tigervnc: restore vncserver script

[Thomas Klausner <tk%giga.or.at@localhost>]

Module Name:	pkgsrc-wip
Committed By:	Thomas Klausner <tk%giga.or.at@localhost>
Pushed By:	wiz
Date:		Sun May 16 23:01:32 2021 +0200
Changeset:	3c1cadaa9170d6005a33bc16d29d2774e214ce02

Modified Files:
	tigervnc/Makefile
	tigervnc/PLIST
Added Files:
	tigervnc/files/vncserver.pl

Log Message:
tigervnc: restore vncserver script

This is not supported by upstream any longer, but the upstream
default way is now systemd...

Use the copy from FreeBSD ports (which is based on the code
previously distributed with tigervnc).

Fix config file installation paths while here.

To see a diff of this commit:
https://wip.pkgsrc.org/cgi-bin/gitweb.cgi?p=pkgsrc-wip.git;a=commitdiff;h=3c1cadaa9170d6005a33bc16d29d2774e214ce02

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

diffstat:
 tigervnc/Makefile           |  18 +
 tigervnc/PLIST              |   9 +-
 tigervnc/files/vncserver.pl | 898 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 921 insertions(+), 4 deletions(-)

diffs:
diff --git a/tigervnc/Makefile b/tigervnc/Makefile
index f67265054c..f74cd52da1 100644
--- a/tigervnc/Makefile
+++ b/tigervnc/Makefile
@@ -49,10 +49,12 @@ SUBST_SED.hpath+=	-e 's|/usr/local/vnc/classes|${PREFIX}/share/vnc/classes|g'
 SUBST_VARS.hpath+=	PREFIX X11BASE
 
 REPLACE_PERL+=	unix/vncserver
+REPLACE_PERL+=	vncserver.pl
 
 post-extract:
 	cd ${WRKDIR} && ${EXTRACTOR} ${_DISTDIR}/${XORG_SERVER_FILE}.tar.bz2
 	cp -r ${WRKDIR}/${XORG_SERVER_FILE}/* ${WRKSRC}/unix/xserver
+	cp ${FILESDIR}/vncserver.pl ${WRKSRC}
 
 post-patch:
 	cd ${WRKSRC}/unix/xserver && ${PATCH} --batch -p1 <../xserver120.patch
@@ -80,6 +82,22 @@ XORG_CONFIGURE_ARGS+=	--disable-config-hal --disable-config-udev --with-pic
 XORG_CONFIGURE_ARGS+=	--disable-unit-tests --disable-devel-docs --disable-selective-werror
 XORG_CONFIGURE_ARGS+=	--disable-dri --enable-dri2 --disable-dri3 --enable-glx --enable-glx-tls
 
+EGDIR=			share/examples/tigervnc
+INSTALLATION_DIRS+=	${EGDIR}
+MAKE_DIRS+=		${PKG_SYSCONFDIR}/pam.d
+MAKE_DIRS+=		${PKG_SYSCONFDIR}/tigervnc
+CONF_FILES+=		${EGDIR}/tigervnc ${PKG_SYSCONFDIR}/pam.d/tigervnc
+CONF_FILES+=		${EGDIR}/vncserver-config-defaults ${PKG_SYSCONFDIR}/tigervnc/vncserver-config-defaults
+CONF_FILES+=		${EGDIR}/vncserver-config-mandatory ${PKG_SYSCONFDIR}/tigervnc/vncserver-config-mandatory
+CONF_FILES+=		${EGDIR}/vncserver.users ${PKG_SYSCONFDIR}/tigervnc/vncserver.users
+
+post-install:
+	${INSTALL_SCRIPT} ${WRKSRC}/vncserver.pl ${DESTDIR}${PREFIX}/bin/vncserver
+	${MV} ${DESTDIR}${PREFIX}/etc/pam.d/tigervnc ${DESTDIR}${PREFIX}/${EGDIR}
+	${MV} ${DESTDIR}${PREFIX}/etc/tigervnc/vncserver-config-defaults ${DESTDIR}${PREFIX}/${EGDIR}
+	${MV} ${DESTDIR}${PREFIX}/etc/tigervnc/vncserver-config-mandatory ${DESTDIR}${PREFIX}/${EGDIR}
+	${MV} ${DESTDIR}${PREFIX}/etc/tigervnc/vncserver.users ${DESTDIR}${PREFIX}/${EGDIR}
+
 .include "../../mk/bsd.prefs.mk"
 
