Player detector

local event
local name
local found

function pulse(color)
   redstone.setBundledOutput("back", color)
   sleep(0.4)
   redstone.setBundledOutput("back", 0)
   sleep(0.4)
end

function door()
   redstone.setBundledOutput("back", colors.white)
   sleep(4)
   redstone.setBundledOutput("back", 0)
end

function floor()
   for i = 1,3 do pulse(colors.magenta) end
   sleep(4)
   for i = 1,3 do pulse(colors.orange) end
end

function reset()
   name = ""
   found = false
end

function waitClick()
   event, name = os.pullEvent("player")
   print(name)
end

function checkName()
   file = io.open("perms", "r")
   for line in file:lines() do
      if name == line then
         found = true
      end
   end
end

function run()
   if found == true then
      print("Yay")
      door()
   else
      print("Boo")
      floor()
   end
end
while true do
  reset()
  waitClick()
  checkName()
  run()
end