#include <stddef.h>
#include <stdio.h>
#include <dirent.h>
#include <stdlib.h>


int
main(int argc, char *argv[])
{
    DIR                *dp;
    struct dirent    *dirp;
    if (argc != 2)
        perror("usage: ls directory_name");
    if ((dp = opendir(argv[1])) == NULL )
        perror("can't open file");
    while ((dirp = readdir(dp)) != NULL )
        printf("%s\n", dirp->d_name);
    closedir(dp);
    exit(0);
}