rt-thread/examples/libc/dirent.c

/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2010-11-17     Bernard      first version
 */
#include <stdio.h>
#include <stdlib.h>

#include <dirent.h>
int libc_dirent()
{
    DIR * dirp;
    long int save3 = 0;
    long int cur;
    int i = 0;
    int result = 0;
    struct dirent *dp;

    dirp = opendir("/");
    for (dp = readdir(dirp); dp != NULL; dp = readdir(dirp))
    {
        /* save position 3 (after fourth entry) */
        if (i++ == 3)
            save3 = telldir(dirp);

        printf("%s\n", dp->d_name);

        /* stop at 400 (just to make sure dirp->__offset and dirp->__size are
         scrambled */
        if (i == 400)
            break;
    }

    printf("going back past 4-th entry...\n");

    /* go back to saved entry */
    seekdir(dirp, save3);

    /* Check whether telldir equals to save3 now.  */
    cur = telldir(dirp);
    if (cur != save3)
    {
        printf("seekdir (d, %ld); telldir (d) == %ld\n", save3, cur);
        result = 1;
    }

    /* print remaining files (3-last) */
    for (dp = readdir(dirp); dp != NULL; dp = readdir(dirp))
        printf("%s\n", dp->d_name);

    closedir(dirp);
    return result;
}