DoorLock

--a simple door lock with immibis peripherals mag-card

    os.loadAPI("StrUtils")

    function inFile(file, string)

      local f = fs.open(file,"r")
      local line

      repeat
        line = f.readLine()
        if string==line then
          f.close()
          return true
        end
      until not line

      f.close()
      return false

    end

    monitor = peripheral.wrap("monitor_0")
    mag = peripheral.wrap("mag card reader_0")


    monitor.setTextScale(1.5)

    while true do

      monitor.setBackgroundColor(colors.black)
      monitor.setTextColor(colors.blue)
      monitor.clear()
      monitor.setCursorPos(1,1)
      monitor.write("Swipe")
      monitor.setCursorPos(1,2)
      monitor.write("Card!")
      monitor.setCursorPos(3,4)
      monitor.setBackgroundColor(colors.blue)
      monitor.write(" ")
      monitor.setCursorPos(2,5)
      monitor.write(" ")
      monitor.setCursorPos(1,6)
      monitor.write(" ")
      monitor.setCursorPos(2,7)
      monitor.write(" ")
      monitor.setCursorPos(3,8)
      monitor.write(" ")

      local event,arg1,arg2,arg3 = os.pullEvent("mag_swipe")

      if inFile("//.keys", StrUtils.SHA1(arg1)) then
        monitor.setBackgroundColor(colors.green)
        monitor.clear()
        rs.setOutput("top",true)
        os.sleep(1.5)
        rs.setOutput("top",false)
      else
        monitor.setBackgroundColor(colors.red)
        monitor.clear()
        os.sleep(5)
      end

    end