deamon.py

import os
import sys
import time


class Deamon(object):
    def __init__(self,
                 stdin='/dev/null',
                 stdout='/dev/null',
                 stderr='/dev/null'):
        self.stdin = stdin
        self.stdout = stdout
        self.stderr = stderr

    def deamonize(self):
        if os.fork():
            os._exit(0)
        os.setsid()
        if os.fork():
            os._exit(0)
        os.chdir('/')
        si = open(self.stdin, 'r')
        so = open(self.stdout, 'a+')
        se = open(self.stderr, 'a+', 0)
        os.dup2(si.fileno(), sys.stdin.fileno())
        os.dup2(so.fileno(), sys.stdout.fileno())
        os.dup2(se.fileno(), sys.stderr.fileno())

    def start(self):
        self.deamonize()
        self.run()

    def run(self):
        raise NotImplementedError


class MyDeamon(Deamon):
    def run(self):
        while True:
            time.sleep(1)

if __name__ == '__main__':
    d = MyDeamon()
    d.start()