from time import sleep
from os import system, name
booted = False
def cscr():
  # for windows
   if name == 'nt':
    comand = system('cls')
   # for mac and linux
   else:
    comand = system('clear')
cscr()
print("SimpleDos is booting up.")
print("Please wait...")
sleep(5)
booted = True
cscr()
while (booted == True):
  cmd = input("C:\\")
  
  if (cmd == "lt"):
    print("There are no files in this directory")
  elif (cmd == "cscr"):
    cscr()
  elif (cmd == "sd"):
    print("SimpleDos is now shutting down...")
    sleep(2)
    booted = False
    cscr()
    exit()
  else: 
    print("Not a valid command")
    print("\a")