Question

Im using sshj and im trying to tail a file, but my problem is that the remote process is never killed.

In the following example code you can see that i try to tail /var/log/syslog, and then i send a kill signal to the process. However after the application has stopped and i list out all the processes on the server, i can still see an active tail process.

Why will not this code kill the process? and what can i do to remedy that?

    SSHClient ssh = new SSHClient();
    ssh.addHostKeyVerifier(new PromiscuousVerifier());
    try {           
        ssh.connect("localhost");
        ssh.authPassword("xxx", "xxx");
        final Session session = ssh.startSession();
        try {
            final Command cmd = session.exec("tail -f /var/log/syslog");
            cmd.signal(Signal.KILL);
            System.out.println("\n** exit status: " + cmd.getExitStatus());
        } catch (IOException e) {
            e.printStackTrace();
        }finally{
            session.close();
        }
    } finally{
        ssh.disconnect();
    }

EDIT

also tried sending all available signals.

            for(Signal s : Signal.values()){
                cmd.signal(s);
            }

Answer 1

This is most likely a problem with the ssh server implementation, as i have tried using two different ssh clients and getting the same result. My solution ended up being a client-side tail logic, instead of “tail -f” to prevent free roaming processes.