3x3 Tunnel

local args = {...}
length = args[1]

function dig()
                while turtle.detect() do
                        turtle.dig()
                        os.sleep(0.5)
                end
end
function digUp()
                while turtle.detectUp() do
                        turtle.digUp()
                        os.sleep(0.5)
                end
end
function forward()
        while turtle.forward()==false do
                os.sleep(1)
                dig()
        end
end



for x=1,length,1 do
    dig()
    forward()
    turtle.turnRight()
    digUp()
    turtle.digDown()
    dig()
    forward()
    digUp()
    turtle.digDown()
    dig()
    forward()
    digUp()
    turtle.digDown()
    turtle.turnLeft()
    dig()
    forward()
    turtle.turnLeft()
    digUp()
    turtle.digDown()
    dig()
    forward()
    digUp()
    turtle.digDown()
    dig()
    forward()
    turtle.turnRight()
    digUp()
    turtle.digDown()
end