Writing image file names within folders into a text file c++ - c++

Question

I wrote a little bit of code to easily add the file names of images i had within a directory and add them to a list in a text file. This worked fine, but when the images were within a sub-folder it would just add the folder name as an entry into the text file.
I need it to be able to check whether it's a folder and then add the correct directory into the text for the images which might be within the sub-folder, e.g subfolder/image.jpg
Can't work out what i'd need to add. This is what I've got so far...
#include<stdio.h>
#include<cstdlib>
#include<iostream>
#include<string.h>
#include<fstream>
#include<dirent.h>
void listFile();
std::ofstream myfile;
int main(){
listFile();
return 0;
}
void listFile(){
DIR *pDIR;
struct dirent *entry;
if( pDIR=opendir("/home/hduser/Example2Files/TrainImages/") ){
while(entry = readdir(pDIR)){
if( strcmp(entry->d_name, ".") != 0 && strcmp(entry->d_name, "..") != 0 )
myfile.open ("/home/hduser/Example2Files/TrainImages/train.txt",std::ios_base::app);
myfile << entry->d_name << "\n";
myfile.close();
}
closedir(pDIR);
}
}

Answer 1

To traverse into directories, you will (probably) have to modify your code such that you have a function that takes the name of a directory, and lists regular files within that directory. If it finds a directory, it should call recursively with the concatenated name of the current directory and the found directory.
To identify if the file is a directory, you can use something like entry.d_type == DT_DIR.