Train Tunnel v2

--Check arguments for correct formatting
local args = { ... }
if #args ~= 1 then      --Check if it's not exactly 3 arguments.
    shell.run("clear")
    print("Invalid number of arguments")
    print("turtletower [height]")
    do return end
end
for i = 1, 1 do            --Step through each argument and make sure it is a number greater than 1.
    if tonumber(args[i]) < 2 then
        shell.run("clear")
        print("Invalid arguments")
        print("All measurements must be numbers greater than 1")
        do return end
    end
end
--------------------------------------------------

--commandline arguments [height]
length = tonumber(args[1])  --length of tunnel
slotnum = 1
function checkSlots()
    if turtle.getItemCount(slotnum) < 1 then
        slotnum = slotnum + 1
        turtle.select(slotnum)
    end
    return
end

for i = 1, length do

    -- Add Some Flooring

    turtle.placeDown()

    turtle.turnLeft()
    turtle.dig()
    turtle.forward()

    -- Dig Most of the Tunnel
    turtle.placeDown()
    turtle.digUp()
    turtle.up()
    turtle.digUp()
    turtle.up()
    turtle.turnRight()
    turtle.turnRight()
    turtle.dig()
    turtle.forward()
    turtle.digDown()
    turtle.down()
    turtle.dig()
    turtle.forward()
    turtle.digUp()
    turtle.digDown()
    turtle.down()

    turtle.placeDown()
    turtle.back()
    turtle.turnLeft()
    turtle.dig()
    turtle.forward()

end