IRC bot

irc.erl

%% First try at making a small IRC bot.
%% Dedicated to ThordenM.
%%
%% Rune Juhl Jacobsen, 2012

-module(irc).
-compile(export_all).

-define(NICK, "lolcat").
-define(USERNAME, "lolcatzz").
-define(REALNAME, "The real fat lolcat").
-define(CHANNELS, ["#penguins"]).

-record(config, {socket, prefix=nil, options=nil}).

%% Set up TCP connection
connect(Address, Port) ->
    {ok, Socket} = gen_tcp:connect(Address, Port, [binary, {active, true}]),
    Config = #config{socket=Socket},
    setup(Config).

%% Initial setup. Receive welcome message, save prefix in Config
setup(Config) when Config#config.prefix == nil ->
    Socket = Config#config.socket,
    receive
        {tcp, Socket, WMsg} ->
            io:format("Received welcome msg: ~s~n", [WMsg]),
            setup(Config#config{prefix=hd(re:split(WMsg, " "))})
    after 120000 ->
            io:format("Didn't receive response in time, exiting."),
            gen_tcp:close(Socket)
    end;

%% Further setup. Send password, nick, username and realname. Recevive
%% MOTD.
setup(Config) when Config#config.options == nil ->
    Socket = Config#config.socket,
    send(Config, [<<"PASS *">>]),
    send(Config, [<<"NICK ">>, <<?NICK>>]),
    send(Config, ["USER ", ?USERNAME, " 8 * :", ?REALNAME]),

    %% receive MOTD
    receive
        {tcp, Socket, Motd} ->
            io:format(
              "Received MOTD:~n~s~n", 
              [string:tokens(erlang:binary_to_list(Motd), "\r\n")])
    end,
    
    %% join channels
    join(Config),

    handle(Config).

%% Handle responses from the IRC server.
handle(Config) ->
    Socket = Config#config.socket,
    receive
        %% Ping messages
        {tcp, Socket, <<"PING", _/binary>>} ->
            send(Config, pong),
            handle(Config);
        %% Errors
        {tcp, Socket, <<"ERROR :", Msg/binary>>} ->
            io:format("Received error: ~p~n", [Msg]),
            gen_tcp:close(Config);
        %% Unknown responses
        {tcp, Socket, Unknown} ->
            io:format("~s~n", [Unknown]),
            handle(Config)
    %% Send ping after 2 minutes. (disabled!)
    %% Enable for infinite ping-pong loop.
    %% after 120000 ->
    %%         send(Config, ping),
    %%         handle(Config)
    end.

%% Join channel
join(Config) ->
    lists:map(fun(Channel) -> join(Config, Channel) end, ?CHANNELS).
join(Config, Channel) ->
    send(Config, ["JOIN ", Channel]).


send(Config, pong) ->
    send(Config, ["PONG ", Config#config.prefix]);
send(Config, ping) ->
    send(Config, ["PING ", Config#config.prefix]);
send(Config, Msg) ->
    gen_tcp:send(Config#config.socket, [Msg, "\r\n"]).

send(Config, Msg, prefix) ->
    send(Config, [Config#config.prefix, " ",Msg]).

...a work in progress, I should note.