A library for creating IRC interfaces to messaging services, allowing them to be used via IRC clients.

ircd.py

import socket
import thread
import re

class IRCd:
    debug = True
    servername = socket.getfqdn("")[:140]
    events = []
    handlers = {}
    def __init__(self, host="127.0.0.1", port=6667):
        self.host = host
        self.port = port

    # Client connection handler
    def clientThread(self, conn):
        # first, the client needs to register
        self.user = {}
        # define some temporary handlers for init
        def nick(m, client, data):
            # set the client's nick
            client.user['nick'] = m.group(1)
            client.debug("Set nick to "+ user['nick'])
            # remove this handler after first run
            client.remove_handler("^NICK\s([\w\d]+)")
            return True

        def user(m, client, data):
            # set the clients supplied details
            client.user['username'] = m.group(1)
            client.user['mode'] = m.group(2)
            client.user['real name'] = m.group(3)
            # if we have a handler for the user command, run it now
            if 'user' in client.handlers:
                client.handlers['users'](m)
            self.debug("Set user to " + user['username'])
            # send the required startup messages
            welcomeMessage = "Welcome...I guess.."
            serverMessage = "Your host is %s, running TaiiwoIRCd" %
                    client.servername
            creationMessage = "This server was created sometime"
            versionMessage = "%s TaiiwoIRCd-1.3.3.7 o o" % client.servername
            nick = client.user['nick']
            reply =  client.response("001", nick, "", welcomeMessage)
            reply += client.response("002", nick, "", serverMessage)
            reply += client.response("003", nick, "", creationMessage)
            reply += client.response("004", nick, "", versionMessage)
            # remove this handler after first run
            client.remove_handler("^USER\s([\w\d]+)\s(\d)\s.\s:?([\w\d\s]+)")
            return reply
        # apply the temporary handlers
        self.add_handler("^NICK\s([\w\d]+)", nick)
        self.add_handler("^USER\s([\w\d]+)\s(\d)\s.\s:?([\w\d\s]+)", user)
        # now we start the main loop waiting for user input
        while True:
            # wait for input from the client
            data = conn.recv(1024)
            self.debug(data)
            if not data:
                # the client disconnected
                break
            reply = False
            # figure out what the client wants and respond
            for event in events:
                # check if the event regex matches data
                m = re.match(event[0], data)
                if m:
                    # if so, run the handler function
                    reply = event[1](m, self, data)
                    reply = "" if typeof(reply) != str() else reply
                    break
            if reply:
                # send the reply to the server
                self.debug(reply)
                conn.sendall(reply)
            else:
                # we didn't have a handler for the command
                self.debug("Command no recognised: " + data)
        # client disconnected
        conn.close()

    # Used to start the sever when all the handlers have been set
    def start(self):
        # create socket
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.debug('Socket created')
        try:
            # bind socket to port
            s.bind((self.host, self.port))
        except socket.error as msg:
            quit('Bind failed. Error Code : ' + str(msg[0]) + ' Message ' + msg[1])
        self.debug('Socket bound to %s on %s' % (self.host, self.port))
        s.listen(10)
        self.debug('Socket now listening...')
        while 1:
            # wait for clients and send their connection to a thread
            conn, addr = s.accept()
            self.debug('Connected with ' + addr[0] + ':' + str(addr[1]))
            thread.start_new_thread(self.clientThread, (conn,))
        s.close()

    # Adds a hander for when the IRC client sends a command
    # regex[string] = a regex that matches the desired IRC command
    # handler[function] = parameters:
    #    [0] = a regex match object of [2], matched with regex[string]
    #    [1] = an instance of self, can be used like an API to call methods
    #        from this class
    #    [2] = an unformatted string of data received from IRC
    def add_handler(self, regex, handler):
        self.events.append([regex, handler])
        return True

    # Removes a hander added by add_handler
    # regex[string] = the regex of the handler to remove
    def remove_handler(self, regex):
        for event in self.events:
            if event[0] == regex:
                self.events.remove(event)
        return True

    # Adds user-defined functions for use in preset add_hander functions
    # name[string] = name of handler
    # handler[function] = can take any parameters and do anything
    def add_user_handler(self, name, handler):
        handlers[name] = handler

    # Adds a handler for the LIST command.
    # handler[function] = takes no parameters and returns a list of dicts in
    #    the form:
    #    {
    #       'name': Name of channel
    #       'topic': Current channel topic
    #       'numUsers': Number of users active in channel
    #    }
    def add_list_handler(self, handler):
        # add the handler to handlers so we can use if from anywhere
        self.add_user_handler('list', handler)
        # create a function to bind to the event
        def list_handler(m, client, data):
            # get list of channels
            channels = client.handlers['list']()
            reply = ""
            # for each channel
            for channel in channels:
                # write an IRC reply and append it
                reply += client.response(
                    322,
                    client.user['nick'],
                    channel['name'] +
                    " " +
                    channel['numUsers'],
                    channel['topic']
                )
            # finally, add the end of list message
            reply += client.reponse(323, client.user['nick'], "", ":End of /LIST")
            return reply
        # now set a handler for the LIST command
        self.add_handler("^LIST", list_handler)

    # A helper function that formats an IRC response
    def response(self, code, nick, value, message):
        value = value + " " if value != "" else ""
        return ":%s %s %s %s:%s\r\n" % (self.servername, code, nick, value, message)

    # Used to only print output if debugging is on
    def debug(self, msg):
        if self.debug:
            print(msg)
            return True
        else:
            return False

if __name__ == '__main__':
    ircd = IRCd()
    ircd.start()