Huh. I was under the impression that it did full verification, as
according to RFC (2)822. Not that that's generally necessary, in fact
it's mostly just outdated crap, (the technical term I believe).
-- Richard Heyes
That's the problem with the filter extension. It's a black box and you never know what it checks, or how. Often it validates poor input as is the case with its URL validation.
Regex means you see what's happening and you have control over it.
I've been using the filter_* validators in some cases, but after inspecting the C source code of this extension and finding multiple side effects in the filters I used, I dropped it and went back to regex/strlen/ctype_*/etc.
Regards, Stan Vassilev