Access this with `telnet 127.0.0.1 56789`

telnet_chat.py

import socket

RECV_BUFFER = 1024
BIND_ADDR = ""
PORT = 56789

conn_inputs = []
conn_outputs = []

listener = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
listener.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
listener.bind((BIND_ADDR, PORT))
listener.listen(5)
conn_inputs.append(listener)

while True:
    read_s, write_s, err_s = select.select(conn_inputs, conn_outputs, [], 0)
    for sock in read_s:
        if sock == listener:
            client, addr = listener.accept()
            conn_inputs.append(client)
            for o in conn_outputs:
                o.send("Client {} connected.\n".format(addr))
            conn_outputs.append(client)
        else:
            peername = sock.getpeername()
            try:
                data = sock.recv(RECV_BUFFER)
                if data:
                    for o in conn_outputs:
                        if o != sock:
                            o.send("{}: {}".format(peername, data))
                else:
                    sock.close()
                    conn_inputs.remove(sock)
                    conn_outputs.remove(sock)
                    for o in conn_outputs:
                        o.send("{} hung up.\n".format(peername))
            except socket.error as e:
                conn_inputs.remove(sock)
                conn_outputs.remove(sock)
listener.close()