According to the Oxford English Dictionary, both grep and grok are English verbs. I'm happy about this, since the OED is about as official as you can get.
I used to do research for the OED and generally if there's evidence that a verb is common in the field (used in magazines, books, etc. by multiple authors and not just in reference to it's original usage) then the OED is willing to include it.
If there's a term that you think matches that criteria but isn't included you can gather up some relevent citations and send them in and they'll consider it for addition.
To get a transparent look at how they do this kind of thing have a look at:
The OED ran an open research project to gather evidence of science fiction terms as they figured the online SF community would be much better at finding this evidence than their own researchers.
grep, n.
Computing.
A Unix command used to search files for the occurrence of a string of characters that matches a specified sequence or pattern, and to output all the lines matching this. Also grep command.
grep, v.
Computing.
1. intr. To search for a string of characters using the grep command. Also trans.: to search (a file) in this way.
2. trans. slang (usu. humorous). Of a person: to search; to scan visually.
