Question

I want to create a method that reads a directory and finds and saves in a data structure all the directories included, as well as all the sub-directories of each directory. Specifically I want the names to be cited as:

folder1
folder11
folder12
folder2
folder21
folder22
folder23

I need obviously a function with recursion.
I use temporary a class member method in a console application as:

private:
 struct dirent *ep;


void DirectoryReader::parseDirectory(char* readingDirectory)
{
char* tempDirectory = (char*)malloc(sizeof(readingDirectory) + 200); 
string temp = readingDirectory;

DIR *dp;
dp = opendir (readingDirectory);
   if (dp != NULL)
     {
       while (ep = readdir (dp))
       {
         puts (ep->d_name);

         temp += readingDirectory;
         temp += "/";
         temp += ep->d_name;

         char * buffer = new char[temp.length()];
         strcpy(buffer,temp.c_str());
         parseDirectory(buffer);
       }
         (void) closedir (dp);
     }
   else
     perror ("Couldn't open the directory");

}

Ok, I know not the best written code, but I want initially to have a view of the names caught. However it does not work properly, since it considers the name of the parent directory more than once. Even if I put the invocation of the same method out (not performing recursion) the first two names are . and .. . Why?

Could you suggest me a function doing the described process or indicate the correction demanded on this function?

Answer 1

as some comment pointed out, boost::filesystem is the usually way to go.
But from your code it seems you are still a newbie to C++, so I’ve rewritten in C++ idiomatic way, adding a bit of useful display. HTH

#include <dirent.h>
#include <iostream>
#include <string>
using namespace std;

struct DirectoryReader
{
    static void parseDirectory(string readingDirectory, int level);
};

void DirectoryReader::parseDirectory(string readingDirectory, int level)
{
    if (DIR *dp = opendir(readingDirectory.c_str()))
    {
        cout << string(level, ' ') << readingDirectory << endl;
        while (struct dirent *ep = readdir(dp))
            if (ep->d_type == DT_DIR && ep->d_name[0] != '.')
                parseDirectory(readingDirectory + "/" + ep->d_name, level + 1);
        closedir(dp);
    }
    else
        cerr << "Couldn't open the directory " << readingDirectory << endl;
}

int main_parsedir(int argc, char **argv)
{
    if (argc > 1)
        DirectoryReader::parseDirectory(argv[1], 0);
    return 0;
}

note that in your code, storing struct dirent *ep; in class is plain wrong, because you overwrite it while recursing…