How can I find the size of all files located inside a folder?

Question

Is there any API in c++ for getting the size of a specified folder?

If not, how can I get the total size of a folder including all subfolders and files?

Answer 1

How about letting OS do it for you:

long long int getFolderSize(string path) 
{
    // command to be executed
    std::string cmd("du -sb ");
    cmd.append(path);
    cmd.append(" | cut -f1 2>&1");

    // execute above command and get the output
    FILE *stream = popen(cmd.c_str(), "r");
    if (stream) {
        const int max_size = 256;
        char readbuf[max_size];
        if (fgets(readbuf, max_size, stream) != NULL) {
            return atoll(readbuf);
        }   
        pclose(stream);            
    }           
    // return error val
    return -1;
}