jay wrote:
> Hello,
>
> If I have multiple Popen calls I need to make, how can I turn these
> into a function?
Since you're only interested in the output of the last command on the
pipeline, I don't see a reason to keep track of them all. I'd do
something like this:
def pipeline( *commandlist ):
last = None
for command in commandlist:
last = Popen( command,
stdin=last.stdout if last else None,
stdout=PIPE )
return last.communicate()[0]
print pipeline( ("ls", "-la", "/etc"),
("grep", "hosts"),
("awk", "{print $1}") )
returns:
lrwxrwxrwx
Hope that helps,
e.
> from subprocess import Popen, PIPE
>
> p1 = Popen(['ls', '-l', '-a', '/etc'],stdout=PIPE)
> p2 = Popen(['grep', 'hosts'], stdin=p1.stdout, stdout=PIPE)
> p3 = Popen(['awk', '{print $1}'], stdin=p2.stdout, stdout=PIPE)
> output = p3.communicate()[0]
>
> p1 = Popen(['ps', '-ef'], stdout=PIPE)
> p2 = Popen(['grep', '-v', '2348'], stdin=p1.stdout, stdout=PIPE)
> output = p2.communicate()[0]
>
> I would be sending an arbitrary number of PIPES with each function call.
>
> I'm a little stumped as to how to handle the variables. If I have an
> arbitrary number of PIPES, how do I declare my variables (p1, p2, p3,
> etc...) ahead of time in the function??
>
> Thanks for any suggestions!
>
> Jay
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>
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