UDP エコーサーバー

udp_echo.erl

-module(udp_echo).

-export([main/0]).

-include_lib("eunit/include/eunit.hrl").

-define(PORT, 5500).

main() ->
    case gen_udp:open(?PORT, [binary, {active, false}]) of
        {ok, Socket} ->
            spawn(fun() -> echo(Socket) end),
            ok;
        {error, Reason} ->
            error(Reason)
    end.


echo(Socket) ->
    case gen_udp:recv(Socket, １４００) of
        {ok, {IpAddress, Port, Data}} ->
            ok = gen_udp:send(Socket, IpAddress, Port, Data),
            echo(Socket);
        {error, Reason} ->
            error(Reason)
    end.