 .if ${X11_TYPE} != "modular"
diff --git a/tigervnc/PLIST b/tigervnc/PLIST
index 43de4486b7..b7fce12a8f 100644
--- a/tigervnc/PLIST
+++ b/tigervnc/PLIST
@@ -2,12 +2,9 @@
 bin/Xvnc
 bin/vncconfig
 bin/vncpasswd
+bin/vncserver
 bin/vncviewer
 bin/x0vncserver
-etc/pam.d/tigervnc
-etc/tigervnc/vncserver-config-defaults
-etc/tigervnc/vncserver-config-mandatory
-etc/tigervnc/vncserver.users
 lib/systemd/system/vncserver@.service
 lib/xorg/modules/extensions/libvnc.la
 libexec/vncserver
@@ -23,6 +20,10 @@ sbin/vncsession
 share/applications/vncviewer.desktop
 share/doc/tigervnc/LICENCE.TXT
 share/doc/tigervnc/README.rst
+share/examples/tigervnc/tigervnc
+share/examples/tigervnc/vncserver-config-defaults
+share/examples/tigervnc/vncserver-config-mandatory
+share/examples/tigervnc/vncserver.users
 share/icons/hicolor/16x16/apps/tigervnc.png
 share/icons/hicolor/22x22/apps/tigervnc.png
 share/icons/hicolor/24x24/apps/tigervnc.png
diff --git a/tigervnc/files/vncserver.pl b/tigervnc/files/vncserver.pl
new file mode 100644
index 0000000000..e8bea40332
--- /dev/null
+++ b/tigervnc/files/vncserver.pl
@@ -0,0 +1,898 @@
+#!/usr/bin/env perl
+#
+#  Copyright (C) 2009-2010 D. R. Commander.  All Rights Reserved.
+#  Copyright (C) 2005-2006 Sun Microsystems, Inc.  All Rights Reserved.
+#  Copyright (C) 2002-2003 Constantin Kaplinsky.  All Rights Reserved.
+#  Copyright (C) 2002-2005 RealVNC Ltd.
+#  Copyright (C) 1999 AT&T Laboratories Cambridge.  All Rights Reserved.
+#
+#  This 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 2 of the License, or
+#  (at your option) any later version.
+#
+#  This software 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 software; if not, write to the Free Software
+#  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+#  USA.
+#
+
+#
+# vncserver - wrapper script to start an X VNC server.
+#
+
+# First make sure we're operating in a sane environment.
+$exedir = "";
+$slashndx = rindex($0, "/");
+if($slashndx>=0) {
+    $exedir = substr($0, 0, $slashndx+1);
+}
+
+&SanityCheck();
+
+#
+# Global variables.  You may want to configure some of these for
+# your site
+#
+
+$geometry = "1024x768";
+#$depth = 16;
+
+$vncUserDir = "$ENV{HOME}/.vnc";
+$vncUserConfig = "$vncUserDir/config";
+
+$vncSystemConfigDir = "/etc/tigervnc";
+$vncSystemConfigDefaultsFile = "$vncSystemConfigDir/vncserver-config-defaults";
+$vncSystemConfigMandatoryFile = "$vncSystemConfigDir/vncserver-config-mandatory";
+
+$skipxstartup = 0;
+$xauthorityFile = "$ENV{XAUTHORITY}" || "$ENV{HOME}/.Xauthority";
+
+$xstartupFile = $vncUserDir . "/xstartup";
+$defaultXStartup
+    = ("#!/bin/sh\n\n".
+       "unset SESSION_MANAGER\n".
+       "unset DBUS_SESSION_BUS_ADDRESS\n".
+       "OS=`uname -s`\n".
+       "if [ \$OS = 'Linux' ]; then\n".
+       "  case \"\$WINDOWMANAGER\" in\n".
+       "    \*gnome\*)\n".
+       "      if [ -e /etc/SuSE-release ]; then\n".
+       "        PATH=\$PATH:/opt/gnome/bin\n".
+       "        export PATH\n".
+       "      fi\n".
+       "      ;;\n".
+       "  esac\n".
+       "fi\n".
+       "if [ -x /etc/X11/xinit/xinitrc ]; then\n".
+       "  exec /etc/X11/xinit/xinitrc\n".
+       "fi\n".
+       "if [ -f /etc/X11/xinit/xinitrc ]; then\n".
+       "  exec sh /etc/X11/xinit/xinitrc\n".
+       "fi\n".
+       "[ -r \$HOME/.Xresources ] && xrdb \$HOME/.Xresources\n".
+       "xsetroot -solid grey\n".
+       "xterm -geometry 80x24+10+10 -ls -title \"\$VNCDESKTOP Desktop\" &\n".
+       "twm &\n");
+
+$defaultConfig
+    = ("## Supported server options to pass to vncserver upon invocation can be listed\n".
+       "## in this file. See the following manpages for more: vncserver(1) Xvnc(1).\n".
