python实现的守护进程(Daemon)用法实例

def createDaemon():
 "'Funzione che crea un demone per eseguire un determinato programma…"'
 import os
 # create - fork 1
 try:
 if os.fork() > 0: os._exit(0) # exit father…
 except OSError, error:
 print 'fork #1 failed: %d (%s)' % (error.errno, error.strerror)
 os._exit(1)
 # it separates the son from the father
 os.chdir('/')
 os.setsid()
 os.umask(0)
 # create - fork 2
 try:
 pid = os.fork()
 if pid > 0:
 print 'Daemon PID %d' % pid
 os._exit(0)
 except OSError, error:
 print 'fork #2 failed: %d (%s)' % (error.errno, error.strerror)
 os._exit(1)
 funzioneDemo() # function demo
def funzioneDemo():
 import time
 fd = open('/tmp/demone.log', 'w')
 while True:
 fd.write(time.ctime()+'
')
 fd.flush()
 time.sleep(2)
 fd.close()
if __name__ == '__main__':
 createDaemon()