How to use ExpectJ in Jython?

Question

In our company we use Jython for some reason. I need to extend it with the ExpectJ, but I could not figure out how to do it.

I managed to download the expectj-2.0.7.jar, expectj-2.0.7-sources.jar and expectj-2.0.7-javadoc.jar files and made them accessible to Jython and Java itself as well.

So I can import it in my python script and JVM also finds the jars (by using a classpath loader hack). But according to ExpectJ's docs, something is still wrong.

import expectj

ex = expectj.ExpectJ()                       # I cannot use the second form of the
                                             # constructor where I can pass a timeout
                                             # parameter

sh = ex.spawn(targetshell, 22, usr, passw)   # There is no spawn method in 
                                             # ExpectJ - but why???

This is where I'm getting stuck. Why doesn't the ExpectJ object have a spawn method? Does anyone have a solution for this?

Answer 1

The following solution is to ensure that spawned process completes before executing the next command. It guarantees the cycle 'send - expect - wait for completion of the command sent in send' and then 'send again - expect again - wait for completion' .

In order to wait for command prompt to finish executing the spawned process, use shell.expect(""). If in case there are further expectJ send and expect commands after this, sequential execution can be ensured. If there is no shell.expect("") the next step shell.send("exit\n") is executed without waiting for the completion of the process that it has already spawned, in the following case scp command is put to completion before next command is issued.

import expectj
expectinator = expectj.ExpectJ();
shell = expectinator.spawn(expectj.SshSpawn(host_name, 22, usr_name, ssh_pwd));
shell.send("scp -r src:usr:dest" + "\r")
shell.expect(remote_box_usr + "'s password:");
shell.send(ssh_pwd + "\r");
shell.expect("");
shell.send("exit\n");
shell.expectClose();