1  #include <dirent.h>
       2  #include <errno.h>
       3  #include <errno.h>
       4  #include <stdio.h>
       5  #include <stdlib.h>
       6  #include <unistd.h>
       7  #include <sys/types.h>
       8  
       9  
      10  int
      11  main (void)
      12  {
      13    DIR *dirp;
      14    struct dirent* ent;
      15  
      16    /* open a dir stream */
      17    dirp = opendir ("/tmp");
      18    if (dirp == NULL)
      19      {
      20        if (errno == ENOENT)
      21  	exit (0);
      22  
      23        perror ("opendir");
      24        exit (1);
      25      }
      26  
      27    /* close the directory file descriptor, making it invalid */
      28    if (close (dirfd (dirp)) != 0)
      29      {
      30        puts ("could not close directory file descriptor");
      31        /* This is not an error.  It is not guaranteed this is possible.  */
      32        return 0;
      33      }
      34  
      35    ent = readdir (dirp);
      36  
      37    return ent != NULL || errno != EBADF;
      38  }