That's one of the most nonsensical comments on all of hackernews. A Markov change could have wrote it.

What do you mean Turing complete? Obviously all 3 programs are running on a Turing complete machine. Xargs is a runner for other commands, obviously those commands can be Turing complete.

I haven't heard of anybody working on a _proof_ for the Turing completeness of xargs, and I think the only conference willing to publish it would be Sigbovik.