From: Philippe Troin <phil@fifi.org>
To: Aaron Davies <agdavi01@louisville.edu>
Cc: zsh-users@sunsite.dk
Subject: Re: Slightly OT: Error-Handling in a Pipeline, preferably non-zsh
Date: 15 Aug 2004 20:03:30 -0700 [thread overview]
Message-ID: <87n00v4we5.fsf@ceramic.fifi.org> (raw)
In-Reply-To: <2FF1BBB1-EF20-11D8-9C9B-000A95EDC31A@louisville.edu>
Aaron Davies <agdavi01@louisville.edu> writes:
> How do I do return-value error handling in the middle of a pipeline?
> I'd ideally like to keep this to as basic a shell level as possible,
> plain (Bourne) sh-compatible if it can be done, though a bash or zsh
> solution will be fine if not. I'm tring to write a simple script that
> will apply a command to all processes matching a name--sort of a
> generalized "killall". At the moment, it looks like this:
>
> #!/bin/sh
>
> name=$1
> shift
>
> ps aux | grep $name | grep -v grep | grep -v $0 | awk '{ print $2 }' |
> xargs $@
>
> and it works fine, and I'd like to keep it at that level of
> simplicity. The only thing is, I'd like to make it stop and return 1
> if there are no matching processes. (At the moment, it calls the
> command with an empty argument list.) The intuitive thing to do seems
> to be
>
> ps aux | grep $name | grep -v grep | ( grep -v $0 || exit 1 ) | awk '{
> print $2 }' | xargs $@
Use your first idiom and check $pipestatus[4].
Phil.
next prev parent reply other threads:[~2004-08-16 3:06 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-08-16 1:04 Aaron Davies
2004-08-16 2:42 ` Bart Schaefer
2004-08-16 3:33 ` Aaron Davies
2004-08-16 7:41 ` Bart Schaefer
2004-08-16 12:40 ` Aaron Davies
2004-08-16 14:53 ` DervishD
2004-08-17 3:06 ` Bart Schaefer
2004-08-16 3:03 ` Philippe Troin [this message]
2004-08-16 3:30 ` Aaron Davies
2004-08-16 7:51 ` Bart Schaefer
2004-08-16 12:41 ` Aaron Davies
2004-08-16 16:08 ` Dan Nelson
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