#!/bin/bash
#
# Version: 1.0 3/30/2007
# Author:  Martin Fick
# Copyright License: GNU GPL2

# This simple program will keep track of your latest display
# if it is set and it will return the last known value if it
# is unset.  Use this in environments where you want your
# display to automatically get set whenever you log into
# remote machines.  Appropriate stderr messages are output
# so that you are aware of your settings.
#
# This display value gets stored in ~/.xdisplay

# To use, put this in your path somewhere, say ~/bin and:
#
# In csh, do:  setenv DISPLAY `xdisplay`
#
# In sh, do:   export DISPLAY `xdisplay`
#


d_read()
{
  cat "$DB"
}

d_write()
{
  echo "$1" > "$DB"
  chmod go-w "$DB"
}


d_fix()
{
  if [ ! -z $(echo "$1"|grep '^:') ] ; then
    echo "$(hostname)$1"
  else
    echo "$1"
  fi
}


DB=/usr2/qmarfic/.xdisplay

if [ -z "$DISPLAY" ] ; then
  if [ -f "$DB" ] ; then
    DISPLAY=$(d_read)
    DISPLAY=$(d_fix "$DISPLAY")
    echo "Display unset, setting to $DISPLAY" >&2

    echo "$DISPLAY"
    exit
  fi

  read "DISPLAY is unset, please set it now:" DISPLAY
  DISPLAY=$(d_fix "$DISPLAY")

  echo "Display unset, setting to $DISPLAY" >&2

else

  DISPLAY=$(d_fix "$DISPLAY")

  echo "Display set, writting $DISPLAY to DB" >&2
fi

d_write "$DISPLAY"

echo "$DISPLAY"