Rudimentary TurboVNC Session Manager

vncsession

#!/bin/bash
#
#  Copyright (C) 2016 D. R. Commander
#
#  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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
#  USA.

# This script provides a rudimentary demonstration of how to implement
# session management with TurboVNC.

if [ "$1" = "" ]; then
	echo
	echo "USAGE: $0 <[user@]server> [session]"
	echo
	echo "session = existing session (e.g. \":1\") or \"new\" to force a new session"
	echo "          to be created"
	echo
	exit 1
fi

if [ ! -x /opt/TurboVNC/bin/vncviewer ]; then
	echo ERROR: TurboVNC Viewer is not installed
	exit 1
fi

FORCENEW=0

if [ "$2" = "new" ]; then
	FORCENEW=1
elif [ "$2" != "" ]; then
	echo Connecting to $1$2 ...
	/opt/TurboVNC/bin/vncviewer $1$2 -tunnel
	exit $?
fi

echo Listing TurboVNC sessions ...
SESSIONS=`ssh $1 "/opt/TurboVNC/bin/vncserver -list >/dev/null && /opt/TurboVNC/bin/vncserver -list | grep \:[0-9] | cut -f1"`
if [ $? -ne 0 ]; then
	echo "ERROR: Could not list TurboVNC sessions on $1."
	exit 1
fi
NSESSIONS=`echo $SESSIONS | wc -w`

if [ $NSESSIONS -eq 0 -o $FORCENEW = 1 ]; then
	echo Starting a new session ...
	SESSIONS=`ssh $1 "/opt/TurboVNC/bin/vncserver -localhost -autokill -nohttpd -securitytypes none 2>&1"`
	if [ $? -ne 0 ]; then
		echo "ERROR: Could not start TurboVNC session on $1."
		exit 1
	fi
	SESSIONS=`echo $SESSIONS | sed s/.*display\ //g | sed s/\ Starting.*//g | cut -f2 -d:`
	SESSIONS=\:$SESSIONS
elif [ $NSESSIONS -gt 1 ]; then
	echo $NSESSIONS sessions available:
	echo $SESSIONS
	echo Defaulting to first session
	SESSIONS=`echo $SESSIONS | cut -f1 -d' '`
fi

echo Connecting to $1$SESSIONS ...
/opt/TurboVNC/bin/vncviewer $1$SESSIONS -tunnel
exit $?

A much nicer TurboVNC Session Manager feature has been implemented in the 3.0 evolving/dev pre-release build of TurboVNC: https://turbovnc.org/DeveloperInfo/PreReleases. It uses the embedded SSH client in the Java TurboVNC Viewer. Please give it a try and let me know what breaks.