Add EchoServer example

1 files changed, 36 insertions, 0 deletions

diff --git a/src/code/2/echo_server/lib/echo_server/echo.ex b/src/code/2/echo_server/lib/echo_server/echo.ex
new file mode 100644
index 0000000..3a96f29
--- /dev/null
+++ b/src/code/2/echo_server/lib/echo_server/echo.ex
@@ -0,0 +1,36 @@
+defmodule EchoServer.Echo do
+
+  def accept(port) do
+    {:ok, socket} = :gen_tcp.listen(
+      port,
+      [:binary, packet: :line, active: false, reuseaddr: true])
+    loop_acceptor(socket)
+  end
+
+  defp loop_acceptor(socket) do
+    {:ok, client} = :gen_tcp.accept(socket)
+    {:ok, pid} = Task.Supervisor.start_child(
+      EchoServer.TaskSupervisor, fn -> serve(client) end)
+    :ok = :gen_tcp.controlling_process(client, pid)
+    loop_acceptor(socket)
+  end
+
+  defp serve(socket) do
+    socket
+      |> read_line
+      |> (fn(x) -> "> " <> x end).()
+      |> write_line(socket)
+
+    serve(socket)
+  end
+
+  defp read_line(socket) do
+    {:ok, data} = :gen_tcp.recv(socket, 0)
+    data
+  end
+
+  defp write_line(line, socket) do
+    :gen_tcp.send(socket, line)
+  end
+
+end