implement interactive shell (with tested solution)

[terefang]

use case: chat on interactive shell (session preserving)

solution: add the following code to SessionDelegate

Channel shellChannel;
Expect4j expect;

    String shell(String command, String terminator)
    {
        expect.send(command);
        return returnShellOutput(terminator);
    }

    String returnShellOutput(String terminator)
    {
        final StringBuffer sb = new StringBuffer();
        BufferChangeLogger bcl = new BufferChangeLogger() {
            @Override
            void bufferChanged(char[] newData, int numChars) {
                sb.append(newData,0,numChars);
            }
        }
        expect.registerBufferChangeLogger(bcl);
        expect.expect(terminator);
        expect.unregisterBufferChangeLogger(bcl);
        int off = sb.toString().lastIndexOf(terminator);
        if(off>0)
        {
            return sb.toString().substring(0, off);
        }
        else
        {
            return sb.toString();
        }
    }

    def newShell(int timeout) {
        if(shellChannel==null)
        {
            connect();
            try
            {
                shellChannel=getSession().openChannel("shell");
                shellChannel.setPty(false);
                expect = new Expect4j(shellChannel.getInputStream(), shellChannel.getOutputStream());
                shellChannel.connect(timeout);
            }
            catch(Exception xe)
            {
                println(xe);
            }
        }
    }

    def exitShell() {
        disconnectShell();
    }

    def disconnectShell() {
        if(shellChannel!=null)
        {
            expect.close();
            shellChannel.close();
        }
        shellChannel=null;
    }

usage:

remoteSession {
   newShell(10000);
   returnShellOutput('prompt#');
   def chatOutput;
   chatOutput = shell('ls -la', 'prompt#'));
   chatOutput = shell('cd /tmp', 'prompt#'));
   chatOutput = shell('ls -la', 'prompt#'));
   exitShell();
}

[northmirko]

Hi @terefang , great idea.
I need this feature, but didn't managed to handle dependencies required to produce jar archive.
Can you show us how to put dependencies in gradle.build or else where ?

[terefang]

AFAIK the only required dependency should be "com.github.cverges:expect4j:1.9"

sorry i am a maven guy