+       "## Several common ones are shown below. Uncomment and modify to your liking.\n".
+       "##\n".
+       "# securitytypes=vncauth,tlsvnc\n".
+       "# desktop=sandbox\n".
+       "# geometry=2000x1200\n".
+       "# localhost\n".
+       "# alwaysshared\n");
+
+chop($host = `uname -n`);
+
+if (-d "/etc/X11/fontpath.d") {
+    $fontPath = "catalogue:/etc/X11/fontpath.d";
+}
+
+@fontpaths = ('/usr/share/X11/fonts', '/usr/share/fonts', '/usr/share/fonts/X11/');
+if (! -l "/usr/lib/X11") {push(@fontpaths, '/usr/lib/X11/fonts');}
+if (! -l "/usr/X11") {push(@fontpaths, '/usr/X11/lib/X11/fonts');}
+if (! -l "/usr/X11R6") {push(@fontpaths, '/usr/X11R6/lib/X11/fonts');}
+push(@fontpaths, '/usr/share/fonts/default');
+
+@fonttypes = ('misc',
+             '75dpi',
+             '100dpi',
+             'Speedo',
+             'Type1');
+
+foreach $_fpath (@fontpaths) {
+    foreach $_ftype (@fonttypes) {
+        if (-f "$_fpath/$_ftype/fonts.dir") {
+            if (! -l "$_fpath/$_ftype") {
+                $defFontPath .= "$_fpath/$_ftype,";
+            }
+        }
+    }
+}
+
+if ($defFontPath) {
+    if (substr($defFontPath, -1, 1) == ',') {
+        chop $defFontPath;
+    }
+}
+
+if ($fontPath eq "") {
+    $fontPath = $defFontPath;
+}
+
+# Check command line options
+
+&ParseOptions("-geometry",1,"-depth",1,"-pixelformat",1,"-name",1,"-kill",1,
+	      "-help",0,"-h",0,"--help",0,"-fp",1,"-list",0,"-fg",0,"-autokill",0,"-noxstartup",0,"-xstartup",1);
+
+&Usage() if ($opt{'-help'} || $opt{'-h'} || $opt{'--help'});
+
+&Kill() if ($opt{'-kill'});
+
+&List() if ($opt{'-list'});
+
+# Uncomment this line if you want default geometry, depth and pixelformat
+# to match the current X display:
+# &GetXDisplayDefaults();
+
+if ($opt{'-geometry'}) {
+    $geometry = $opt{'-geometry'};
+}
+if ($opt{'-depth'}) {
+    $depth = $opt{'-depth'};
+    $pixelformat = "";
+}
+if ($opt{'-pixelformat'}) {
+    $pixelformat = $opt{'-pixelformat'};
+}
+if ($opt{'-noxstartup'}) {
+    $skipxstartup = 1;
+}
+if ($opt{'-xstartup'}) {
+    $xstartupFile = $opt{'-xstartup'};
+}
+if ($opt{'-fp'}) {
+    $fontPath = $opt{'-fp'};
+    $fpArgSpecified = 1;
+}
+
+&CheckGeometryAndDepth();
+
+# Create the user's vnc directory if necessary.
+if (!(-e $vncUserDir)) {
+    if (!mkdir($vncUserDir,0755)) {
+	die "$prog: Could not create $vncUserDir.\n";
+    }
+}
+
+# Find display number.
+if ((@ARGV > 0) && ($ARGV[0] =~ /^:(\d+)$/)) {
+    $displayNumber = $1;
+    shift(@ARGV);
+    if (!&CheckDisplayNumber($displayNumber)) {
+	die "A VNC server is already running as :$displayNumber\n";
+    }
+} elsif ((@ARGV > 0) && ($ARGV[0] !~ /^-/) && ($ARGV[0] !~ /^\+/)) {
+    &Usage();
+} else {
+    $displayNumber = &GetDisplayNumber();
+}
+
+$vncPort = 5900 + $displayNumber;
+
+if ($opt{'-name'}) {
+    $desktopName = $opt{'-name'};
+} else {
+    $desktopName = "$host:$displayNumber ($ENV{USER})";
+}
+
+my %default_opts;
+my %config;
+
+# We set some reasonable defaults. Config file settings
+# override these where present.
+$default_opts{desktop} = &quotedString($desktopName);
+$default_opts{auth} = &quotedString($xauthorityFile);
+$default_opts{geometry} = $geometry if ($geometry);
+$default_opts{depth} = $depth if ($depth);
+$default_opts{pixelformat} = $pixelformat if ($pixelformat);
+$default_opts{rfbwait} = 30000;
+$default_opts{rfbauth} = "$vncUserDir/passwd";
+$default_opts{rfbport} = $vncPort;
+$default_opts{fp} = $fontPath if ($fontPath);
+$default_opts{pn} = "";
+
+# Load user-overrideable system defaults
+LoadConfig($vncSystemConfigDefaultsFile);
+
+# Then the user's settings
+LoadConfig($vncUserConfig);
+
+# And then override anything set above if mandatory settings exist.
