Strip mining

 local length = 5

local args = {...}
if #args == 0 then
  print("strip <wiederholungen>")
  return
end
local rept = args[1]

function refuel()
  if turtle.getFuelLevel() <= 64 then
    print("Searching for fuel...")
    for i=1,14 do
      turtle.select(i)
      turtle.refuel()
    end
  end
end

function unload()
  for i=1,14 do
    if turtle.getItemCount(i) == 0 then
      return
    end
  end

  if turtle.detectDown() then
    turtle.digDown()
  end

  if turtle.getItemCount(15) > 0 then
    turtle.select(15)
    turtle.placeDown()
    for i=1,14 do
      turtle.select(i)
      turtle.dropDown()
    end
  end
end

function dig(start)
  turtle.dig()
  turtle.forward()
  turtle.digUp()
  if not start then
    turtle.digDown()
  end
end

function gang()
  for i=1,5 do
    dig(false)
  end

  turtle.turnRight()
  turtle.turnRight()

  for i=1,5 do
    turtle.forward()
  end
end

function mine()
  refuel()
  dig(true)
  dig(true)
  dig(true)
  turtle.turnLeft()
  gang()
  turtle.forward()
  gang()
  turtle.select(16)
  turtle.place()
  turtle.turnRight()
  unload()
end

for i=1,rept do
  mine()
end