Skip site navigation (1)Skip section navigation (2)
Date:      Sat, 28 Aug 2010 18:42:29 +0400
From:      Anonymous <swell.k@gmail.com>
To:        Alexander Best <arundel@freebsd.org>
Cc:        freebsd-hackers@freebsd.org
Subject:   Re: tiny patch to prevent head from closing pipes
Message-ID:  <86aao694tm.fsf@gmail.com>
In-Reply-To: <20100828141625.GA69240@freebsd.org> (Alexander Best's message of "Sat, 28 Aug 2010 14:16:25 %2B0000")
References:  <20100828141625.GA69240@freebsd.org>

next in thread | previous in thread | raw e-mail | index | archive | help
Alexander Best <arundel@freebsd.org> writes:

> hi there,
>
> i just had subversion complain about a broken pipe while piping its output
> through awk straight to head [1]. i decided to add a switch to head which will
> tell it to never close a pipe unless the input has stopped [2].

You can do same with sh(1), e.g.

  $ svn log | (IFS=; while read li; do [ $((i+=1)) -le 10 ] && echo "$li"; done)

versus

  $ svn log | (IFS=; while read li && [ $((i+=1)) -le 10 ]; do echo "$li"; done)
  ...
  svn: Write error: Broken pipe


But I think subversion should

> there's probably a much more efficient way of discarding the input without
> closing the pipe unless the input ceased. it's just a 5 minute hack in order to
> see if people find the idea useful or not. ;)

Can you give an example of usefulness that does not involve subversion?



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?86aao694tm.fsf>