Kostarev Vladislav, 203, lab_1b

client.py

@@ -0,0 +1,76 @@
+import socket
+import threading
+import time
+import sys
+import os
+import errno
+
+
+if len(sys.argv) != 3:
+    print("Select IP and server port!")
+    sys.exit()
+
+client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+client_socket.connect((sys.argv[1], int(sys.argv[2])))
+client_socket.setblocking(False)
+
+my_nick = input("Your nickname: ")
+nickname = my_nick.encode('ascii')
+nickname_header = len(nickname).to_bytes(5, byteorder='big')
+client_socket.send(nickname_header + nickname)
+
+
+def get_package(sock):
+    header = sock.recv(5)
+
+    if not len(header):
+        print('Connection was closed by server')
+        client_socket.close()
+        os._exit(0)
+
+    length = int.from_bytes(header, byteorder='big', signed=False)
+
+    return sock.recv(length).decode('ascii')
+
+
+def receiving():
+    while True:
+        try:
+            nick = get_package(client_socket)
+            message = get_package(client_socket)
+
+            if message == f'Nickname {nick} is already in use!':
+                print(message)
+                print('Please log in to the chat again with a new nickname')
+                client_socket.close()
+                os._exit(0)
+
+            print('<{}> [{}] {}'.format(time.strftime('%H:%M', time.localtime()), nick, message))
+
+        # for blocking sockets
+        except IOError as e:
+            if e.errno != errno.EAGAIN and e.errno != errno.EWOULDBLOCK:
+                print('Reading error: {}'.format(str(e)))
+                client_socket.close()
+                sys.exit()
+
+
+def sending():
+    while True:
+        try:
+            message = input()
+
+            if message:
+                enc_message = message.encode('ascii')
+                message_header = len(enc_message).to_bytes(5, byteorder='big')
+                client_socket.send(message_header + enc_message)
+                # print('<{}> [{}] {}'.format(time.strftime('%H:%M', time.localtime()), my_nick, message))
+        except KeyboardInterrupt:
+            os._exit(0)
+
+
+receive_thread = threading.Thread(target=receiving)
+receive_thread.daemon = True
+receive_thread.start()
+
+sending()

server.py

@@ -0,0 +1,91 @@
+import socket
+import select
+import sys
+
+
+if len(sys.argv) != 3:
+    print("Select IP and port")
+    sys.exit()
+
+
+ip = sys.argv[1]
+port = int(sys.argv[2])
+
+
+server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+server.bind((ip, port))
+server.listen()
+sockets_list = [server]  # list of sockets
+clients = {}  # list of connected clients
+print(f'Server online')
+
+
+def broadcast(sock, nick, msg, header):
+    for tmp in clients:
+        if tmp != sock:
+            tmp.send(nick['header'] + nick['data'] + header + msg)
+
+
+def receive_message(sock):
+    try:
+        header = sock.recv(5)
+    except ConnectionResetError:
+        return False
+
+    if not len(header):
+        return False
+
+    length = int.from_bytes(header, byteorder='big', signed=False)
+
+    return {'header': header, 'data': sock.recv(length)}
+
+
+def close_connection(sock):
+    nick = clients[sock]
+    print(f"Connection from {clients[sock]['data'].decode('ascii')} was closed")
+    data = f"{nick['data'].decode('ascii')} left the chat".encode('ascii')
+    header = len(data).to_bytes(5, byteorder='big')
+
+    broadcast(some_socket, nick, data, header)
+
+    sockets_list.remove(sock)
+    del clients[sock]
+
+
+while True:
+    read_sockets, _, exception_sockets = select.select(sockets_list, [], sockets_list)
+
+    for some_socket in read_sockets:
+        if some_socket == server:
+            client_socket, client_address = server.accept()
+            nickname = receive_message(client_socket)
+
+            if nickname is False:
+                continue
+
+            if nickname in clients.values():
+                ms = f"Nickname {nickname['data'].decode('ascii')} is already in use!".encode('ascii')
+                header = len(ms).to_bytes(5, byteorder='big')
+                client_socket.send(nickname['header'] + nickname['data'] + header + ms)
+                continue
+
+            sockets_list.append(client_socket)
+            clients[client_socket] = nickname
+
+            print(f"{nickname['data'].decode('ascii')} was connected from {client_address}")
+
+            message = f"{nickname['data'].decode('ascii')} joined!".encode('ascii')
+            message_header = len(message).to_bytes(5, byteorder='big')
+
+            broadcast(client_socket, nickname, message, message_header)
+
+        else:
+            message = receive_message(some_socket)
+
+            if message is False:
+                close_connection(some_socket)
+                continue
+
+            nickname = clients[some_socket]
+            broadcast(some_socket, nickname, message['data'], message['header'])