mytunnel.lua

length = tonumber(arg[1])
if length == nil then
print("set length please")
exit()
end
if turtle.getFuelLevel() <= (3*length) then
print("not enough fuel")
end
current = 0
while current < length do
res = turtle.dig()
if not res then break end
res = turtle.forward()
if not res then break end
current = current + 1
res = turtle.digUp()
if not res then break end
end
turtle.turnLeft()
turtle.turnLeft()
while current > 0 do
turtle.dig()
if turtle.forward() then
current = current - 1
end
end