List of files given a Path in C++

Question

I am trying to create a program that randomly chooses a folder given a base path, then within the new folder randomly chooses a video to be opened and start playing.

My main issue is finding the number of files within a path given. Is there any function that can do something like that? Or similar? What kind of headers do I need? etc..

The random part is kind of easy. After fixing that issue I would like to know if I am able to launch a video for example while executing the program, which should the last step of my program.

I have searched a lot before posting that, I know you might think its already out there, but I was not able to find something specific enough for what I want.

I hope you can help me.

Which OS are you using? Also, please post the code you have tried so far to interface with the file system. — Ryan Bemrose, Jun 14 '15 at 17:33
possible duplicate of [File count in a directory using C++](http://stackoverflow.com/questions/2802188/file-count-in-a-directory-using-c) — smac89, Jun 14 '15 at 17:46

peper0 · Answer 1 · 2015-06-14T17:55:03.590

You should look into boost.filesystem. C++ without boost (or another library set, like Qt) has very limited capabilities.

There is an example in doc:

int main(int argc, char* argv[])
{
  path p (argv[1]);   // p reads clearer than argv[1] in the following code

  try
  {
    if (exists(p))    // does p actually exist?
    {
      if (is_regular_file(p))        // is p a regular file?   
        cout << p << " size is " << file_size(p) << '\n';

      else if (is_directory(p))      // is p a directory?
      {
        cout << p << " is a directory containing:\n";

        copy(directory_iterator(p), directory_iterator(), // directory_iterator::value_type
          ostream_iterator<directory_entry>(cout, "\n")); // is directory_entry, which is
                                                          // converted to a path by the
                                                          // path stream inserter
      }

      else
        cout << p << " exists, but is neither a regular file nor a directory\n";
    }
    else
      cout << p << " does not exist\n";
  }

  catch (const filesystem_error& ex)
  {
    cout << ex.what() << '\n';
  }

  return 0;
}

Of course you can use the directory_iterator inside "for" loop:

#include <boost/filesystem.hpp>
#include <boost/range/iterator_range.hpp>
#include <iostream>

using namespace boost::filesystem;

int main(int argc, char *argv[])
{
    path p(argc > 1? argv[1] : ".");

    if(is_directory(p)) {
        std::cout << p << " is a directory containing:\n";

        for(auto& entry : boost::make_iterator_range(directory_iterator(p), {}))
            std::cout << entry << "\n";
    }
}

score 0 · Answer 2 · answered Jun 14 '15 at 17:45

You obviously need to modify this function to make it work for you. But this is a function that I was able to find and make. I think it requires windows.h. What it does is that it adds the filenames of all the files inside Bin/Pictures to a vector called mTextureNames.

 void Editor::LoadTextureFileNames()
    {   
        string folder = "../Bin/Pictures/";
        char search_path[200];
        sprintf(search_path, "%s*.*", folder.c_str());
        WIN32_FIND_DATA fd; 
        HANDLE hFind = ::FindFirstFile(search_path, &fd); 
        if(hFind != INVALID_HANDLE_VALUE) { 
            do { 
                // read all (real) files in current folder
                // , delete '!' read other 2 default folder . and ..
                if(! (fd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ) {
                    this->mTextureNames.push_back(fd.cFileName);
                }
            }while(::FindNextFile(hFind, &fd)); 
            ::FindClose(hFind); 
        } 
    }

score 0 · Answer 3 · edited May 23 '17 at 12:29

My main issue is finding the number of files within a path given.

Though the function glob called is C, it shouldn't be a problem if your C++ compiler is compatible with C. You can always wrap it in C++ :) Man glob describes how to use it. The GLOB_ONLYDIR lets you limit the results to directories.

The easiest way to play the videos is by calling system() and execute the video in your favorite player

List of files given a Path in C++

3 Answers3