How to kill a python child process created with subprocess.check_output() when the parent dies?

by

Yes, you can achieve this by two methods. Both of them require you to use Popen instead of check_output. The first is a simpler method, using try..finally, as follows:

from contextlib import contextmanager

@contextmanager
def run_and_terminate_process(*args, **kwargs):
try:
    p = subprocess.Popen(*args, **kwargs)
    yield p        
finally:
    p.terminate() # send sigterm, or ...
    p.kill()      # send sigkill

def main():
    with run_and_terminate_process(args) as running_proc:
        # Your code here, such as running_proc.stdout.readline()

This will catch sigint (keyboard interrupt) and sigterm, but not sigkill (if you kill your script with -9).

The other method is a bit more complex, and uses ctypes’ prctl PR_SET_PDEATHSIG. The system will send a signal to the child once the parent exits for any reason (even sigkill).

import signal
import ctypes
libc = ctypes.CDLL("libc.so.6")
def set_pdeathsig(sig = signal.SIGTERM):
    def callable():
        return libc.prctl(1, sig)
    return callable
p = subprocess.Popen(args, preexec_fn = set_pdeathsig(signal.SIGTERM))

More Related Contents:

  1. Sub-process in Python execute two task? [closed]
  2. How to terminate a python subprocess launched with shell=True
  3. How to use `subprocess` command with pipes
  4. ImageMagick not authorized to convert PDF to an image
  5. Python spawn off a child subprocess, detach, and exit
  6. Python: how to kill child process(es) when parent dies?
  7. Cross-platform subprocess with hidden window
  8. How to get output from subprocess.Popen(). proc.stdout.readline() blocks, no data prints out
  9. ‘yes’ reporting error with subprocess communicate()
  10. Understanding python subprocess.check_output’s first argument and shell=True [duplicate]
  11. Sending a password over SSH or SCP with subprocess.Popen
  12. How to install and import Python modules at runtime
  13. Actual meaning of ‘shell=True’ in subprocess
  14. Python subprocess readlines() hangs
  15. Execute Python script via crontab
  16. Launch a completely independent process
  17. Multiple inputs and outputs in python subprocess communicate
  18. Python C program subprocess hangs at “for line in iter”
  19. running multiple bash commands with subprocess
  20. python getoutput() equivalent in subprocess [duplicate]
  21. Calling a python script from command line without typing “python” first
  22. How to run multiple commands synchronously from one subprocess.Popen command?
  23. OSError 38 [Errno 38] with multiprocessing
  24. How do I eliminate Windows consoles from spawned processes in Python (2.7)? [duplicate]
  25. How can I send a signal from a python program?
  26. Get local network interface addresses using only proc?
  27. Environment Variables when script run by cron
  28. On linux SUSE or RedHat, how do I load Python 2.7
  29. subprocess call ffmpeg (command line)
  30. How can I capture the stdout output of a child process?

Leave a Comment