Client

"""
    Python 3
    Usage: python3 TCPClient3.py localhost 12000
    coding: utf-8
    
    Author: Wei Song (Tutor for COMP3331/9331)
"""
from socket import *
import sys

#Server would be running on the same host as Client
if len(sys.argv) != 3:
    print("\n===== Error usage, python3 TCPClient3.py SERVER_IP SERVER_PORT ======\n");
    exit(0);
serverHost = sys.argv[1]
serverPort = int(sys.argv[2])
serverAddress = (serverHost, serverPort)

# define a socket for the client side, it would be used to communicate with the server
clientSocket = socket(AF_INET, SOCK_STREAM)

# build connection with the server and send message to it
clientSocket.connect(serverAddress)

while True:
    message = input("===== Please type any messsage you want to send to server: =====\n")
    clientSocket.sendall(message.encode())

    # receive response from the server
    # 1024 is a suggested packet size, you can specify it as 2048 or others
    data = clientSocket.recv(1024)
    receivedMessage = data.decode()

    # parse the message received from server and take corresponding actions
    if receivedMessage == "":
        print("[recv] Message from server is empty!")
    elif receivedMessage == "user credentials request":
        print("[recv] You need to provide username and password to login")
    elif receivedMessage == "download filename":
        print("[recv] You need to provide the file name you want to download")
    else:
        print("[recv] Message makes no sense")
        
    ans = input('\nDo you want to continue(y/n) :')
    if ans == 'y':
        continue
    else:
        break

# close the socket
clientSocket.close()