vncserver - android_external_tigervnc - Gitiles

 #!/usr/bin/env perl
 #
 #  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.
 #

 &SanityCheck();

 #
 # Global variables.  You may want to configure some of these for your site.
 #

 $geometry = "1024x768";
 $depth = 16;
 $vncJavaFiles = (((-d "/usr/share/vnc/classes") && "/usr/share/vnc/classes") ||
                  ((-d "/usr/local/vnc/classes") && "/usr/local/vnc/classes"));
 $vncUserDir = "$ENV{HOME}/.vnc";
 $xauthorityFile = "$ENV{XAUTHORITY}" || "$ENV{HOME}/.Xauthority";

 $defaultXStartup
     = ("#!/bin/sh\n\n".
        "[ -r \$HOME/.Xresources ] && xrdb \$HOME/.Xresources\n".
        "xsetroot -solid grey\n".
        "vncconfig -iconic &\n".
        "xterm -geometry 80x24+10+10 -ls -title \"\$VNCDESKTOP Desktop\" &\n".
        "twm &\n");

 chop($host = `uname -n`);


 # Check command line options

 &ParseOptions("-geometry",1,"-depth",1,"-pixelformat",1,"-name",1,"-kill",1,
 	      "-help",0,"-h",0,"--help",0);

 &Usage() if ($opt{'-help'} || $opt{'-h'} || $opt{'--help'});

 &Kill() if ($opt{'-kill'});

 # 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'};
 }

 &CheckGeometryAndDepth();


 # Create the user's vnc directory if necessary.

 if (!(-e $vncUserDir)) {
     if (!mkdir($vncUserDir,0755)) {
 	die "$prog: Could not create $vncUserDir.\n";
     }
 }

 # Make sure the user has a password.

 ($z,$z,$mode) = stat("$vncUserDir/passwd");
 if (!(-e "$vncUserDir/passwd") || ($mode & 077)) {
     warn "\nYou will require a password to access your desktops.\n\n";
     system("vncpasswd -q $vncUserDir/passwd");
     if (($? >> 8) != 0) {
 	exit 1;
     }
 }

 # 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] !~ /^-/)) {
     &Usage();
 } else {
     $displayNumber = &GetDisplayNumber();
 }

 $vncPort = 5900 + $displayNumber;

 $desktopLog = "$vncUserDir/$host:$displayNumber.log";
 unlink($desktopLog);

 # Make an X server cookie - use as the seed the sum of the current time, our
 # PID and part of the encrypted form of the password.  Ideally we'd use
 # /dev/urandom, but that's only available on Linux.

 srand(time+$$+unpack("L",`cat $vncUserDir/passwd`));
 $cookie = "";
 for (1..16) {
     $cookie .= sprintf("%02x", int(rand(256)) % 256);
 }

 system("xauth -f $xauthorityFile add $host:$displayNumber . $cookie");
 system("xauth -f $xauthorityFile add $host/unix:$displayNumber . $cookie");

 if ($opt{'-name'}) {
     $desktopName = $opt{'-name'};
 } else {
     $desktopName = "$host:$displayNumber ($ENV{USER})";
 }

 # Now start the X VNC Server

 $cmd = "Xvnc :$displayNumber";
 $cmd .= " -desktop " . &quotedString($desktopName);
 $cmd .= " -httpd $vncJavaFiles" if ($vncJavaFiles);
 $cmd .= " -auth $xauthorityFile";
 $cmd .= " -geometry $geometry" if ($geometry);
 $cmd .= " -depth $depth" if ($depth);
 $cmd .= " -pixelformat $pixelformat" if ($pixelformat);
 $cmd .= " -rfbwait 30000";
 $cmd .= " -rfbauth $vncUserDir/passwd";
 $cmd .= " -rfbport $vncPort";
 $cmd .= " -pn";