+# WARNING: "Mandatory" is used loosely here! As the man page says,
+# there is nothing stopping someone from EASILY subverting the
+# settings in $vncSystemConfigMandatoryFile by simply passing
+# CLI args to vncserver, which trump config files! To properly
+# hard force policy in a non-subvertible way would require major
+# development work that touches Xvnc itself.
+LoadConfig($vncSystemConfigMandatoryFile, 1);
+
+#
+# Check whether VNC authentication is enabled, and if so, prompt the user to
+# create a VNC password if they don't already have one.
+#
+
+$securityTypeArgSpecified = 0;
+$vncAuthEnabled = 0;
+$passwordArgSpecified = 0;
+@vncAuthStrings = ("vncauth", "tlsvnc", "x509vnc");
+
+# ...first we check our configuration files' settings
+if ($config{'securitytypes'}) {
+  $securityTypeArgSpecified = 1;
+  foreach $arg2 (split(',', $config{'securitytypes'})) {
+    if (grep {$_ eq lc($arg2)} @vncAuthStrings) {
+      $vncAuthEnabled = 1;
+    }
+  }
+}
+
+# ...and finally we check CLI args, which in the case of the topic at
+# hand (VNC auth or not), override anything found in configuration files
+# (even so-called "mandatory" settings).
+for ($i = 0; $i < @ARGV; ++$i) {
+    # -SecurityTypes can be followed by a space or "="
+    my @splitargs = split('=', $ARGV[$i]);
+    if (@splitargs <= 1 && $i < @ARGV - 1) {
+        push(@splitargs, $ARGV[$i + 1]);
+    }
+    if (lc(@splitargs[0]) eq "-securitytypes") {
+        if (@splitargs > 1) {
+            $securityTypeArgSpecified = 1;
+        }
+        foreach $arg2 (split(',', @splitargs[1])) {
+            if (grep {$_ eq lc($arg2)} @vncAuthStrings) {
+                $vncAuthEnabled = 1;
+            }
+        }
+    }
+    if ((lc(@splitargs[0]) eq "-password")
+     || (lc(@splitargs[0]) eq "-passwordfile"
+     || (lc(@splitargs[0]) eq "-rfbauth"))) {
+        $passwordArgSpecified = 1;
+    }
+}
+
+if ((!$securityTypeArgSpecified || $vncAuthEnabled) && !$passwordArgSpecified) {
+    ($z,$z,$mode) = stat("$vncUserDir/passwd");
+    if (!(-e "$vncUserDir/passwd") || ($mode & 077)) {
+        warn "\nYou will require a password to access your desktops.\n\n";
+        system($exedir."vncpasswd -q $vncUserDir/passwd");
+        if (($? >> 8) != 0) {
+            exit 1;
+        }
+    }
+}
+
+$desktopLog = "$vncUserDir/$host:$displayNumber.log";
+unlink($desktopLog);
+
+# Make an X server cookie and set up the Xauthority file
+# mcookie is a part of util-linux, usually only GNU/Linux systems have it.
+$cookie = `mcookie`;
+# Fallback for non GNU/Linux OS - use /dev/urandom on systems that have it,
+# otherwise use perl's random number generator, seeded with the sum
+# of the current time, our PID and part of the encrypted form of the password.
+if ($cookie eq "" && open(URANDOM, '<', '/dev/urandom')) {
+  my $randata;
+  if (sysread(URANDOM, $randata, 16) == 16) {
+    $cookie = unpack 'h*', $randata;
+  }
+  close(URANDOM);
+}
+if ($cookie eq "") {
+  srand(time+$$+unpack("L",`cat $vncUserDir/passwd`));
+  for (1..16) {
+    $cookie .= sprintf("%02x", int(rand(256)) % 256);
+  }
+}
+
+open(XAUTH, "|xauth -f $xauthorityFile source -");
+print XAUTH "add $host:$displayNumber . $cookie\n";
+print XAUTH "add $host/unix:$displayNumber . $cookie\n";
+close(XAUTH);
+
+# Now start the X VNC Server
+
+# We build up our Xvnc command with options
+$cmd = $exedir."Xvnc :$displayNumber";
+
+foreach my $k (sort keys %config) {
+  $cmd .= " -$k $config{$k}";
+  delete $default_opts{$k}; # file options take precedence
+}
+
+foreach my $k (sort keys %default_opts) {
+  $cmd .= " -$k $default_opts{$k}";
+}
+
+# Add color database stuff here, e.g.:
+# $cmd .= " -co /usr/lib/X11/rgb";
+
