signal_signal.py

#!/usr/bin/env python

# this is from The Python
# Standard Library by example
# ISBN13: 9780321767349

import signal
import os
import time


def receive_signal(signum, stack):
    print 'Received:', signum

# Register signal handlers
signal.signal(signal.SIGUSR1, receive_signal)
signal.signal(signal.SIGUSR2, receive_signal)

# Print the process ID so it can be used with 'kill'
# to send this program signals.
print 'My PID is:', os.getpid()

while True:
    print 'Waiting... '
    time.sleep(3)