Branch

tArgs = {...}
length = tArgs[1]

if #tArgs ~= 1 then
  print("Usage: branch <length>")
end


local function forward()
  while not turtle.forward() do
    turtle.digDown()
    turtle.dig()
    turtle.digUp()
    turtle.attack()
  end
end


local function tunnel()
  forward()
  if not turtle.detectDown() then
    turtle.select(1)
    turtle.placeDown()
  end
end


for i = 1,length do
  tunnel()
end
turtle.digUp()
turtle.digDown()

for i = 1,length do
  turtle.back()
end