I did a SuperSearch, and didn't turn up anything directly related to my question, so...

I've been using this code and regex as the heart of an is_MD5 subroutine:

if ($hash =~ /[0-9a-f]{32}/i) { return(1); }

Now I'd like to generalize it for other hex hash strings, and I think I've negated it correctly like so:

if ($hash =~ /[^0-9a-fA-F]/ ) { return(0); }

The new code continues into some other checks as long as the entire hash string is good hex. It works with all my test cases, but I don't have a large enough set to find any performance difference. Am I doing something stupid that could bite me down the road?

Update: Kyle, thanks, it was couched in other checks, but the more atomic the better, IMO. Davidrw, THANKS! I've seen that but forgot about it.

In reply to hex-only regex by dwhite20899

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