Comments on: set timeout for a shell command in python

By: philipp.keller

philipp.keller — Tue, 17 Aug 2010 19:16:22 +0000

Hm, I've just tested in Python 2.6.1 and here it works. Let me know when you find the reason behind this (IMO a good place to post python questions is stackoverflow.com)

By: Abhishek Kona

Abhishek Kona — Tue, 17 Aug 2010 15:51:51 +0000

Does not seem to work in Python 2.6.5

process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
File “/usr/lib/python2.6/subprocess.py”, line 633, in __init__
errread, errwrite)
File “/usr/lib/python2.6/subprocess.py”, line 1139, in _execute_child
raise child_exception

By: wrybread

wrybread — Tue, 04 Mar 2008 23:51:55 +0000

Also note that the process module has timeout built in. No need to poll, no need to terminate the spawned process:

http://trentm.com/projects/process/

import process
try:
p = process.ProcessOpen(“notepad.exe”)
p.wait(timeout=5)
except process.ProcessError:
print “timeout!”

By: wrybread

wrybread — Mon, 03 Mar 2008 08:41:46 +0000

Small typo in the above Windows code. Should read:

import ctypes
TerminateProcess = ctypes.windll.kernel32.TerminateProcess
TerminateProcess(int(popen._handle), -1)

(Note the underscore added before “handle”).

By: Giovanni Bajo

Giovanni Bajo — Fri, 22 Feb 2008 15:26:09 +0000

For Windows, you can use:

import ctypes
TerminateProcess = ctypes.windll.kernel32.TerminateProcess
TerminateProcess(int(process.handle), -1)

By: Lee Steensland

Lee Steensland — Tue, 02 Oct 2007 16:40:58 +0000

With a one more line of code, and a change to another, your function will act exactly like popen: Note, this requires python 2.4+ Enjoy!

PLAIN TEXT

PYTHON:

def TIMEOUT_COMMAND(command, timeout):
"""call shell-command and either return its output or kill it
if it doesn't normally exit within timeout seconds and return None"""
import subprocess, datetime, os, time, signal
cmd = command.split(" ")
start = datetime.datetime.now()
process = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
while process.poll() is None:
time.sleep(0.2)
now = datetime.datetime.now()
if (now - start).seconds> timeout:
os.kill(process.pid, signal.SIGKILL)
os.waitpid(-1, os.WNOHANG)
return None
return process.stdout.readlines()

By: Joe Rantala

Joe Rantala — Fri, 18 May 2007 15:33:44 +0000

Note that os.kil is not available on windows. Too bad

By: philipp.keller

philipp.keller — Fri, 30 Mar 2007 07:35:31 +0000

Thanks Juan, I fixed the function and the example so the errors won't occur anymore. Sorry for the inconvenience.

By: Juan Manuel Caicedo

Juan Manuel Caicedo — Fri, 30 Mar 2007 03:03:58 +0000

I tried to use the function but I found two problems.

First, the command argument is passed as a string, not a list. Using a string I was having the following error:

OSError: [Errno 2] No such file or directory

Then, a 'No such process' error appeared when the process has run for too long. That happend when the os.kill function was called for the second time. I added a 'return None' to fix this problem.