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Killing a script running in a process via os.system ()

I have a python script that starts several processes. Each process basically just calls the shell script:

from multiprocessing import Process
import os
import logging

def thread_method(n = 4):
    global logger
    command = "~/Scripts/run.sh " + str(n) + " >> /var/log/mylog.log"
    if (debug): logger.debug(command)
    os.system(command)

I am running several of these threads that are designed to run in the background. I want to have a timeout for these threads, so if it exceeds the timeout, they will be killed:

t = []
for x in range(10):
    try:
        t.append(Process(target=thread_method, args=(x,) ) )
        t[-1].start()
    except Exception as e:
        logger.error("Error: unable to start thread")
        logger.error("Error message: " + str(e))
logger.info("Waiting up to 60 seconds to allow threads to finish")
t[0].join(60)
for n in range(len(t)):
    if t[n].is_alive():
    logger.info(str(n) + " is still alive after 60 seconds, forcibly terminating")
     t[n].terminate()

The problem is that calling terminate () in the process threads does not kill the running run.sh script - it continues to run in the background until I forcibly kill it from the command line or finish internally. Is there a way to end and kill the subshell created by os.system ()?

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4 answers

, , subprocess, Popen.terminate(). Process.terminate() . . Process.terminate().

+4

Python 3.3 -: http://docs.python.org/dev/library/subprocess.html

, Python 2.x, :

+2

Based on Stop Python output from reading without freezing? :

import os
import time
from subprocess import Popen

def start_process(n, stdout):
    # no need for `global logger` you don't assign to it
    command = [os.path.expanduser("~/Scripts/run.sh"), str(n)]
    logger.debug(command) # no need for if(debug); set logging level instead
    return Popen(command, stdout=stdout) # run directly

# no need to use threads; Popen is asynchronous 
with open('/tmp/scripts_output.txt') as file:
    processes = [start_process(i, file) for i in range(10)]

    # wait at most timeout seconds for the processes to complete
    # you could use p.wait() and signal.alarm or threading.Timer instead
    endtime = time.time() + timeout
    while any(p.poll() is None for p in processes) and time.time() < endtime:
        time.sleep(.04)

    # terminate unfinished processes
    for p in processes:
        if p.poll() is None:
            p.terminate()
            p.wait() # blocks if `kill pid` is ignored

Use p.wait(timeout)if available.

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