Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!eecae!tank!mimsy!chris
From: chris@mimsy.UUCP (Chris Torek)
Newsgroups: comp.unix.questions
Subject: Re: Re^4: Bourne Shell: Variable defined?
Message-ID: <16536@mimsy.UUCP>
Date: 26 Mar 89 04:59:27 GMT
References: <1819@umbc3.UMBC.EDU> <9899@smoke.BRL.MIL> <2202@solo1.cs.vu.nl> <2209@solo2.cs.vu.nl>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 13

>I wrote:
>>	if [ "${vax+X}" ]; then echo is set; else echo not set; fi

In article <2209@solo2.cs.vu.nl> maart@cs.vu.nl (Maarten Litmaath) notes
that the ""s are not needed (true) and suggests instead:

	[ ${foo+bar} ] && echo core || echo dumped

Alas, `||' misbehaves in some `sh'es when -e is set, whereas `if'
misbehaves in fewer (but not none).
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@mimsy.umd.edu	Path:	uunet!mimsy!chris