Description

   The closedir function closes a directory stream and frees
   the structure associated with the dir_pointer argument. Upon
   return, the value of dir_pointer does not necessarily point to an
   accessible object of the type DIR.

   The type DIR, which is defined in the <dirent.h> header file,
   represents a directory stream that 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.

                                  NOTE

      An open directory must always be closed with the closedir
      function to ensure that the next attempt to open the
      directory is successful.