def METHOD_NAME():
    """Loop forever:
       1) send startup acknowledgment
       2) read line from stdino
       3) parse line
             execute command if valid
             nak command     if invalid
       4) repeat
    """
    startup_ack()
    while True:
        try:
            line=sys.stdin.readline().strip()
            saveline(line)
            if (line == ""): nak_reply("empty_line")
            else:            do_cmd(line)
        except BrokenPipeError: sys.stdout.close()
        except Exception as e:
            nak_reply("_exception=%s"%e)