# Read username, output from factory interfacing to OS, drop connections

from twisted.internet import defer, endpoints, protocol, reactor, utils
from twisted.protocols import basic


class FingerProtocol(basic.LineReceiver):
    def lineReceived(self, user):
        d = self.factory.getUser(user)

        def onError(err):
            return b"Internal error in server"

        d.addErrback(onError)

        def writeResponse(message):
            self.transport.write(message + b"\r\n")
            self.transport.loseConnection()

        d.addCallback(writeResponse)


class FingerFactory(protocol.ServerFactory):
    protocol = FingerProtocol

    def getUser(self, user):
        return utils.getProcessOutput(b"finger", [user])


fingerEndpoint = endpoints.serverFromString(reactor, "tcp:1079")
fingerEndpoint.listen(FingerFactory())
reactor.run()