Sure, he wrote _a_ version of grep, and probably the first, but who cares? "The" (sure, you might run some bsd grep) current version of grep certainly doesn't.
No, he wrote grep. Before he wrote it there was no grep. And yes, he's recognized as a great programmer. With Multics, Unix, B, C, UTF-8 Plan9, Inferno and grep to his name (and probably others that I forgot) he has more than deserved that.
Future grep versions, including the FSF one, were all re-implementations.
I do not agree he was a great programmer. All of his programs are trivial from a computer science perspective.
In fact, you can quite easily check this by trying to let an LLM generate a program like grep. It can do that. Now, there also exist programs for which LLMs can't generate code, because it's too complex.
Yes, so you say, and I'm the pope on alternate Sundays. Appeals to authority are meaningless without identity. Meanwhile, I highly doubt you are qualified to polish Thompson's shoes, all I see is an AC novelty account making dumb claims with hindsight. Anyway, enough with you, off to the ignore list.
Not sure what kind of idiotic website this is that people more qualifed than the average idiot here are "flagged". Thompson is completely irrelevant to computer science. Any idiot can write a program, but only some people can make an actual contribution. Knuth actually did something useful in comparison. Also, Knuth was able to articulate.
Ken Thompson wrote grep, and he is definitely recognised as such.