sigusr1_debug.py

"""Start interactive console on SIGUSR1 signal.
run:
$ python ./sigusr1_debug.py

and in another window
$ ps aux|grep sigusr1_debug
$ kill -10 [process pid]
and in first window you get:
.
Signal received : entering python shell.
Traceback:
  File "sigusr1_debug.py", line 27, in <module>
    time.sleep(1)

>>>
"""
import code
import signal
import time
import traceback


def debug(sig, frame):
    """Interrupt running process, and provide a python prompt for
    interactive debugging."""
    d = {'_frame': frame}         # Allow access to frame object.
    d.update(frame.f_globals)  # Unless shadowed by global
    d.update(frame.f_locals)

    i = code.InteractiveConsole(d)
    message = "Signal received : entering python shell.\nTraceback:\n"

    message += ''.join(traceback.format_stack(frame))
    i.interact(message)


def listen():
    signal.signal(signal.SIGUSR1, debug)  # Register handler


listen()
while 1:
    time.sleep(1)
    print('.')