Run a program from python, and have it continue to run after the script is killed
nohup, python, subprocess
Solution
The usual way to do this on Unix systems is to fork and exit if you're the parent. Have a look at `os.fork()` .
Here's a function that does the job:
def spawnDaemon(func):
# do the UNIX double-fork magic, see Stevens' "Advanced
# Programming in the UNIX Environment" for details (ISBN 0201563177)
try:
pid = os.fork()
if pid > 0:
# parent process, return and keep running
return
except OSError, e:
print >>sys.stderr, "fork #1 failed: %d (%s)" % (e.errno, e.strerror)
sys.exit(1)
os.setsid()
# do second fork
try:
pid = os.fork()
if pid > 0:
# exit from second parent
sys.exit(0)
except OSError, e:
print >>sys.stderr, "fork #2 failed: %d (%s)" % (e.errno, e.strerror)
sys.exit(1)
# do stuff
func()
# all done
os._exit(os.EX_OK)
Problem
I've tried running things like this: ``` subprocess.Popen(['nohup', 'my_command'], stdout=open('/dev/null', 'w'), stderr=open('logfile.log', 'a')) ``` This works if the parent script exits gracefully, but if I kill the script (Ctrl-C), all my child processes are killed too. Is there a way to avoid this? The platforms I care about are OS X and Linux, using Python 2.6 and Python 2.7.