mark

write("Put flooring in slot #2.\n\n")
sleep(1.5)
write("Put floor markers in slot #16 \n\n")
sleep(1.5)
write("click 'enter' when ready.")
read()

-- variables
local length = 0
local dug = 0
term.write("How long should I make it? ")
length = read()
length = length-1
--functions
function myfuel()
    if turtle.getFuelLevel() < 21 then
        print("fuel level is  ..  "..turtle.getFuelLevel())
        turtle.select(1)
        turtle.refuel(1)
        print("I refueled to  ..  "..turtle.getFuelLevel())
    end
end

function dig()
    for i = 1, length do
        turtle.dig()
        turtle.forward()
        turtle.select(2)
        turtle.placeDown()
    end
end

function gobck()
    for i = 1, length do
    turtle.back()
    sleep(.6)
    end
end

function marker()
    turtle.select(16)
    turtle.place()
end

-- start script

print("GO")
turtle.turnLeft()
print("GO")
turtle.turnLeft()
print("GO")
turtle.turnLeft()
print("GO")
turtle.turnLeft()

--dig tunnel
for i = 1, 4 do
    myfuel()
    dig()--advance length
    turtle.turnRight()

end

--place markers

myfuel()
turtle.turnLeft()
gobck()


for i = 1, 3 do
    myfuel()
    turtle.turnLeft()
    turtle.back()
    marker()
    length = length-1
    gobck()
    length = length+1
    sleep(.2)
end


--go home
turtle.back()
marker()