bool Switcher::Daemon() {

  base::YamlConfig config;

  if (!config_.ReadConfig(config_file_)) {

    fprintf(stderr, "read config file fail.\n");

    return false;

  }

  bool is_daemon = config_.Get<bool>(kService, "is_daemon");

  if (!is_daemon) {

    return true;

  }

  if (fork() != ) {

    exit();

  }

  setsid();

  if (fork() != ) {

    exit();

  }

  close();

  close();

  close();

  open("/dev/null", O_RDWR);

  dup();

  dup();

  std::string stdout_log_path;

  if(config_.Get<std::string>(kService, kStdoutLogPath, &stdout_log_path)) {

    string filename = stdout_log_path + "." + DateString_();

    int fd = open(filename.c_str(), O_WRONLY | O_APPEND | O_CREAT, );

    if (fd != -) {

      // 将STDOUT, STDERROR 重定向到文件

      dup2(fd, STDOUT_FILENO);

      dup2(fd, STDERR_FILENO);

      close(fd);

    }

  }

  return true;

}