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Python - SIGPIPE handled bug

Dieter Maurer dieter at handshake.de
Sun Jan 23 05:10:43 EST 2000 
Hallo Randall

Randall Hopper <aa8vb at yahoo.com> writes on Fri, 21 Jan 2000 16:29:25 -0500:
>     > python -c "for i in xrange(1000): print 'Some output'" | head -2
>     Some output
>     Some output
>     Traceback (innermost last):
>       File "<string>", line 1, in ?
>     IOError: [Errno 32] Broken pipe
>   ---------------------------------------------------------------------------
> 
> python getting a SIGPIPE is appropriate behavior.  "Whether" it gets a
> SIGPIPE is up to the shell, in UNIX:
It seems, that in your case Python does not get a SIGPIPE but
the "write" returns "-1" and "errno==EPIPE".

According to POSIX, this is the behaviour, if SIGPIPE is not handled
by the default action:
       EPIPE  fd is connected to a pipe or socket  whose  reading
              end  is closed.  When this happens the writing pro­
              cess will receive a SIGPIPE signal; if it  catches,
              blocks or ignores this the error EPIPE is returned.

The SIGPIPE handling under Python 1.5.2/Linux 2/Bash seems to be
to ignore the signal (possibly inherited from the bash!).

If you do not like this, use:
	import signal
	signal.signal(signal.SIGPIPE,signal.SIG_DFL)

Dieter
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