.
+	# Submits 'n' messages of 'm' lines using the "emailrelay-submit" utility.
 	my ( $spool_dir , $n , $m ) = @_ ;
 	for my $i ( 1 .. $n )
 	{
@@ -755,6 +769,10 @@ sub processIsRunning
 
 sub nextPort
 {
+	# Returns the next port number in sequence. The implementation
+	# uses a state file, which is created if necessary with a random
+	# port number. O/s file locking is used to avoid races on the
+	# state file contents.
 	my $first = 16000 ;
 	my $last = 32000 ;
 	my $file = ".tmp.port" ;
diff --git a/test/TestServer.pm b/test/TestServer.pm
index 5e31e1d..e7dc3cd 100644
--- a/test/TestServer.pm
+++ b/test/TestServer.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -18,7 +18,7 @@
 #
 # TestServer.pm
 #
-# A wrapper for running the "emailrelay-test-server" program.
+# A wrapper for running the "emailrelay_test_server" program.
 #
 # See also: emailrelay_test_server.cpp
 #
@@ -50,7 +50,7 @@ sub new
 
 	my %me = (
 		m_port => $port ,
-		m_exe => System::exe( $bin_dir , "emailrelay-test-server" ) ,
+		m_exe => System::exe( $bin_dir , "emailrelay_test_server" ) ,
 		m_logfile => System::tempfile("test-server.out") ,
 		m_pidfile => System::tempfile("test-server.pid") ,
 		m_pid => undef ,
diff --git a/test/Verifier.pm b/test/Verifier.pm
index 8d7dab8..923cb9e 100644
--- a/test/Verifier.pm
+++ b/test/Verifier.pm
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -18,7 +18,7 @@
 #
 # Verifier.pm
 #
-# A wrapper for running the "emailrelay-test-verifier" program.
+# A wrapper for running the "emailrelay_test_verifier" program.
 #
 # See also: Helper
 #
@@ -31,7 +31,7 @@ package Verifier ;
 sub new
 {
 	my ( $classname , $port ) = @_ ;
-	return bless { h => new Helper( "emailrelay-test-verifier" , $port ) } , $classname ;
+	return bless { h => new Helper( "emailrelay_test_verifier" , $port ) } , $classname ;
 }
 
 sub port { return shift->{h}->port(@_) }
diff --git a/test/certificates/Makefile.am b/test/certificates/Makefile.am
index 8657143..d1e058e 100644
--- a/test/certificates/Makefile.am
+++ b/test/certificates/Makefile.am
@@ -1,5 +1,5 @@
 #
-## Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 ## 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
diff --git a/test/emailrelay-loop-test.sh b/test/emailrelay-loop-test.sh
deleted file mode 100644
index b4acf85..0000000
--- a/test/emailrelay-loop-test.sh
+++ /dev/null
@@ -1,88 +0,0 @@
-#!/bin/sh
-#
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
-# 
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-# 
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-# 
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-# ===
-#
-# emailrelay-loop-test.sh
-#
-# Starts a polling E-MailRelay server that loops back to itself and runs forever.
-#
-# usage: emailrelay-loop-test.sh [-v] [<exe>]
-#        -v  - use valgrind
-#
-# To get a good valgrind report make use of the admin 'terminate' command
-# to quit the server cleanly. The admin port is recorded in the ".info" file.
-#
-
-# configure
-thisdir="`cd \`dirname $0\` ; pwd`"
-if test "$1" = "-v" ; then v="valgrind --leak-check=full --show-reachable=yes --num-callers=50 " ; shift ; fi
-if test "$1" != "" ; then exe="$1" ; fi
-if test "$1" = ""
-then
-	exe="$thisdir/../src/main/emailrelay"
-	test -x "$exe" || exe="$thisdir/../emailrelay"
-fi
-submit="${exe}-submit"
-tmp="/tmp"
-port_1=`perl -e 'print int(rand()*1000) + 1025'`
-port_2=`expr $port_1 + 1`
-files="100"
-lines="100" # per file
-characters="10000" # per line
-options="--user daemon"
-id="`basename $0`.$$.tmp"
-base="$tmp/$id"
-base_="$base"
-if test "`uname -o`" = "Msys"
-then
-	realtmp="`mount | grep 'on /tmp' | sed 's/ .*//' | sed 's:\\\\:/:g'`"
-	base_="$realtmp/$id"
-	options="--hidden --no-daemon --log-file=$base_/log.txt"
-	files="10" # otherwise too slow to create them
-fi
-
-# check
-test -x "$exe" -a -x "$submit" || echo `basename $0`: error: cannot execute "[$exe] or [$submit]" >&2
-test -x "$exe" -a -x "$submit" || exit 1
-
-# initialise
-trap "e=\$? ; rm -rf $base ; exit $e" 0
-trap "rm -rf $base ; exit 127" 1 2 3 13 15
-mkdir "${base}"
-perl -e 'print "To: me\n\n";for($i=0;$i<'"$lines"';$i++){print "x" x '"$characters"',"\n"}' > $base/.tmp
-for i in `perl -e 'print join(" ",1..'"$files"'),"\n"'` ; do $submit -f me -s $base me < $base/.tmp ; done
-echo $port_1 $port_2 > $base/.info
-echo $base > $tmp/`basename $0 .sh`.txt
-
-if test "`uname -o`" = "Msys"
-then
-	verifier="$base_/verifier.js"
-	echo 'WScript.Stdout.WriteLine("");' >> $verifier
-	echo 'WScript.Stdout.WriteLine(WScript.Arguments(0));' >> $verifier
-	echo 'WScript.Quit(1);' >> $verifier
-else
-	verifier="$base/verifier"
-	echo '#!/bin/sh' > $verifier
-	echo 'echo ""' >> $verifier
-	echo 'echo $1' >> $verifier
-	echo 'exit 1' >> $verifier
-	chmod +x $verifier
-fi
-
-# run
-set -x
-${v}${exe} --spool-dir=$base_ --log --no-daemon --port $port_1 --admin $port_2 --admin-terminate --forward-to=localhost:$port_1 --poll 1 --address-verifier $verifier --log-time $options --size 9999999 --pid-file $base_/pidfile
diff --git a/test/emailrelay-soak-test.sh b/test/emailrelay-soak-test.sh
deleted file mode 100644
index af78fa4..0000000
--- a/test/emailrelay-soak-test.sh
+++ /dev/null
@@ -1,271 +0,0 @@
-#!/bin/sh
-#
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
-# 
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-# 
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-# 
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-# ===
-#
-# emailrelay-soak-test.sh
-#
-# Soak tests the E-MailRelay system to check for large memory leaks.
-#
-# It starts two servers, with a proxy fronting onto one of them,
-# then in a loop it creates a large message file and runs a client
-# to forward it to both the proxy and the naked server. The main
-# loop can be stopped by creating a ".stop" file.
-#
-# Run 'ps' manually to check for large leaks.
-#
-# Files are created under a sub-directory of /tmp.
-#
-# usage: emailrelay-soak-test.sh [-v] [<exe>]
-#        -v  - use valgrind
-#
-# (As a side-effect it does "killall emailrelay".)
-#
-
-# configuration
-#
-exe="`dirname $0`/../src/main/emailrelay"
-content="/etc/services"
-pp="1001" # port prefix
-valgrind=""
-valgrind_sw=""
-sleep=1
-if test "${1}" = "-v"
-then
-	shift
-	valgrind="valgrind"
-	valgrind_sw="--leak-check=full --show-reachable=no --num-callers=50"
-	sleep=4
-fi
-test -z "${1}" || exe="${1}"
-
-# configuration fallback
-#
-bin_dir="`dirname $0`"
-if test \! -f "${exe}" -a -x "${bin_dir}/../emailrelay"
-then
-	exe="${bin_dir}/../emailrelay"
-	echo `basename $0`: using executable \"${exe}\" >&2
-fi
-
-# initialisation
-#
-as_client="--no-syslog --no-daemon --dont-serve --forward --forward-to" # no --log
-as_server="--log" # no --close-stderr
-as_proxy="--log --immediate --forward-to" # no --close-stderr
-base_dir="/tmp/`basename $0`.$$.tmp"
-auth_file="${base_dir}/`basename $0 .sh`.auth"
-mkdir "${base_dir}"
-trap "Cleanup 0" 0
-trap "Cleanup 1" 1 2 3 13 15
-
-Cleanup()
-{
-	echo cleaning up...
-	trap "" 0 1 2 3 13 15
-	pids="`cat server-1.pid server-2.pid proxy.pid 2>/dev/null`"
-	if test "$pids" != ""
-	then
-		kill $pids
-		sleep 1
-		kill -9 $pids 2>/dev/null
-	fi
-	rm -rf ${base_dir} 2>/dev/null
-	echo ... done
-	exit
-}
-
-Auth()
-{
-	echo "server plain joe joe+00s+3Dpassword"
-	echo "client plain joe joe+00s+3Dpassword"
-}
-
-Content()
-{
-	echo "To:" ${USER}@`uname -n`
-	echo "Subject: test message from process" $$
-	echo "From: tester"
-	echo ""
-	for i in 1 1 1 1 1 1 1 1 1 1
-	do
-		cat "${content}"
-	done
-}
-
-Envelope()
-{
-	echo "X-MailRelay-Format: #2821.5"
-	echo "X-MailRelay-Content: 8bit"
-	echo "X-MailRelay-From: me"
-	echo "X-MailRelay-ToCount: 1"
-	echo "X-MailRelay-To-Remote:" ${USER}@`uname -n`
-	echo "X-MailRelay-Authentication: anon"
-	echo "X-MailRelay-Client: 127.0.0.1"
-	echo "X-MailRelay-ClientCertificate: "
-	echo "X-MailRelay-MailFromAuthIn: "
-	echo "X-MailRelay-MailFromAuthOut: "
-	echo "X-MailRelay-End: 1"
-}
-
-CrLf()
-{
-	sed 's/$/£/' | tr '£' '\r'
-}
-
-CreateMessage()
-{
-	spool_dir="${1}"
-
-	Content | CrLf > ${spool_dir}/emailrelay.$$.1.content
-	Envelope | CrLf > ${spool_dir}/emailrelay.$$.1.envelope
-}
-
-RunClient()
-{
-	to_address="${1}"
-	spool_dir="${2}"
-
-	${exe} ${as_client} ${to_address} --spool-dir ${spool_dir} --client-auth ${auth_file}
-}
-
-Send()
-{
-	to_address="${1}"
-
-	dir="${base_dir}/spool-send"
-	mkdir -p "${dir}"
-
-	CreateMessage "${dir}"
-	RunClient "${to_address}" "${dir}"
-}
-
-RunServer()
-{
-	port="${1}"
-	spool_dir="${2}"
-	log="${3}"
-	pid_file="${4}"
-
-	if test "`echo ${pid_file} | grep '^/'`" = ""
-	then
-		pid_file="`pwd`/${pid_file}"
-	fi
-
-	mkdir -p "${spool_dir}"
-	set -x
-	${valgrind} ${valgrind_sw} ${exe} ${as_server} --port ${port} --spool-dir ${spool_dir} \
-		--pid-file ${pid_file} \
-		--server-auth ${auth_file} \
-		--admin-terminate \
-		--admin `expr ${port} + 100` --forward-to localhost:smtp --no-syslog \
-		--no-daemon > "${log}" 2>&1 &
-	set +x
-}
-
-RunProxy()
-{
-	port="${1}"
-	to_address="${2}"
-	spool_dir="${3}"
-	log="${4}"
-	pid_file="${5}"
-
-	if test "`echo ${pid_file} | grep '^/'`" = ""
-	then
-		pid_file="`pwd`/${pid_file}"
-	fi
-
-	mkdir -p "${spool_dir}"
-	set -x
-	${valgrind} ${valgrind_sw} ${exe} ${as_proxy} ${to_address} --port ${port} --spool-dir ${spool_dir} \
-		--pid-file ${pid_file} \
-		--server-auth ${auth_file} \
-		--client-auth ${auth_file} \
-		--admin-terminate \
-		--admin `expr ${port} + 100` --no-syslog \
-		--no-daemon > "${log}" 2>&1 &
-	set +x
-}
-
-Init()
-{
-	killall emailrelay 2>/dev/null
-	Auth > ${auth_file}
-}
-
-RunServers()
-{
-	RunServer ${pp}3 ${base_dir}/spool-3 server-2.out server-2.pid
-	RunProxy ${pp}1 localhost:${pp}3 ${base_dir}/spool-1 proxy.out proxy.pid
-	RunServer ${pp}2 ${base_dir}/spool-2 server-1.out server-1.pid
-	sleep $sleep # to allow pid files time to be written
-}
-
-CheckServers()
-{
-	if test \! -f server-1.pid -o \! -f server-2.pid -o \! -f proxy.pid
-	then
-		echo `basename $0`: error starting 'server(s)' >&2
-		cat server-?.out proxy.out 2>/dev/null | grep -v "^==" | sed 's/^/    /' >&2
-		exit 1
-	fi
-}
-
-StopServers()
-{
-	for port in ${pp}1 ${pp}2 ${pp}3
-	do
-    	perl -e '
-        	use IO::Socket ;
-        	my $p = $ARGV[0] + 100 ;
-        	my $c = "terminate" ;
-        	my $s = new IO::Socket::INET( PeerHost=>"127.0.0.1" , PeerPort=>$p , Proto=>"tcp" ) or die ;
-        	$s->send( $c . "\r\n" ) or die ;
-        	my $buffer = "" ;
-        	alarm( 2 ) ;
-        	$s->recv( $buffer , 1024 ) ;
-    	' $port
-	done
-}
-
-Ps()
-{
-	echo `basename $0`: output from \"ps -l -p `cat server-2.pid` -p `cat server-1.pid` -p `cat proxy.pid`\"...
-	ps -l -p `cat server-2.pid` -p `cat server-1.pid` -p `cat proxy.pid` | sed 's/^/     /'
-}
-
-Main()
-{
-	rm -f .stop 2>/dev/null
-	while test ! -f .stop
-	do
-		Send localhost:${pp}1
-		Send localhost:${pp}2
-		echo -n .
-		rm -f ${base_dir}/spool-?/*content
-	done
-	rm -f .stop
-	StopServers
-	sleep 2
-}
-
-Init
-RunServers
-CheckServers
-Ps
-Main
-
diff --git a/test/emailrelay-chain-test.sh b/test/emailrelay_chain_test.sh
old mode 100644
new mode 100755
similarity index 93%
rename from test/emailrelay-chain-test.sh
rename to test/emailrelay_chain_test.sh
index 9bfbe22..bdd9507
--- a/test/emailrelay-chain-test.sh
+++ b/test/emailrelay_chain_test.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -16,7 +16,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 # ===
 #
-# emailrelay-chain-test.sh
+# emailrelay_chain_test.sh
 #
 # Tests the E-MailRelay system.
 #
@@ -45,12 +45,14 @@
 # If this test takes more a minute (without valgrind) then it
 # has failed.
 #
-# usage: emailrelay-chain-test.sh [-v] [-f] [-d] [-n] [-s] [<exe-dir> [<content-file>]]
-#	-v    use valgrind
-#	-f    use fetchmail
-#	-d    use --debug
-#	-n    no cleanup
-#	-s    smaller content
+# usage: emailrelay_chain_test.sh [-V] [-f] [-v] [-n] [-s] [{-d|-b} <dir>]
+#            -d  -- buildroot directory
+#            -b  -- binary directory
+#            -V  -- use valgrind
+#            -f  -- use fetchmail
+#            -v  -- use "--debug"
+#            -n  -- no cleanup
+#            -s  -- smaller content
 #
 
