#!/bin/sh -- # A comment mentioning perl, indented bash's sake.
eval 'exec perl -S $0 ${1+"$@"}'
        if 0;

$Term = 'xterm';
chop($term = `basename $Term`);
$Term_Args_Needed  = '-title %TITLE -geometry %GEOMETRY -display %DISPLAY';
$Term_Args_Options = '-bg %BG -fg %FG -fn %FONT';

chop($Hostname = `hostname`);
if ( $Hostname eq '' ) {
	$Hostname = 'localhost';
}

$Master_Cmd = "rlogin $Hostname | tee -a %TAILFILE";
$Master_Term_Cmd = "-e sh -c \'%CMD\'";

$Master_Extra_Opts = 1;
$Slave_Extra_Opts  = 1;

$tail = 'tail';
foreach $dir (split(/:/, $ENV{PATH})) {
	if ( -x "$dir/fast_tail" ) {
		$tail = "$dir/fast_tail";
		last;
	}
}

$Slave_Cmd  = "$tail -f %TAILFILE";
$Slave_Term_Cmd  = '-e %CMD';

$Test_Display = 'xdpyinfo -d %DISPLAY';

$Split_VT_Cmd = 'splitvt';
$Split = 0;

$Rlogin = 0;
$Rsh = 'rsh -n';
$Master_Term = 1;

$Bg = 'floralwhite';
$Fg = 'black';
$Geometry = '80x55';
$Slave_Position = '+30+30';

$Read_Geometry = '';
$Font = '6x13';
$Master_Display = '';

$Debug = 0;

chop($Program = `basename $0`);
$PROGRAM = $Program;
$PROGRAM =~ y/a-z/A-Z/;

$Tail_File = "$ENV{HOME}/$Program.$$";

$Usage = <<"END";

$Program: Start up a master $term along with slave's on other displays showing
	what is happening on the master. 

Usage: $Program [<options>] <display1> [<display2> ...] 

Options:
	-f <file>	Use <file> for tty output.
			(instead of $Tail_File)

	-r		Use rlogin instead of xhosting, (unless display
			matches an X display with ":n", hack - use "::n" to
			force it back to rlogin). Once rlogin'ed $term
			is started on that local display (or "::n").

	-t		Don't start a separate $term for master, use
			the current terminal.

	-s		Split the $term into 2 windows using the 
			"$Split_VT_Cmd" program. This is like the "talk"
			command where communication is symmetrical.

	-d <display>	Set master's display.
	-g <geometry>	Set $term geometry ($Geometry)
	-p <position>	Set optional +X+Y position (useful with -n)

	-F <font>	Set $term font.    ($Font)
	-bg <background> set bg color.     ($Bg)
	-fg <foreground> set fg color.     ($Fg)
	-nm		Shut off font and color choices for master.
	-ns		Shut off font and color choices for slaves.

	-D		Turn on debugging output.

END

LOOP:	
while (@ARGV) {
    $_ = shift;
    CASE: {
	/^-D$/  && ($Debug = 1, last CASE);
	/^-r$/  && ($Rlogin = 1, last CASE);
	/^-t$/  && ($Master_Term = 0, last CASE);
	/^-s$/  && ($Split = 1, last CASE);
	/^-f$/  && ($Tail_File = shift, last CASE);
	/^-fg$/ && ($Fg = shift, last CASE);
	/^-bg$/ && ($Bg = shift, last CASE);
	/^-g/   && ($Geometry = shift, $Read_Geometry = 1, last CASE);
	/^-p/   && ($Position = shift, last CASE);
	/^-d/  && ($Master_Display = shift, last CASE);
	/^-ns$/ && ($Slave_Extra_Opts = 0, last CASE);
	/^-nm$/ && ($Master_Extra_Opts = 0, last CASE);
	/^--$/  && (last LOOP);	# -- means end of switches
	/^-(-.*)$/ && (unshift(@ARGV, $1), last CASE);
	/^(-h|-help)$/ && ((print $Usage), exit 0, last CASE);
	if ( /^-(..+)$/ ) {	# split bundled switches:
		local($y, $x) = ($1, '');
		foreach $x (reverse(split(//, $y))) { unshift(@ARGV,"-$x") };
		last CASE;
	}
	/^-/ && ((print "Invalid arg: $_\n$Usage"), exit 1, last CASE);
	unshift(@ARGV,$_);
	last LOOP;
    }
}

if ( $Master_Display eq '' ) {
	if ( $ENV{DISPLAY} ne '' ) {
		$Master_Display = $ENV{DISPLAY};
	} else {
		$Master_Display = ':0.0';
	}
}
$ENV{DISPLAY} = $Master_Display;