 # Add font path and color database stuff here, e.g.:
 #
 # $cmd .= " -fp /usr/lib/X11/fonts/misc/,/usr/lib/X11/fonts/75dpi/";
 # $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);

 warn "\nNew '$desktopName' desktop is $host:$displayNumber\n\n";

 # Create the user's xstartup script if necessary.

 if (!(-e "$vncUserDir/xstartup")) {
     warn "Creating default startup script $vncUserDir/xstartup\n";
     open(XSTARTUP, ">$vncUserDir/xstartup");
     print XSTARTUP $defaultXStartup;
     close(XSTARTUP);
     chmod 0755, "$vncUserDir/xstartup";
 }

 # Run the X startup script.

 warn "Starting applications specified in $vncUserDir/xstartup\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;

 system("$vncUserDir/xstartup >> " . &quotedString($desktopLog) . " 2>&1 &");

 exit;


 ###############################################################################
 #
 # 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";
 	}

 	while (($width % 4)!=0) {
 	    $width = $width + 1;
 	}

 	while (($height % 2)!=0) {
 	    $height = $height + 1;
 	}

 	$geometry = "${width}x$height";
     } else {
 	die "$prog: geometry $geometry is invalid\n";
     }

     if (($depth < 8) || ($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, pack('S n x12', $AF_INET, 6000 + $n))) {
 	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, pack('S n x12', $AF_INET, 5900 + $n))) {
 	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".
 	"                 <Xvnc-options>...\n\n".
 	"       $prog -kill <X-display>\n\n");
 }


 #
 # 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";
     system("kill $pid");
     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 $cmd ("uname","xauth","Xvnc","vncpasswd") {
 	for (split(/:/,$ENV{PATH})) {
 	    if (-x "$_/$cmd") {
 		next cmd;
 	    }
 	}
 	die "$prog: couldn't find \"$cmd\" on your PATH.\n";
     }

     #
     # Check the HOME environment variable is set
     #

     if (!defined($ENV{HOME})) {
 	die "$prog: The HOME environment variable is not set.\n";
     }
     chdir($ENV{HOME});

     #
     # 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;
     }
 }
	#!/usr/bin/env perl
	#
	# 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.
	#

	&SanityCheck();

	#
	# Global variables. You may want to configure some of these for your site.
	#

	$geometry = "1024x768";
	$depth = 16;
	$vncJavaFiles = (((-d "/usr/share/vnc/classes") && "/usr/share/vnc/classes") \|\|
	((-d "/usr/local/vnc/classes") && "/usr/local/vnc/classes"));
	$vncUserDir = "$ENV{HOME}/.vnc";
	$xauthorityFile = "$ENV{XAUTHORITY}" \|\| "$ENV{HOME}/.Xauthority";

	$defaultXStartup
	= ("#!/bin/sh\n\n".
	"[ -r \$HOME/.Xresources ] && xrdb \$HOME/.Xresources\n".
	"xsetroot -solid grey\n".
	"vncconfig -iconic &\n".
	"xterm -geometry 80x24+10+10 -ls -title \"\$VNCDESKTOP Desktop\" &\n".
	"twm &\n");

	chop($host = `uname -n`);


	# Check command line options

	&ParseOptions("-geometry",1,"-depth",1,"-pixelformat",1,"-name",1,"-kill",1,
	"-help",0,"-h",0,"--help",0);

	&Usage() if ($opt{'-help'} \|\| $opt{'-h'} \|\| $opt{'--help'});

	&Kill() if ($opt{'-kill'});

	# 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'};
	}

	&CheckGeometryAndDepth();


	# Create the user's vnc directory if necessary.

	if (!(-e $vncUserDir)) {
	if (!mkdir($vncUserDir,0755)) {
	die "$prog: Could not create $vncUserDir.\n";
	}
	}

	# Make sure the user has a password.

	($z,$z,$mode) = stat("$vncUserDir/passwd");
	if (!(-e "$vncUserDir/passwd") \|\| ($mode & 077)) {
	warn "\nYou will require a password to access your desktops.\n\n";
	system("vncpasswd -q $vncUserDir/passwd");
	if (($? >> 8) != 0) {
	exit 1;
	}
	}

