Computercraft Turtle FollowTheLine Script

turtle.refuel()
local blockname = "minecraft:cobblestone"

while true
do
 local success, data = turtle.inspectDown()

 if success then
   if data.name == blockname then
    turtle.forward()
   else
    turtle.back()
    turtle.turnRight()
   end
 end

 -- sleep(1)
end