Getting SSH output into StreamReader from long running SSH commands

Question

I’m attempting to capture output from a long running SSH command that may take a few seconds to initially produce any text output once called and may take up to a minute to fully complete.

The below code snippet works fine if I issue a simple command to execute such as ls that produces immediate output into the output stream.

However, I get nothing returned and SSH disconnects if I run a command that doesn’t instantly produce any output.

using (var sshClient = new SshClient(target, 22, userName, password))
{
    sshClient.Connect();
    var cmd = sshClient.CreateCommand(command);
    var result = cmd.BeginExecute();

    using (var reader = new StreamReader(cmd.OutputStream))
    {
        while (!reader.EndOfStream || !result.IsCompleted)
        {
            string line = reader.ReadLine();
            if (line != null)
            {
                Console.WriteLine(line);
            }
        }
        sshClient.Disconnect();
    }
}

Yas Ikeda · Accepted Answer · 2018-11-27 23:39:54Z

1

BeginExecute begins an asynchronous command execution. You need to wait and keep reading the output stream until it completes.

In a simple way,

        using (var sshClient = new SshClient(host, 22, username, password)) {
            sshClient.Connect();
            var cmd = sshClient.CreateCommand("for i in `seq 1 10`; do sleep 1; echo $i; done");
            var asyncResult = cmd.BeginExecute();
            var outputReader = new StreamReader(cmd.OutputStream);
            string output;
            while (!asyncResult.IsCompleted) {
                output = outputReader.ReadToEnd();
                Console.Out.Write(output);
            }
            output = outputReader.ReadToEnd();
            Console.Out.Write(output);
        }

answered Nov 27, 2018 at 23:39

Yas Ikeda

1,0961 gold badge12 silver badges19 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

highlander Over a year ago

Thank you, I'm getting the expected results now.

Collectives™ on Stack Overflow

Getting SSH output into StreamReader from long running SSH commands

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related