ansaurus

Question

Redirecting stdio from a command in os.system() in python

Answer 1

A:

Redirect stderr as well as stdout.

mcandre 2010-07-07 18:02:11

That don't do the job quote from http://docs.python.org/library/os.html#process-managementos.system(command) Execute the command (a string) in a subshell. This is implemented by calling the Standard C function system(), and has the same limitations. Changes to sys.stdin, etc. are not reflected in the environment of the executed command.

Xavier Combelle 2010-07-07 18:06:19

Answer 2

A:

You can redirect stderr and stdout to /dev/null as part of the command itself.

os.system(cmd + "> /dev/null 2>&1")

ealdent 2010-07-07 18:07:38

That work only on an unix system

Xavier Combelle 2010-07-07 18:11:18

Answer 3

A:

If you want to completely eliminate the console that launches with the python program, you can save it with the .pyw extension.

I may be misunderstanding the question, though.

Sean O'Hollaren 2010-07-07 18:09:02

Answer 4

+4 A:

You could consider running the program via subprocess.Popen, with subprocess.PIPE communication, and then shove that output where ever you would like, but as is, os.system just runs the command, and nothing else.

from subprocess import Popen, PIPE

p = Popen(['command', 'and', 'args'], stdout=PIPE, stderr=PIPE, stdin=PIPE)

output = p.stdout.read()
p.stdin.write(input)

Much more flexible in my opinion. You might want to look at the full documentation: Python Subprocess module

Blue Peppers 2010-07-07 18:09:39

Mmm...okay. So than the command is executed on the line P = Popen(...), yes? And it will only show the output when calling p.stdout.read()...yes? Thank you

Leif Andersen 2010-07-07 18:46:14

Okay...the commands did run, but in a separate thread. Is there anyway I can either hault the program while the commands run, or keep it in the same thread? Thank you.

Leif Andersen 2010-07-07 18:54:59

Simply, use p.wait(). However, apparently this can result in deadlocking when using PIPE stdout if the program generates enough output. See the full documentation at http://docs.python.org/library/subprocess.html#subprocess.Popen.wait . However, I think it should work..

Blue Peppers 2010-07-07 19:02:12

Hmm...okay, thanks. Also, it appears that using p.communicate() (rather than p.stdout will help clear the pipe. Thanks.

Leif Andersen 2010-07-07 19:16:27

ansaurus

tags:

views:

answers:

Redirecting stdio from a command in os.system() in python

related questions