Example calling scandirat() in glibc

scandirat.c

#define _DEFAULT_SOURCE
#define _GNU_SOURCE
#include <dirent.h>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

/* Compile with
   gcc -Wall -Wextra -O2 scandirat.c -o scandirat
 */

int main(void)
{
    struct dirent **namelist;
    int dirfd, count;

    dirfd = open("/", O_CLOEXEC|O_DIRECTORY|O_RDONLY);
    if (dirfd < 0) {
        err(EXIT_FAILURE, NULL);
    }

    count = scandirat(dirfd, ".", &namelist, NULL, alphasort);
    if (count < 0) {
        perror("scandirat");
        err(EXIT_FAILURE, NULL);
    }

    for (int i=0; i<count; i++) {
        printf("%s\n", namelist[i]->d_name);
        free(namelist[i]);
    }

    free(namelist);
    close(dirfd);
    exit(EXIT_SUCCESS);
}

alex@bertha:~$ gcc -Wall -Wextra -O2 scandirat.c -o scandirat
alex@bertha:~$ ./scandirat 
.
..
bin
boot
cdrom
dev
...
tmp
usr
var
vmlinuz
vmlinuz.old