daemon.py 文件源码

def run(self):
        self_cmdline = self.get_cmdlime(os.getpid())
        pid = os.fork()
        if pid < 0:
            raise OSError('create subprocess fail')
        elif pid == 0:
            if self.chdir:
                os.chdir(self.chdir)
            os.umask(0)
            os.setsid()
            os.close(0)
            if self.logfile:
                f = open(self.logfile, 'a')
                os.dup2(f.fileno(), 1)
                os.dup2(f.fileno(), 2)
            else:
                os.close(1)
                os.close(2)
            args = self.cmdline.split()
            os.execlp(args[0], *args)
            os._exit(-1)
        else:
            self.pid = pid
            self.time = datetime.now().strftime('%Y-%m-%d %H:%m:%S')
            while True:
                cmdline = self.get_cmdlime(pid)
                if cmdline is None or cmdline != self_cmdline:
                    break
                time.sleep(0.05)
            if not self.is_alive():
                raise OSError('daemon exit')
            self.proc_cmdline = cmdline
            return pid