That's the "lazy, dumb" way of doing it --- write another string library. A much better way is to design your algorithms so they need a minimum of string manipulation, which is unfortunately on the more difficult side for text-based protocols like HTTP.

Personally, I wish HTTP messages were closer to something like ASN.1 DER; there's little in the way of string manipulation necessary for those, and all the lengths are prefixes instead of "try to find the terminator" (and don't forget to not run past the end of the buffer...)