/* readdir.c */

#include <procfs.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <dirent.h>

int main(
int argc,
char **argv)
{
  DIR *procdir;
  struct dirent *de;

/* make sure user provided a directory name */

   if (argv < 2)
   {
      fprintf(stderr, "Usage is readdir dir-name \n");
      exit(1);
   }

/* The opendir function is used to open a directory for */
/* reading by readdir()                                 */

   procdir = opendir(argv[1]);

/* After any system call it is important to verify that */
/* it actually worked rather than blindly pressing on   */
/* assuming that it did.  If it failed the perror()     */
/* function will convert the code stored in "errno"     */
/* to a moderately informative message..                */
/* For example, try readdir /home/westall/acad/cs422    */
/* or readdir /home/westall/blah/blah/blah              */

   if (procdir == 0)
   {
      perror("open failed");
      exit(1);
   }

/* The readdir() function returns a pointer to the next */
/* struct dirent in the directory or NULL at end        */
/* The d_name element holds the file or subdir name     */

/* The %-10s format code says to left justify the string */
/* in a field of width 10.                               */

   while ((de = readdir(procdir)) != 0)
      printf("%-10s \n", de->d_name);

}