import sys,os,signal,time
counter = 0
def handler(sig,ignore):
    global counter
    counter+=1
    time.sleep(1)  # do some work in the handler
    return

if __name__ == "__main__": 
    signal.signal(signal.SIGUSR2, handler)

    pid = os.fork()
    if (pid == 0):   # child
        for i in range(5):
            os.kill(os.getppid(), signal.SIGUSR2)
            print "sent SIGUSR2 to parent"
        sys.exit(0)

    try:
        os.wait()
    except:
        pass    # ignore l'exception en cas de reception d'un signal 
    print "counter=%d" %(counter) 
    sys.exit(0)