#!/bin/bash

#+
# NAME:
#	vnc
# PURPOSE:
#	Control use of vncserver.
# CALLING SEQUENCE:
#	vnc
#	vnc list
#	vnc start
#	vnc kill
#	vnc kill=session
# INPUTS:
#	session		vnc session number
# PROCEDURE:
# >	No argument displays syntax information
# >	Arg 'list' displays all sessions stored in the file ~/.vnc/vnc.log
# >	If argument 'start' is specified then the program vncserver is called to
#	start a new vnc session. The session number is stored in the file
#	~/.vnc/vnc.log
# >	If argument 'kill' is specified (without a session number) then an
#	attempt is made to kill every vnc session listed in the file
#	~/.vnc/vnc.log. When a session is killed successfully the matching
#	entry in ~/.vnc/vnc.log is removed.
# >	If 'kill=session' is specified as argument the vnc session
#	with the specified number is killed, and removed from ~/.vnc/vnc.log
# >	When a session is killed several files are automatically deleted
#	(# is a one-digit integer)
#	- a *.pid file: ~/.vnc/cass180.ucsd.edu:#.pid
#	- a link to an X-server: /tmp/.X11-unix/X#
#	- a lock file /tmp/X#-lock
# >	Not automatically deleted is a log file:
#	- ~/.vnc/cass180.ucsd.edu:#.log
#	This file can get quite big (Gigabytes) and is explicitly deleted
#	by this script.
# MODIFICATION HISTORY:
#	JAN-2001, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
#-

if [ "$(which vncserver 2> /dev/null)" == "" ]; then
	echo "vnc: vncserver not found; not installed or not in path"
	exit 1
fi

vncdir=~/.vnc
vnclog=$vncdir/vnc.log
vnctmp=$vncdir/vnc.tmp

touch $vnclog

if [ -z "$1" ]; then
	echo "syntax 1:   vnc start    (starts a new vnc session)"
	echo "syntax 2:   vnc start=i  (starts a new vnc session on specified display)"
	echo "syntax 3:   vnc list     (lists all vnc sessions)"
	echo "syntax 4:   vnc kill     (kills all vnc sessions)"
	echo "syntax 5:   vnc kill=i   (i=integer; kills the specified vnc sessions)"

elif [ "$1" == "list" ]; then
	cat $vnclog |
	while read line; do
		echo $line
	done
	echo "------------------------------"

elif [ "$(echo $1 | gawk -F= '{print $1}')" == "start" ]; then
	vncserver :"$(echo $1 | gawk -F= '{print $2}')" 2> $vnctmp
	session=$(cat $vnctmp | grep "desktop is $HOSTNAME")
	if [ $? == 0 ]; then
		echo $session
		session=$(echo "$session" | gawk -F" desktop is " '{print $2}')
		echo $session >> $vnclog
	fi

else
	mv $vnclog $vnctmp
	touch $vnclog

	cat $vnctmp |
	while read line; do
		on_host=$line 
		session=$(echo $line | gawk -F: '{print $2}')

		if [ "$1" == "kill=$session" -o "$1" == "kill" ]; then
			kill_session=1
		else
			kill_session=0
		fi

		if [ $kill_session == 1 ]; then
			vncserver -kill :$session
			echo Killed vnc session $on_host
			rm -vf $vncdir/$on_host.log
		else
			echo $line >> $vnclog
		fi
	done

fi

if [ -f $vnctmp ]; then
	rm -vf $vnctmp
fi

exit 0