Simple screen brightness app that leverages xbacklight

conf.lua

function love.conf(t)
  t.version = "0.9.2"
  t.window.title = "Screen Brightness"
  t.window.width = 400
  t.window.height = 32
end

main.lua

local temp_file = "xbacklight"

function love.load()
  love.filesystem.write(temp_file,"0")
  os.execute("xbacklight > \""..love.filesystem.getSaveDirectory().."\"/"..
    temp_file)
  current = love.filesystem.read(temp_file)/100 or 0
end

function love.draw()
  love.graphics.rectangle("fill",0,0,
    current*love.graphics.getWidth(),
    love.graphics.getHeight())
end

function love.mousepressed(x,y,button)
  current = x/love.graphics.getWidth()
  os.execute("xbacklight -set "..math.floor(current*100))
end