Extremely simple "distributed echo server" server in Python (Telnet clients should be able to connect to it).

telnet.py

#!/usr/bin/env python3

import socket

# Read "distributed echo server" as "(distributed echo) server". The "server"
# is not "distributed" but the echos are "distributed" to every connected
# client.

# Connect to the server with `telnet localhost 5000`.

server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.setblocking(False)
server.bind(('localhost', 5000))
server.listen(5)

connections = []

while True:
    try:
        connection, address = server.accept()
        connection.setblocking(False)
        connections.append(connection)
    except BlockingIOError:
        pass

    for connection in connections:
        try:
            message = connection.recv(4096)
        except BlockingIOError:
            continue

        for connection in connections:
            connection.send(message)

This isn't Telnet, this is an Echo server (plus distribution of messages to all connected clients).

This isn't Telnet, this is an Echo server (plus distribution of messages to all connected clients).

Fair enough. I'll update the description.

Session stopped
- Press to exit tab
- Press R to restart session
- Press S to save terminal output to file

Network error: Connection refused

telnet.exe 127.0.0.1 5000
Trying 127.0.0.1...                     
                                                                                                                          
telnet: Unable to connect to remote host: Connection refused                

@QGB you are trying to connect to localhost but the script was binding your host name. I changed it to bind to localhost, so telnet localhost 5000 should work as expected.