Running program in separate X display

It may often be handy to run some program in separate X display. I.e. 3D games for gaining performance, or making alt+tab-style switching possible with ctrl+alt+[F7-F12].

The simplest way would be:

xinit appname -- :10

Basic script

But if you have ~/.xinitrc in place, you should use full path to app to override it. Also there can be some environment variables and X options to pass. So the smart way would be to pack it all into a wrapper:

#!/bin/bash

# use this vt:
# first available VT
LVT=`fgconsole --next-available`
#LVT=7

# use this display number
NEWDISP=":10" 


# test if executable exists
[ -x "$(which $* 2> /dev/null)" ] 
if [ "$?" != "0" ] ; then
echo "No such executable!"
# if running from X, display zenity dialog:
[ -z "$DISPLAY" ] || zenity --error --text="No such executable!" 2> /dev/null
exit 127
fi

# if runing from X, display zenity dialog:
[ -z "$DISPLAY" ] || zenity --question --title "Launch?" --text="Will launch \"$*\" on tty$LVT. Continue?" 2> /dev/null || exit 1

echo "Will launch \"$*\" on tty$LVT..."
[ -z "$DISPLAY" ] && sleep 1s


# this flag is used for indicating unaccessible or broken DRI. 
# it is set, for example, when using fglrx+compiz-manager
# Some games will refuse to start if it is set.
# unsetting it should not do any harm, and can be useful.
unset LIBGL_ALWAYS_INDIRECT


##########################################################
# main execution line with automatic full path retrieval.
xinit "$(which $* 2> /dev/null)" -- $NEWDISP vt$LVT -nolisten tcp -br &
##########################################################

# set our new dislplay
DISPLAY=$NEWDISP
# wait some timefor X to load
sleep 4s

# then we set useful parameters

# disable non-linear mouse acceleration
xset m 1 0

# disable hard-coded default 10m screensaver
xset s 0 0

# while X is running, persistently do something useful
# i.e. prevent apps from enabling mouse acceleration and screensaver
while xset -q > /dev/null
do 
xset m 1 0
xset s 0 0
sleep 3s
done

wait
sleep 5

General principle: set variables before xinit line, and xset parameters after.

Save it as /usr/bin/xrun

After that launching app in separate X display should be as easy as typing

xrun appname

remove lines containing zenity, if you do not have zenity installed.

--Psycho zs 13:02, 18 December 2010 (EST)