 # parse the command line
@@ -60,17 +62,19 @@ opt_use_fetchmail="0"
 opt_smaller="0"
 opt_debug="0"
 opt_no_cleanup="0"
-while getopts 'vfdnsa:' opt ; do
-	case "$opt" in
-		v) opt_use_valgrind="1" ;;
-		f) opt_use_fetchmail="1" ;;
-		s) opt_smaller="1" ;;
-		d) opt_debug="1" ;;
-		n) opt_no_cleanup="1" ;;
+while echo "$1" | grep -q '^-'
+do
+	case "$1" in
+		-V) opt_use_valgrind="1" ; shift ;;
+		-f) opt_use_fetchmail="1" ; shift ;;
+		-s) opt_smaller="1" ; shift ;;
+		-v) opt_debug="1" ; shift ;;
+		-n) opt_no_cleanup="1" ; shift ;;
+		-d) shift ; opt_exe_dir="$1/src/main" ; shift ;;
+		-b) shift ; opt_exe_dir="$1" ; shift ;;
+		*) echo `basename $0`: usage error "($1)" >&2 ; exit 2 ;;
 	esac
 done
-shift `expr $OPTIND - 1`
-opt_exe_dir="$1"
 
 # configuration
 #
diff --git a/test/emailrelay-test.pl b/test/emailrelay_test.pl
similarity index 93%
rename from test/emailrelay-test.pl
rename to test/emailrelay_test.pl
index 4de6274..7959b2b 100755
--- a/test/emailrelay-test.pl
+++ b/test/emailrelay_test.pl
@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -16,15 +16,15 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 # ===
 #
-# emailrelay-test.pl
+# emailrelay_test.pl
 #
 # Tests the E-MailRelay system. Individual named tests are defined in
 # testWhatever() subroutines. By default all tests are run (or skipped)
 # in sequence.
 #
 # usage:
-#   emailrelay-test.pl { list | fixup ... }
-#   emailrelay-test.pl [-d <bin-dir>] [-x <testbin-dir>] [-o <openssltool-dir>] [-c <certs-dir>] [-k] [-v] [-t] [-T <config>] [<test-name> ...]
+#   emailrelay_test.pl { list | fixup ... }
+#   emailrelay_test.pl [-d <bin-dir>] [-x <testbin-dir>] [-o <openssltool-dir>] [-c <certs-dir>] [-k] [-v] [-t] [-T <config>] [<test-name> ...]
 #      -d  - directory containing emailrelay binary
 #      -x  - directory containing test program binaries
 #      -o  - directory containing the openssl tool
@@ -99,7 +99,6 @@ $Server::with_valgrind = $opts{V} if exists $opts{V} ;
 $Server::bin_dir = $opt_bin_dir ;
 $Helper::bin_dir = $opt_test_bin_dir ;
 $TestServer::bin_dir = $opt_test_bin_dir ;
-$Openssl::keep = 1 if exists $opts{t} ;
 $Openssl::log_fn = sub { System::log_("running [$_[0]] ($_[1])") } ;
 $OpensslFileStore::log_cat_fn = sub { System::log_("creating [$_[0]]") } ;
 $OpensslFileStore::unlink_fn = sub { System::unlink($_[0]) } ;
@@ -117,7 +116,15 @@ sub requireUnix
 
 sub requireUnixDomainSockets
 {
-	requireUnix() ; # assume --with-uds
+	my $has_uds ;
+	if( System::unix() )
+	{
+		my $server = new Server() ;
+		$has_uds = $server->hasUnixDomainSockets() ;
+		$server->cleanup() ;
+	}
+	die "skipped: no unix domain socket support\n"
+		if !$has_uds ;
 }
 
 sub requireRoot
@@ -200,7 +207,8 @@ sub testServerShowsHelp
 	Check::ok( $server->run(\%args,undef,undef,0) , "failed to run" , $server->message() , $server->command() ) ;
 	Check::that( $server->rc() == 0 , "non-zero exit" ) ;
 	Check::fileNotEmpty( $server->stdout() ) ;
-	Check::fileEmpty( $server->stderr() ) ;
+	Check::fileEmpty( $server->stderr() ) if System::unix() ;
+	Check::fileEmpty( $server->log() ) ;
 
 	# tear down
 	$server->cleanup() ;
@@ -209,7 +217,8 @@ sub testServerShowsHelp
 sub testServerStartsAndStops
 {
 	_testServerStartsAndStops( 0 ,
-		AsServer => 1 ,
+		Log => 1 ,
+		LogFile => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
 		PidFile => 1 ,
@@ -222,7 +231,8 @@ sub testServerStartsAndStopsAsRoot
 	requireUnix() ;
 	requireRootOrSudo() ;
 	_testServerStartsAndStops( 1 ,
-		AsServer => 1 ,
+		Log => 1 ,
+		LogFile => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
 		PidFile => 1 ,
@@ -240,10 +250,11 @@ sub _testServerStartsAndStops
 	my $sudo_prefix = $as_root ? System::sudoPrefix() : "" ;
 
 	# test that the server starts up
+	(new FileHandle($server->log(),"w"))->close() if $as_root ; # (log file permissions)
 	Check::ok( $server->run(\%args,$sudo_prefix) , "failed to run" , $server->message() ) ;
 	Check::that( $server->rc() == 0 , "immediate error" ) ;
 	Check::fileExists( $server->stdout() ) ;
-	Check::fileExists( $server->stderr() ) ;
+	Check::fileExists( $server->log() ) ;
 	Check::fileExists( $server->pidFile() , "pid file" ) ;
 	Check::numeric( $server->pid() , "pid file" ) ;
 	Check::running( $server->pid() , $server->message() ) ;
@@ -255,7 +266,9 @@ sub _testServerStartsAndStops
 	Check::notRunning( $server->pid() ) ;
 	Check::fileDeleted( $server->pidFile() , "pid file" ) if System::unix() ;
 	Check::fileEmpty( $server->stdout() ) ;
-	Check::fileDoesNotContain( $server->stderr() , [ "error" , "warning" , "exception" , "core" ] , "stderr" ) ;
+	Check::fileEmpty( $server->stderr() ) if System::unix() ;
+	Check::fileContains( $server->log() , "smtp server on" , "log" ) ;
+	Check::fileDoesNotContain( $server->log() , [ "error" , "warning" , "exception" , "core" ] , "log" ) ;
 
 	# tear down
 	$server->cleanup() ;
@@ -265,7 +278,8 @@ sub testServerAdminTerminate
 {
 	# setup
 	my %args = (
-		AsServer => 1 ,
+		Log => 1 ,
+		LogFile => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
 		Admin => 1 ,
@@ -287,7 +301,10 @@ sub testServerAdminTerminate
 	$server->wait() ;
 	Check::notRunning( $server->pid() ) ;
 	Check::fileDeleted( $server->pidFile() , "pid file" ) if System::unix() ;
-	Check::fileDoesNotContain( $server->stderr() , [ "error" , "warning" , "exception" , "core" ] , "stderr" ) ;
+	Check::fileEmpty( $server->stderr() ) if System::unix() ;
+	Check::fileContains( $server->log() , "smtp server on" , "log" ) ;
+	Check::fileContains( $server->log() , "admin server on" , "log" ) ;
+	Check::fileDoesNotContain( $server->log() , [ "error" , "warning" , "exception" , "core" ] , "log" ) ;
 
 	# tear down
 	$server->cleanup() ;
@@ -381,7 +398,8 @@ sub testServerIdentityRunningAsRoot
 {
 	# setup
 	my %args = (
-		AsServer => 1 ,
+		Log => 1 ,
+		LogFile => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
 		PidFile => 1 ,
@@ -409,7 +427,8 @@ sub testServerIdentityRunningSuidRoot
 {
 	# setup
 	my %args = (
-		AsServer => 1 ,
+		Log => 1 ,
+		LogFile => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
 		PidFile => 1 ,
@@ -459,6 +478,7 @@ sub _testServerSmtpSubmit
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -486,7 +506,6 @@ sub _testServerSmtpSubmit
 	Check::fileNotEmpty( $content ) ;
 	Check::fileLineCount( $content , 1 , "Received" ) ;
 	Check::fileLineCount( $content , 100 , $line ) ;
-	Check::fileContains( $server->stderr() , "client protocol violation" ) if $pipelined_quit ;
 
 	# tear down
 	$server->kill() ;
@@ -498,6 +517,7 @@ sub testServerPermissions
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Port => 1 ,
 		PidFile => 1 ,
@@ -538,12 +558,13 @@ sub testServerPop
 {
 	# setup
 	my %args = (
+		Log => 1 ,
+		LogFile => 1 ,
+		Verbose => 1 ,
 		Pop => 1 ,
 		PopAuth => 1 ,
 		PopPort => 1 ,
 		NoSmtp => 1 ,
-		Log => 1 ,
-		Verbose => 1 ,
 		Domain => 1 ,
 		PidFile => 1 ,
 		SpoolDir => 1 ,
@@ -573,12 +594,13 @@ sub testServerPopDisconnect
 {
 	# setup
 	my %args = (
+		Log => 1 ,
+		LogFile => 1 ,
+		Verbose => 1 ,
 		Pop => 1 ,
 		PopAuth => 1 ,
 		PopPort => 1 ,
 		NoSmtp => 1 ,
-		Log => 1 ,
-		Verbose => 1 ,
 		Domain => 1 ,
 		PidFile => 1 ,
 		SpoolDir => 1 ,
@@ -593,9 +615,9 @@ sub testServerPopDisconnect
 	$pop_client->login( "me" , "secret" ) ;
 
 	# test that the server sees the client disconnect
-	System::waitForFileLine( $server->stderr() , "pop connection from" ) ;
+	System::waitForFileLine( $server->log() , "pop connection from" ) ;
 	$pop_client->disconnect() ;
-	System::waitForFileLine( $server->stderr() , "pop connection closed" ) ;
+	System::waitForFileLine( $server->log() , "pop connection closed" ) ;
 
 	# tear down
 	$server->kill() ;
@@ -607,8 +629,8 @@ sub testServerFlushNoMessages
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
-		AsServer => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
 		Admin => 1 ,
@@ -638,8 +660,8 @@ sub testServerFlushNoServer
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
-		AsServer => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
 		Admin => 1 ,
@@ -673,6 +695,7 @@ sub testServerFlush
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -722,6 +745,7 @@ sub testServerPolling
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -764,6 +788,7 @@ sub testServerWithBadClient
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -801,6 +826,7 @@ sub testServerSizeLimit
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -826,7 +852,7 @@ sub testServerSizeLimit
 	Check::that( $rsp =~ m/^552 / , "large message submission did not fail as it should have" ) ;
 	Check::fileMatchCount( $server->spoolDir()."/emailrelay.*.content" , 0 ) ;
 	Check::fileMatchCount( $server->spoolDir()."/emailrelay.*.envelope*" , 0 ) ;
-	Check::fileContains( $server->stderr() , "552 message exceeds fixed maximum message size" ) ;
+	Check::fileContains( $server->log() , "552 message exceeds fixed maximum message size" ) ;
 
