Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!lll-winken!uunet!mcvax!guido
From: guido@cwi.nl (Guido van Rossum)
Newsgroups: comp.windows.x
Subject: Re: Figuring out the right DISPLAY variable when you rlogin.
Message-ID: <8054@boring.cwi.nl>
Date: 25 Apr 89 15:20:28 GMT
References: <2647@buengc.BU.EDU> <19688@iuvax.cs.indiana.edu> <2475@helios.ee.lbl.gov>
Sender: news@cwi.nl
Reply-To: guido@cwi.nl (Guido van Rossum)
Organization: The Royal Society for Prevention of Cruelty to Amoebae
Lines: 53

Locally, we use this script (called xremote) which can start an
arbitrary program remotely.  We also have a specialization (called
xrlogin) which is equivalent to "xremote <hostname> xterm -ls".  All
this only works for sh or ksh (no csh lovers here).  Improvements over
other scripts published before: knows not to touch $DISPLAY if it
doesn't start with ":" or "unix:"; sets $PATH to find most X utilities
(you may have to change this according to local circumstances); and it
has a -d option to display error messages in case something is wrong
and you can't figure out what because all I/O is lost normally (usually
a bad .rhosts file, or a bad path).  (The script closes all file
descriptors because we encountered some problems in rshd.)

#!/bin/sh
#
# xremote [-d] hostname xclientname [argument] ...
#
# Run an X client in the background in a remote machine.
# The following tricks are necessary:
# - set or patch the DISPLAY variable
# - set the remote PATH variable

case $1 in
-d)
  set -x; shift; redirect="";;
*)
  redirect="</dev/null >/dev/null 2>&1  3>&- 4>&- 5>&- 6>&- 7>&- 8>&- 9>&- &";;
esac

case $# in
0|1)	echo "usage: xremote [-d] hostname xclientname [argument] ..." 1>&2;
	exit 2;;
esac

host=$1
shift

local=`hostname`

case $DISPLAY in
:*)	display=$local$DISPLAY;;
unix:*)	display=`echo "$DISPLAY" | sed "s/unix/$local/"`;;
*)	display=$DISPLAY;;
esac

rsh	"$host" \
	"DISPLAY=$display" \
	"PATH=:/bin:/usr/bin:/usr/ucb:/usr/local:/usr/local/X/bin" \
	"$@ $redirect" $redirect

--
Guido van Rossum, Centre for Mathematics and Computer Science (CWI), Amsterdam
guido@cwi.nl or mcvax!guido or guido%cwi.nl@uunet.uu.net
"Repo man has all night, every night."