simple telnet server

.gitignore

*.swp
*.beam

telnet.erl

-module(telnet).
-export([start/0,serve/1]).

-define(PORT, 8765).

start() ->
    {ok, ListenSocket} = gen_tcp:listen(?PORT, [binary, {packet,0},{active,true}]),
    start_servers(ListenSocket).

start_servers(ListenSocket) -> 
    spawn(?MODULE, serve, [ListenSocket]).

serve(ListenSocket) ->
    msg("listen on ~p",[ListenSocket]),
    case gen_tcp:accept(ListenSocket) of
        {ok, Socket} -> 
            msg("accepted: ~p",[Socket]),
            start_servers(ListenSocket),
            inet:setopts(Socket,[{active,true}]),
            wait(Socket);
        {error, closed} ->
            msg("error: closed")
    end.

wait(Socket) ->
    receive
        {tcp, Socket, <<"stop\r\n">>} ->
            msg("stopping."),
            gen_tcp:close(Socket);
        {tcp, Socket, Data} ->
            msg("received: ~ts",[Data]),
            gen_tcp:send(Socket, <<"got it\r\n",Data/binary>>),
            wait(Socket);
        {tcp_closed, Socket} ->
            msg("tcp_closed");
        Any ->
            msg("unkown: ~p", [Any])
    end.

msg(Msg) ->
    io:format(pid_to_list(self()) ++ " " ++ Msg ++ "~n").

msg(Msg, Params) ->
    io:format(pid_to_list(self()) ++ " " ++ Msg ++ "~n", Params).