dig.lua

args={...}
if (#args < 1) then
    print("Usage: <programname> striplength")
    return
end

function empty()
    turtle.select(16)
    turtle.digDown()
    turtle.placeDown()
    for i = 1, 15, 1 do
        turtle.select(i)
        turtle.dropDown()
    end
    turtle.select(1)
end

function forward()
    while (turtle.forward() ~= true) do
        if (turtle.detect()) then
            turtle.dig()
        else
            turtle.attack()
        end
    end
end

function dig()
    if (turtle.detectUp()) then
        turtle.digUp()
    end
    if (turtle.detect()) then
        turtle.dig()
    end
    forward()
end

turnLeft = true
i_max = tonumber(args[1])
j_max = 3
while (turtle.detect() ~= true) do
    forward()
end
while (true) do
    j = 1
    while (j <= j_max) do
        dig()
        j = j + 1
    end
    for k = 1, 2, 1 do
        if (turnLeft) then
            turtle.turnLeft()
        else
            turtle.turnRight()
        end
        i = 1
        while (i <= i_max) do
            turtle.select(16)
            if (turtle.getItemCount() < 2) then
                break
            end
            turtle.select(15)
            if (turtle.getItemCount() > 0) then
                empty()
            end
            turtle.select(1)
            if (turtle.getFuelLevel() <= 100) then
                break
            end
            while (i <= i_max and turtle.detect() ~= true) do
                forward()
                i = i + 1
            end
            dig()
            i = i + 1
        end
        turtle.turnLeft()
        turtle.turnLeft()
        i = 1
        while (i <= i_max) do
            forward()
            i = i + 1
        end
        if (turnLeft) then
            turtle.turnLeft()
        else
            turtle.turnRight()
        end
        turnLeft = not turnLeft
    end
    turtle.select(16)
    if (turtle.getItemCount() < 2) then
        break
    end
    if (turtle.getFuelLevel() <= 100) then
        break
    end
    print("Done with strip, fuel level:")
    print(turtle.getFuelLevel())
end