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From: chet@odin.INS.CWRU.Edu (Chet Ramey)
Newsgroups: comp.unix.questions
Subject: Re: What does this sh script line do?
Message-ID: <1991Jun12.200958.19849@usenet.ins.cwru.edu>
Date: 12 Jun 91 20:09:58 GMT
References: <1991Jun11.045504.26169@thunder.mcrcim.mcgill.edu> <2142@mitisft.Convergent.COM>
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In article <2142@mitisft.Convergent.COM> dold@mitisft.Convergent.COM (Clarence Dold) writes:

>> . ${NEWSCONFIG-/usr/lib/news/bin/config}

>Isn't the correct syntax ":-" ?  My shell likes it with or without the : 
>. ${NEWSCONFIG:-/usr/lib/news/bin/config}

No, not necessarily.  The `-' causes sh to substitute the RHS if the LHS
is unset.  The `:-' causes substitution if the LHS is unset or null.

Chet
-- 
                    ``You shoot John Sununu.  Twice.''

Chet Ramey			  Internet: chet@po.CWRU.Edu
Case Western Reserve University	  NeXT Mail: chet@macbeth.INS.CWRU.Edu