14.2.4 Simple Program to List a Directory

Here’s a simple program that prints the names of the files in the current working directory:

#include <stdio.h>
#include <sys/types.h>
#include <dirent.h>

int
main (void)
{
  DIR *dp;
  struct dirent *ep;

  dp = opendir ("./");
  if (dp != NULL)
    {
      while (ep = readdir (dp))
        puts (ep->d_name);
      (void) closedir (dp);
    }
  else
    perror ("Couldn't open the directory");

  return 0;
}

The order in which files appear in a directory tends to be fairly random. A more useful program would sort the entries (perhaps by alphabetizing them) before printing them; see Scanning Directory Content, and Array Sort Function.