illumos gate

The readdir(3C) routine returns pointers to a private buffer attached to the struct DIR returned by opendir(3C) and at times overwritten (and thus invalidated) by subsequent readdir() calls. The manual notes that:

       The pointer returned by readdir() points to data that can be overwritten
       by another call to readdir() on the same directory stream. These data are
       not overwritten by another call to readdir() on a different directory
       stream.

The text in both the readdir(3C) and the closedir(3C) pages should explicitly call out the fact that a closedir(3C) will also invalidate any pointers previously returned by readdir(), as it frees the dd_buf while tearing down the struct DIR.