How to access to folders not to files in a specific folder in c++?

Question

Suppose i have a folder, In this folder exist some files and folders, I want to access to folders not to files. How do i do that. I know to exist this function in c++ : FindFirstFileA and i write following code, but this work for files.

WIN32_FIND_DATAA ffd;
string s = "E:\\OpenCV\\SABT\\Old";

HANDLE hFind = FindFirstFileA(s.c_str(), &ffd);

if (INVALID_HANDLE_VALUE == hFind)
{
    printf("no file found");
    return -1;
}

if (ffd.dwFileAttributes == FILE_ATTRIBUTE_DIRECTORY)
{

    do
    {
        std::string fn = path + ffd.cFileName;
        printf("file %s\n", fn.c_str());

    } while (FindNextFileA(hFind, &ffd) != 0);
}

Answer 1

You are checking ffd.dwFileAttributes the wrong way. It is a bitmask, and a directory can have multiple attributes at a time, so you need to use the & bitwise AND operator instead of the == equality operator.

Don't forget to also check/ignore the "." and ".." entries when enumerating subfolders. And call FindClose() when you are done enumerating.

Try something more like this instead:

WIN32_FIND_DATAA ffd;
string path = "E:\\OpenCV\\SABT\\Old\\";

HANDLE hFind = FindFirstFileA((path + "*.*").c_str(), &ffd);

if (INVALID_HANDLE_VALUE == hFind)
{
    if (GetLastError() == ERROR_FILE_NOT_FOUND)
       printf("no folders found\n");
    else
       printf("error searching for folders\n");
    return -1;
}

do
{
    if (ffd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
    {
        if ((lstrcmpA(ffd.cFileName, ".") != 0) &&
            (lstrcmpA(ffd.cFileName, "..") != 0))
        {
            std::string fn = path + ffd.cFileName;
            printf("%s\n", fn.c_str());
        }
    }
}
while (FindNextFileA(hFind, &ffd));

if (GetLastError() != ERROR_NO_MORE_FILES)
{
    printf("error searching for folders\n");
}

FindClose(hFind);

Answer 2

You want this:

WIN32_FIND_DATAA ffd;
string s = "E:\\OpenCV\\SABT\\Old";

HANDLE hFind = FindFirstFileA(s.c_str(), &ffd);

if (INVALID_HANDLE_VALUE == hFind)
{
   printf("no file found");
   return -1;
}

do
{
   if (ffd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
   {
     std::string fn = path + ffd.cFileName;
     printf("file %s\n", fn.c_str());
   }
} while (FindNextFileA(hFind, &ffd) != 0);