Date: Mon, 19 Mar 2007 15:52:41 +0100 (CET) From: Oliver Fromme <olli@lurza.secnetix.de> To: freebsd-hackers@FreeBSD.ORG, youshi10@u.washington.edu Subject: Re: Possible grep(1) bug or user error :)? Message-ID: <200703191452.l2JEqfkp044819@lurza.secnetix.de> In-Reply-To: <45FC61FF.3090009@u.washington.edu>
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Garrett Cooper wrote:
> I was recently grepping a directory and outputting to a file located in
> the same directory as follows:
>
> grep -ri {key} * > {key}.found
>
> The thing is that grep kept on feeding off of the {key}.found file and
> eventually ate up all the free space on the device (~12GB).
>
> Thankfully it wasn't one of my primary devices, so deleting it wasn't an
> issue. However I was wondering if this case should be considered (in
> error checking) and another option should be added to output grep info
> to a file, instead of /dev/stdout, which would affect the behavior of
> the --exclude flag (i.e. the output file would automatically be added to
> --exclude's relevant array of non-searched arguments).
It's not a problem with grep, it's a problem with your shell.
Obviously you're using csh or tcsh, which create any files
for redirection _first_, and then expand wildcards, so the
redirected file is included in the expansion. That's one of
the reasons csh/tcsh is considered harmful. :-)
No other shell has that behaviour, i.e. all of sh, ksh, zsh
and bash expand the wildcard first, then create the file for
redirection, so it is not included in the expansion of the
wildcard (unless it already existed before, of course).
Best regards
Oliver
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