+foreach $arg (@ARGV) {
+  $cmd .= " " . &quotedString($arg);
+}
+$cmd .= " >> " . &quotedString($desktopLog) . " 2>&1";
+
+# Run $cmd and record the process ID.
+$pidFile = "$vncUserDir/$host:$displayNumber.pid";
+system("$cmd & echo \$! >$pidFile");
+
+# Give Xvnc a chance to start up
+
+sleep(3);
+if ($fontPath ne $defFontPath) {
+    unless (kill 0, `cat $pidFile`) {
+        if ($fpArgSpecified) {
+	    warn "\nWARNING: The first attempt to start Xvnc failed, probably because the font\n";
+	    warn "path you specified using the -fp argument is incorrect.  Attempting to\n";
+	    warn "determine an appropriate font path for this system and restart Xvnc using\n";
+	    warn "that font path ...\n";
+        } else {
+	    warn "\nWARNING: The first attempt to start Xvnc failed, possibly because the font\n";
+	    warn "catalog is not properly configured.  Attempting to determine an appropriate\n";
+	    warn "font path for this system and restart Xvnc using that font path ...\n";
+        }
+	$cmd =~ s@-fp [^ ]+@@;
+	$cmd .= " -fp $defFontPath" if ($defFontPath);
+	system("$cmd & echo \$! >$pidFile");
+	sleep(3);
+    }
+}
+unless (kill 0, `cat $pidFile`) {
+    warn "Could not start Xvnc.\n\n";
+    unlink $pidFile;
+    open(LOG, "<$desktopLog");
+    while (<LOG>) { print; }
+    close(LOG);
+    die "\n";
+}
+
+warn "\nNew '$desktopName' desktop is $host:$displayNumber\n\n";
+
+# Create the user's xstartup script if necessary.
+if (! $skipxstartup) {
+    if (!(-e "$xstartupFile")) {
+	warn "Creating default startup script $xstartupFile\n";
+	open(XSTARTUP, ">$xstartupFile");
+        print XSTARTUP $defaultXStartup;
+        close(XSTARTUP);
+        chmod 0755, "$xstartupFile";
+    }
+}
+
+# Create the user's config file if necessary.
+if (!(-e "$vncUserDir/config")) {
+    warn "Creating default config $vncUserDir/config\n";
+    open(VNCUSERCONFIG, ">$vncUserDir/config");
+    print VNCUSERCONFIG $defaultConfig;
+    close(VNCUSERCONFIG);
+    chmod 0644, "$vncUserDir/config";
+}
+
+# Run the X startup script.
+if (! $skipxstartup) {
+    warn "Starting applications specified in $xstartupFile\n";
+}
+warn "Log file is $desktopLog\n\n";
+
+# If the unix domain socket exists then use that (DISPLAY=:n) otherwise use
+# TCP (DISPLAY=host:n)
+
+if (-e "/tmp/.X11-unix/X$displayNumber" ||
+    -e "/usr/spool/sockets/X11/$displayNumber")
+{
+    $ENV{DISPLAY}= ":$displayNumber";
+} else {
+    $ENV{DISPLAY}= "$host:$displayNumber";
+}
+$ENV{VNCDESKTOP}= $desktopName;
+
+if ($opt{'-fg'}) {
+    if (! $skipxstartup) {
+        system("$xstartupFile >> " . &quotedString($desktopLog) . " 2>&1");
+    }
+    if (kill 0, `cat $pidFile`) {
+        $opt{'-kill'} = ':'.$displayNumber;
+        &Kill();
+    }
+} else {
+    if ($opt{'-autokill'}) {
+    	if (! $skipxstartup) {
+            system("($xstartupFile; $0 -kill :$displayNumber) >> "
+	     . &quotedString($desktopLog) . " 2>&1 &");
+    	}
+    } else {
+    	if (! $skipxstartup) {
+            system("$xstartupFile >> " . &quotedString($desktopLog)
+	     . " 2>&1 &");
+    	}
+    }
+}
+
+exit;
+
+###############################################################################
+# Functions
+###############################################################################
+
+#
+# Populate the global %config hash with settings from a specified
+# vncserver configuration file if it exists
+#
+# Args: 1. file path
+#       2. optional boolean flag to enable warning when a previously
+#          set configuration setting is being overridden
+#
+sub LoadConfig {
+  local ($configFile, $warnoverride) = @_;
+  local ($toggle) = undef;
+
+  if (stat($configFile)) {
+    if (open(IN, $configFile)) {