 	# tear down
 	$server->kill() ;
@@ -838,6 +864,7 @@ sub testClientContinuesIfNoSecrets
 	# setup
 	my %server_args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -863,12 +890,12 @@ sub testClientContinuesIfNoSecrets
 	System::createFile( $server->serverSecrets() , "server login me secret" ) ;
 	System::submitSmallMessage( $client->spoolDir() ) ;
 	Check::ok( $server->run(\%server_args) , "failed to run server" , $server->message() ) ;
-	System::waitForFile( $server->stderr() ) ;
+	System::waitForFile( $server->log() ) ;
 
 	# test that the client gets as far as issuing the mail command
 	Check::ok( $client->run(\%client_args) , "failed to run client" , $client->message() ) ;
-	System::waitForFileLine( $server->stderr() , "MAIL FROM:" ) ;
-	System::waitForFileLine( $server->stderr() , "530 authentication required" ) ;
+	System::waitForFileLine( $server->log() , "MAIL FROM:" ) ;
+	System::waitForFileLine( $server->log() , "530 authentication required" ) ;
 
 	# tear down
 	$server->kill() ;
@@ -881,6 +908,7 @@ sub testClientSavesReasonCode
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		SpoolDir => 1 ,
@@ -915,6 +943,7 @@ sub testFilter
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -967,6 +996,7 @@ sub testFilterIdentity
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -1012,6 +1042,7 @@ sub testFilterFailure
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -1043,7 +1074,49 @@ sub testFilterFailure
 	$smtp_client->submit( 1 ) ;
 	Check::fileMatchCount( $server->spoolDir()."/emailrelay.*.content" , 0 ) ;
 	Check::fileMatchCount( $server->spoolDir()."/emailrelay.*.envelope*" , 0 ) ;
-	Check::fileContains( $server->stderr() , "rejected by filter: .foo bar." ) ;
+	Check::fileContains( $server->log() , "rejected by filter: .foo bar." ) ;
+
+	# tear down
+	$server->kill() ;
+	$server->cleanup() ;
+}
+
+sub testFilterTimeout
+{
+	# setup
+	my %args = (
+		Log => 1 ,
+		LogFile => 1 ,
+		Verbose => 1 ,
+		Domain => 1 ,
+		Port => 1 ,
+		SpoolDir => 1 ,
+		PidFile => 1 ,
+		Filter => 1 ,
+		FilterTimeout => 1 ,
+	) ;
+	requireThreads() ;
+	my $server = new Server() ;
+	Filter::create( $server->filter() , {} , {
+			unix => [
+				"sleep 3" ,
+				"exit 0" ,
+			] ,
+			win32 => [
+				"WScript.Sleep(3000) ;" ,
+				"WScript.Quit(0) ;" ,
+			] ,
+		} ) ;
+	Check::ok( $server->run(\%args) , "failed to run" , $server->message() ) ;
+	Check::running( $server->pid() , $server->message() ) ;
+	my $smtp_client = new SmtpClient( $server->smtpPort() , $System::localhost ) ;
+	Check::ok( $smtp_client->open() ) ;
+
+	# test that the filter times out
+	$smtp_client->submit( 1 ) ;
+	Check::fileMatchCount( $server->spoolDir()."/emailrelay.*.content" , 0 ) ;
+	Check::fileMatchCount( $server->spoolDir()."/emailrelay.*.envelope*" , 0 ) ;
+	Check::fileContains( $server->log() , "filter done: ok=0 response=.error. reason=.*timeout" ) ;
 
 	# tear down
 	$server->kill() ;
@@ -1067,6 +1140,7 @@ sub _testFilterWithFileDeletion
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -1119,6 +1193,7 @@ sub testFilterRescan
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -1143,7 +1218,7 @@ sub testFilterRescan
 
 	# test that the rescan is triggered by the filter exit code
 	$smtp_client->submit() ;
-	System::waitForFileLine( $server->stderr() , "forwarding: .rescan" , "no rescan message in the log file" ) ;
+	System::waitForFileLine( $server->log() , "forwarding: .rescan" , "no rescan message in the log file" ) ;
 
 	# tear down
 	$server->kill() ;
@@ -1155,6 +1230,7 @@ sub testFilterParallelism
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -1205,6 +1281,7 @@ sub testScannerPass
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -1226,7 +1303,7 @@ sub testScannerPass
 	$smtp_client->submit_end() ;
 	Check::fileContains( $scanner->logfile() , "new connection from" ) ;
 	Check::fileContains( $scanner->logfile() , "send ok" ) ;
-	Check::fileDoesNotContain( $server->stderr() , "452 " ) ;
+	Check::fileDoesNotContain( $server->log() , "452 " ) ;
 	Check::fileMatchCount( $server->spoolDir()."/emailrelay.*.envelope" , 1 ) ;
 
 	# tear down
@@ -1241,6 +1318,7 @@ sub testScannerBlock
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -1260,8 +1338,8 @@ sub testScannerBlock
 	$smtp_client->submit_start() ;
 	$smtp_client->submit_line( "send foobar" ) ; # (the test scanner treats the message body as a script)
 	$smtp_client->submit_end( 1 ) ; # 1 <= expect the "." command to fail
-	Check::fileContains( $server->stderr() , "rejected by filter: .foobar" ) ;
-	Check::fileContains( $server->stderr() , "452 foobar" ) ;
+	Check::fileContains( $server->log() , "rejected by filter: .foobar" ) ;
+	Check::fileContains( $server->log() , "452 foobar" ) ;
 	Check::fileMatchCount( $server->spoolDir()."/emailrelay.*.envelope" , 0 ) ;
 
 	# tear down
@@ -1276,6 +1354,7 @@ sub testScannerTimeout
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -1297,9 +1376,9 @@ sub testScannerTimeout
 	$smtp_client->submit_line( "sleep 3" ) ;
 	$smtp_client->submit_line( "send foobar" ) ;
 	$smtp_client->submit_end( 1 ) ;
-	Check::fileDoesNotContain( $server->stderr() , "452 foobar" ) ;
-	Check::fileContains( $server->stderr() , "filter done: ok=0 response=.failed. reason=.*timeout" ) ;
-	Check::fileContains( $server->stderr() , "452 failed" ) ;
+	Check::fileDoesNotContain( $server->log() , "452 foobar" ) ;
+	Check::fileContains( $server->log() , "filter done: ok=0 response=.failed. reason=.*timeout" ) ;
+	Check::fileContains( $server->log() , "452 failed" ) ;
 
 	# tear down
 	$server->kill() ;
@@ -1313,6 +1392,7 @@ sub testScannerOverUnixDomainSockets
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -1336,7 +1416,7 @@ sub testScannerOverUnixDomainSockets
 	$smtp_client->submit_end() ;
 	Check::fileContains( $scanner->logfile() , "new connection from (/|\\\\0)" ) ;
 	Check::fileContains( $scanner->logfile() , "send ok" ) ;
-	Check::fileDoesNotContain( $server->stderr() , "452 " ) ;
+	Check::fileDoesNotContain( $server->log() , "452 " ) ;
 	Check::fileMatchCount( $server->spoolDir()."/emailrelay.*.envelope" , 1 ) ;
 
 	# tear down
@@ -1351,6 +1431,7 @@ sub testNetworkVerifierPass
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -1371,7 +1452,7 @@ sub testNetworkVerifierPass
 	$smtp_client->submit_line( "just testing" ) ;
 	$smtp_client->submit_end() ;
 	Check::fileContains( $verifier->logfile() , "sending valid" ) ;
-	Check::fileDoesNotContain( $server->stderr() , "452 " ) ;
+	Check::fileDoesNotContain( $server->log() , "452 " ) ;
 	Check::fileMatchCount( $server->spoolDir()."/emailrelay.*.envelope" , 1 ) ;
 
 	# tear down
@@ -1386,6 +1467,7 @@ sub testNetworkVerifierFail
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -1404,7 +1486,7 @@ sub testNetworkVerifierFail
 	# test that the verifier can reject
 	$smtp_client->submit_start( "fail\@here" , 1 ) ; # (the test verifier interprets the recipient string)
 	Check::fileContains( $verifier->logfile() , "sending error" ) ;
-	Check::fileContains( $server->stderr() , "VerifierError" ) ; # see emailrelay_test_verifier.cpp
+	Check::fileContains( $server->log() , "VerifierError" ) ; # see emailrelay_test_verifier.cpp
 	Check::fileMatchCount( $server->spoolDir()."/emailrelay.*.envelope" , 0 ) ;
 
 	# tear down
@@ -1419,6 +1501,7 @@ sub testProxyConnectsOnce
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -1453,12 +1536,12 @@ sub testProxyConnectsOnce
 		$smtp_client->submit_end() ;
 	}
 	$smtp_client->close() ;
-	System::waitForFileLine( $server_2->stderr() , "smtp connection closed" ) ;
+	System::waitForFileLine( $server_2->log() , "smtp connection closed" ) ;
 	Check::fileMatchCount( $spool_dir_1 ."/emailrelay.*", 0 ) ;
 	Check::fileMatchCount( $spool_dir_2 ."/emailrelay.*.envelope", $n ) ;
 	Check::fileMatchCount( $spool_dir_2 ."/emailrelay.*.content", $n ) ;
-	Check::fileLineCount(  $server_2->stderr() , 1 , "smtp connection from" ) ;
-	Check::fileLineCount(  $server_2->stderr() , 1 , "smtp connection closed" ) ;
+	Check::fileLineCount(  $server_2->log() , 1 , "smtp connection from" ) ;
+	Check::fileLineCount(  $server_2->log() , 1 , "smtp connection closed" ) ;
 
 	# tear down
 	$server_1->kill() ;
@@ -1474,6 +1557,7 @@ sub testClientFilterPass
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		SpoolDir => 1 ,
@@ -1542,6 +1626,7 @@ sub testClientFilterBlock
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		SpoolDir => 1 ,
@@ -1634,11 +1719,9 @@ sub testClientNetworkFilter
 	my $spool_dir_1 = System::createSpoolDir( "spool-1" ) ;
 	my $spool_dir_2 = System::createSpoolDir( "spool-2" ) ;
 	System::submitMessageText( $spool_dir_1 , "send ok" ) ;
-	System::submitMessageText( $spool_dir_1 , "send ok" , "shutdown" ) ;
-	System::submitMessageText( $spool_dir_1 , "send ok" , "shutdown" ) ;
 	System::submitMessageText( $spool_dir_1 , "send _failed_" ) ;
 	System::submitMessageText( $spool_dir_1 , "send ok" ) ;
-	Check::fileMatchCount( $spool_dir_1 ."/emailrelay.*.envelope", 5 ) ;
+	Check::fileMatchCount( $spool_dir_1 ."/emailrelay.*.envelope", 3 ) ;
 	my $server_1 = new Server(undef,undef,undef,$spool_dir_1) ;
 	my $server_2 = new Server(System::nextPort(),undef,System::nextPort(),$spool_dir_2) ;
 	my $scanner = new Scanner( $server_1->scannerAddress() ) ;
@@ -1649,11 +1732,11 @@ sub testClientNetworkFilter
 	Check::ok( $server_1->run(\%args) , "failed to run" , $server_1->message() ) ;
 
 	# test that the messages are fowarded or not according to the filter
-	System::waitForFiles( $spool_dir_2."/emailrelay.*.envelope", 4 ) ;
+	System::waitForFiles( $spool_dir_2."/emailrelay.*.envelope", 2 ) ;
 	System::waitForFiles( $spool_dir_1."/emailrelay.*.envelope.bad", 1 ) ;
 	Check::allFilesContain( $spool_dir_1."/emailrelay.*.envelope.bad" , "_failed_" ) ;
-	Check::fileContains( $scanner->logfile() , "info:.*new connection" , undef , 3 ) ;
-	Check::fileContains( $scanner->logfile() , "info:.*file: " , undef , 5 ) ;
+	Check::fileContains( $scanner->logfile() , "info:.*new connection" , undef , 1 ) ;
+	Check::fileContains( $scanner->logfile() , "info:.*file: " , undef , 3 ) ;
 
 	# tear down
 	$server_1->kill() ;
@@ -1671,6 +1754,7 @@ sub testClientGivenUnknownMechanisms
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		SpoolDir => 1 ,
@@ -1693,7 +1777,7 @@ sub testClientGivenUnknownMechanisms
 
 	# test that protocol fails and one message fails
 	Check::ok( $emailrelay->run( \%args ) , "failed to run" , $emailrelay->message() ) ;
-	System::waitForFileLine( $emailrelay->stderr() , "cannot do authentication required by " ) ;
+	System::waitForFileLine( $emailrelay->log() , "cannot do authentication required by " ) ;
 	Check::fileMatchCount( $spool_dir ."/emailrelay.*.envelope", 1 ) ;
 	Check::fileMatchCount( $spool_dir ."/emailrelay.*.envelope.bad", 1 ) ;
 
