Communicating with legacy Source Code Control

Had a situation where I needed an old source control system written in Foxpro to pick up on file changes and consolidate them. The file changes could occur via any external package, but I was only interested in files in certain directories.

There were a couple of ways to handle the file once the change had been detected, but how to detect the change? The answer came by .Net's fileSystemWatcher. Run a .Net service that watches for changes. The next step was then how to communicate the changes to VFP, the answer there was sockets. I could have used interop, but the nice thing about sockets is that they are light.

The result was a simple event handler that detects a change and sends a message to the Source Code Control that it has something to process :

/// 

/// Track changes in the filesystem and pass them over to the legacy SCC system.
/// 
/// 
/// 
protected void writeFileEvent(object sender, FileSystemEventArgs e)
{
 string cModFile = e.FullPath.ToString();
 cModFile = cModFile.ToLower();
 // Exclude files that don't have to be stored
 if (cModFile.IndexOf("develop\\pending") != -1 ||
      Path.GetExtension(cModFile) == "" ||
      cModFile.IndexOf("develop\\bin") != -1 ||
      cModFile.IndexOf("\\prog\\ide.log") != -1 ||
      cModFile.IndexOf("\\prog\\symbols\\") != -1 ||
      cModFile.IndexOf("\\prog") == -1){
  return;
 }
 // Record the file to be processed
 string cLogFile = "\\formwork\\develop\\pending\\" + 
            Guid.NewGuid().ToString() +".xml";
        // Create an instance of StreamWriter to write text to a file.
        // The using statement also closes the StreamWriter.
        using (StreamWriter sw = new StreamWriter(cLogFile)) 
        {
            // Add some text to the file.
            sw.Write("" +
             "" +
             cModFile + "");
            sw.Close();
        }
  
        //create a new client socket ...
 // Don't really have to wait for a response. 
        // The file has been recorded (above) for processing
 // so the next time the SCC starts it will pick up on the change anyway.
 // However, if the SCC is running now let it know there is work to be done so
 // it doesn't have to poll the directory.
        Socket m_socClient = new Socket(AddressFamily.InterNetwork,
                   SocketType.Stream, ProtocolType.Tcp);
        String szIPSelected  = "127.0.0.1";
        int  alPort = 8000;
        
        System.Net.IPAddress remoteIPAddress = 
                    System.Net.IPAddress.Parse(szIPSelected);
        System.Net.IPEndPoint remoteEndPoint = 
                    new System.Net.IPEndPoint(remoteIPAddress, alPort);
        m_socClient.Connect(remoteEndPoint);
        String szData = cLogFile;
        byte[] byData = System.Text.Encoding.ASCII.GetBytes(szData);
        m_socClient.Send(byData);
 m_socClient.Close ();
}