gen_udp2.erl

-module(gen_udp2).

-export([open/1, open/2, close/1]).

-export([recv/3, send/4]).



open(Port) ->
    open(Port, []).

open(Port, Opts) ->
    Addr = proplists:get_value(ip, Opts, any),
    {ok, Socket} = socket:open(inet, dgram, udp),
    {ok, _OutPort} = socket:bind(Socket, #{family => inet, port => Port, addr => Addr}),
    {ok, Socket}.


close(Socket) ->
    ok = socket:close(Socket),
    ok.


recv(Socket, Length, Timeout) ->
    case socket:recvfrom(Socket, Length, [], Timeout) of
        {ok, {#{family := _Family, port := Port, addr := Addr}, Data}} ->
            {ok, {Addr, Port, Data}};
        {error, Reason} ->
            {error, Reason}
    end.


send(Socket, Address, Port, Packet) ->
    ok = socket:sendto(Socket, Packet, #{family => inet, port => Port, addr => Address}, []).