@@ -1709,6 +1793,7 @@ sub testClientAuthenticationFailure
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		SpoolDir => 1 ,
@@ -1731,7 +1816,7 @@ sub testClientAuthenticationFailure
 
 	# test that protocol fails and one message fails
 	Check::ok( $emailrelay->run( \%args ) , "failed to run" , $emailrelay->message() ) ;
-	System::waitForFileLine( $emailrelay->stderr() , "authentication failed" ) ;
+	System::waitForFileLine( $emailrelay->log() , "authentication failed" ) ;
 	System::waitForFiles( $spool_dir ."/emailrelay.*.envelope.bad", 1 ) ;
 	Check::fileMatchCount( $spool_dir ."/emailrelay.*.envelope", 1 ) ;
 
@@ -1747,6 +1832,7 @@ sub testClientMessageFailure
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		SpoolDir => 1 ,
@@ -1786,6 +1872,7 @@ sub testClientInvalidRecipients
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		SpoolDir => 1 ,
@@ -1828,6 +1915,7 @@ sub testClientInvalidRecipientsWithForwardToSome
 	# setup
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		SpoolDir => 1 ,
@@ -1882,6 +1970,7 @@ sub _testTlsServer
 	requireOpensslTool() ; # Openssl::runClient()
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -1889,6 +1978,7 @@ sub _testTlsServer
 		SpoolDir => 1 ,
 		ServerTls => 1 ,
 		ServerTlsRequired => 1 ,
+		ServerTlsPrivateKey => 1 ,
 		ServerTlsCertificate => 1 ,
 		ServerTlsVerify => $server_verify ,
 		TlsConfig => 1 ,
@@ -1896,16 +1986,28 @@ sub _testTlsServer
 		AdminTerminate => 1 ,
 	) ;
 	my $openssl = _newOpenssl() ;
-	my $server_cert = $openssl->concatenate( @$server_cert_names ) ;
+	my $server_key ;
+	my $server_cert ;
+	if( @{$server_cert_names}[0] =~ m/\.key$/ )
+	{
+		my ($key_name,@cert_names) = @$server_cert_names ;
+		$server_key = $openssl->concatenate( $key_name ) ;
+		$server_cert = $openssl->concatenate( @cert_names ) ;
+	}
+	else
+	{
+		$server_key = undef ;
+		$server_cert = $openssl->concatenate( @$server_cert_names ) ;
+	}
 	my $server_ca = $openssl->concatenate( @$server_ca_names ) ;
 	my $client_cert = $openssl->concatenate( @$client_cert_names ) ;
 	my $client_ca = $openssl->concatenate( @$client_ca_names ) ;
 	my $spool_dir = System::createSpoolDir() ;
-	my $emailrelay = new Server( undef , undef , undef , $spool_dir , $server_cert , $server_ca ) ;
+	my $emailrelay = new Server( undef , undef , undef , $spool_dir , [$server_key,$server_cert] , $server_ca ) ;
 	my $admin_client = new AdminClient( $emailrelay->adminPort() , $System::localhost ) ;
 	Check::ok( $emailrelay->run(\%args) , "failed to start" , $emailrelay->message() ) ;
 	Check::ok( $admin_client->open() , "cannot connect for admin" , $emailrelay->adminPort() ) ;
-	my $server_log = $emailrelay->stderr() ;
+	my $server_log = $emailrelay->log() ;
 
 	# test
 	my $client_log = System::tempfile( "sclient" ) ;
@@ -2013,6 +2115,7 @@ sub _testTlsClient
 	requireOpensslTool() ; # Openssl::runServer()
 	my %args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		PidFile => 1 ,
@@ -2040,7 +2143,7 @@ sub _testTlsClient
 	my $admin_client = new AdminClient( $emailrelay->adminPort() , $System::localhost ) ;
 	Check::ok( $emailrelay->run( \%args ) , "failed to start" , $emailrelay->message() ) ;
 	Check::ok( $admin_client->open() , "cannot connect for admin" ) ;
-	my $client_log = $emailrelay->stderr() ;
+	my $client_log = $emailrelay->log() ;
 
 	# test
 	my $server_log = System::tempfile( "sserver" ) ;
@@ -2108,6 +2211,7 @@ sub _testTls
 	requireTls() ;
 	my %client_args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		SpoolDir => 1 ,
@@ -2122,6 +2226,7 @@ sub _testTls
 	) ;
 	my %server_args = (
 		Log => 1 ,
+		LogFile => 1 ,
 		Verbose => 1 ,
 		Domain => 1 ,
 		Port => 1 ,
@@ -2162,8 +2267,8 @@ sub _testTls
 	$client->set_dst( $server_port ) ;
 	Check::ok( $server->run( \%server_args ) , "failed to start" , $server->message() ) ;
 	$client->run( \%client_args ) ;
-	my $client_log = $client->stderr() ;
-	my $server_log = $server->stderr() ;
+	my $client_log = $client->log() ;
+	my $server_log = $server->log() ;
 
 	# test
 	if( $special == 1 )
@@ -2332,11 +2437,14 @@ while( <$f> )
 # special command-line commands
 if( scalar(@ARGV) == 1 && $ARGV[0] eq "list" )
 {
+	# "list" to list the test names
 	print join("\n",(@tests,"")) ;
 	exit 0 ;
 }
 if( scalar(@ARGV) == 4 && $ARGV[0] eq "fixup" )
 {
+	# "fixup" to edit the makefile
+	# eg: emailrelay_test.pl fixup Makefile.am.in Makefile.am TESTING_TESTS
 	my ( $fixup , $makefile_in , $makefile_out , $marker ) = @ARGV ;
 	my $value = join(".test \\\n\t",@tests) . ".test" ;
 	my $fh_in = new FileHandle( $makefile_in , "r" ) or die "error: cannot open [$makefile_in]\n" ;
diff --git a/test/emailrelay-test.sh b/test/emailrelay_test.sh
similarity index 52%
rename from test/emailrelay-test.sh
rename to test/emailrelay_test.sh
index c125c1e..17f3dd9 100755
--- a/test/emailrelay-test.sh
+++ b/test/emailrelay_test.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -16,19 +16,35 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 # ===
 #
-# emailrelay-test.sh
+# emailrelay_test.sh
 #
-# Tests the E-MailRelay system using "emailrelay-test.pl".
+# Tests the E-MailRelay system using "emailrelay_test.pl" or some other
+# shell script that takes "-d <exe-dir>".
 #
-# usage: emailrelay-test.sh [-q] [<perl-script-options>] [<test-name> ...]
+# usage:
+#    emailrelay_test.sh [-q] [<perl-script-options>] [<test-name> ...]
+#    emailrelay_test.sh --sh <test-script>
 #
 
+this_dir="`cd \`dirname \"$0\"\` && pwd`"
+
+# run another shell script if asked
+if test "$1" = "--sh"
+then
+	shift
+	script="$1"
+	shift
+	buildroot="`cd .. && pwd`"
+	exec "$script" -d "$buildroot" "$@"
+	exit 1
+fi
+
 # test for perl
 perl -e "use Carp; use FileHandle; use Getopt::Std; use IO::Socket; use IO::Select; exit(99);" 2>/dev/null
 rc=$?
 if test $rc -ne 99
 then
-	echo `basename $0`: no perl, or missing perl modules >&2
+	echo `basename $0`: warning: no perl, or missing perl modules: skipping all tests >&2
 	exit 77 # for automake
 fi
 
@@ -36,19 +52,30 @@ fi
 quiet=0
 if test "$1" = "-q"
 then
-	# no shift - pass it on
+	# no shift here - pass it on
 	quiet=1
 fi
 
-# run the tests
-if test -z "$srcdir" ; then srcdir="`cd \`dirname \"$0\"\` && pwd`" ; fi
-chmod +x "$0" "$srcdir/emailrelay-test.pl" 2>/dev/null
+# check the perl script
+if test -z "$srcdir"
+then
+	srcdir="$this_dir"
+fi
+perl_script="$srcdir/emailrelay_test.pl"
+chmod +x "$0" "$perl_script" 2>/dev/null
+if test ! -e "$perl_script"
+then
+	echo `basename $0`: error: no perl script: "$perl_script" >&2
+	exit 1
+fi
+
+# run the emailrelay_test.pl tests
 if sh -c "true </dev/tty" 2>/dev/null
 then
 	# redirect stdin because "make -j" and "openssl s_server"
-	perl -I"${srcdir}" "$srcdir/emailrelay-test.pl" "$@" </dev/tty
+	perl -I"${srcdir}" "$perl_script" "$@" </dev/tty
 else
-	perl -I"${srcdir}" "$srcdir/emailrelay-test.pl" "$@"
+	perl -I"${srcdir}" "$perl_script" "$@"
 fi
 rc=$?
 
diff --git a/test/emailrelay_test_client.cpp b/test/emailrelay_test_client.cpp
index 2d4d0b4..7371efc 100644
--- a/test/emailrelay_test_client.cpp
+++ b/test/emailrelay_test_client.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -24,15 +24,17 @@
 // of email messages on each one in turn.
 //
 // usage:
-//      emailrelay-test-client [-qQ] [-v [-v]] [<port>]
-//      emailrelay-test-client [-qQ] [-v [-v]] <addr-ipv4> <port> [<connections> [<iterations> [<lines> [<line-length> [<messages>]]]]]
+//      emailrelay_test_client [-qQ] [-v [-v]] [<port>]
+//      emailrelay_test_client [-qQ] [-v [-v]] <addr-ipv4> <port> [<connections> [<iterations> [<lines> [<line-length> [<messages>]]]]]
 //         -v -- verbose logging
 //         -q -- send "."&"QUIT" instead of "."
 //         -Q -- send "."&"QUIT" and immediately disconnect
+//         -s -- slow (if connections is 1)
 //
 
 #define _WINSOCK_DEPRECATED_NO_WARNINGS
 #include "gdef.h"
+#include "gsleep.h"
 #include <cstring> // std::size_t
 #include <iostream>
 #include <string>
@@ -49,6 +51,7 @@
 int cfg_verbosity = 0 ;
 bool cfg_eager_quit = false ;
 bool cfg_eager_quit_disconnect = false ;
+bool cfg_slow = false ;
 
 #ifdef _WIN32
 using read_size_type = int ;
@@ -99,6 +102,7 @@ public:
 	bool runSome() ;
 	bool done() const ;
 	void close() ;
+	bool errors() const ;
 
 private:
 	void connect( const Address & ) ;
@@ -109,12 +113,15 @@ private:
 	void sendMessage( int , int , bool ) ;
 	static void close_( SOCKET fd ) ;
 	static void shutdown( SOCKET fd ) ;
+
+private:
 	SOCKET m_fd ;
 	int m_messages{0} ;
 	int m_lines{0} ;
 	int m_line_length{0} ;
 	int m_state{0} ;
 	bool m_done{false} ;
+	std::size_t m_errors{0U} ; // unexpected protocol responses
 } ;
 
 Test::Test()
@@ -228,19 +235,33 @@ void Test::waitline( const char * match )
 		else if( c == '\n' ) line.append( "\\n" ) ;
 		else line.append( 1U , c ) ;
 	}
+	bool ok =
+		line.find("250 ") == 0U ||
+		line.find("250-") == 0U ||
+		line.find("220 ") == 0U ||
+		line.find("354 ") == 0U ;
+	if( !ok )
+		m_errors++ ;
 	if( cfg_verbosity )
-		std::cout << m_fd << ": rx<<: [" << line << "]" << std::endl ;
+		std::cout << m_fd << ": rx<<: [" << line << "]" << (ok?"":" ** ERROR **") << std::endl ;
+}
+
+bool Test::errors() const
+{
+	return m_errors != 0U ;
 }
 
 void Test::send( const char * p )
 {
 	if( cfg_verbosity ) std::cout << m_fd << ": tx>>: [" << std::string(p,strcspn(p,"\r\n")) << "]" << std::endl ;
+	if( cfg_slow ) sleep( 1 ) ;
 	::send( m_fd , p , static_cast<send_size_type>(std::strlen(p)) , 0 ) ;
 }
 
 void Test::send( const char * p , std::size_t n )
 {
 	if( cfg_verbosity > 1 ) std::cout << m_fd << ": tx>>: [<" << n << " bytes>]" << std::endl ;
+	if( cfg_slow ) sleep( 1 ) ;
 	::send( m_fd , p , static_cast<send_size_type>(n) , 0 ) ;
 }
 
@@ -299,12 +320,13 @@ int main( int argc , char * argv [] )
 			return 0 ;
 		}
 
-		while( argc > 1 && argv[1][0] == '-' && (argv[1][1] == 'v' || argv[1][1] == 'q' || argv[1][1] == 'Q') )
+		while( argc > 1 && argv[1][0] == '-' && (argv[1][1] == 'v' || argv[1][1] == 'q' || argv[1][1] == 'Q' || argv[1][1] == 's') )
 		{
 			char c = argv[1][1] ;
 			if( c == 'v' ) cfg_verbosity++ ;
 			if( c == 'q' ) cfg_eager_quit = true ;
 			if( c == 'Q' ) cfg_eager_quit = cfg_eager_quit_disconnect = true ;
+			if( c == 's' ) cfg_slow = true ;
 			for( int i = 1 ; (i+1) <= argc ; i++ )
 				argv[i] = argv[i+1] ;
 			argc-- ;
@@ -348,6 +370,7 @@ int main( int argc , char * argv [] )
 			std::cout << "messages-per-connection: " << messages << std::endl ;
 		}
 
