linux 服务 守护进程

import os
import sys
import time

def daemonize():
    try:
        pid = os.fork()
        if pid > 0:
            # Exit first parent
            sys.exit(0)
    except OSError as err:
        sys.stderr.write(f'Fork #1 failed: {err}\n')
        sys.exit(1)

    # Decouple from parent environment
    os.chdir('/')
    os.setsid()
    os.umask(0)

    # Do second fork
    try:
        pid = os.fork()
        if pid > 0:
            # Exit from second parent
            sys.exit(0)
    except OSError as err:
        sys.stderr.write(f'Fork #2 failed: {err}\n')
        sys.exit(1)

    # Redirect standard file descriptors
    sys.stdout.flush()
    sys.stderr.flush()
    si = open(os.devnull, 'r')
    so = open(os.devnull, 'a+')
    se = open(os.devnull, 'a+')

    os.dup2(si.fileno(), sys.stdin.fileno())
    os.dup2(so.fileno(), sys.stdout.fileno())
    os.dup2(se.fileno(), sys.stderr.fileno())

def main():
    while True:
        # Your daemon code here
        time.sleep(10)

if __name__ == '__main__':
    daemonize()
    main()