Not "his challenger"; it was not a contest. It would be more proper to say "his reviewer, the inventor of Unix pipes, using the review column to advertise UNIX®". See a previous discussion here: https://news.ycombinator.com/item?id=22406070
Incidentally, a couple of days after that thread, the current fastest submissions (which, like Knuth, all use tries) were posted at the question https://codegolf.stackexchange.com/questions/188133/bentleys... mentioned in a sibling comment. (AFAICT that comment should say "200 times faster", not "30 times faster", but anyway in light of the original context it's not meaningful to compare the two approaches either for efficiency or ease of implementation or anything else.)
Thanks for the extra context!
Yes, my 'challenger' didn't mean to imply a formal contest.
Codegolf page with solutions up to 30 times faster than the McIlroy shell script solution - https://codegolf.stackexchange.com/questions/188133/bentleys...
Interesting, that they can only get 30 times faster with modern technology and more complications.
I guess, if you really wanted to solve this fast, you'd massively parallelize.
In any case, this was more about easy of implementation than about runtime speed.
Basically, Knuth was writing a beautiful but excessively low level program. His challenger wrote a dozen lines of shell-script.