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From: ghe@nucthy.physics.orst.edu (Guangliang He)
Newsgroups: comp.unix.questions
Subject: Re: Bourne shell question
Keywords: pipe, logical 'or' and " pg ".
Message-ID: <13022@orstcs.CS.ORST.EDU>
Date: 11 Oct 89 00:00:31 GMT
References: <1943@sactoh0.UUCP>
Sender: usenet@orstcs.CS.ORST.EDU
Reply-To: ghe@nucthy.PHYSICS.ORST.EDU (Guangliang He)
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Organization: Dept. of Physics, Oregon State University
Lines: 26

Sorry to post it, but the mailer on our machine dosen't know the UUCP
domain.

In article <1943@sactoh0.UUCP> jak@sactoh0.UUCP (Jay A. Konigsberg) writes:
> 
> [deleted text here] 
> ls -l | grep "^d" | pg || echo "There are no subdirectories"
> 
> When the pipe into " pg " is removed it works ok, but I would like
> to keep the pg in the script.
> [deleted text here] 
> 

When you have 'pg' in your script, the exit status of left hand side
always 0. Without the 'pg', when 'grep' fails, the exit status of left
hand side is a non zero value so the script goes to the right hand side
of the || op.  Then it echos "There ..."

Hope it helps.
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