xnest

#!/bin/sh
# $Id: xnest,v 1.3 2002/06/24 07:33:44 james Exp $
#
# Script to start a nested X server (Xnest) session.  Good for WM hacking.
#
# Copyfnord (K) 3168, James A. Crippen <james@unlambda.com>
# This file is in the public domain.  It's just a throwaway.  No
# warranties expressed or implied.  If it breaks you get to keep
# both pieces.
#
# If you run this in the foreground you will get messages on your terminal.
# If however you run this script as
#   xnest 2>&1 >> $HOME/.xnest-errors &
# you will get an xterm in the Xnest server that will watch this log file.
#
# NOTES:
# This has only been tested with XFree86 4.  It will *probably* work with
# other X distributions but there's no guarantee.  Please contribute
# changes and enhancements back to me.
#
# You should probably change the FONTPATH to your own liking.
#
# This script doesn't load any X resource files explicitly.  They may
# be loaded implicitly though.

# First check if X is running.
if [ -z "$DISPLAY" ]; then
    echo "X doesn't appear to be running.  Lose lose."
    exit 1
fi

# Overwrite the log file.  This is for the test at the end of the script.
LOGFILE=$HOME/.xnest-errors
cat /dev/null > $LOGFILE

# Add one to current DISPLAY variable.  The assumption is that the next
# DISPLAY will be unused.  The sed cruft strips out the colon and the
# screen number (y in :x.y).
DISPNUM=`echo $DISPLAY | sed -e 's/://' -e 's/\..//'`
NEWDISPLAY=:`expr $DISPNUM + 1`

echo "Xnest display will be $NEWDISPLAY but if that is in use you'll lose."

# Set up the font path.  This must be configured for each system.  Why
# does this exist?  Because Xnest (in XFree86) doesn't read the host
# X server's font path, nor does it read the font path in the XF86Config
# file.  Instead it uses the X default, which is not what *I* want.
XROOT=/usr/X11R6
FONTS=$XROOT/lib/X11/fonts
FONTPATH=$FONTS/efont,$FONTS/Type1,$FONTS/TTF,$FONTS/100dpi,$FONTS/75dpi,$FONTS/misc,$FONTS/local

# Now run Xnest.
#  -ac turns off access control (otherwise you can't get to the Xnest server)
#  -fp sets the font path
#  -p  sets the screen-saver timeout
#
# By default Xnest makes a window 3/4 the size of the screen.  Specific
# resolutions can be set with -geometry.
#
# There are lots of other options for Xnest.  Read the manual pages Xnest(1)
# and Xserver(1) for details.
echo "Starting Xnest..."
Xnest $NEWDISPLAY -ac -p 0 -fp $FONTPATH &

# For convenience we switch DISPLAY variables.  Everything from here onwards
# will use the Xnest display automatically.  Exporting it should allow
# programs started from within the xterm/window manager to get the right
# DISPLAY value.
export DISPLAY=$NEWDISPLAY

# Now start an xterm.  This *must* be done first after starting Xnest.
# Otherwise things get confused.  After the last program exits the Xnest
# server (like all X servers) will reset itself, and will flush the
# configured fontpath, colormap, all properties, etc.
echo "Starting xterm as first client."
xterm &

# Set the background to something less horrible than 50% stipple.
echo "Changing the background to something mutual."
#xsetroot -solid gray45

# Now read the xmodmap file.
if [ -r $HOME/.xmodmap ]; then
    echo "Reading \$HOME/.xmodmap..."
    xmodmap $HOME/.xmodmap
else
    echo "No \$HOME/.xmodmap file found!  Oh well."
fi

# If we're writing the log file then start an xterm to watch it.  'test -s'
# means 'regular file exists and is not empty'.
if [ -s $LOGFILE ]; then
    echo "Starting xterm to watch the log file."
    xterm -geometry 120x10-0-0 -fn 5x8 -name 'Xnest log' -title 'Xnest log' \
        -bg rgb:0/0/5a -fg steelblue1 -e tail -f $LOGFILE &
else
    echo "Logfile appears to be empty.  Not watching it."
fi

# Now run the window manager.
#exec eclipse
xterm