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Re: test for "command not found" before expanding shell parameters
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From: |
Chet Ramey |
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Subject: |
Re: test for "command not found" before expanding shell parameters |
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Date: |
Tue, 22 Apr 2014 16:03:29 -0400 |
> On Mon, Apr 21, 2014 at 3:16 AM, Andreas Schwab <schwab@linux-m68k.org> wrote:
> > And if $greo is null the condition will also be true.
>
> Really? <runs quick test> I'll be damned. That explains this problem
> I've been having.
Yes. `test' operates based on the number of arguments it receives. If you
don't quote `$greo' and it expands to nothing, test receives a single
argument (-n), tests it for nullness, and returns success.
Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRU chet@case.edu http://cnswww.cns.cwru.edu/~chet/