HackOS

print("Welcome to HackOS.")
while true do
  print("Please input a command.")
  input = read()
  if input:lower() == "help" then
    print("Hello. I am HackOS. I am a system that is")
    print("designed to help you out in this world.")
    print("I am NOT a replica of HAL9000, I am not")
    print("sentient and won't try to kill you. In fact,")
    print("I try to help you out with tips you ignore.")
    print("So, press any key to clear and move on.")
    print("Also: Type cmds to see the full list.")
    os.pullEvent("char")
  end
  if input:lower() == "cmds" then
    print("Commands are:")
    print("cmds -- Shows this list")
    print("help -- Shows the system helplist")
    print("exit -- Shuts down the system")
    os.pullEvent("char")
  end
  if input:lower() == "exit" then
    shell.run("shutdown")
  end
  if input:lower() == "edit" then
    print("Input passkey:")
    P = read("*")
    if P == "No" then
      print("Access granted.")
      sleep(2)
      shell.run("edit HackOS")
    else
      print("Access denied.")
      sleep(2)
    end
  end
  if input:lower() == "tips" then
    print("Checking database...")
    if fs.exists("disk/") then
      print("Downloading tip...")
      D = fs.open("disk/tip","r")
      Tr = D:readAll()
      D.close()
      T = fs.open("tips","w")
      T:write(Tr)
      T.close()
      W = true
    end
    if fs.exists("tips") then
      if W == true then
        print("Reading new tip...")
      else
        print("No new tips at this time. Reading old tip...")
      end
      E = fs.open("tips","r")
      print(E:readAll())
      E.close()
    else
      print("There are no tips at this time.")
    end
    os.pullEvent("char")
  end
  term.clear()
  term.setCursorPos(1,1)
end