Question

I’m trying to write a function that returns a list of all files on current folder and all of its sub folders. I wrote this code:

#include <iostream>
#include <dirent.h>
#include <cstring>

using namespace std;

int main() {
   DIR* dir; dirent* pdir;
   //From my workspace
   dir=opendir(".");     
   while (pdir=readdir(dir)) {
       if(/**********This pdir is a directory**********/) {
           /**********RECURSIVE CALL SHOULD BE HERE**********/
           cout<<pdir->d_name<<endl;
       }
   }
   closedir(dir);
   return 0;
}

I searched for it in google and I don’t know how to:

• Check if the current pdir is directory
• Go inside the directory and perform the recursive call on it

Meanwhile I have everything on main because I still don’t know what arguments the recursive function should have.

Any hints?

Answer 1

Isolate that code in a procedure that takes the base directory path as a parameter, so you can actually perform the recursive call. It should be something like

void recursive_file_list(const char * directory)
{
    // ...
}

Then, to check if the pdir you obtained is a directory, you have two routes:

• you can check if pdir->d_type==DT_DIR; this gives you this information immediately, but it’s not portable (POSIX does not mandate the existence of the d_type member); also, it’s not supported for all the filesystems, so you may get DT_UNKNOWN. If you want to follow symlinks, you have to perform extra checks also if you get DT_LNK. In these cases, you must fall back to lstat (see the point below);
• you can instead portably use lstat to get information about each file, checking in particular the st_mode field of struct stat.