Enter all subfolders - Recursive - c++

Question

How can I write a program that enters all of a folder' subfolders?
I wrote some code, but it does not enter the subfolders.
void main(int argc, char *argv[])
{
char* dirPath = argv[1];
struct stat statbuf;
DIR *dir;
struct dirent *ent;
size_t arglen = strlen(argv[1]);
if ((dir = opendir (dirPath)) != NULL) {
while ((ent = readdir (dir)) != NULL) {
printf(ent->d_name, "%s\n");
}
closedir (dir);
} else {
perror ("Problem");
}
}
I tried using the stat() function recursively.

Answer 1

http://www.lemoda.net/c/recursive-directory/
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <string.h>
#include <errno.h>
/* "readdir" etc. are defined here. */
#include <dirent.h>
/* limits.h defines "PATH_MAX". */
#include <limits.h>
/* List the files in "dir_name". */
static void
list_dir (const char * dir_name)
{
DIR * d;
/* Open the directory specified by "dir_name". */
d = opendir (dir_name);
/* Check it was opened. */
if (! d) {
fprintf (stderr, "Cannot open directory '%s': %s\n",
dir_name, strerror (errno));
exit (EXIT_FAILURE);
}
while (1) {
struct dirent * entry;
const char * d_name;
/* "Readdir" gets subsequent entries from "d". */
entry = readdir (d);
if (! entry) {
/* There are no more entries in this directory, so break
out of the while loop. */
break;
}
d_name = entry->d_name;
/* Print the name of the file and directory. */
printf ("%s/%s\n", dir_name, d_name);
#if 0
/* If you don't want to print the directories, use the
following line: */
if (! (entry->d_type & DT_DIR)) {
printf ("%s/%s\n", dir_name, d_name);
}
#endif /* 0 */
if (entry->d_type & DT_DIR) {
/* Check that the directory is not "d" or d's parent. */
if (strcmp (d_name, "..") != 0 &&
strcmp (d_name, ".") != 0) {
int path_length;
char path[PATH_MAX];
path_length = snprintf (path, PATH_MAX,
"%s/%s", dir_name, d_name);
printf ("%s\n", path);
if (path_length >= PATH_MAX) {
fprintf (stderr, "Path length has got too long.\n");
exit (EXIT_FAILURE);
}
/* Recursively call "list_dir" with the new path. */
list_dir (path);
}
}
}
/* After going through all the entries, close the directory. */
if (closedir (d)) {
fprintf (stderr, "Could not close '%s': %s\n",
dir_name, strerror (errno));
exit (EXIT_FAILURE);
}
}
int main ()
{
list_dir ("/usr/share/games");
return 0;
}

Answer 2

Another example, using file tree walk (ftw or nftw)
These have the advantage of providing your own callback funtion with a struct stat, a filename and a type (FTW_D, etc.) Call fnmatch to eliminate unwanted entries. Files that start with a "." are "hidden files". ls does not show them by default. ls -a will list them.
#include <sys/types.h>
#include <stdlib.h>
#include <stdio.h>
#include <ftw.h>
int callback(const char *fname,
const struct stat *st,
int type,
struct FTW *ftw)
{
// call fnmatch() here or use type to decide about printing
// printf file name and type , ??? on stat error FTW_NS, default to "????"
printf("%s\n", fname);
return 0;
}
int main(int argc, char **argv)
{
int fd_max=8; // max file desriptors
int retval=nftw( (argc==1)?"." :argv[1], callback, fd_max, FTW_ANYERR);
return retval;
}