python守护进程

import os
import time

def demo():
try:
if os.fork() > 0:
os._exit(0)
except OSError, error:
print 'fork #1 failed: %d (%s)' % (error.errno, error.strerror)
os._exit(1)

os.chdir('/')
os.setsid()
os.umask(0)

try:
if os.fork():
os._exit(0)
except OSError, error:
print 'fork #2 failed: %d (%s)' % (error.errno, error.strerror)
os._exit(1)

test()

def test():
f = open('/home/tomcat/py/log/demo.log', 'w')
while True:
f.write(time.ctime()+'\n')
f.flush()
time.sleep(2)
f.close()

if __name__ == '__main__':
demo()