+      while (<IN>) {
+        next if /^#/;
+        if (my ($k, $v) = /^\s*(\w+)\s*=\s*(.+)$/) {
+          $k = lc($k); # must normalize key case
+          if ($warnoverride && $config{$k}) {
+            print("Warning: $configFile is overriding previously defined '$k' to be '$v'\n");
+          }
+          $config{$k} = $v;
+        } elsif ($_ =~ m/^\s*(\S+)/) {
+          # We can't reasonably warn on override of toggles (e.g. AlwaysShared)
+          # because it would get crazy to do so. We'd have to check if the
+          # current config file being loaded defined the logical opposite setting
+          # (NeverShared vs. AlwaysShared, etc etc).
+          $toggle = lc($1); # must normalize key case
+          $config{$toggle} = $k;
+        }
+      }
+      close(IN);
+    }
+  }
+}
+
+#
+# CheckGeometryAndDepth simply makes sure that the geometry and depth values
+# are sensible.
+#
+
+sub CheckGeometryAndDepth
+{
+    if ($geometry =~ /^(\d+)x(\d+)$/) {
+	$width = $1; $height = $2;
+
+	if (($width<1) || ($height<1)) {
+	    die "$prog: geometry $geometry is invalid\n";
+	}
+
+	$geometry = "${width}x$height";
+    } else {
+	die "$prog: geometry $geometry is invalid\n";
+    }
+
+    if ($depth && (($depth < 8) || ($depth > 32))) {
+	die "Depth must be between 8 and 32\n";
+    }
+}
+
+
+#
+# GetDisplayNumber gets the lowest available display number.  A display number
+# n is taken if something is listening on the VNC server port (5900+n) or the
+# X server port (6000+n).
+#
+
+sub GetDisplayNumber
+{
+    foreach $n (1..99) {
+	if (&CheckDisplayNumber($n)) {
+	    return $n+0; # Bruce Mah's workaround for bug in perl 5.005_02
+	}
+    }
+
+    die "$prog: no free display number on $host.\n";
+}
+
+
+#
+# CheckDisplayNumber checks if the given display number is available.  A
+# display number n is taken if something is listening on the VNC server port
+# (5900+n) or the X server port (6000+n).
+#
+
+sub CheckDisplayNumber
+{
+    local ($n) = @_;
+
+    socket(S, $AF_INET, $SOCK_STREAM, 0) || die "$prog: socket failed: $!\n";
+    eval 'setsockopt(S, &SOL_SOCKET, &SO_REUSEADDR, pack("l", 1))';
+    if (!bind(S, sockaddr_in(6000 + $n, &INADDR_ANY))) {
+	close(S);
+	return 0;
+    }
+    close(S);
+
+    socket(S, $AF_INET, $SOCK_STREAM, 0) || die "$prog: socket failed: $!\n";
+    eval 'setsockopt(S, &SOL_SOCKET, &SO_REUSEADDR, pack("l", 1))';
+    if (!bind(S, sockaddr_in(5900 + $n, &INADDR_ANY))) {
+	close(S);
+	return 0;
+    }
+    close(S);
+
+    if (-e "/tmp/.X$n-lock") {
+	warn "\nWarning: $host:$n is taken because of /tmp/.X$n-lock\n";
+	warn "Remove this file if there is no X server $host:$n\n";
+	return 0;
+    }
+
+    if (-e "/tmp/.X11-unix/X$n") {
+	warn "\nWarning: $host:$n is taken because of /tmp/.X11-unix/X$n\n";
+	warn "Remove this file if there is no X server $host:$n\n";
+	return 0;
+    }
+
+    if (-e "/usr/spool/sockets/X11/$n") {
+	warn("\nWarning: $host:$n is taken because of ".
+             "/usr/spool/sockets/X11/$n\n");
+	warn "Remove this file if there is no X server $host:$n\n";
+	return 0;
+    }
+
+    return 1;
+}
+
+
+#
+# GetXDisplayDefaults uses xdpyinfo to find out the geometry, depth and pixel
+# format of the current X display being used.  If successful, it sets the
+# options as appropriate so that the X VNC server will use the same settings
+# (minus an allowance for window manager decorations on the geometry).  Using
+# the same depth and pixel format means that the VNC server won't have to
+# translate pixels when the desktop is being viewed on this X display (for
+# TrueColor displays anyway).
+#
+
+sub GetXDisplayDefaults
+{
+    local (@lines, @matchlines, $width, $height, $defaultVisualId, $i,
