CC program

os.pullEvent = os.pullEventRaw

 w,h = term.getSize()

function reset()
  term.clear()
  term.setCursorPos(1,1)
end

function printCentered( y,s )
   local x = math.floor((w - string.len(s)) / 2)
   term.setCursorPos(x,y)
   term.clearLine()
   term.write( s )
end

function cPrint(str,ln)
  w, h = term.getSize()
  length = string.len(str)
  term.setCursorPos((w / 2) - (length / 2),ln)
  print(str)
end

function cSlowPrint(str,ln)
  w, h = term.getSize()
  length = string.len(str)
  term.setCursorPos((w / 2) - (length / 2),ln)
  textutils.slowPrint(str)
end

nOption = 1
loggedUser = "none"


function drawMenu()
   term.clear()
   term.setCursorPos(1,1)
   term.write("logged in as: "..loggedUser)
term.setCursorPos(1,2)
shell.run("id")

end

function rebootAnim()

reset()

  cPrint("[ Rebooting OS... ]",9)

  cPrint(" | ",11)
  sleep(0.3)

  cPrint(" \ ",11)
  sleep(0.3)

  cPrint(" - ",11)
  sleep(0.3)

  cPrint(" / ",11)
  sleep(0.3)

  cPrint(" | ",11)
  sleep(0.3)

  cPrint(" \ ",11)
  sleep(0.3)

  cPrint(" - ",11)
  sleep(0.3)

  cPrint(" / ",11)
  sleep(0.3)

  cPrint(" | ",11)
  sleep(0.3)

  cPrint(" \ ",11)
  sleep(0.3)

  cPrint(" - ",11)
  sleep(0.3)

  cPrint(" / ",11)
  sleep(0.3)



  os.reboot()

end


function CommandPrompt()

    if loggedUser == "admin" then

reset()

print("Logged in as: Admin")


elseif loggedUser == "guest" then

reset()

cPrint("###############################",7)
cPrint("#                             #",8)
cPrint("#     Permission Denied.      #",9)
cPrint("#     Returning to menu...    #",10)
cPrint("#                             #",11)
cPrint("###############################",12)

sleep(2)

mainMenu()

  else

  end
end

--GUI


term.clear()

function drawFrontend()

    if n0ption == 1 then  --Command
cPrint("[ Command ]         Programs    ",7)
cPrint("  Lock Screen       ........    ",8)
cPrint("  ...........       .........   ",10)
cPrint("  Manage Files      Settings    ",11)
cPrint("  Shutdown           Reboot     ",12)


elseif n0ption == 2 then  -- LockScreen
cPrint("  Command           Programs    ",7)
cPrint("[ Lock Screen ]     ........    ",8)
cPrint("  ...........       .........   ",10)
cPrint("  Manage Files      Settings    ",11)
cPrint("  Shutdown           Reboot     ",12)

elseif n0ption == 3 then  -- ?
cPrint("  Command           Programs    ",7)
cPrint("  Lock Screen       ........    ",8)
cPrint("[ ........... ]     .........   ",10)
cPrint("  Manage Files      Settings    ",11)
cPrint("  Shutdown           Reboot     ",12)

elseif n0ption == 4 then  -- Manage Files
cPrint("  Command           Programs    ",7)
cPrint("  Lock Screen       ........    ",8)
cPrint("  ...........       .........   ",10)
cPrint("[ Manage Files ]    Settings    ",11)
cPrint("  Shutdown           Reboot     ",12)

elseif n0ption == 5 then  -- Shutdown
cPrint("  Command           Programs    ",7)
cPrint("  Lock Screen       ........    ",8)
cPrint("  ...........       .........   ",10)
cPrint("  Manage Files      Settings    ",11)
cPrint("[ Shutdown ]         Reboot     ",12)

elseif n0ption == 6 then  -- Programs
cPrint("  Command         [ Programs ]  ",7)
cPrint("  Lock Screen       ........    ",8)
cPrint("  ...........       .........   ",10)
cPrint("  Manage Files      Settings    ",11)
cPrint("  Shutdown           Reboot     ",12)

elseif n0ption == 7 then  -- ??
cPrint("[ Command ]         Programs    ",7)
cPrint("  Lock Screen     [ ........ ]  ",8)
cPrint("  ...........       .........   ",10)
cPrint("  Manage Files      Settings    ",11)
cPrint("  Shutdown           Reboot     ",12)

elseif n0ption == 8 then  -- ??
cPrint("  Command           Programs    ",7)
cPrint("  Lock Screen       ........    ",8)
cPrint("  ...........     [ ......... ] ",10)
cPrint("  Manage Files      Settings    ",11)
cPrint("  Shutdown           Reboot     ",12)

elseif n0ption == 9 then  -- Settings
cPrint("  Command           Programs    ",7)
cPrint("  Lock Screen       ........    ",8)
cPrint("  ...........       .........   ",10)
cPrint("  Manage Files    [ Settings ]  ",11)
cPrint("  Shutdown           Reboot     ",12)

elseif n0ption == 10 then -- Reboot
cPrint("  Command           Programs    ",7)
cPrint("  Lock Screen       ........    ",8)
cPrint("  ...........       .........   ",10)
cPrint("  Manage Files      Settings    ",11)
cPrint("  Shutdown         [ Reboot ]   ",12)


    else
  end
end



function lockScreen()

  reset()

  cPrint("##############################",7)
  cPrint("#                            #",8)
  cPrint("# Username:                  #",9)
  cPrint("# Password:                  #",10)
  cPrint("#                            #",11)
  cPrint("##############################",12)

  term.setCursorPos(20,9)
  term.write(": ")
  username = read()

  term.setCursorPos(20,10)
  term.write(": ")
  password = read("*")


    if username == "admin" and password == "eiVae9" then

  loggedUser = "admin"
    sleep(1)
    mainMenu()

elseif username == "guest" and password == "guest" then

  loggedUser = "guest"
    sleep(1)
    mainMenu()

else

  sleep(1)
  reset()
cPrint("Wrong password...",10)
cPrint("Try again!",11)

lockScreen()




  end
end


--Display

function mainMenu()

  drawMenu()
  drawFrontend()

while true do
 local e,p = os.pullEvent()
 if e == "key" then
  local key = p
  if key == 17 or key == 200 then

   if nOption > 1 then
    nOption = nOption - 1
    drawMenu()
    drawFrontend()
   end
  elseif key == 31 or key == 208 then
  if nOption < 10 then
  nOption = nOption + 1
  drawMenu()
  drawFrontend()
end
elseif key == 28 then

      break
    end
  end
end
term.clear()


if nOption  == 1 then
CommandPrompt()
elseif nOption == 2 then
lockScreen()
elseif nOption == 3 then

elseif n0ption == 4 then
manageFiles()
elseif n0ption == 5 then
os.shutdown()
elseif n0ption == 6 then

elseif n0ption == 7 then
programsMenu()
elseif n0ption == 8 then

elseif n0ption == 9 then
osSettings()
elseif n0ption == 10 then
rebootAnim()
else
  end
end

--lockScreen()
mainMenu()