Echo servers

blockin_tcp.py

import socket, threading

serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serversocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
serversocket.bind(('0.0.0.0', 8082))
serversocket.listen(5)

def connection_handler(socket):
    while True:
        data = socket.recv(1024)
        if not data: # https://manpages.debian.org/buster/manpages-dev/recv.2.en.html#RETURN_VALUE
            return 'gg'
        socket.send(data)

while True:
    connectiontoclient, address = serversocket.accept()
    t = threading.Thread(target=connection_handler, args=(connectiontoclient,))
    t.start()

select_socket.py

import socket, threading, time, select

serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serversocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
serversocket.bind(('0.0.0.0', 811))
serversocket.listen(5)

connections = set()

def ready_handler(sockets, writable):
    for socket in sockets:
        data = socket.recv(1024)
        if not data:
            connections.remove(socket)
        if socket in writable:
            try:
                socket.send(data)
            except:
                pass
def select_checker():
    while True:
        ready, writable, error = select.select(connections,connections,connections, 2)
        if ready:
            ready_handler(ready, writable)

t = threading.Thread(target=select_checker)
t.start()

# init socket connections list
# spawn connection accepter, add to list when connected
# spawn checker, every 1 second sleep and run select
# if checker sees some stuff, run read_operation

while True:
    connectiontoclient, address = serversocket.accept()
    connections.add(connectiontoclient)