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From: Giorgos Keramidas <keramida@ceid.upatras.gr>
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Date: Mon, 09 Jun 2008 17:24:54 +0300
In-Reply-To: <20080608230712.GA24307@ayn.mi.celestial.com> (Bill Campbell's
	message of "Sun, 8 Jun 2008 16:07:12 -0700")
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Subject: Re: Grep Guru
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On Sun, 8 Jun 2008 16:07:12 -0700, Bill Campbell <freebsd@celestial.com> wrote:
> On Mon, Jun 09, 2008, Raphael Becker wrote:
>>On Sun, Jun 08, 2008 at 10:15:50PM +0200, Wojciech Puchar wrote:
>>> find . -type f -print0|xargs -0 grep <grepoptions> <text to search>
>>
>>There's no more need for find | xargs
>>
>>Try:
>>
>>find . -type -f -exec grep <grepoptions> <text to search> {} \+
>>
>>-exec foo {} \+ behaves like xargs foo
>>-exec foo {} \; exec foo for every file
>
> The issue here is that grep execs grep for each file found while
> xargs batches the files.

The \+ trick behaves like xargs, so this shouldn't be an issue :)

> This is of particular importance if one wants to see the file
> names in the output.

You can ensure the same even if xargs picks up a single file to grep
with

    xargs -0 grep pattern /dev/null

This will cost an open() / read() pair for each batch of files, but it
ensures that grep will always see at least two file names, and it should
print the filename of any matching files.