I didn't like that C itself was missing, because C is still my language of choice for some tasks and I still use it because I'm happy about it, I don't feel I would need any of its competitors. Maybe if this benchmark included C it would be some argument to give them a try. So I decided to do it for you.
It took me 30 minutes, only change is that I don't check if file is binary, I guess. I liked that I was doing it in C because I know it and I'm comfortable with it. Few checks in man and everything's clear. Only disadvantage of C is that it doesn't have standard API for directories, so my code is only for POSIX. Here's the code: https://github.com/BartekLew/dumbgrep
The other thing are sources you've done. They are almost the same (it'd be nice to see the more feeling of the language, idiomatic code, etc.) and I didn't like reading them at all, not a clean code and all are longer than my C code.
Another thing is that C has very narrow application nowadays. A benchmark should be focussed on them and not on generic algorithms.