In any case, strcpy_s (which is a good replacement for strcpy) is part of the C11 standard. I'm confused how that isn't considered portable.
Well, I mean, the docs specifically call that out: "If src is less than len characters long, the remainder of dst is filled with ‘\0’ characters. Otherwise, dst is not terminated."
So if you want null termination in all cases, you need to pass len-1, not len.
The idea may not be perfect, but for C which is intended to be low overhead, strcpy_s is about as good as it gets. If you want something more user friendly, that is what C++ is for with std::string, or library implementations like Boost or QT string.
Source, and why does it matter who made it?
>designed by some intern
You don't know that, nor is that how standards work.
>other compilers may or may not
So you've said basically nothing.
>it is worthless in any case.
It offers a low-overhead, safer alternative to strcpy. Is it perfect? No. But it's one of the better C options for those limited to the standard library.