tiny patch to prevent head from closing pipes

Anonymous swell.k at gmail.com
Sat Aug 28 14:45:32 UTC 2010

Alexander Best <arundel at 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)


  $ 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?

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