Simple test case for Linux's PR_SET_PDEATHSIG

pdeathsig.py

#!/usr/bin/env python3

import os
import sys
import time
import prctl
import signal

def do_the_thing():
    pid = os.fork()
    if pid == 0:
        # PR_SET_PDEATHSIG is preserved across exec(2) but gets cleared after fork(2).
        # Modern bash, it appears, translates "echo" directly into write(2),
        # i.e. doesn't fork&exec /bin/echo.
        # This is not true for sleep, though. So the sleep invocation below may become
        # a zombie?
        prctl.set_pdeathsig(signal.SIGTERM)
        os.execv('/bin/sh', ['/bin/sh', '-c', 'while :; do echo "still running: $$"; sleep 1; done'])
    else:
        time.sleep(5)
        print('killing the parent')
        os.kill(os.getpid(), signal.SIGKILL)

do_the_thing()