Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!munnari!otc!uqcspe!tony
From: tony@uqcspe.OZ (Tony O'Hagan)
Newsgroups: comp.unix.wizards
Subject: sh(1) traps & exit status
Message-ID: <1639@uqcspe.OZ>
Date: Thu, 29-Oct-87 21:07:23 EST
Article-I.D.: uqcspe.1639
Posted: Thu Oct 29 21:07:23 1987
Date-Received: Thu, 5-Nov-87 05:58:02 EST
Reply-To: tony@uqcspe.oz (Tony O'Hagan)
Organization: Computer Science, Queensland Uni, Australia
Lines: 34
Keywords: shell, trap, status

In the process of designing systems written (or prototyped) in
bourne shell, I often have scripts that are required to return a
useful exit status.  The problem arises when using traps to clean up
and reliably return the correct status when I'm finnished.
My current solution looks something like this :-

#!/bin/sh
	:
	:
ts=2	# default trap exit status
tdir=/tmp/myprog.$$
trap 'rm -fr $tdir; exit $ts' 0 1 2 3 15
mkdir $tdir || exit 2
input=$tdir/input
output=$tdir/output
	:
	exit 2	# some sort of error 
	:
	ts=1; exit 1	# return exit status 1
	:
ts=0; exit 0	# good-bye

I hate having to assign the exit status to a variable before every exit.
This doesn't work:
	trap 'ts=$?; rm -fr $tdir; exit $ts' 0 1 2 3 15

Anyone found a simpler, cleaner method for this problem ?

	Tony O'Hagan

Computer Science Department,	ACSnet:		tony@uqcspe.oz
University of Queensland,	UUCP:		..!uunet!munnari!uqcspe.oz!tony
St Lucia, Brisbane, 4067	JANET:		uqcspe.oz!tony@ukc
Australia.			Internet:	tony%uqcspe.oz@uunet.uu.net
Phone: +61 7 377 4125		Smar