学习 Twisted 框架并遇到手指服务器问题

Question

我正在使用 Twisted Documentation Finger 教程 (http://twistedmatrix.com/documents/current/core/howto/tutorial/intro.html) 为我正在从事的项目学习 Twisted 框架，但我无法让我的程序正常工作。

这是服务器的代码，当我telnet localhost 12345 时它应该返回“No such User”，但它只是停留在那里，没有任何反应。

from twisted.internet import protocol, reactor
from twisted.protocols import basic

class FingerProtocol(basic.LineReceiver):
    def lineReceived(self, user):
        self.transport.write("No such user\r\n")
        self.transport.loseConnection()

class FingerFactory(protocol.ServerFactory):
    protocol = FingerProtocol

reactor.listenTCP(12345, FingerFactory()) 
reactor.run()

我已经通过python twisted-finger.py 和sudo python twisted-finger.py 运行了服务器，但都没有成功。

有谁明白为什么这没有返回它应该返回的消息？

Answer 1

您必须先向服务器发送一个手指请求，然后它才会响应。

根据finger rfc：

Send a single "command line", ending with <CRLF>.

The command line:

    Systems may differ in their interpretations of this line.  However,
    the basic scheme is straightforward:  if the line is null (i.e. just
    a <CRLF> is sent) then the server should return a "default" report
    which lists all people using the system at that moment.  If on the
    other hand a user name is specified (e.g. FOO<CRLF>) then the
    response should concern only that particular user, whether logged in
    or not.

尝试在 telnet 中输入一个单词并按回车键。