+		bool errors = false ;
 		for( int i = 0 ; iterations < 0 || i < iterations ; i++ )
 		{
 			std::vector<Test> test( connections ) ;
@@ -367,13 +390,18 @@ int main( int argc , char * argv [] )
 			{
 				t.close() ;
 			}
+			if( std::any_of( test.begin() , test.end() , [](Test &t){return t.errors();} ) )
+				errors = true ;
 		}
+		if( errors )
+			throw std::runtime_error( "got some error responses" ) ;
 
+		std::cerr << "done" << std::endl ;
 		return 0 ;
 	}
 	catch( std::exception & e )
 	{
-		std::cerr << "exception: " << e.what() << std::endl ;
+		std::cerr << "ERROR: " << e.what() << std::endl ;
 	}
 	return 1 ;
 }
diff --git a/test/emailrelay_test_keygen.cpp b/test/emailrelay_test_keygen.cpp
index 65305e2..a2b5f82 100644
--- a/test/emailrelay_test_keygen.cpp
+++ b/test/emailrelay_test_keygen.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
diff --git a/test/emailrelay_test_scanner.cpp b/test/emailrelay_test_scanner.cpp
index af2831c..6cea0b8 100644
--- a/test/emailrelay_test_scanner.cpp
+++ b/test/emailrelay_test_scanner.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -19,7 +19,7 @@
 ///
 // A dummy network processor for testing "emailrelay --filter net:<host>:<port>".
 //
-// usage: emailrelay-test-scanner [--port <port-or-address>] [--log] [--log-file <file>] [--debug] [--pid-file <pidfile>]
+// usage: emailrelay_test_scanner [--port <port-or-address>] [--log] [--log-file <file>] [--debug] [--pid-file <pidfile>]
 //
 // Listens on port 10020 by default. Each request is a 'content' filename
 // and the file should contain a mini script with commands of:
@@ -40,6 +40,7 @@
 #include "gtimerlist.h"
 #include "gfile.h"
 #include "gprocess.h"
+#include "gscope.h"
 #include "gstr.h"
 #include "garg.h"
 #include "gfile.h"
@@ -59,7 +60,7 @@ namespace Main
 class Main::ScannerPeer : public GNet::ServerPeer
 {
 public:
-	ScannerPeer( GNet::ExceptionSinkUnbound esu , GNet::ServerPeerInfo ) ;
+	ScannerPeer( GNet::ExceptionSinkUnbound esu , GNet::ServerPeerInfo && ) ;
 private:
 	void onDelete( const std::string & ) override ;
 	bool onReceive( const char * , std::size_t , std::size_t , std::size_t , char ) override ;
@@ -68,10 +69,10 @@ private:
 	bool processFile( std::string , std::string ) ;
 } ;
 
-Main::ScannerPeer::ScannerPeer( GNet::ExceptionSinkUnbound esu , GNet::ServerPeerInfo peer_info ) :
+Main::ScannerPeer::ScannerPeer( GNet::ExceptionSinkUnbound esu , GNet::ServerPeerInfo && peer_info ) :
 	ServerPeer(esu.bind(this),std::move(peer_info),GNet::LineBufferConfig::autodetect())
 {
-	G_LOG_S( "ScannerPeer::ctor: new connection from " << peerAddress().second.displayString() ) ;
+	G_LOG_S( "ScannerPeer::ctor: new connection from " << peerAddress().displayString() ) ;
 }
 
 void Main::ScannerPeer::onDelete( const std::string & )
@@ -151,7 +152,7 @@ bool Main::ScannerPeer::processFile( std::string path , std::string eol )
 		}
 		if( line.find("shutdown") == 0U )
 		{
-			socket().shutdown() ;
+			socket().shutdown() ; // no more sends (FIN)
 		}
 		if( line.find("disconnect") == 0U )
 		{
@@ -185,11 +186,13 @@ class Main::Scanner : public GNet::Server
 public:
 	Scanner( GNet::ExceptionSink , const GNet::Address & , unsigned int idle_timeout ) ;
 	~Scanner() override ;
-	std::unique_ptr<GNet::ServerPeer> newPeer( GNet::ExceptionSinkUnbound ebu , GNet::ServerPeerInfo ) override ;
+	std::unique_ptr<GNet::ServerPeer> newPeer( GNet::ExceptionSinkUnbound ebu , GNet::ServerPeerInfo && ) override ;
 } ;
 
 Main::Scanner::Scanner( GNet::ExceptionSink es , const GNet::Address & address , unsigned int idle_timeout ) :
-	GNet::Server(es,address,GNet::ServerPeerConfig(idle_timeout),GNet::ServerConfig())
+	GNet::Server(es,address,
+		GNet::ServerPeer::Config().set_idle_timeout(idle_timeout),
+		GNet::Server::Config().set_uds_open_permissions())
 {
 	G_LOG_S( "Scanner::ctor: listening on " << address.displayString() ) ;
 }
@@ -199,11 +202,11 @@ Main::Scanner::~Scanner()
 	serverCleanup() ; // base class early cleanup
 }
 
-std::unique_ptr<GNet::ServerPeer> Main::Scanner::newPeer( GNet::ExceptionSinkUnbound ebu , GNet::ServerPeerInfo peer_info )
+std::unique_ptr<GNet::ServerPeer> Main::Scanner::newPeer( GNet::ExceptionSinkUnbound ebu , GNet::ServerPeerInfo && peer_info )
 {
 	try
 	{
-		return std::unique_ptr<GNet::ServerPeer>( new ScannerPeer( ebu , peer_info ) ) ;
+		return std::unique_ptr<GNet::ServerPeer>( new ScannerPeer( ebu , std::move(peer_info) ) ) ;
 	}
 	catch( std::exception & e )
 	{
@@ -226,6 +229,7 @@ static int run( const GNet::Address & address , unsigned int idle_timeout )
 
 int main( int argc , char * argv [] )
 {
+	std::string pid_file ;
 	try
 	{
 		G::Arg arg( argc , argv ) ;
@@ -233,7 +237,7 @@ int main( int argc , char * argv [] )
 		bool debug = arg.remove("--debug") ;
 		std::string log_file = arg.index("--log-file",1U) ? arg.v(arg.index("--log-file",1U)+1U) : std::string() ;
 		std::string port_str = arg.index("--port",1U) ? arg.v(arg.index("--port",1U)+1U) : std::string("10020") ;
-		std::string pid_file = arg.index("--pid-file",1U) ? arg.v(arg.index("--pid-file",1U)+1U) : std::string() ;
+		pid_file = arg.index("--pid-file",1U) ? arg.v(arg.index("--pid-file",1U)+1U) : std::string() ;
 		unsigned int idle_timeout = 10U ;
 
 		GNet::Address address = G::Str::isNumeric(port_str) ?
@@ -258,6 +262,7 @@ int main( int argc , char * argv [] )
 
 		int rc = run( address , idle_timeout ) ;
 		std::cout << "done" << std::endl ;
+		std::remove( pid_file.c_str() ) ;
 		return rc ;
 	}
 	catch( std::exception & e )
@@ -268,6 +273,7 @@ int main( int argc , char * argv [] )
 	{
 		std::cerr << "exception\n" ;
 	}
+	std::remove( pid_file.c_str() ) ;
 	return 1 ;
 }
 
diff --git a/test/emailrelay_test_server.cpp b/test/emailrelay_test_server.cpp
index 3a8f7e1..562a3a5 100644
--- a/test/emailrelay_test_server.cpp
+++ b/test/emailrelay_test_server.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -19,7 +19,7 @@
 ///
 // A dummy smtp server for testing purposes.
 //
-// usage: emailrelay-test-server [--quiet] [--tls] [--auth-foo-bar] [--auth-cram] [--auth-login] [--auth-plain]
+// usage: emailrelay_test_server [--quiet] [--tls] [--auth-foo-bar] [--auth-cram] [--auth-login] [--auth-plain]
 //        [--auth-ok] [--slow] [--fail-at <n>] [--drop] [--ipv6] [--port <port>]
 //
 
@@ -31,6 +31,7 @@
 #include "gstr.h"
 #include "garg.h"
 #include "ggetopt.h"
+#include "goptionsusage.h"
 #include "gpath.h"
 #include "gserver.h"
 #include "gserverpeer.h"
@@ -59,7 +60,7 @@ namespace
 	}
 }
 
-struct Config
+struct TestServerConfig
 {
 	bool m_ipv6 ;
 	unsigned int m_port ;
@@ -74,7 +75,7 @@ struct Config
 	bool m_tls ;
 	bool m_quiet ;
 	unsigned int m_idle_timeout ;
-	Config( bool ipv6 , unsigned int port , bool auth_foo_bar , bool auth_cram , bool auth_login , bool auth_plain ,
+	TestServerConfig( bool ipv6 , unsigned int port , bool auth_foo_bar , bool auth_cram , bool auth_login , bool auth_plain ,
 		bool auth_ok , bool slow , int fail_at , bool drop , bool tls , bool quiet , unsigned int idle_timeout ) :
 			m_ipv6(ipv6) ,
 			m_port(port) ,
@@ -96,7 +97,7 @@ struct Config
 class Peer : public GNet::ServerPeer
 {
 public:
-	Peer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo , Config ) ;
+	Peer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo && , TestServerConfig ) ;
 	void onDelete( const std::string & ) override ;
 	void onSendComplete() override ;
 	bool onReceive( const char * , std::size_t , std::size_t , std::size_t , char ) override ;
@@ -108,7 +109,7 @@ private:
 
 private:
 	GNet::ExceptionSink m_es ;
-	Config m_config ;
+	TestServerConfig m_config ;
 	GNet::Timer<Peer> m_slow_timer ;
 	bool m_in_data ;
 	bool m_in_auth_1 ;
@@ -119,18 +120,21 @@ private:
 class Server : public GNet::Server
 {
 public:
-	Server( GNet::ExceptionSink , Config c ) ;
+	Server( GNet::ExceptionSink , TestServerConfig ) ;
 	~Server() override ;
-	std::unique_ptr<GNet::ServerPeer> newPeer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo ) override ;
-	Config m_config ;
+	std::unique_ptr<GNet::ServerPeer> newPeer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo && ) override ;
+	TestServerConfig m_config ;
 } ;
 
-Server::Server( GNet::ExceptionSink es , Config config ) :
-	GNet::Server(es,GNet::Address(config.m_ipv6?GNet::Address::Family::ipv6:GNet::Address::Family::ipv4,config.m_port),GNet::ServerPeerConfig(config.m_idle_timeout),GNet::ServerConfig()) ,
+Server::Server( GNet::ExceptionSink es , TestServerConfig config ) :
+	GNet::Server(es,
+		GNet::Address(config.m_ipv6?GNet::Address::Family::ipv6:GNet::Address::Family::ipv4,config.m_port),
+		GNet::ServerPeer::Config()
+			.set_socket_protocol_config( GNet::SocketProtocol::Config().set_read_buffer_size(config.m_slow?3U:G::limits::net_buffer) )
+			.set_idle_timeout(config.m_idle_timeout),
+		GNet::Server::Config()) ,
 	m_config(config)
 {
-	if( m_config.m_slow )
-		GNet::SocketProtocol::setReadBufferSize( 3U ) ;
 }
 
 Server::~Server()
@@ -138,12 +142,12 @@ Server::~Server()
 	serverCleanup() ; // base class early cleanup
 }
 
-std::unique_ptr<GNet::ServerPeer> Server::newPeer( GNet::ExceptionSinkUnbound esu , GNet::ServerPeerInfo info )
+std::unique_ptr<GNet::ServerPeer> Server::newPeer( GNet::ExceptionSinkUnbound esu , GNet::ServerPeerInfo && peer_info )
 {
 	try
 	{
-		G_LOG_S( "Server::newPeer: new connection from " << info.m_address.displayString() ) ;
-		return std::unique_ptr<GNet::ServerPeer>( new Peer( esu , info , m_config ) ) ;
+		G_LOG_S( "Server::newPeer: new connection from " << peer_info.m_address.displayString() ) ;
+		return std::unique_ptr<GNet::ServerPeer>( new Peer( esu , std::move(peer_info) , m_config ) ) ;
 	}
 	catch( std::exception & e )
 	{
@@ -154,8 +158,8 @@ std::unique_ptr<GNet::ServerPeer> Server::newPeer( GNet::ExceptionSinkUnbound es
 
