Ponging

gistfile1.ex

defmodule TCPServer do

  def listen(port) do
    tcp_options = [:list, {:packet, 0}, {:active, false}, {:reuseaddr, true}]
    {:ok, l_socket} = :gen_tcp.listen(port, tcp_options)
    do_listen(l_socket)
  end

  defp do_listen(l_socket) do
    {:ok, socket} = :gen_tcp.accept(l_socket)
     spawn(fn() -> do_server(socket) end)
     do_listen(l_socket)
  end

  defp do_server(socket) do
    case :gen_tcp.recv(socket, 0) do
    { :ok, data } ->
        :gen_tcp.send(socket, respond_to(data))
        do_server(socket)
    { :error, :closed } ->
        :ok
    end
  end

  defp respond_to(data) do
    "pong"
  end

end