CODEWITHSUNDEEP
pythonsocketstwisted
Rudker
Rudker

Reputation: 711

Get the bare socket fd from a Twisted protocol in python?

What I would like to do is combine Twisted with the Cmd module in python's stdlib.

In short I would like to be able to get the bare-bones socket fd object from a connected Protocol to use as the stdin of the cmd.Cmd module in the stdlib.

In Long, My client that interfaces with my server uses the Cmd module to process commands and send those commands to the server.

On my server I would also like to use the same command processing method with the builting Cmd module. To do this i would need to specify the stdin and stdout of the command interpreter. I could do this easily with the builtin sockets module, but i would like to do it with twisted if possible.

Here is some code to do what i want with plain sockets:

(Works with telnet)

# server
import socket
import cmd

class CmdProcessor(cmd.Cmd, object):
    def __init__(self, sock, addr):
        network = sock.makefile()
        super(CmdProcessor, self).__init__(stdin=network, stdout=network)
        self.sock = sock
        self.addr = addr

        # Run the cmd.Cmd processing loop
        self.cmdloop()

    def do_sayhi(self, args):
        # When 'sayhi' is recieved over the socket,
        self.sock.send("Hey yourself!")

    def do_quit(self, args):
        self.sock.close()


if __name__ == "__main__":
    server_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    server_sock.bind(("0.0.0.0", 2319))
    server_sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    server_sock.listen(5)

    sock, addr = server_sock.accept()
    print("Connection accepted")
    connection = CmdProcessor(sock, addr)

This is almost what i want to to do. I just typed this up quick so i may be missing somthing. Half of it works. Currently, if you telnet into the server like:

telnet 127.0.0.1 2319

And you send 'sayhi' nothing happens. But if you type 'sayhi' at the terminal you started the server from (There is a (Cmd) prompt) the output goes to the telnet client. So the stdout of the cmd.Cmd is working. But not the stdin. That probably has something to do with the fact that telnet sends CR-LF ('\r\n') by default. Where the cmd module may just listen for \n.

So how can get the fd or file object from a protocol in twisted to do what i am trying do achieve here with bare sockets?

And any insights on what the input from telnet connected to the server is not registering with the CmdProcessor?

Any advice, tips or pointers welcome. (Wait no, no pointers.) Thanks.

Upvotes: 2

Views: 328

Answers (2)

PankajM
PankajM

Reputation: 417

You can add use_rawinput = False

class CmdProcessor(cmd.Cmd, object):
    use_rawinput = False
    def __init__(self, sock, addr):
    ....

This produces response for sayhi from telnet

Upvotes: 0

Jean-Paul Calderone
Jean-Paul Calderone

Reputation: 48315

I suggest that instead you might want to look at Manhole.

In general, the point of Twisted is not to use Python socket objects directly. That's a big part of Twisted's job. When you want to interact with the network using Twisted, you use Twisted's APIs instead - protocols and transports, if you're thinking about the lowest level.

Upvotes: 1

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