 //
 
-Peer::Peer( GNet::ExceptionSinkUnbound esu , GNet::ServerPeerInfo info , Config config ) :
-	GNet::ServerPeer(esu.bind(this),info,GNet::LineBufferConfig::smtp()) ,
+Peer::Peer( GNet::ExceptionSinkUnbound esu , GNet::ServerPeerInfo && peer_info , TestServerConfig config ) :
+	GNet::ServerPeer(esu.bind(this),std::move(peer_info),GNet::LineBufferConfig::smtp()) ,
 	m_es(esu.bind(this)) ,
 	m_config(config) ,
 	m_slow_timer(*this,&Peer::onSlowTimeout,m_es) ,
@@ -164,14 +168,14 @@ Peer::Peer( GNet::ExceptionSinkUnbound esu , GNet::ServerPeerInfo info , Config
 	m_in_auth_2(false) ,
 	m_message(0)
 {
-	send( "220 test server\r\n" ) ;
+	send( "220 test server\r\n"_sv ) ;
 	if( m_config.m_slow )
 		m_slow_timer.startTimer( 0U ) ;
 }
 
 void Peer::onSlowTimeout()
 {
-	sleep_ms( 800 ) ;
+	sleep_ms( 10 ) ;
 	m_slow_timer.startTimer( 0U , 10 ) ;
 }
 
@@ -308,11 +312,13 @@ bool Peer::onReceive( const char * line_data , std::size_t line_size , std::size
 
 void Peer::tx( const std::string & s )
 {
-	std::string ss( s ) ;
-	G::Str::trimRight( ss , "\n\r" ) ;
 	if( !m_config.m_quiet )
+	{
+		std::string ss( s ) ;
+		G::Str::trimRight( ss , "\n\r" ) ;
 		std::cout << "tx>>: [" << ss << "]" << std::endl ;
-	send( s ) ;
+	}
+	send( s ) ; // GNet::ServerPeer::send()
 }
 
 //
@@ -346,7 +352,7 @@ int main( int argc , char * argv [] )
 		}
 		if( opt.contains("help") )
 		{
-			opt.options().showUsage( {} , std::cout , arg.prefix() ) ;
+			G::OptionsUsage(opt.options()).output( {} , std::cout , arg.prefix() ) ;
 			return 0 ;
 		}
 
@@ -388,7 +394,7 @@ int main( int argc , char * argv [] )
 		std::unique_ptr<GNet::EventLoop> event_loop = GNet::EventLoop::create() ;
 		GNet::ExceptionSink es ;
 		GNet::TimerList timer_list ;
-		Server server( es , Config(ipv6,port,auth_foo_bar,auth_cram,auth_login,auth_plain,auth_ok,slow,fail_at,drop,tls,quiet,idle_timeout) ) ;
+		Server server( es , TestServerConfig(ipv6,port,auth_foo_bar,auth_cram,auth_login,auth_plain,auth_ok,slow,fail_at,drop,tls,quiet,idle_timeout) ) ;
 
 		event_loop->run() ;
 
diff --git a/test/emailrelay_test_verifier.cpp b/test/emailrelay_test_verifier.cpp
index b7eb9c1..80de546 100644
--- a/test/emailrelay_test_verifier.cpp
+++ b/test/emailrelay_test_verifier.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+// Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -19,7 +19,7 @@
 ///
 // A dummy network address verifier for testing "emailrelay --verifier net:<transport-address>".
 //
-// usage: emailrelay-test-verifier [--ipv6] [--port <port>] [--log] [--log-file <file>] [--debug] [--pid-file <pidfile>]
+// usage: emailrelay_test_verifier [--ipv6] [--port <port>] [--log] [--log-file <file>] [--debug] [--pid-file <pidfile>]
 //
 // The action of the verifier is dictated by special sub-strings in the
 // recipient:
@@ -42,6 +42,7 @@
 #include "gserverpeer.h"
 #include "gfile.h"
 #include "ggetopt.h"
+#include "goptionsusage.h"
 #include "garg.h"
 #include "gsleep.h"
 #include "glogoutput.h"
@@ -59,7 +60,7 @@ namespace Main
 class Main::VerifierPeer : public GNet::ServerPeer
 {
 public:
-	VerifierPeer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo info ) ;
+	VerifierPeer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo && ) ;
 private:
 	void onDelete( const std::string & ) override ;
 	bool onReceive( const char * , std::size_t , std::size_t , std::size_t , char ) override ;
@@ -68,10 +69,10 @@ private:
 	bool processLine( std::string ) ;
 } ;
 
-Main::VerifierPeer::VerifierPeer( GNet::ExceptionSinkUnbound ebu , GNet::ServerPeerInfo info ) :
-	GNet::ServerPeer( ebu.bind(this) , info , GNet::LineBufferConfig::newline() )
+Main::VerifierPeer::VerifierPeer( GNet::ExceptionSinkUnbound ebu , GNet::ServerPeerInfo && peer_info ) :
+	GNet::ServerPeer( ebu.bind(this) , std::move(peer_info) , GNet::LineBufferConfig::newline() )
 {
-	G_LOG_S( "VerifierPeer::ctor: new connection from " << info.m_address.displayString() ) ;
+	G_LOG_S( "VerifierPeer::ctor: new connection from " << peerAddress().displayString() ) ;
 }
 
 void Main::VerifierPeer::onDelete( const std::string & )
@@ -96,7 +97,7 @@ bool Main::VerifierPeer::processLine( std::string line )
 	G_LOG_S( "VerifierPeer::processLine: line: \"" << line << "\"" ) ;
 
 	G::StringArray part ;
-	G::Str::splitIntoFields( line , part , "|" ) ;
+	G::Str::splitIntoFields( line , part , '|' ) ;
 	std::string to = part.at(0U) ;
 
 	bool local = to.find("L") != std::string::npos ;
@@ -108,7 +109,7 @@ bool Main::VerifierPeer::processLine( std::string line )
 	if( abort )
 	{
 		G_LOG_S( "VerifierPeer::processLine: sending 100" ) ;
-		send( "100\n" ) ;
+		send( "100\n"_sv ) ; // GNet::ServerPeer::send()
 	}
 	else if( blackhole )
 	{
@@ -121,17 +122,17 @@ bool Main::VerifierPeer::processLine( std::string line )
 	else if( valid && local )
 	{
 		G_LOG_S( "VerifierPeer::processLine: sending postmaster" ) ;
-		send( "0|postmaster|Postmaster <postmaster@localhost>\n" ) ;
+		send( "0|postmaster|Postmaster <postmaster@localhost>\n"_sv ) ; // GNet::ServerPeer::send()
 	}
 	else if( valid )
 	{
 		G_LOG_S( "VerifierPeer::processLine: sending valid" ) ;
-		send( "1|" + to + "\n" ) ;
+		send( "1|" + to + "\n" ) ; // GNet::ServerPeer::send()
 	}
 	else
 	{
 		G_LOG_S( "VerifierPeer::processLine: sending error" ) ;
-		send( "2|VerifierError\n" ) ;
+		send( "2|VerifierError\n"_sv ) ; // GNet::ServerPeer::send()
 	}
 	return true ;
 }
@@ -143,11 +144,15 @@ class Main::Verifier : public GNet::Server
 public:
 	Verifier( GNet::ExceptionSink , bool ipv6 , unsigned int port , unsigned int idle_timeout ) ;
 	~Verifier() override ;
-	std::unique_ptr<GNet::ServerPeer> newPeer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo ) override ;
+	std::unique_ptr<GNet::ServerPeer> newPeer( GNet::ExceptionSinkUnbound , GNet::ServerPeerInfo && ) override ;
 } ;
 
 Main::Verifier::Verifier( GNet::ExceptionSink es , bool ipv6 , unsigned int port , unsigned int idle_timeout ) :
-	GNet::Server( es , GNet::Address(ipv6?GNet::Address::Family::ipv6:GNet::Address::Family::ipv4,port) , GNet::ServerPeerConfig(idle_timeout) , GNet::ServerConfig() )
+	GNet::Server(es,
+		GNet::Address(ipv6?GNet::Address::Family::ipv6:GNet::Address::Family::ipv4,port),
+		GNet::ServerPeer::Config()
+			.set_all_timeouts(idle_timeout),
+		GNet::Server::Config())
 {
 }
 
@@ -156,11 +161,11 @@ Main::Verifier::~Verifier()
 	serverCleanup() ; // base class early cleanup
 }
 
