def start(self, *args, **kw):
        """Start the daemon."""
        pid = None
        if os.path.exists(self.pidfile):
            with open(self.pidfile, 'r') as fp:
                pid = int(fp.read().strip())

        if pid:
            msg = 'pidfile (%s) exists. Daemon already running?\n'
            sys.stderr.write(msg % self.pidfile)
            sys.exit(1)

        self.daemonize()
        self.run(*args, **kw)