+	   $red, $green, $blue);
+
+    $wmDecorationWidth = 4;	# a guess at typical size for window manager
+    $wmDecorationHeight = 24;	# decoration size
+
+    return if (!defined($ENV{DISPLAY}));
+
+    @lines = `xdpyinfo 2>/dev/null`;
+
+    return if ($? != 0);
+
+    @matchlines = grep(/dimensions/, @lines);
+    if (@matchlines) {
+	($width, $height) = ($matchlines[0] =~ /(\d+)x(\d+) pixels/);
+
+	$width -= $wmDecorationWidth;
+	$height -= $wmDecorationHeight;
+
+	$geometry = "${width}x$height";
+    }
+
+    @matchlines = grep(/default visual id/, @lines);
+    if (@matchlines) {
+	($defaultVisualId) = ($matchlines[0] =~ /id:\s+(\S+)/);
+
+	for ($i = 0; $i < @lines; $i++) {
+	    if ($lines[$i] =~ /^\s*visual id:\s+$defaultVisualId$/) {
+		if (($lines[$i+1] !~ /TrueColor/) ||
+		    ($lines[$i+2] !~ /depth/) ||
+		    ($lines[$i+4] !~ /red, green, blue masks/))
+		{
+		    return;
+		}
+		last;
+	    }
+	}
+
+	return if ($i >= @lines);
+
+	($depth) = ($lines[$i+2] =~ /depth:\s+(\d+)/);
+	($red,$green,$blue)
+	    = ($lines[$i+4]
+	       =~ /masks:\s+0x([0-9a-f]+), 0x([0-9a-f]+), 0x([0-9a-f]+)/);
+
+	$red = hex($red);
+	$green = hex($green);
+	$blue = hex($blue);
+
+	if ($red > $blue) {
+	    $red = int(log($red) / log(2)) - int(log($green) / log(2));
+	    $green = int(log($green) / log(2)) - int(log($blue) / log(2));
+	    $blue = int(log($blue) / log(2)) + 1;
+	    $pixelformat = "rgb$red$green$blue";
+	} else {
+	    $blue = int(log($blue) / log(2)) - int(log($green) / log(2));
+	    $green = int(log($green) / log(2)) - int(log($red) / log(2));
+	    $red = int(log($red) / log(2)) + 1;
+	    $pixelformat = "bgr$blue$green$red";
+	}
+    }
+}
+
+
+#
+# quotedString returns a string which yields the original string when parsed
+# by a shell.
+#
+
+sub quotedString
+{
+    local ($in) = @_;
+
+    $in =~ s/\'/\'\"\'\"\'/g;
+
+    return "'$in'";
+}
+
+
+#
+# removeSlashes turns slashes into underscores for use as a file name.
+#
+
+sub removeSlashes
+{
+    local ($in) = @_;
+
+    $in =~ s|/|_|g;
+
+    return "$in";
+}
+
+
+#
+# Usage
+#
+
+sub Usage
+{
+    die("\nusage: $prog [:<number>] [-name <desktop-name>] [-depth <depth>]\n".
+	"                 [-geometry <width>x<height>]\n".
+	"                 [-pixelformat rgbNNN|bgrNNN]\n".
+	"                 [-fp <font-path>]\n".
+	"                 [-fg]\n".
+	"                 [-autokill]\n".
+	"                 [-noxstartup]\n".
+	"                 [-xstartup <file>]\n".
+	"                 <Xvnc-options>...\n\n".
+	"       $prog -kill <X-display>\n\n".
+	"       $prog -list\n\n");
+}
+
+
+#
+# List
+#
+
+sub List
+{
+    opendir(dir, $vncUserDir);
+    my @filelist = readdir(dir);
+    closedir(dir);
+    print "\nTigerVNC server sessions:\n\n";
+    print "X DISPLAY #\tPROCESS ID\n";
+    foreach my $file (@filelist) {
+	if ($file =~ /$host:(\d+)$\.pid/) {
+	    chop($tmp_pid = `cat $vncUserDir/$file`);
+	    if (kill 0, $tmp_pid) {
+		print ":".$1."\t\t".`cat $vncUserDir/$file`;
+	    } else {
+		unlink ($vncUserDir . "/" . $file);
+	    }
+	}
+    }
+    exit;
+}
+
+
+#
+# Kill
+#
+
+sub Kill
+{
+    $opt{'-kill'} =~ s/(:\d+)\.\d+$/$1/; # e.g. turn :1.0 into :1
+
+    if ($opt{'-kill'} =~ /^:\d+$/) {
+	$pidFile = "$vncUserDir/$host$opt{'-kill'}.pid";
+    } else {
+	if ($opt{'-kill'} !~ /^$host:/) {
+	    die "\nCan't tell if $opt{'-kill'} is on $host\n".
+		"Use -kill :<number> instead\n\n";
+	}
+	$pidFile = "$vncUserDir/$opt{'-kill'}.pid";
+    }
+
+    if (! -r $pidFile) {
+	die "\nCan't find file $pidFile\n".
+	    "You'll have to kill the Xvnc process manually\n\n";
+    }
+
+    $SIG{'HUP'} = 'IGNORE';
+    chop($pid = `cat $pidFile`);
