Lumberjack

-- advanced turtle lumberjack
shell.run('clear')
print("Please put Dirt in Slot 1, Saplings in Slot 2, and a log in Slot 3.")
print("Number of Trees To Plant?")
local x = io.read()
local dirt, sapling, log = 1, 2, 3

-- get into position
turtle.up()
turtle.turnLeft()
turtle.turnLeft()
turtle.back()
turtle.back()
turtle.back()

-- initial planting
for i = 0, x do
  turtle.digDown()
  turtle.select(dirt)
  turtle.placeDown()
  turtle.back()
  turtle.select(sapling)
  turtle.place()
  turtle.back()
  turtle.back()
  turtle.back()
end
turtle.turnLeft()
turtle.forward()
turtle.turnRight()

--chop trees
while true do
  -- sleep for 30 seconds
  os.sleep(30)
  -- check all trees for any that have grown
  for i = 0, x do
    turtle.forward()
    turtle.forward()
    turtle.forward()
    turtle.forward()
    turtle.turnRight()
    turtle.select(log)
    -- if the tree has grown
    if turtle.compare() then
      turtle.dig()
      turtle.forward()
      -- harvest the tree
      while turtle.detectUp() do
      turtle.digUp()
      turtle.up()
      end
      -- return to the ground
      while not turtle.detectDown() do
        turtle.down()
      end
      -- plant a new sapling
      turtle.back()
      turtle.select(sapling)
      turtle.place()
    end
    turtle.turnLeft()
  end
  -- round the corner
  turtle.forward()
  turtle.turnRight()
  turtle.forward()
  turtle.forward()
  turtle.turnRight()
  turtle.forward()
end