C - freopen or freopen_s

These functions, declared inside stdio.h, both have one thing that I couldn't find the use of:


== FILE * freopen( "asd.txt", "r+", oneFILE*variable ); ==

Why does this shit return a (FILE *)?
- The oneFILE*variable gets its previously held file closed, all good.
- The oneFILE*variable gets loaded with the "asd.txt" with "r+" attribute, all good.

Then the function fucking returns the same pointer, again, the same thing that has been fucking stored inside the oneFILE*variable, why?


== errno_t freopen_s( ONEdummyFILE**variable, "asd.txt", "r+", oneFILE*variable ) ==

Same shit again, why am I giving a retarded, no-use, dummy FILE** variable?

What the fuck is this? Does it have another explanation?