+    warn "Killing Xvnc process ID $pid\n";
+
+    if (kill 0, $pid) {
+	system("kill $pid");
+	sleep(1);
+	if (kill 0, $pid) {
+	    print "Xvnc seems to be deadlocked.  Kill the process manually and then re-run\n";
+	    print "    ".$0." -kill ".$opt{'-kill'}."\n";
+	    print "to clean up the socket files.\n";
+	    exit
+	}
+
+    } else {
+	warn "Xvnc process ID $pid already killed\n";
+	$opt{'-kill'} =~ s/://;
+
+	if (-e "/tmp/.X11-unix/X$opt{'-kill'}") {
+	    print "Xvnc did not appear to shut down cleanly.";
+	    print " Removing /tmp/.X11-unix/X$opt{'-kill'}\n";
+	    unlink "/tmp/.X11-unix/X$opt{'-kill'}";
+	}
+	if (-e "/tmp/.X$opt{'-kill'}-lock") {
+	    print "Xvnc did not appear to shut down cleanly.";
+	    print " Removing /tmp/.X$opt{'-kill'}-lock\n";
+	    unlink "/tmp/.X$opt{'-kill'}-lock";
+	}
+    }
+
+    unlink $pidFile;
+    exit;
+}
+
+
+#
+# ParseOptions takes a list of possible options and a boolean indicating
+# whether the option has a value following, and sets up an associative array
+# %opt of the values of the options given on the command line. It removes all
+# the arguments it uses from @ARGV and returns them in @optArgs.
+#
+
+sub ParseOptions
+{
+    local (@optval) = @_;
+    local ($opt, @opts, %valFollows, @newargs);
+
+    while (@optval) {
+	$opt = shift(@optval);
+	push(@opts,$opt);
+	$valFollows{$opt} = shift(@optval);
+    }
+
+    @optArgs = ();
+    %opt = ();
+
+    arg: while (defined($arg = shift(@ARGV))) {
+	foreach $opt (@opts) {
+	    if ($arg eq $opt) {
+		push(@optArgs, $arg);
+		if ($valFollows{$opt}) {
+		    if (@ARGV == 0) {
+			&Usage();
+		    }
+		    $opt{$opt} = shift(@ARGV);
+		    push(@optArgs, $opt{$opt});
+		} else {
+		    $opt{$opt} = 1;
+		}
+		next arg;
+	    }
+	}
+	push(@newargs,$arg);
+    }
+
+    @ARGV = @newargs;
+}
+
+
+# Routine to make sure we're operating in a sane environment.
+sub SanityCheck
+{
+    local ($cmd);
+
+    # Get the program name
+    ($prog) = ($0 =~ m|([^/]+)$|);
+
+    #
+    # Check we have all the commands we'll need on the path.
+    #
+
+ cmd:
+    foreach $cmd ("uname","xauth") {
+	for (split(/:/,$ENV{PATH})) {
+	    if (-x "$_/$cmd") {
+		next cmd;
+	    }
+	}
+	die "$prog: couldn't find \"$cmd\" on your PATH.\n";
+    }
+
+    if($exedir eq "") {
+      cmd2:
+	foreach $cmd ("Xvnc","vncpasswd") {
+	    for (split(/:/,$ENV{PATH})) {
+		if (-x "$_/$cmd") {
+		    next cmd2;
+		}
+	    }
+	    die "$prog: couldn't find \"$cmd\" on your PATH.\n";
+	}
+    }
+    else {
+      cmd3:
+	foreach $cmd ($exedir."Xvnc",$exedir."vncpasswd") {
+	    for (split(/:/,$ENV{PATH})) {
+		if (-x "$cmd") {
+		    next cmd3;
+		}
+	    }
+	    die "$prog: couldn't find \"$cmd\".\n";
+	}
+    }
+
+    if (!defined($ENV{HOME})) {
+	die "$prog: The HOME environment variable is not set.\n";
+    }
+
+    #
+    # Find socket constants. 'use Socket' is a perl5-ism, so we wrap it in an
+    # eval, and if it fails we try 'require "sys/socket.ph"'.  If this fails,
+    # we just guess at the values.  If you find perl moaning here, just
+    # hard-code the values of AF_INET and SOCK_STREAM.  You can find these out
+    # for your platform by looking in /usr/include/sys/socket.h and related
+    # files.
+    #
+
+    chop($os = `uname`);
+    chop($osrev = `uname -r`);
+
+    eval 'use Socket';
+    if ($@) {
+	eval 'require "sys/socket.ph"';
+	if ($@) {
+	    if (($os eq "SunOS") && ($osrev !~ /^4/)) {
+		$AF_INET = 2;
+		$SOCK_STREAM = 2;
+	    } else {
+		$AF_INET = 2;
+		$SOCK_STREAM = 1;
+	    }
+	} else {
+	    $AF_INET = &AF_INET;
+	    $SOCK_STREAM = &SOCK_STREAM;
+	}
+    } else {
+	$AF_INET = &AF_INET;
+	$SOCK_STREAM = &SOCK_STREAM;
+    }
+}