chat.erl

-module(chat).

-export([server/1, client/0]).

server(Clients) ->
    receive
        {client, Client} ->
            server(Clients ++ [Client]);
        {msg, Message} ->
            send_message(Message, Clients),
            server(Clients)
    end.

%% client show message when receive.
client() ->
    receive
        {msg, Message} ->
            io:format("~p~n", [Message])
    end,
    client().

%% broadcast message to all clients.
send_message(_Message, []) -> ok;
send_message(Message, [HClient | TClients]) ->
    HClient ! {msg, Message},
    send_message(Message, TClients).