Newsgroups: comp.unix.shell
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!uunet!convex!usenet
From: Tom Christiansen <tchrist@convex.COM>
Subject: Re: how to force rsh to exit with status of remote command
Message-ID: <1991Jun03.132744.29465@convex.com>
Sender: usenet@convex.com (news access account)
Nntp-Posting-Host: pixel.convex.com
Reply-To: tchrist@convex.COM (Tom Christiansen)
Organization: CONVEX Software Development, Richardson, TX
References: <18999@cgl.ucsf.EDU>
Date: Mon, 03 Jun 1991 13:27:44 GMT
Lines: 84

From the keyboard of rodgers@maxwell.mmwb.ucsf.edu (R. P. C. Rodgers, M.D.):
:Reading the manual pages concerned with rsh and experimentation thus
:far fail to show how rsh can be made to exit with the status of the command
:it is executing on a remote host (if indeed this is possible...).
:The rsh always seems to exit with a status of 0, even if the command on the
:remote hosts fails.

rsh will exit !0 if it fails to make the connection, or loses it,
or whatnot.  I use maarten Litmaath's "ersh" front end [enclosed]
when I want an rsh that gives me the remote status.

--tom

#!/bin/sh
# @(#)ersh 2.4 91/01/30 Maarten Litmaath
# This rsh front-end returns the exit status of the remote command.
# It works OK with sh/csh-compatible shells on the remote (!) side.
# If there is no remote command present, /usr/ucb/rlogin is invoked.
# Usage: see rsh(1).

unset hostname lflag nflag user

case $1 in
-l)
	;;
*)
	hostname=$1
	shift
esac

case $1 in
-l)
	lflag=-l
	user=$2
	shift 2
esac

case $1 in
-n)
	nflag=-n
	shift
esac

case $hostname in
'')
	hostname=$1
	shift
esac

case $# in
0)
	exec /usr/ucb/rlogin $lflag ${user+"$user"} "$hostname"
esac

AWK='
	NR > 1 {
		print prev;
		prev = $0;
		prev1 = $1;
		prev2 = $2;
	}
	NR == 1 {
		prev = $0;
		prev1 = $1;
		prev2 = $2;
	}
	END {
		if (prev1 ~ /[0-9]*[0-9]0/)
			exit(prev1 / 10);
		if (prev1 == "0")
			exit(prev2);
		print prev;
		exit(1);
	}
'

exec 3>&1

/usr/ucb/rsh "$hostname" $lflag ${user+"$user"} $nflag \
	"(${*-:}); sh -c '"'echo "$0 $1" >&2'\'' $?0 "$status"' \
	2>&1 >&3 3>&- | awk "$AWK" >&2 3>&-
--
Tom Christiansen		tchrist@convex.com	convex!tchrist
	    "Perl is to sed as C is to assembly language."  -me