if (result != NULL)  result->_mode = 0;
freopen64 (filename, mode, fp)     const char* filename;     const char* mode;     FILE *fp;{#ifdef _G_OPEN64  FILE *result;  CHECK_FILE (fp, NULL);  if (!(fp->_flags & _IO_IS_FILEBUF))    return NULL;  _IO_cleanup_region_start ((void (*) __P ((void *))) _IO_funlockfile, fp);  _IO_flockfile (fp);  result = _IO_freopen64 (filename, mode, fp);  _IO_funlockfile (fp);  _IO_cleanup_region_end (0);  return result;#else  __set_errno (ENOSYS);  return NULL;#endif}