#include <sys/types.h>
#include <sys/dir.h>
#include <dirent.h>
#include <stdlib.h>

/* see man readdir and dirent */

int main(void)
{
  DIR *dirp;
  struct dirent *dir_entry;

  /* "." means current directory */
  if ((dirp = opendir(".")) == NULL)
    return NULL;

  while ((dir_entry = readdir(dirp)) != NULL) 
    printf("There is a file %s in this directory\n", dir_entry->d_name);
  
  closedir(dirp);
}