how to use smbclient

smbls.c

#include <samba-4.0/libsmbclient.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>

void die(const char* format, ...)
{
    va_list vl;
    va_start(vl, format);
    vfprintf(stderr, format, vl);
    va_end(vl);
    exit(1);
}

void auth_fn(const char *srv, const char *shr, char *wg,
        int wglen, char *un, int unlen, char *pw, int pwlen)
{
    fprintf(stderr, "srv: '%s'\n", srv);
    fprintf(stderr, "shr: '%s'\n", shr);
    fprintf(stderr, "wg: '%s', wglen: %d\n", wg, wglen);
    fprintf(stderr, "un: '%s', unlen: %d\n", un, unlen);
    fprintf(stderr, "pwlen: %d\n", pwlen);
    char* pass = getenv("SMB_PASS");
    if (!pass)
    {
        die("SMB_PASS not set, unknown samba password\n");
    }
    strncpy(pw, pass, strlen(pass));
    fprintf(stderr, "pw: '%s'\n", pw);
}

int interesting_dirent(struct smbc_dirent* dirent)
{
    return (dirent->smbc_type == 7 || dirent->smbc_type == 8 ||
            dirent->smbc_type == 9);
}

int is_file(struct smbc_dirent* d)
{
    return d->smbc_type == 8;
}

void usage(const char* app)
{
    fprintf(stderr, "usage: %s smb_share\n", app);
    exit(1);
}

int main(int argc, char** argv)
{
    if (argc != 2)
    {
        usage(argv[0]);
    }
    int e = smbc_init(&auth_fn, 1);
    if (e)
    {
        die("smbc_init failed with code: %d\n", e);
    }
    int dir_fd = smbc_opendir(argv[1]);
    fprintf(stderr, "dir_fd: %d\n", dir_fd);
    if (dir_fd < 0)
    {
        die("smbc_opendir failed: %s\n", strerror(errno));
    }

    const int size = 10000;
    char dirsbuf[size];
    e = smbc_getdents(dir_fd, (struct smbc_dirent*) dirsbuf, size);
    if (e == 0 || e < size)
    {
        fprintf(stderr, "No more dirents\n");
    }
    else if (e < 0)
    {
        die("smbc_getdents failed: %s\n", strerror(errno));
    }
    char* current = dirsbuf;
    for (int i = 0; i < e; ++i)
    {
        struct smbc_dirent* d = (struct smbc_dirent*) current;
        if (interesting_dirent(d))
        {
            char* url = calloc(1, strlen(argv[1]) + strlen(d->name) + 1);
            strcat(url, argv[1]);
            strcat(url, d->name);
            fprintf(stderr, "%s\t", url);
            struct stat fs;
            int e = smbc_stat(url, &fs);
            free(url);
            if (e < 0)
            {
                die("smbc_stat: failed for '%s'\n", url);
            }
            fprintf(stderr, " size: %ld\n", fs.st_size);
        }
        current += d->dirlen;
    }
    smbc_closedir(dir_fd);

    return e;
}