$Tail_File2 = "$Tail_File.2";

open(TAIL, ">$Tail_File") || die "Could not open tail file: $Tail_File: $!";
$msg = "** START of \"$Program\" tracing... (tailing $Tail_File) **\n** Press CTRL-C when you want to Quit. **\n";
if ($Split) {
	$msg .= "** And log out of login session in above window **\n";
	$msg .= "** Press CTRL-W to switch between windows **\n";
	$msg .= "** Press CTRL-O then 'h' for splitvt help **\n";
}
$msg .= "\n";
print TAIL $msg;
close(TAIL);

if ( $Split ) {
	open(TAIL, ">$Tail_File2") || die "Could not open tail file: $Tail_File2: $!";
	print TAIL $msg;
	close(TAIL);
}

if ( ! $Master_Term && ! $Read_Geometry ) {
	&Setup_Rows_Columns();
}
if ( $Position ne '' ) {
	$Geometry .= $Position;
	$Slave_Geometry = $Geometry;
	$Master_Geometry = $Geometry;
} else {
	$Slave_Geometry = $Geometry . $Slave_Position;
	$Master_Geometry = $Geometry . "-30-30";
}

# Start slaves 
$Slave_Count = 0;
foreach $slave (@ARGV) {
	&Start_Slave($slave);
}

print STDERR "$Program: $Slave_Count slaves launched.\n";

&Start_Master();


$msg = "\n** END of \"$Program\" tracing ... Press CTRL-C to Exit. **\n";
if ( $Split ) {
	$msg .= "** And also log out of login session in above window **\n";
}

open(TAIL, ">>$Tail_File") || die "Could not open tail file: $Tail_File: $!";
print TAIL $msg;
close(TAIL);
sleep 1;

if ( $Split ) {
	open(TAIL, ">>$Tail_File2") || die "Could not open tail file: $Tail_File2: $!";
	print TAIL $msg;
	close(TAIL);
}

unlink($Tail_File);
unlink($Tail_File2);

exit 0;


sub Start_Slave {
	local($slave) = @_;

	local($targs) = $Term_Args_Options;
	if ( ! $Slave_Extra_Opts ) {
		$targs = '';
	}

	local($cmd);
	$cmd = "$Term $Term_Args_Needed $targs $Slave_Term_Cmd";

	local($tc) = '';
	if ( $Split ) {
		local($top) = $Master_Cmd; 
		$top =~ s/%TAILFILE/$Tail_File2/g;
		$top = &Shell_Wrap_Cmd($top);
		local($bot) = $Slave_Cmd; 
		$bot =~ s/%TAILFILE/$Tail_File/g;
		$bot = &Shell_Wrap_Cmd($bot);
		$tc = "$Split_VT_Cmd -upper $top -lower $bot";
	} else {
		$tc = $Slave_Cmd;
		$tc =~ s/%TAILFILE/$Tail_File/g;
	}

	$cmd =~ s/%CMD/$tc/g;

	local($display) = '';
	local($remotehost) = '';
	local($rlogin) = 0;

	if ( $Rlogin ) {
		if ( $slave =~ /^(.*):(:\d+)/ ) {
			$remotehost = $1;
			$display = $2;
			$rlogin = 1;
		} elsif ( $slave =~ /^(.*)(:\d+)/ ) {
			$rlogin = 0;
		} else {
			$remotehost = $slave;
			$rlogin = 1;
		}
	} else {
		if ( $slave =~ /:\d+/ ) {
			$display = $slave;
		} else {
			$display = "$slave:0.0";
		}
	}

	if ( ! $rlogin ) {
		if ( ! &Test_Display($display) ) {
			print STDERR "$Program: Could not open display: $display, skipping.\n";
			return;
		}
	}

