How to (quickly) check if UNC Path is available

Question

How can I check if a UNC Path is available? I have the problem that the check takes about half a minute if the share is not available :

var fi = new DirectoryInfo(@"\\hostname\samba-sharename\directory");  if (fi.Exists) //... 

Is there a faster way to check if a folder is available? I'm using Windows XP and C#.

Answer 1

How's this for a quick and dirty way to check - run the windows net use command and parse the output for the line with the network path of interest (e.g. \\vault2) and OK. Here's an example of the output:

C:\>net use New connections will be remembered.  Status       Local     Remote                    Network  ------------------------------------------------------------------------------- OK           O:        \\smarty\Data       Microsoft Windows Network Disconnected P:        \\dummy\Data       Microsoft Windows Network OK                     \\vault2\vault2           Microsoft Windows Network The command completed successfully. 

It's not a very .netish solution, but it's very fast, and sometimes that matters more :-).

And here's the code to do it (and LINQPad tells me that it only takes 150ms, so that's nice)

void Main() {     bool available = QuickBestGuessAboutAccessibilityOfNetworkPath(@"\\vault2\vault2\dir1\dir2");     Console.WriteLine(available); }  public static bool QuickBestGuessAboutAccessibilityOfNetworkPath(string path) {     if (string.IsNullOrEmpty(path)) return false;     string pathRoot = Path.GetPathRoot(path);     if (string.IsNullOrEmpty(pathRoot)) return false;     ProcessStartInfo pinfo = new ProcessStartInfo("net", "use");     pinfo.CreateNoWindow = true;     pinfo.RedirectStandardOutput = true;     pinfo.UseShellExecute = false;     string output;     using (Process p = Process.Start(pinfo)) {         output = p.StandardOutput.ReadToEnd();     }     foreach (string line in output.Split('\n'))     {         if (line.Contains(pathRoot) && line.Contains("OK"))         {             return true; // shareIsProbablyConnected         }     }     return false; } 

Or you could probably go the route of using WMI, as alluded to in this answer to How to ensure network drives are connected for an application?