Check if Remote folder exists - Renci.ssh

Question

I want to check if a remote folder exists before listing the files inside it. But this code is giving me SftpPathNotFoundException : No such file

I know that the folder that is being checked doesn't exist and thats the reason I would like to handle it.

var sftp = new SftpClient(sftpHost, username, password);
string sftpPath30s = "/home/Vendors/clips/1/4/4";

if (sftp.Exists(sftpPath30s))
   {
     var files30s = sftp.ListDirectory(sftpPath30s); //error here
     if(files30s!=null)
       {
          Console.writeline("code doesn't reach here");
       }
   }

This code works fine for other existing folders like "/home/Vendors/clips/1/4/3" etc.

Answer 1

mu

Let's say such a method exist. What then?

if (sftp.FolderExists(sftpPath30s))
{
   var files30s = sftp.ListDirectory(sftpPath30s);
   if(files30s!=null)
   {
       ...
   }
}

Is that Ok?

Most Certainly Not!

What happens if between checking if the file exists, and actually getting the file, the file is deleted, or moved?

So you need to write this:

if (sftp.FolderExists(sftpPath30s))
{
   try
   {
       var files30s = sftp.ListDirectory(sftpPath30s);
       if(files30s!=null)
       {
           ...
       }
   }
   catch (SftpPathNotFoundException) {}
}

At which point you don't gain anything from the check. You still have to add a try catch. Instead, it just means you have to do an extra call over the network and make your code more complex. So just do this:

try
{
   var files30s = sftp.ListDirectory(sftpPath30s);
   if(files30s!=null)
   {
       ...
   }
}
catch (SftpPathNotFoundException) {}

Answer 2

the sftp.Exists() method gives you false positive in that case, if it find a part of the directory it echo true even that not all the path is exist. i would recommend to change you'r code to this:

 if (IsDirectoryExist(sftpPath30s))
   {
     var files30s = sftp.ListDirectory(sftpPath30s); 

   }
else
{
     //Do what you want
}

and then the method 'IsDirectoryExists':

     private bool IsDirectoryExists(string path)
    {
        bool isDirectoryExist = false;

        try
        {
            sftp.ChangeDirectory(path);
            isDirectoryExist = true;
        }
        catch (SftpPathNotFoundException)
        {
            return false;
        }
        return isDirectoryExist;
    }

dont forget change back the directory you working on in case it metters!