-std::unique_ptr<GNet::ServerPeer> Main::Verifier::newPeer( GNet::ExceptionSinkUnbound ebu , GNet::ServerPeerInfo info )
+std::unique_ptr<GNet::ServerPeer> Main::Verifier::newPeer( GNet::ExceptionSinkUnbound ebu , GNet::ServerPeerInfo && peer_info )
 {
 	try
 	{
-		return std::unique_ptr<GNet::ServerPeer>( new VerifierPeer( ebu , info ) ) ;
+		return std::unique_ptr<GNet::ServerPeer>( new VerifierPeer( ebu , std::move(peer_info) ) ) ;
 	}
 	catch( std::exception & e )
 	{
@@ -202,7 +207,7 @@ int main( int argc , char * argv [] )
 		}
 		if( opt.contains("help") )
 		{
-			opt.options().showUsage( {} , std::cout , arg.prefix() ) ;
+			G::OptionsUsage(opt.options()).output( {} , std::cout , arg.prefix() ) ;
 			return 0 ;
 		}
 		bool log = opt.contains("log") ;
diff --git a/unity/Makefile.am b/unity/Makefile.am
new file mode 100644
index 0000000..aba3b75
--- /dev/null
+++ b/unity/Makefile.am
@@ -0,0 +1,150 @@
+#
+## Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
+## 
+## This program is free software: you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation, either version 3 of the License, or
+## (at your option) any later version.
+## 
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+## 
+## You should have received a copy of the GNU General Public License
+## along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+#
+# Makefile.am
+#
+# By default this makefile does nothing.
+#
+# Optionally creates 'unity build' source files and builds them.
+#
+# Usage:
+#     make programs
+#
+# Also:
+#     make sources
+#     make tidy
+#
+# Unity builds might build faster and can result in better-optimised
+# executables. They can also make is easier to do static code
+# analysis.
+#
+
+if GCONFIG_GUI
+
+SOURCES_ = \
+	emailrelay.cpp \
+	emailrelay-passwd.cpp \
+	emailrelay-submit.cpp \
+	emailrelay-gui.cpp
+
+PROGRAMS_ = \
+	emailrelay \
+	emailrelay-passwd \
+	emailrelay-submit \
+	emailrelay-gui
+
+AM_CPPFLAGS = \
+	-D "G_SBINDIR=$(sbindir)" \
+	-D "G_SPOOLDIR=$(e_spooldir)" \
+	-D "G_INITDIR=$(e_initdir)" \
+	-D "G_SYSCONFDIR=$(e_sysconfdir)" \
+	-D "G_ICONDIR=$(e_icondir)" \
+	-D "G_LIBEXECDIR=$(e_libexecdir)" \
+	-D "G_MANDIR=$(mandir)" \
+	-D "G_DOCDIR=$(e_docdir)" \
+	-D "G_EXAMPLESDIR=$(e_examplesdir)" \
+	-I . \
+	$(GCONFIG_QT_CFLAGS)
+
+MOC = moc_guidialog.cpp moc_guipage.cpp moc_pages.cpp
+
+else
+
+SOURCES_ = \
+	emailrelay.cpp \
+	emailrelay-passwd.cpp \
+	emailrelay-submit.cpp
+
+PROGRAMS_ = \
+	emailrelay \
+	emailrelay-passwd \
+	emailrelay-submit
+
+AM_CPPFLAGS =
+
+MOC =
+
+endif
+
+IFLAGS = \
+	-I$(top_builddir)/src \
+	-I$(top_srcdir)/src/glib \
+	-I$(top_srcdir)/src/gssl \
+	-I$(top_srcdir)/src/gnet \
+	-I$(top_srcdir)/src/gauth \
+	-I$(top_srcdir)/src/gpop \
+	-I$(top_srcdir)/src/gsmtp \
+	-I$(top_srcdir)/src/win32 \
+	-I$(top_srcdir)/src/gui \
+	-I$(top_srcdir)/src/main
+
+CDB = compile_commands.json
+
+$(SOURCES_) $(CDB): Makefile Makefile.in
+	-chmod +x $(top_srcdir)/bin/make2unity || true
+	$(top_srcdir)/bin/make2unity --cdb --cdb-cxx="$(CXX)" --cdb-top=$(top_srcdir) --base=$(top_srcdir)/src $(SOURCES_)
+
+.PHONY: programs
+programs: $(PROGRAMS_)
+
+.PHONY: sources
+sources: $(SOURCES_)
+
+.PHONY: cdb
+cdb: $(CDB)
+
+.PHONY: moc
+moc: $(MOC)
+
+emailrelay: emailrelay.cpp
+	$(CXX) $(CXXFLAGS) $(CPPFLAGS) $(IFLAGS) -o $@ $< $(LIBS) $(GCONFIG_TLS_LIBS)
+	-strip $@
+
+emailrelay-submit: emailrelay-submit.cpp
+	$(CXX) $(CXXFLAGS) $(CPPFLAGS) $(IFLAGS) -o $@ $< $(LIBS) $(GCONFIG_TLS_LIBS)
+	-strip $@
+
+emailrelay-passwd: emailrelay-passwd.cpp
+	$(CXX) $(CXXFLAGS) $(CPPFLAGS) $(IFLAGS) -o $@ $< $(LIBS) $(GCONFIG_TLS_LIBS)
+	-strip $@
+
+emailrelay-gui: emailrelay-gui.cpp $(MOC)
+	$(CXX) $(AM_CPPFLAGS) $(CXXFLAGS) $(CPPFLAGS) $(IFLAGS) -o $@ $< $(LIBS) $(GCONFIG_TLS_LIBS) $(GCONFIG_QT_LIBS)
+	-strip $@
+
+moc_guidialog.cpp: $(top_srcdir)/src/gui/guidialog.h
+	$(GCONFIG_QT_MOC) $< -o $@
+
+moc_guipage.cpp: $(top_srcdir)/src/gui/guipage.h
+	$(GCONFIG_QT_MOC) $< -o $@
+
+moc_pages.cpp: $(top_srcdir)/src/gui/pages.h
+	$(GCONFIG_QT_MOC) $< -o $@
+
+.PHONY: tidy
+tidy: emailrelay.cpp .clang-tidy $(CDB)
+	clang-tidy emailrelay.cpp
+
+.PHONY: tidygui
+tidygui: emailrelay.cpp .clang-tidy $(CDB) $(MOC)
+	clang-tidy emailrelay-gui.cpp
+
+.clang-tidy:
+	cp $(top_srcdir)/src/.clang-tidy .
+
+CLEANFILES = $(SOURCES_) $(PROGRAMS_) $(CDB) .clang-tidy $(MOC)
+
diff --git a/unity/Makefile.in b/unity/Makefile.in
new file mode 100644
index 0000000..ed821a5
--- /dev/null
+++ b/unity/Makefile.in
@@ -0,0 +1,565 @@
+# Makefile.in generated by automake 1.16.1 from Makefile.am.
+# @configure_input@
+
+# Copyright (C) 1994-2018 Free Software Foundation, Inc.
+
+# This Makefile.in is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY, to the extent permitted by law; without
+# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+# PARTICULAR PURPOSE.
+
+@SET_MAKE@
+
+#
+#
+#
+# Makefile.am
+#
+# By default this makefile does nothing.
+#
+# Optionally creates 'unity build' source files and builds them.
+#
+# Usage:
+#     make programs
+#
+# Also:
+#     make sources
+#     make tidy
+#
+# Unity builds might build faster and can result in better-optimised
+# executables. They can also make is easier to do static code
+# analysis.
+#
+VPATH = @srcdir@
+am__is_gnu_make = { \
+  if test -z '$(MAKELEVEL)'; then \
+    false; \
+  elif test -n '$(MAKE_HOST)'; then \
+    true; \
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+    true; \
+  else \
+    false; \
+  fi; \
+}
+am__make_running_with_option = \
+  case $${target_option-} in \
+      ?) ;; \
+      *) echo "am__make_running_with_option: internal error: invalid" \
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+  sane_makeflags=$$MAKEFLAGS; \
+  if $(am__is_gnu_make); then \
+    sane_makeflags=$$MFLAGS; \
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+      *\\[\ \	]*) \
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+PACKAGE_TARNAME = @PACKAGE_TARNAME@
+PACKAGE_URL = @PACKAGE_URL@
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+PATH_SEPARATOR = @PATH_SEPARATOR@
+PKG_CONFIG = @PKG_CONFIG@
+PKG_CONFIG_LIBDIR = @PKG_CONFIG_LIBDIR@
+PKG_CONFIG_PATH = @PKG_CONFIG_PATH@
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+QT_LIBS = @QT_LIBS@
+QT_LRELEASE = @QT_LRELEASE@
+QT_MOC = @QT_MOC@
+RANLIB = @RANLIB@
+SED = @SED@
+SET_MAKE = @SET_MAKE@
+SHELL = @SHELL@
+STRIP = @STRIP@
+VERSION = @VERSION@
+abs_builddir = @abs_builddir@
+abs_srcdir = @abs_srcdir@
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+docdir = @docdir@
+dvidir = @dvidir@
+e_bsdinitdir = @e_bsdinitdir@
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+e_examplesdir = @e_examplesdir@
+e_icondir = @e_icondir@
+e_initdir = @e_initdir@
+e_libexecdir = @e_libexecdir@
+e_pamdir = @e_pamdir@
+e_rundir = @e_rundir@
+e_spooldir = @e_spooldir@
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+mkdir_p = @mkdir_p@
+oldincludedir = @oldincludedir@
+pdfdir = @pdfdir@
+prefix = @prefix@
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+top_build_prefix = @top_build_prefix@
+top_builddir = @top_builddir@
+top_srcdir = @top_srcdir@
+@GCONFIG_GUI_FALSE@SOURCES_ = \
+@GCONFIG_GUI_FALSE@	emailrelay.cpp \
+@GCONFIG_GUI_FALSE@	emailrelay-passwd.cpp \
+@GCONFIG_GUI_FALSE@	emailrelay-submit.cpp
+
+@GCONFIG_GUI_TRUE@SOURCES_ = \
+@GCONFIG_GUI_TRUE@	emailrelay.cpp \
+@GCONFIG_GUI_TRUE@	emailrelay-passwd.cpp \
+@GCONFIG_GUI_TRUE@	emailrelay-submit.cpp \
+@GCONFIG_GUI_TRUE@	emailrelay-gui.cpp
+
+@GCONFIG_GUI_FALSE@PROGRAMS_ = \
+@GCONFIG_GUI_FALSE@	emailrelay \
+@GCONFIG_GUI_FALSE@	emailrelay-passwd \
+@GCONFIG_GUI_FALSE@	emailrelay-submit
+
+@GCONFIG_GUI_TRUE@PROGRAMS_ = \
+@GCONFIG_GUI_TRUE@	emailrelay \
+@GCONFIG_GUI_TRUE@	emailrelay-passwd \
+@GCONFIG_GUI_TRUE@	emailrelay-submit \
+@GCONFIG_GUI_TRUE@	emailrelay-gui
+
+@GCONFIG_GUI_FALSE@AM_CPPFLAGS = 
+@GCONFIG_GUI_TRUE@AM_CPPFLAGS = \
+@GCONFIG_GUI_TRUE@	-D "G_SBINDIR=$(sbindir)" \
+@GCONFIG_GUI_TRUE@	-D "G_SPOOLDIR=$(e_spooldir)" \
+@GCONFIG_GUI_TRUE@	-D "G_INITDIR=$(e_initdir)" \
+@GCONFIG_GUI_TRUE@	-D "G_SYSCONFDIR=$(e_sysconfdir)" \
+@GCONFIG_GUI_TRUE@	-D "G_ICONDIR=$(e_icondir)" \
+@GCONFIG_GUI_TRUE@	-D "G_LIBEXECDIR=$(e_libexecdir)" \
+@GCONFIG_GUI_TRUE@	-D "G_MANDIR=$(mandir)" \
+@GCONFIG_GUI_TRUE@	-D "G_DOCDIR=$(e_docdir)" \
+@GCONFIG_GUI_TRUE@	-D "G_EXAMPLESDIR=$(e_examplesdir)" \
+@GCONFIG_GUI_TRUE@	-I . \
+@GCONFIG_GUI_TRUE@	$(GCONFIG_QT_CFLAGS)
+
+@GCONFIG_GUI_FALSE@MOC = 
+@GCONFIG_GUI_TRUE@MOC = moc_guidialog.cpp moc_guipage.cpp moc_pages.cpp
+IFLAGS = \
+	-I$(top_builddir)/src \
+	-I$(top_srcdir)/src/glib \
+	-I$(top_srcdir)/src/gssl \
+	-I$(top_srcdir)/src/gnet \
+	-I$(top_srcdir)/src/gauth \
+	-I$(top_srcdir)/src/gpop \
+	-I$(top_srcdir)/src/gsmtp \
+	-I$(top_srcdir)/src/win32 \
+	-I$(top_srcdir)/src/gui \
+	-I$(top_srcdir)/src/main
+
+CDB = compile_commands.json
+CLEANFILES = $(SOURCES_) $(PROGRAMS_) $(CDB) .clang-tidy $(MOC)
+all: all-am
+
+.SUFFIXES:
+$(srcdir)/Makefile.in: @MAINTAINER_MODE_TRUE@ $(srcdir)/Makefile.am  $(am__configure_deps)
+	@for dep in $?; do \
+	  case '$(am__configure_deps)' in \
+	    *$$dep*) \
+	      ( cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh ) \
+	        && { if test -f $@; then exit 0; else break; fi; }; \
+	      exit 1;; \
+	  esac; \
+	done; \
+	echo ' cd $(top_srcdir) && $(AUTOMAKE) --gnu unity/Makefile'; \
+	$(am__cd) $(top_srcdir) && \
+	  $(AUTOMAKE) --gnu unity/Makefile
+Makefile: $(srcdir)/Makefile.in $(top_builddir)/config.status
+	@case '$?' in \
+	  *config.status*) \
+	    cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh;; \
+	  *) \
+	    echo ' cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__maybe_remake_depfiles)'; \
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+
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+	list='$(DISTFILES)'; \
+	  dist_files=`for file in $$list; do echo $$file; done | \
+	  sed -e "s|^$$srcdirstrip/||;t" \
+	      -e "s|^$$topsrcdirstrip/|$(top_builddir)/|;t"`; \
+	case $$dist_files in \
+	  */*) $(MKDIR_P) `echo "$$dist_files" | \
+			   sed '/\//!d;s|^|$(distdir)/|;s,/[^/]*$$,,' | \
+			   sort -u` ;; \
+	esac; \
+	for file in $$dist_files; do \
+	  if test -f $$file || test -d $$file; then d=.; else d=$(srcdir); fi; \
+	  if test -d $$d/$$file; then \
+	    dir=`echo "/$$file" | sed -e 's,/[^/]*$$,,'`; \
+	    if test -d "$(distdir)/$$file"; then \
+	      find "$(distdir)/$$file" -type d ! -perm -700 -exec chmod u+rwx {} \;; \
+	    fi; \
+	    if test -d $(srcdir)/$$file && test $$d != $(srcdir); then \
+	      cp -fpR $(srcdir)/$$file "$(distdir)$$dir" || exit 1; \
+	      find "$(distdir)/$$file" -type d ! -perm -700 -exec chmod u+rwx {} \;; \
+	    fi; \
+	    cp -fpR $$d/$$file "$(distdir)$$dir" || exit 1; \
+	  else \
+	    test -f "$(distdir)/$$file" \
+	    || cp -p $$d/$$file "$(distdir)/$$file" \
+	    || exit 1; \
+	  fi; \
+	done
+check-am: all-am
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+
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+	if test -z '$(STRIP)'; then \
+	  $(MAKE) $(AM_MAKEFLAGS) INSTALL_PROGRAM="$(INSTALL_STRIP_PROGRAM)" \
+	    install_sh_PROGRAM="$(INSTALL_STRIP_PROGRAM)" INSTALL_STRIP_FLAG=-s \
+	      install; \
+	else \
+	  $(MAKE) $(AM_MAKEFLAGS) INSTALL_PROGRAM="$(INSTALL_STRIP_PROGRAM)" \
+	    install_sh_PROGRAM="$(INSTALL_STRIP_PROGRAM)" INSTALL_STRIP_FLAG=-s \
+	    "INSTALL_PROGRAM_ENV=STRIPPROG='$(STRIP)'" install; \
+	fi
+mostlyclean-generic:
+
+clean-generic:
+	-test -z "$(CLEANFILES)" || rm -f $(CLEANFILES)
+
+distclean-generic:
+	-test -z "$(CONFIG_CLEAN_FILES)" || rm -f $(CONFIG_CLEAN_FILES)
+	-test . = "$(srcdir)" || test -z "$(CONFIG_CLEAN_VPATH_FILES)" || rm -f $(CONFIG_CLEAN_VPATH_FILES)
+
+maintainer-clean-generic:
+	@echo "This command is intended for maintainers to use"
+	@echo "it deletes files that may require special tools to rebuild."
+clean: clean-am
+
+clean-am: clean-generic mostlyclean-am
+
+distclean: distclean-am
+	-rm -f Makefile
+distclean-am: clean-am distclean-generic
+
+dvi: dvi-am
+
+dvi-am:
+
+html: html-am
+
+html-am:
+
+info: info-am
+
+info-am:
+
+install-data-am:
+
+install-dvi: install-dvi-am
+
+install-dvi-am:
+
+install-exec-am:
+
+install-html: install-html-am
+
+install-html-am:
+
+install-info: install-info-am
+
+install-info-am:
+
+install-man:
+
+install-pdf: install-pdf-am
+
+install-pdf-am:
+
+install-ps: install-ps-am
+
+install-ps-am:
+
+installcheck-am:
+
+maintainer-clean: maintainer-clean-am
+	-rm -f Makefile
+maintainer-clean-am: distclean-am maintainer-clean-generic
+
+mostlyclean: mostlyclean-am
+
+mostlyclean-am: mostlyclean-generic
+
+pdf: pdf-am
+
+pdf-am:
+
+ps: ps-am
+
+ps-am:
+
+uninstall-am:
+
+.MAKE: install-am install-strip
+
+.PHONY: all all-am check check-am clean clean-generic cscopelist-am \
+	ctags-am distclean distclean-generic distdir dvi dvi-am html \
+	html-am info info-am install install-am install-data \
+	install-data-am install-dvi install-dvi-am install-exec \
+	install-exec-am install-html install-html-am install-info \
+	install-info-am install-man install-pdf install-pdf-am \
+	install-ps install-ps-am install-strip installcheck \
+	installcheck-am installdirs maintainer-clean \
+	maintainer-clean-generic mostlyclean mostlyclean-generic pdf \
+	pdf-am ps ps-am tags-am uninstall uninstall-am
+
+.PRECIOUS: Makefile
+
+
+$(SOURCES_) $(CDB): Makefile Makefile.in
+	-chmod +x $(top_srcdir)/bin/make2unity || true
+	$(top_srcdir)/bin/make2unity --cdb --cdb-cxx="$(CXX)" --cdb-top=$(top_srcdir) --base=$(top_srcdir)/src $(SOURCES_)
+
+.PHONY: programs
+programs: $(PROGRAMS_)
+
+.PHONY: sources
+sources: $(SOURCES_)
+
+.PHONY: cdb
+cdb: $(CDB)
+
+.PHONY: moc
+moc: $(MOC)
+
+emailrelay: emailrelay.cpp
+	$(CXX) $(CXXFLAGS) $(CPPFLAGS) $(IFLAGS) -o $@ $< $(LIBS) $(GCONFIG_TLS_LIBS)
+	-strip $@
+
+emailrelay-submit: emailrelay-submit.cpp
+	$(CXX) $(CXXFLAGS) $(CPPFLAGS) $(IFLAGS) -o $@ $< $(LIBS) $(GCONFIG_TLS_LIBS)
+	-strip $@
+
+emailrelay-passwd: emailrelay-passwd.cpp
+	$(CXX) $(CXXFLAGS) $(CPPFLAGS) $(IFLAGS) -o $@ $< $(LIBS) $(GCONFIG_TLS_LIBS)
+	-strip $@
+
+emailrelay-gui: emailrelay-gui.cpp $(MOC)
+	$(CXX) $(AM_CPPFLAGS) $(CXXFLAGS) $(CPPFLAGS) $(IFLAGS) -o $@ $< $(LIBS) $(GCONFIG_TLS_LIBS) $(GCONFIG_QT_LIBS)
+	-strip $@
+
+moc_guidialog.cpp: $(top_srcdir)/src/gui/guidialog.h
+	$(GCONFIG_QT_MOC) $< -o $@
+
+moc_guipage.cpp: $(top_srcdir)/src/gui/guipage.h
+	$(GCONFIG_QT_MOC) $< -o $@
+
+moc_pages.cpp: $(top_srcdir)/src/gui/pages.h
+	$(GCONFIG_QT_MOC) $< -o $@
+
+.PHONY: tidy
+tidy: emailrelay.cpp .clang-tidy $(CDB)
+	clang-tidy emailrelay.cpp
+
+.PHONY: tidygui
+tidygui: emailrelay.cpp .clang-tidy $(CDB) $(MOC)
+	clang-tidy emailrelay-gui.cpp
+
+.clang-tidy:
+	cp $(top_srcdir)/src/.clang-tidy .
+
+# Tell versions [3.59,3.63) of GNU make to not export all variables.
+# Otherwise a system limit (for SysV at least) may be exceeded.
+.NOEXPORT:
diff --git a/winbuild.pl b/winbuild.pl
index 96a5e65..8931c1a 100644
--- a/winbuild.pl
+++ b/winbuild.pl
@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 #
-# Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
+# Copyright (C) 2001-2022 Graeme Walker <graeme_walker@users.sourceforge.net>
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -69,16 +69,18 @@ my $cmake_args = {
 } ;
 