	# 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] !~ /^-/)) {
	&Usage();
	} else {
	$displayNumber = &GetDisplayNumber();
	}

	$vncPort = 5900 + $displayNumber;

	$desktopLog = "$vncUserDir/$host:$displayNumber.log";
	unlink($desktopLog);

	# Make an X server cookie - use as the seed the sum of the current time, our
	# PID and part of the encrypted form of the password. Ideally we'd use
	# /dev/urandom, but that's only available on Linux.

	srand(time+$$+unpack("L",`cat $vncUserDir/passwd`));
	$cookie = "";
	for (1..16) {
	$cookie .= sprintf("%02x", int(rand(256)) % 256);
	}

	system("xauth -f $xauthorityFile add $host:$displayNumber . $cookie");
	system("xauth -f $xauthorityFile add $host/unix:$displayNumber . $cookie");

	if ($opt{'-name'}) {
	$desktopName = $opt{'-name'};
	} else {
	$desktopName = "$host:$displayNumber ($ENV{USER})";
	}

	# Now start the X VNC Server

	$cmd = "Xvnc :$displayNumber";
	$cmd .= " -desktop " . &quotedString($desktopName);
	$cmd .= " -httpd $vncJavaFiles" if ($vncJavaFiles);
	$cmd .= " -auth $xauthorityFile";
	$cmd .= " -geometry $geometry" if ($geometry);
	$cmd .= " -depth $depth" if ($depth);
	$cmd .= " -pixelformat $pixelformat" if ($pixelformat);
	$cmd .= " -rfbwait 30000";
	$cmd .= " -rfbauth $vncUserDir/passwd";
	$cmd .= " -rfbport $vncPort";
	$cmd .= " -pn";

	# Add font path and color database stuff here, e.g.:
	#
	# $cmd .= " -fp /usr/lib/X11/fonts/misc/,/usr/lib/X11/fonts/75dpi/";
	# $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);

	warn "\nNew '$desktopName' desktop is $host:$displayNumber\n\n";

	# Create the user's xstartup script if necessary.

	if (!(-e "$vncUserDir/xstartup")) {
	warn "Creating default startup script $vncUserDir/xstartup\n";
	open(XSTARTUP, ">$vncUserDir/xstartup");
	print XSTARTUP $defaultXStartup;
	close(XSTARTUP);
	chmod 0755, "$vncUserDir/xstartup";
	}

	# Run the X startup script.

	warn "Starting applications specified in $vncUserDir/xstartup\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;

	system("$vncUserDir/xstartup >> " . &quotedString($desktopLog) . " 2>&1 &");

	exit;


	###############################################################################
	#
	# 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";
	}

	while (($width % 4)!=0) {
	$width = $width + 1;
	}

	while (($height % 2)!=0) {
	$height = $height + 1;
	}

	$geometry = "${width}x$height";
	} else {
	die "$prog: geometry $geometry is invalid\n";
	}

	if (($depth < 8) \|\| ($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, pack('S n x12', $AF_INET, 6000 + $n))) {
	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, pack('S n x12', $AF_INET, 5900 + $n))) {
	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".
	" <Xvnc-options>...\n\n".
	" $prog -kill <X-display>\n\n");
	}


	#
	# 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";
	system("kill $pid");
	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 $cmd ("uname","xauth","Xvnc","vncpasswd") {
	for (split(/:/,$ENV{PATH})) {
	if (-x "$_/$cmd") {
	next cmd;
	}
	}
	die "$prog: couldn't find \"$cmd\" on your PATH.\n";
	}

	#
	# Check the HOME environment variable is set
	#

	if (!defined($ENV{HOME})) {
	die "$prog: The HOME environment variable is not set.\n";
	}
	chdir($ENV{HOME});

	#
	# 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;
	}
	}