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Date: Thu, 06 Dec 2012 11:46:32 +0800
From: David Xu <davidxu@freebsd.org>
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To: Marco Steinbach <coco@executive-computing.de>
Subject: Re: grep -Dskip doesn't skip FIFOs
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On 2012/12/06 11:28, David Xu wrote:
> On 2012/12/06 07:07, Marco Steinbach wrote:
>> Hi there,
>>
>> grep(1) does not seem to skip FIFOs when told to.
>
> <snip>
>
> I think you need a patch to fix it, the bug is in ggrep, it tries to
> open a FIFO before checking if it is a FIFO, then blocked.
>
> http://people.freebsd.org/~davidxu/patch/grep.c.diff
>
> _______________________________________________

>

or the patch:
http://people.freebsd.org/~davidxu/patch/grep.c.diff2

The patch opens file with O_NONBLOCK, then turns off O_NONBLOCK,
and only checks if a file is a FIFO in reset() function.