struct Job {
        SFtp    sftp;
        FileOut file;
        int     index;
};

Array<Job> jobs;


//........

const char *sftp_server     = "demo.wftpserver.com";
const char *sftp_user       = "demo-user";
const char *sftp_password   = "demo-user";
const char *remote_path     = "/download";

bool SFtpDownloader::ReadDir(Ssh::DirList& ls)
{
    // We'll get the directory listing, using a synchronous (blocking) call.
  
    SFtp browser;
    browser.WhenDo << [&] {ProcessEvents(); };                                                  // GUI should be responsive...
    if(browser.Connect(sftp_server, 2222, sftp_user, sftp_password)) {
 
        // Let us use a convenience method which works on paths, not file descriptors.

        if(browser.ListDir(remote_path, ls))
            return true; 
    }
    Exclamation(browser.GetErrorDesc());
    return false;
}

void SFtpDownloader::Download()
{
    // Wait for the queue to be processed.
 
   if(!jobs.IsEmpty())
        return;
    
    Ssh::DirList ls;
    if(!ReadDir(ls))
        return;
    for(int i = 0, j = 0; i < ls.GetCount(); i++) {

        // We can work on directory entries easily.

        Ssh::DirEntry& e        = ls[i];
        const Ssh::Attrs& attrs = e.GetAttrs();

        // Let us simply try to download all files with *.jpg extension to the current directory, asynchronously.
        // Here, thanks to AsyncQueue, asynchronous calls work in a fire-and-forget fashion. Similar to "batch processing". 
        // E.g., any number of Sftp commands/jobs can be queued to be processed without intervention (till they're finished, or failed, of course). 

        if(attrs.IsFile() && GetFileExt(e.GetName()).IsEqual(".jpg")) {
            Job& job    = jobs.Add();
            job.index   = j;
            job.file.Open(Format("%s/SFtpExample-%d-%s", GetHomeDirectory(), job.index, e.GetName()));
            job.sftp.StartConnect(sftp_server, 2222, sftp_user, sftp_password);
            job.sftp.StartGet(job.file, Format("%s/%s", remote_path, e.GetName()), Ssh::READ, 0755, THISBACK2(DownloadProgress, job.index, e.GetName()));
            j++;
        }
    }
    
    //  Below loop does asynchronous job processing. 

    while(!jobs.IsEmpty()) {
        int i = 0;
        SocketWaitEvent we;
        we.Add(jobs[i].sftp.GetSocket());
        we.Wait(10);
        while(i < jobs.GetCount()) {
            SFtp& sftp = jobs[i].sftp;
            sftp.Do();
            if(!sftp.InProgress()) { 
                // For the sake of simplicity, we do not differentiate between success and failure.
                jobs.Remove(i);
                break;
            }
            ProcessEvents();
            i++;
        }
    }
}

//........