A basic FileSender example

getfile.py

import sys
from twisted.protocols import basic
from twisted.internet import defer, endpoints, protocol, task


class GetFileProtocol(basic.LineReceiver):
    delimiter = '\n'

    def lineReceived(self, line):
        parts = line.split(None, 1)
        if not parts or parts[0] != b'GET':
            self.transport.write(b"Invalid command.\n")
            self.transport.loseConnection()
            return

        path = parts[1]
        fileobj = open(path, "rb")
        sender = basic.FileSender()

        def finish(ignored):
            fileobj.close()
            self.transport.loseConnection()

        finished = sender.beginFileTransfer(fileobj, self.transport)
        finished.addBoth(finish)


@defer.inlineCallbacks
def main(reactor, description):
    server = endpoints.serverFromString(reactor, description)
    yield server.listen(protocol.Factory.forProtocol(GetFileProtocol))
    yield defer.Deferred()


task.react(main, sys.argv[1:])