Question

I’m using Ganymede ssh2 to connect to server from my Java app and do some work there.
It works perfectly but problems are ssh commands that request approval, eg.
a command

stop someService

returns

Are you sure (y/n)?

and after appropriate key stroke (y/n) it moves on.

Currently I’m using implementation given by ssh2 ganymed example, smth like this:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import ch.ethz.ssh2.Connection;
import ch.ethz.ssh2.Session;
import ch.ethz.ssh2.StreamGobbler;

public class ConnectUtil(String hostname, String username, String password, String command)
{

    try
    {
        Connection conn = new Connection(hostname);
        conn.connect();

        boolean isAuthenticated = conn.authenticateWithPassword(username, password);

        if (isAuthenticated == false)
            throw new IOException("Authentication failed.");

        Session sess = conn.openSession();

        sess.execCommand(command);

        InputStream stdout = new StreamGobbler(sess.getStdout());

        BufferedReader br = new BufferedReader(new InputStreamReader(stdout));

        while (true)
        {
            String line = br.readLine();
            if (line == null)
                break;
            System.out.println(line);
        }
        sess.close();
        conn.close();
    }
    catch (IOException e)
    {
        e.printStackTrace(System.err);
    }       
}

After calling this util class with above mentioned command(‘stop someService’), it gets stucked at

String line = br.readLine();

and everything breaks after server timeout.

Any ideas on how to solve this issue are more than welcome.

Thanks a lot,
Milos.

Answer 1

Assuming Session has a getStdin() method, you should write the response to the question to that.

Either that or find out if the command that’s demanding input has a ‘non-interactive’ mode that won’t prompt.