David,

no doubt that C/C++ code will beat VFP at character handling in naerly all cases. But somehow I doubt that the OP's " relatively large ascii strings " are supposed to be in the range all of you were testing - I got the impression that it was more a case of URL-mangling. Especially since the C is not terribly difficult, the fact that such a question was asked smells of premature optimization to add such tiny bits into a project where probably no C/C++ skills exist.

Consider that the speed difference of different implementation strategies might vary with the string length<bg>. For instance the "horrible" Substr() performance compared to heap-allocated memory comes into play only around 2**9 bytes - most URL's are shorter. The part where C++ "shines" will be relatively smaller, even if all non-naive implementations approach linear cost factor.

I *do* hope that "portions of web pages that are intentionally obfuscated" are each not that large, as the tripled lenght has to sent even in todays DSL-times...

regards

thomas