import socket # UVOZI MODUL SOCKET
s=socket.socket()
host=socket.gethostname()
port=2222
s.bind((host,port))
s.listen(5)
while True:
    conn, addr=s.accept()
    print("Connection established!", addr)
    poruka='Hello!'
    conn.send(poruka.encode())
    conn.close()


import socket
s=socket.socket()
host=socket.gethostname()
port=2222
s.connect((host,port))
print(s.recv(1024).decode())
s.close()



import socket

import tkinter
import time
from tkinter import font
from tkinter import *

userpass={"Koncar":"321","Milica":"321","Biljana":"222"}
top=tkinter.Tk()
top.geometry("500x400")
font=font.Font(top, family="Verdana", size=12)

Label0=tkinter.Label(top, text="Server Side\r\n", font=font)
Label0.pack(side=TOP)

s=socket.socket()
host=socket.gethostname()
port=2222
s.bind((host,port))
s.listen(5)
conn, addr=s.accept()
poruka="Login required to continue..."
conn.send(poruka.encode())

username=conn.recv(20).decode
password=conn.recv(20).decode

for usr, pas in userpass.item():
    if username==usr and password==pas:
        Label1=tkinter.Label(top, text="Connected to "+username+" at "+time.asctime(time.localtime(time.time())), font=font)
        poruka="Greetings, "+username+"!"
        conn.send(poruka.encode())
        break
else:
    pogresno="Error. Invalid login credentials."
    conn.send(pogresno.encode())
    Label2=tkinter.Label(top, text="Unknown user tried to connect at "+time.asctime(time.localtime(time.time())), font=font)
    Label2.pack()

top.mainloop()