Python: How to prevent subprocesses from receiving CTRL-C / Control-C / SIGINT

Somebody in the #python IRC-Channel (Freenode) helped me by pointing out the preexec_fn parameter of subprocess.Popen(…):

If preexec_fn is set to a callable
object, this object will be called in
the child process just before the
child is executed. (Unix only)

Thus, the following code solves the problem (UNIX only):

import subprocess
import signal

def preexec_function():
    # Ignore the SIGINT signal by setting the handler to the standard
    # signal handler SIG_IGN.
    signal.signal(signal.SIGINT, signal.SIG_IGN)

my_process = subprocess.Popen(
    ["my_executable"],
    preexec_fn = preexec_function
)

Note: The signal is actually not prevented from reaching the subprocess. Instead, the preexec_fn above overwrites the signal’s default handler so that the signal is ignored. Thus, this solution may not work if the subprocess overwrites the SIGINT handler again.

Another note: This solution works for all sorts of subprocesses, i.e. it is not restricted to subprocesses written in Python, too. For example the dedicated server I am writing my wrapper for is in fact written in Java.