Stripmine

--Stripmine
--This sends a turtle down to bedrock mineing below and infront as it goes down.
--It then moves forward 2
--and mines back up to the same level
--This will create a 1X4 hole to bedrock

function fuel()

    while turtle.getFuelLevel() < 500 do
        print("Looking for Fuel")
            for slot = 1,16 do
            if turtle.getFuelLevel() < 500 then
                        turtle.select(slot)
                            repeat
                            until turtle.refuel(1) == false or turtle.getFuelLevel() > 500
                    end
            end
    end
end

function digdown()
    local distance = 0
    repeat
        distance = distance + 1
        turtle.suck()
        turtle.dig()
                turtle.suckDown()
                turtle.digDown()
        until turtle.down() == false
    return distance
end

function moveforward(distance)
    repeat
        turtle.dig()
        if turtle.forward() then
            distance= distance - 1
        else
            turtle.digUp()
            turtle.up()
        end
    until distance== 0
end

function digup(distance)
    repeat
        distance= distance - 1
        turtle.suck()
        turtle.dig()
                turtle.digUp()
        turtle.up()
        until distance <= 1
end

function freeslots()
    local free = 0
    for slot = 1,16 do
                turtle.select(slot)
        if turtle.getItemCount == 0 then
            free = free + 1
        end
        end
    return free
end

local depth

repeat
    fuel()
    depth = digdown()
    moveforward(2)
    digup(depth)
    moveforward(2)
until freeslots() < 5