On Wed, 06 Jan 2010 19:05:40 -0800, Steven K. Wong wrote:
> Well, the example code at
> http://www.python.org/ ... /subprocess.html#replacing-shell-pipeline
> has the same issue:
> Perhaps the doc can be improved to remind folks to close p1.stdout if
> the calling process doesn't need it, unless
On Wed, 06 Jan 2010 11:39:37 -0800, Steven K. Wong wrote:
> Suppose now all the prog1.poll() calls/loop are replaced by a single
> prog1.wait(). Without the explicit prog1.stdout.close(), prog1.wait()
> will not return, so the calling process still hangs. Because calling
> prog1.wait() means that
Well, the example code at
http://www.python.org/doc/2.6.2/library/subprocess.html#replacing-shell-pipeline
has the same issue:
output=`dmesg | grep hda`
==>
p1 = Popen(["dmesg"], stdout=PIPE)
p2 = Popen(["grep", "hda"], stdin=p1.stdout, stdout=PIPE)
output = p2.communicate()[0]
After communicate
On Jan 6, 10:30 am, Nobody wrote:
> I think that you should close prog1.stdout here. Otherwise, there will
> be two readers on the pipe (the calling process and prog2). Even if one of
> them dies, there's always the possibility that the caller might eventually
> decide to read prog1.stdout itself.
On Tue, 05 Jan 2010 15:50:39 -0800, Steven K. Wong wrote:
> Below, I have a Python script that launches 2 child programs, prog1
> and prog2, with prog1's stdout connected to prog2's stdin via a pipe.
> (It's like executing "prog1 | prog2" in the shell.)
>
> If both child programs exit with 0, the
BTW, I'm using Python 2.6.2 on Linux.
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Below, I have a Python script that launches 2 child programs, prog1
and prog2, with prog1's stdout connected to prog2's stdin via a pipe.
(It's like executing "prog1 | prog2" in the shell.)
If both child programs exit with 0, then the script runs to
completion. But if prog2 exits with non-0, prog1
