文件路径拆分

void _splitpath(
   const char *path,
   char *drive,
   char *dir,
   char *fname,
   char *ext 
);
void _wsplitpath(
   const wchar_t *path,
   wchar_t *drive,
   wchar_t *dir,
   wchar_t *fname,
   wchar_t *ext 
);