WallBuilder

-- pastebin get WV9seckz WallBuilder

length = 35

function selectNetherrack()
    for i = 1, 16, 1 do
        item = turtle.getItemDetail(i)
        if item and item.count > 0 then
            if item.name == "minecraft:netherrack" then
                turtle.select(i)
                return true
            end
        end
    end
    return false
end

cnt = 0
while cnt < length do
    cnt2 = 0
    while turtle.down() do
        cnt2 = cnt2 + 1
    end
    while cnt2 > 0 do

        turtle.up()
        cnt2 = cnt2 - 1
        if selectNetherrack() then
            turtle.placeDown()
        end
    end
    if selectNetherrack() then
        while not turtle.forward() do turtle.dig() end
        cnt = cnt + 1
    else
        while not selectNetherrack() do
            print("Bitte Netherrack ins Inventar geben!")
            read()
        end
    end
end
turtle.turnLeft()
turtle.turnLeft()

while cnt > 0 do
    while not turtle.forward() do turtle.dig() end
end