client.py

import socket, select, string, sys,struct
import pickle
 
def send(channel,*args):
    buffers=pickle.dumps(args)
    value=socket.htonl(len(buffers))
    size=struct.pack("L",value)
    channel.send(size)
    channel.send(buffers)
def prompt() :
    sys.stdout.write('<Username>')
    sys.stdout.flush()
if __name__ == "__main__":
    if(len(sys.argv) < 3) :
        print('Usage : filename hostname port ' )
        sys.exit()
    host = sys.argv[1]
    port = int(sys.argv[2])
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.settimeout(2)
    try :
        s.connect((host, port))
    except :
        print('Unable to connect')
        sys.exit()
    print( 'Connected to remote host. Start sending messages' )
    prompt()
    while True:
        rlist = [sys.stdin, s]
        read_list, write_list, error_list = select.select(rlist , [], [])
        for sock in read_list:
            if sock == s:
                data = sock.recv(4096)
                if not data :
                    print ('\nDisconnected from chat server')
                    sys.exit()
                else :
                    sys.stdout.write(data.decode()+"\n")
                    prompt()
            else :
                msg = sys.stdin.readline()
                s.send(msg.encode())
                prompt()