Description

   The seekdir function sets the position of the next readdir
   operation on the directory stream specified by dir_pointer to
   the position specified by location. The value of location should
   be returned from an earlier call to telldir.

   If the value of location was not returned by a call to the
   telldir function, or if there was an intervening call to the
   rewinddir function on this directory stream, the effect is
   unspecified.

   The type DIR, defined in the <dirent.h> header file, represents
   a directory stream. A directory stream is an ordered sequence of
   all the directory entries in a particular directory. Directory
   entries represent files. You can remove files from or add files
   to a directory asynchronously to the operation of the readdir
   function.

   See readdir, rewinddir, and telldir.