Turtle tunnel that will wall up sides and ceiling?

I've been searching the forums and reddit and a few other places for about 2 days now and can't seem to find a turtle tunnel (3x3 preferrably) that will wall up the sides and ceiling as it digs along. It's frustrating when he digs along and then gets lost among lava that's caved in from the ceiling or sides and it takes me about 20 minutes to wall it up to get to him.

I'm found a few that will make bridges as they go across say a chasm, but can't seem to find any that fill in the walls and ceiling. Anybody have one that they've seen/used or am I going to finally learn how to code my own today?

This should be fairly easy to program, so my best advice is.. Get cracking :D/>

if you run into trouble doing this, feel free to ask for help :)/>
thats what we are here for :)/>

Will do - will dissect some of the other simple tunnel programs I've seen and see if I can modify one of those first before starting from scratch. If I get lost enough I'll take to the tutorials and start from scratch

i lend you a hand on it :)/>

heres something to help you with falling blocks like gravel and sand :)/>

Spoiler

function fallingblocks()
        local success, data = turtle.inspect()
        local successa, dataa = turtle.inspectUp()
        local fBlocks =
                {
                ["minecraft:sand"] = true,
                ["minecraft:gravel"] = true
                }
        if fBlocks[data.name] or fBlocks[dataa.name] then
                return true
        else
                return false
        end
end