 # version
-chomp( my $version = eval { FileHandle->new("VERSION")->gets() } || "2.3.1" ) ;
+chomp( my $version = eval { FileHandle->new("VERSION")->gets() } || "2.4" ) ;
 
 # makefile conditionals
 my %switches = (
 	GCONFIG_BSD => 0 ,
+	GCONFIG_DNSBL => 1 ,
 	GCONFIG_EPOLL => 0 ,
+	GCONFIG_GETTEXT => 0 ,
 	GCONFIG_GUI => 1 , # << zero if no qt libraries
+	GCONFIG_ICONV => 0 ,
 	GCONFIG_INSTALL_HOOK => 0 ,
 	GCONFIG_INTERFACE_NAMES => 1 ,
-	GCONFIG_IPV6 => 1 ,
 	GCONFIG_MAC => 0 ,
 	GCONFIG_PAM => 0 ,
 	GCONFIG_TESTING => 1 ,
@@ -86,6 +88,7 @@ my %switches = (
 	GCONFIG_TLS_USE_OPENSSL => 0 ,
 	GCONFIG_TLS_USE_BOTH => 0 ,
 	GCONFIG_TLS_USE_NONE => 0 ,
+	GCONFIG_UDS => 0 ,
 	GCONFIG_WINDOWS => 1 ,
 ) ;
 
@@ -152,6 +155,7 @@ warn "error: cannot find mbedtls source: please download from tls.mbed.org " .
 if( $no_cmake || $no_msbuild || $no_qt || $no_mbedtls )
 {
 	warn "error: missing prerequisites: please install the missing components" ,
+		( -f "winbuild.cfg" ? "" : " or use a winbuild.cfg configuration file" ) ,
 		( ($no_qt||$no_mbedtls) ? " or unset configuration items in winbuild.pl\n" : "\n" ) ;
 	die "error: missing prerequisites\n" unless ( scalar(@ARGV) > 0 && $ARGV[0] eq "mingw" ) ;
 }
@@ -309,30 +313,31 @@ sub create_cmake_file
 
 	# force static or dynamic linking of the c++ runtime by
 	# switching between /MD and /MT -- use static linking
-	# by default but keep the gui dynamically linked to
-	# avoid separate runtime states in Qt and non-Qt code --
-	# note that the gui code is self-contained by virtue
-	# of "glibsources.cpp"
+	# by default but keep the gui dynamically linked so that
+	# it can use the Qt binary distribution -- for public
+	# distribution of a statically linked gui program use
+	# "emailrelay-gui.pro" -- note that the gui build is
+	# self-contained by virtue of "glibsources.cpp"
 	#
 	my $dynamic_runtime = ( $m->path() =~ m/gui/ ) ;
 	{
 		print $fh '# choose dynamic or static linking of the c++ runtime' , "\n" ;
 		print $fh 'set(CompilerFlags' , "\n" ;
-        print $fh '    CMAKE_CXX_FLAGS' , "\n" ;
-        print $fh '    CMAKE_CXX_FLAGS_DEBUG' , "\n" ;
-        print $fh '    CMAKE_CXX_FLAGS_RELEASE' , "\n" ;
-        print $fh '    CMAKE_C_FLAGS' , "\n" ;
-        print $fh '    CMAKE_C_FLAGS_DEBUG' , "\n" ;
-        print $fh '    CMAKE_C_FLAGS_RELEASE' , "\n" ;
-        print $fh ')' , "\n" ;
+		print $fh '    CMAKE_CXX_FLAGS' , "\n" ;
+		print $fh '    CMAKE_CXX_FLAGS_DEBUG' , "\n" ;
+		print $fh '    CMAKE_CXX_FLAGS_RELEASE' , "\n" ;
+		print $fh '    CMAKE_C_FLAGS' , "\n" ;
+		print $fh '    CMAKE_C_FLAGS_DEBUG' , "\n" ;
+		print $fh '    CMAKE_C_FLAGS_RELEASE' , "\n" ;
+		print $fh ')' , "\n" ;
 		print $fh 'foreach(CompilerFlag ${CompilerFlags})' , "\n" ;
 		if( $dynamic_runtime )
 		{
-  			print $fh '    string(REPLACE "/MT" "/MD" ${CompilerFlag} "${${CompilerFlag}}")' , "\n" ;
+			print $fh '    string(REPLACE "/MT" "/MD" ${CompilerFlag} "${${CompilerFlag}}")' , "\n" ;
 		}
 		else
 		{
-  			print $fh '    string(REPLACE "/MD" "/MT" ${CompilerFlag} "${${CompilerFlag}}")' , "\n" ;
+			print $fh '    string(REPLACE "/MD" "/MT" ${CompilerFlag} "${${CompilerFlag}}")' , "\n" ;
 		}
 		print $fh 'endforeach()' , "\n" ;
 	}
@@ -344,7 +349,7 @@ sub create_cmake_file
 	}
 
 	my $definitions = join( " " , "G_WINDOWS=1" , $m->definitions() ) ;
-	my $includes = join( " " , "." , ".." , $m->includes($m->top()) , '"${MBEDTLS_INCLUDE_DIRS}"' ) ;
+	my $includes = join( " " , "." , ".." , $m->includes($m->base()) , '"${MBEDTLS_INCLUDE_DIRS}"' ) ;
 
 	my @libraries = $m->libraries() ;
 	for my $library ( @libraries )
@@ -372,9 +377,9 @@ sub create_cmake_file
 		{
 			if( ! $tls_libs_fixed )
 			{
-  				print $fh '    string(REPLACE "/Release" "/Debug" MBEDTLS_LIBRARY_DEBUG "${MBEDTLS_LIBRARY}")' , "\n" ;
-  				print $fh '    string(REPLACE "/Release" "/Debug" MBEDX509_LIBRARY_DEBUG "${MBEDX509_LIBRARY}")' , "\n" ;
-  				print $fh '    string(REPLACE "/Release" "/Debug" MBEDCRYPTO_LIBRARY_DEBUG "${MBEDCRYPTO_LIBRARY}")' , "\n" ;
+				print $fh '    string(REPLACE "/Release" "/Debug" MBEDTLS_LIBRARY_DEBUG "${MBEDTLS_LIBRARY}")' , "\n" ;
+				print $fh '    string(REPLACE "/Release" "/Debug" MBEDX509_LIBRARY_DEBUG "${MBEDX509_LIBRARY}")' , "\n" ;
+				print $fh '    string(REPLACE "/Release" "/Debug" MBEDCRYPTO_LIBRARY_DEBUG "${MBEDCRYPTO_LIBRARY}")' , "\n" ;
 				$tls_libs_fixed = 1 ;
 			}
 			$tls_libs =
@@ -606,14 +611,14 @@ sub install
 	if( $with_gui )
 	{
 		install_copy( "$arch/src/gui/Release/emailrelay-gui.exe" , "$install/emailrelay-setup.exe" ) ;
-		install_copy( "$arch/test/Release/emailrelay-test-keygen.exe" , "$install" ) ;
+		install_copy( "$arch/test/Release/emailrelay_test_keygen.exe" , "$install" ) ;
 
 		install_mkdir( "$install/payload" ) ;
 		install_payload_cfg( "$install/payload/payload.cfg" ) ;
 		install_core( "$arch/src/main/Release" , "$install/payload/files" ) ;
 
 		install_copy( "$arch/src/gui/Release/emailrelay-gui.exe" , "$install/payload/files" ) ;
-		install_copy( "$arch/test/Release/emailrelay-test-keygen.exe" , "$install/payload/files" ) ;
+		install_copy( "$arch/test/Release/emailrelay_test_keygen.exe" , "$install/payload/files" ) ;
 
 		install_gui_dependencies( $msvc_base , $arch ,
 			{ exe => "$install/emailrelay-setup.exe" } ,
@@ -680,7 +685,7 @@ sub install_mingw
 	{
 		my $fh = new FileHandle( "$install_mingw/emailrelay-submit-test.bat" , "w" ) or die ;
 		my $cmd = "\@echo off\r\n" ;
-		$cmd .= "emailrelay-submit.exe -n -s \@app --from postmaster " ;
+		$cmd .= "emailrelay-submit.exe -N -n -s \@app --from postmaster " ;
 		$cmd .= "-C U3ViamVjdDogdGVzdA== " ; # subject
 		$cmd .= "-C = " ;
 		$cmd .= "-C VGVzdCBtZXNzYWdl " ; # body
@@ -800,11 +805,11 @@ sub install_core
 		doc/forwardto.png doc
 		doc/whatisit.png doc
 		doc/serverclient.png doc
-    	doc/*.html doc
-    	doc/developer.txt doc
-    	doc/reference.txt doc
-    	doc/userguide.txt doc
-    	doc/windows.txt doc
+		doc/*.html doc
+		doc/developer.txt doc
+		doc/reference.txt doc
+		doc/userguide.txt doc
+		doc/windows.txt doc
 		doc/windows.txt readme-windows.txt
 		doc/doxygen-missing.html doc/doxygen/index.html
 	) ;
@@ -842,8 +847,7 @@ sub run_tests
 {
 	my ( $main_bin_dir , $test_bin_dir ) = @_ ;
 	my $dash_v = "" ; # or "-v"
-	my $script = "test/emailrelay-test.pl" ;
-	## $script = ( $script."_") if ! -f $script ;
+	my $script = "test/emailrelay_test.pl" ;
 	system( "perl -Itest \"$script\" $dash_v -d \"$main_bin_dir\" -x \"$test_bin_dir\" -c \"test/certificates\"" ) ;
 }