Mirroring session (TTY) on AIX using portmir

Sometimes we want to see the screen of the session of another user in, order to solve any problem remotely. Portmir is an interesting AIX’s command and help us to achieve this.
Portmir is part of bos.sysmgt.serv_aid filand filesetis and it’s shipped on AIX OS.

What is portmir?

From man page:
Description

The portmir command allows one TTY stream (monitor) to attach to another TTY stream (target) and monitor the user session that is
taking place on that stream. This is accomplished by pushing a special “mirror” module into both the target and monitor TTY
streams.

Let see how portmir works with examples.

Users loggued on the system:

[root@lpar:/] who
root        pts/0       Nov 17 16:39     (pc1.domain.net)
israel      pts/1       Nov 21 16:23     (pc2.domain.net)
pepe        pts/2       Nov 21 16:24      (pc3.domain.net)

So, let’s mirror the TTY of user ‘israel’. Just type:

[root@lpar:/] portmir -t pts/1

portmir: Remote user connected, mirroring active.

On ‘israel’ session appears:

[root@lpar:/]
portmir: Remote user connected, mirroring active.

So, now root user can write on ‘israel’ session if needed. But user ‘israel’ also can write on its session and will be observed by root.
Once root finished to solve the problem, from any session type:

[root@lpar:/] portmir -o

portmir: Mirroring is stopped.

But only root or any user from similar provilegde can use portmir. If a non-root user try to portmir another user, it gets this error:

[israel@lpar:/]  portmir -t pts/2

portmir: Cannot open /home/anotheruser/.mir: A file or directory in the path name does not exist.

Another use of portmir is that you can send ‘portmir’ session to another user. Let’s see this example.
We’re going to send output from portmir of user ‘israel’ to user ‘pepe’. Here pts/1 if TTY of user ‘israel’ and pst/2 is TTY of user ‘pepe’

[root@lpar:/]  portmir -t pts/1 -m pts/2

portmir: Remote user connected, mirroring active.

Now, root user can continue working without impact on another sessions, but everything ‘israel’ do on its session will be shown on ‘pepe’s session.
To disable mirroring just type this command in any of ‘israel’ or ‘pepe’s session.

[israel@lpar:/]  portmir -o
portmir: Mirroring is stopped.

Just thanks if the post was helpful