Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!crdgw1!uunet!convex!usenet
From: tchrist@convex.COM (Tom Christiansen)
Newsgroups: comp.unix.questions
Subject: Re: Return status of 'rsh'
Message-ID: <1991Apr10.000843.5391@convex.com>
Date: 10 Apr 91 00:08:43 GMT
References: <PBROWN.91Apr9194949@vtopus.cs.vt.edu>
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Reply-To: tchrist@convex.COM (Tom Christiansen)
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Organization: CONVEX Software Development, Richardson, TX
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From the keyboard of pbrown@vtopus.cs.vt.edu (Patrick R. Brown):
:I am trying to set up a shell script to check for mail on a remote
:machine.  The script is the following:
:
:	#! /bin/sh
:	#
:	#	Check mail on CSGrad since I can't get mail here!!!!
:	#
:	if [ `rsh csgrad mail -e` ]
:	then
:		echo You have mail on CSGrad.
:	else
:		echo You do not have mail on CSGrad.
:	fi
:
:This looks nice, but it doesn't work.  (I never "have" mail, even when
:I do) What can I do (if anything) to get 'rsh' to return the status of
:the command being run remotely.  The Ultrix man pages don't have
:anything to say on this topic.  If 'rsh' won't do this, are there any
:other ideas?

You can use Maarten Litmath's ersh script where you have rsh.  Your
script will behave as you expect it to.

--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>&-