Recursive upload to FTP server in C#

Question

I would need to upload a folder (which contains sub folders and files) from one server to another from C# code. I have done few research and found that we can achieve this using FTP. But with that I am able to move only files and not the entire folder. Any help here is appreciated.

Cariotta

Answer 1

The FtpWebRequest (nor any other FTP client in .NET framework) indeed does not have any explicit support for recursive file operations (including uploads). You have to implement the recursion yourself:

• List the local directory
• Iterate the entries, uploading files and recursing into subdirectories (listing them again, etc.)

void UploadFtpDirectory(
  string sourcePath, string url, NetworkCredential credentials)
{
    IEnumerable<string> files = Directory.EnumerateFiles(sourcePath);
    foreach (string file in files)
    {
        using (WebClient client = new WebClient())
        {
            Console.WriteLine($"Uploading {file}");
            client.Credentials = credentials;
            client.UploadFile(url + Path.GetFileName(file), file);
        }
    }

    IEnumerable<string> directories = Directory.EnumerateDirectories(sourcePath);
    foreach (string directory in directories)
    {
        string name = Path.GetFileName(directory);
        string directoryUrl = url + name;

        try
        {
            Console.WriteLine($"Creating {name}");
            FtpWebRequest requestDir =
              (FtpWebRequest)WebRequest.Create(directoryUrl);
            requestDir.Method = WebRequestMethods.Ftp.MakeDirectory;
            requestDir.Credentials = credentials;
            requestDir.GetResponse().Close();
        }
        catch (WebException ex)
        {
            FtpWebResponse response = (FtpWebResponse)ex.Response;
            if (response.StatusCode ==
                  FtpStatusCode.ActionNotTakenFileUnavailable)
            {
                // probably exists already
            }
            else
            {
                throw;
            }
        }

        UploadFtpDirectory(directory, directoryUrl + "/", credentials);
    }
}

For the background of complicated code around creating the folders, see:
How to check if an FTP directory exists

Use the function like:

string sourcePath = @"C:\source\local\path";
// root path must exist
string url = "ftp://ftp.example.com/target/remote/path/";
NetworkCredential credentials = new NetworkCredential("username", "password");

UploadFtpDirectory(sourcePath, url, credentials);

A simpler variant, if you do not need a recursive upload:
Upload directory of files to FTP server using WebClient

---

Or use FTP library that can do the recursion on its own.

For example with WinSCP .NET assembly you can upload whole directory with a single call to the Session.PutFilesToDirectory:

// Setup session options
SessionOptions sessionOptions = new SessionOptions
{
    Protocol = Protocol.Ftp,
    HostName = "ftp.example.com",
    UserName = "username",
    Password = "password",
};

using (Session session = new Session())
{
    // Connect
    session.Open(sessionOptions);

    // Download files
    session.PutFilesToDirectory(
      @"C:\source\local\path", "/target/remote/path").Check();
}

The Session.PutFilesToDirectory method is recursive by default.

(I'm the author of WinSCP)

Dryden