simple tree harvest function

function harvest()
    turtle.select(1)

    local success, data = turtle.inspect()
    wood = data.name
    print(wood)

    while turtle.detect() do
        turtle.dig()
    end

    turtle.forward()

    while true do
        local success, data = turtle.inspectUp()
        if data.name == wood then
            turtle.digUp()
            turtle.up()
        else
            break
        end
    end

    while not turtle.detectDown() do
        turtle.down()
    end
    turtle.back()
end