Efene

#
# A simple TCP echo server
#
# To run:
#
#   $ efene tcp_echo.ef
#   Starting server at port 8000
#
# And in another terminal:
#
#   $ telnet localhost 8000
#   Trying 127.0.0.1...
#   Connected to localhost.
#   Escape character is '^]'.
#   hi
#   hi
#   hello
#   hello
#

@public
def start(port = 8000):
    """
    Starts a TCP echo server
    """
    print("Starting server at port {port}")

    case gen_tcp.listen(port, [binary, {packet: 0}, {active: false}]):
        {ok, listen_socket} ->
            accept(listen_socket)
        {error, reason} ->
            print("Error starting server: {reason}")

@private
def accept(listen_socket):
    """
    Accepts a connection
    """
    case gen_tcp.accept(listen_socket):
        {ok, socket} ->
            spawn(fn(): loop(socket))
            accept(listen_socket)
        {error, reason} ->
            print("Error accepting connection: {reason}")

@private
def loop(socket):
    """
    Waits for data and echos it back
    """
    case gen_tcp.recv(socket, 0):
        {ok, data} ->
            gen_tcp.send(socket, data)
            loop(socket)
        {error, reason} ->
            print("Connection closed: {reason}")