	$Slave_Count++;
	$cmd =~ s/%TITLE/${PROGRAM}-slave-#$Slave_Count/g;
	$cmd =~ s/%BG/$Bg/g;
	$cmd =~ s/%FG/$Fg/g;
	$cmd =~ s/%GEOMETRY/$Slave_Geometry/g;
	$cmd =~ s/%FONT/$Font/g;

	$cmd =~ s/%TAILFILE/$Tail_File/g;

	$cmd =~ s/%DISPLAY/$display/g;

	
	if ( $rlogin ) {
		$cmd =~ s/#/\\#/g;
		$cmd = "$Rsh $remotehost \"$cmd\" &";
	} else {
		$cmd = "$cmd &";
	}
	print STDERR "$Program: Slave: $cmd\n" if $Debug;
	system($cmd);
	sleep 1;
}

sub Start_Master {
	
	local($cmd);

	local($targs) = $Term_Args_Options;
	if ( ! $Master_Extra_Opts ) {
		$targs = '';
	}

	local($cmd);
	if ( $Master_Term ) {
		$cmd = "$Term $Term_Args_Needed $targs $Master_Term_Cmd";
	}

	local($tc) = '';
	if ( $Split ) {
		local($top) = $Master_Cmd; 
		$top =~ s/%TAILFILE/$Tail_File/g;
		$top = &Shell_Wrap_Cmd($top);
		local($bot) = $Slave_Cmd; 
		$bot =~ s/%TAILFILE/$Tail_File2/g;
		$bot = &Shell_Wrap_Cmd($bot);
		$tc = "$Split_VT_Cmd -upper $top -lower $bot";
	} else {
		$tc = $Master_Cmd;
		$tc =~ s/%TAILFILE/$Tail_File/g;
	}

	

	if ( ! $Master_Term ) {
		$cmd = $tc;
	} else {
		$cmd =~ s/%CMD/$tc/g;
	}


	$cmd =~ s/%TITLE/${PROGRAM}-master/g;
	$cmd =~ s/%BG/$Bg/g;
	$cmd =~ s/%FG/$Fg/g;
	$cmd =~ s/%GEOMETRY/$Master_Geometry/g;
	$cmd =~ s/%FONT/$Font/g;

	$cmd =~ s/%TAILFILE/$Tail_File/g;

	$cmd =~ s/%DISPLAY/$Master_Display/g;
	
	print STDERR "$Program: Master: $cmd\n" if $Debug;
	local($rc) = system($cmd);
	if ( $rc == 0 ) {
		print STDERR "$Program: Finished:  $cmd\n" if $Debug;
	} else {
		print STDERR "$Program: Problem running: $cmd\n";
		return 0;
	}
	return 1;
}

sub Test_Display {
	local($display) = @_;

	local($cmd) = $Test_Display;
	$cmd =~ s/%DISPLAY/$display/g;

	local($rc) = system("$cmd 1>/dev/null 2>&1");

	if ( $rc != 0 ) {
		print STDERR "$Program: Could not open display: $display\n" if $Debug;
		return 0;
	} else {
		return 1;
	}
}

sub Setup_Rows_Columns {
	
	open(STTY, "stty -a|");

	local($rows) = '';
	local($cols) = '';

	while (<STTY>) {
		if ( /rows\s*=\s*(\d+)\b/ ) {
			$rows = $1;
		}
		if ( /columns\s*=\s*(\d+)\b/ ) {
			$cols = $1;
		}
	}
	if ($rows eq '' ) {
		$rows = $ENV{LINES};
	}
	if ($rows eq '' ) {
		$rows = '25';
	}
	if ($cols eq '' ) {
		$cols = $ENV{COLUMNS};
	}
	if ($cols eq '' ) {
		$cols = '80';
	}
	$Geometry = "${cols}x${rows}";
}

sub Shell_Wrap_Cmd {
	local($cmd) = @_;
	
	$Tmp_Count++;
	local($tmp) = "/tmp/$Program.$$.$Tmp_Count";

	open(TMP, ">$tmp");
	chmod(0700,$tmp);

	print TMP "#!/bin/sh\n";
	print TMP "(sleep 5; rm -f $tmp) &\n";
	print TMP "$cmd\n";
	print TMP "exit 0\n";
	close(TMP);
	return $tmp;
}