import time, os, signal

LOG_FILE = 'test.log'

log_file = open(LOG_FILE, 'a')

def log(msg):

    log_file.write(msg + '\n')

    log_file.flush()

def SigUSR1Handler(signum, frame):

    print "Reacting on USR1 signal (signal 10)"

    global log_file

    log_file.close()

    log_file = open(LOG_FILE, 'a')

    return

def init():

    if os.path.isfile('/var/usr/dump_test_log.pid'):

        print 'Have to stop server first'

        os.exit(1)

    else:

        print 'Starting server...'

        #write process id file

        f = open('/var/run/dump_test_log.pid', 'w')

        f.write(str(os.getpid()))

        f.flush()

        f.close()

        print 'Process start with pid ', os.getpid()

    signal.signal(signal.SIGUSR1, SigUSR1Handler)

def main():

    init()

    count = 1

    while True:

      log('log line #%d, pid: %d' % (count, os.getpid()))

    count = count + 1

    time.sleep(1)

if __name__ == '__main__':

    main()