\begin{Verbatim}[commandchars=@\[\]]
@PYaD[#!/usr/bin/env python]

@PYay[import] @PYaV[subprocess]

@PYay[from] @PYaV[twisted.internet] @PYay[import] defer, stdio, protocol, reactor
@PYay[from] @PYaV[twisted.protocols] @PYay[import] basic

@PYay[class] @PYaN[Repl](basic@PYbe[.]LineReceiver):
    delimiter @PYbe[=] @PYad[']@PYao[\n]@PYad[']
    prompt_string @PYbe[=] @PYad[']@PYad[>>> ]@PYad[']

    @PYay[def] @PYaK[prompt](@PYaA[self]):
        @PYaA[self]@PYbe[.]transport@PYbe[.]write(@PYaA[self]@PYbe[.]prompt_string)

    @PYay[def] @PYaK[connectionMade](@PYaA[self]):
        @PYaA[self]@PYbe[.]sendLine(@PYad[']@PYad[Welcome to Repl]@PYad['])
        @PYaD[# store factory and connector upon connection to the stdout]
        @PYaA[self]@PYbe[.]factory @PYbe[=] CFactory()
        @PYaA[self]@PYbe[.]connector @PYbe[=] reactor@PYbe[.]connectTCP(
            @PYad[']@PYad[127.0.0.1]@PYad['], @PYaw[1234], @PYaA[self]@PYbe[.]factory)
        @PYaA[self]@PYbe[.]prompt()

    @PYay[def] @PYaK[lineReceived](@PYaA[self], line):
        @PYay[if] @PYan[not] line:
            @PYaA[self]@PYbe[.]prompt()
            @PYay[return]

        @PYaA[self]@PYbe[.]issueCommand(line)

    @PYay[def] @PYaK[issueCommand](@PYaA[self], command):
        @PYaD[# write to the connector's transport, not the one writing on stdout]
        @PYaA[self]@PYbe[.]connector@PYbe[.]transport@PYbe[.]write(@PYad["]@PYbf[%s]@PYbf[%s]@PYad["] @PYbe[%] (command, @PYaA[self]@PYbe[.]delimiter))
        @PYaD[# register the callback on the factory's deferred]
        @PYaA[self]@PYbe[.]factory@PYbe[.]deferred@PYbe[.]addCallback(@PYaA[self]@PYbe[.]_checkResponse)

    @PYay[def] @PYaK[_checkResponse](@PYaA[self], args):
        success, num_lines, data @PYbe[=] args
        @PYay[if] num_lines @PYbe[>] @PYaw[20]:
            @PYaA[self]@PYbe[.]lessify(data)
        @PYay[else]:
            @PYaA[self]@PYbe[.]sendLine(data)
        @PYaA[self]@PYbe[.]prompt()
        @PYaD[# recreate the deferred each time we have the response]
        @PYaA[self]@PYbe[.]factory@PYbe[.]deferred @PYbe[=] defer@PYbe[.]Deferred()

    @PYay[def] @PYaK[lessify](@PYaA[self], data):
        p @PYbe[=] subprocess@PYbe[.]Popen(@lb[]@PYad["]@PYad[less]@PYad["]@rb[], stdin@PYbe[=]subprocess@PYbe[.]PIPE)
        p@PYbe[.]stdin@PYbe[.]write(data)
        p@PYbe[.]stdin@PYbe[.]close()
        p@PYbe[.]wait()


@PYay[class] @PYaN[Client](basic@PYbe[.]LineReceiver):
    delimiter @PYbe[=] @PYad[']@PYao[\n]@PYad[']

    @PYay[def] @PYaK[connectionMade](@PYaA[self]):
        @PYaA[self]@PYbe[.]buffer @PYbe[=] @lb[]@rb[]
        @PYaA[self]@PYbe[.]cmd_success @PYbe[=] @PYaA[True]

    @PYay[def] @PYaK[lineReceived](@PYaA[self], line):
        @PYay[if] line@PYbe[.]startswith(@PYad[']@PYad[OK]@PYad[']):
            @PYay[return]
        @PYay[if] line@PYbe[.]startswith(@PYad[']@PYad[ERR]@PYad[']):
            @PYaA[self]@PYbe[.]cmd_success @PYbe[=] @PYaA[False]
            @PYay[return]

        @PYay[if] line @PYbe[==] @PYad[']@PYad[END]@PYad[']:
            @PYaA[self]@PYbe[.]responseFinished(
                @PYaX[len](@PYaA[self]@PYbe[.]buffer), @PYad["]@PYao[\n]@PYad["]@PYbe[.]join(@PYaA[self]@PYbe[.]buffer))
            @PYaA[self]@PYbe[.]buffer @PYbe[=] @lb[]@rb[]
        @PYay[else]:
            @PYaA[self]@PYbe[.]buffer@PYbe[.]append(line)

    @PYay[def] @PYaK[responseFinished](@PYaA[self], num_lines, data):
        @PYaD[# just fire the callback]
        @PYaA[self]@PYbe[.]factory@PYbe[.]deferred@PYbe[.]callback((
            @PYaA[self]@PYbe[.]cmd_success, num_lines, data))

    @PYay[def] @PYaK[connectionLost](@PYaA[self], reason):
        reactor@PYbe[.]stop()


@PYay[class] @PYaN[CFactory](protocol@PYbe[.]ClientFactory):
    protocol @PYbe[=] Client

    @PYay[def] @PYaK[__init__](@PYaA[self]):
        @PYaA[self]@PYbe[.]deferred @PYbe[=] defer@PYbe[.]Deferred()

@PYay[if] __name__ @PYbe[==] @PYad["]@PYad[__main__]@PYad["]:
    stdio@PYbe[.]StandardIO(Repl())
    reactor@PYbe[.]run()
\end{Verbatim}