LandMark Placer

function checkFuel()
        if(turtle.getFuelLevel() < 2) then
                turtle.select(16)
                if(turtle.refuel(1)==false) then
                        print("Turtle needs more fuel in slot 16.")
                        print("Press enter to continue.")
                        io.read()
                        checkFuel()
                end
                turtle.select(15)
        end
end

 function moveUp()
        checkFuel()
        while(turtle.up()==false)do turtle.digUp() end
end

function moveDown()
        checkFuel()
        while(turtle.down()==false)do turtle.digDown() end
end

function move()
        checkFuel()
        while(turtle.forward()==false)do turtle.dig() end
end

function moveBack()
        checkFuel()
        while(turtle.back()==false)do end
end

local args = { ... }

function main()
    local quarryWidth

    if(#args == 1) then
        quarryWidth = tonumber(args[1])
        if(quarryWidth<2 or quarryWidth>64) then
            print("Invalid Width")
            return
        end
    else
        print("Usage: "..shell.getRunningProgram().." <diameter>")
        return
    end

    for temp2=2,1,-1 do
        for temp=quarryWidth-1,1,-1 do
            move()
        end
        turtle.select(2)
        turtle.digDown()
        turtle.placeDown()
        moveBack()
        turtle.select(1)
        turtle.place()

        for temp=quarryWidth-1,2,-1 do
            moveBack()
        end
        turtle.turnRight()
    end

end

main()