As you know, GNU/Linux is a multi-user OS. For example: two users are working on the same machine, and want to have same session to work together. By default, each one will get a different tty (terminal) and it's over. The sessions are separated.
The technique I am going to describe is useful in real-world, when I and my friend came together to learn Linux CLI via the Internet - we started Skype session (for VoIP) and shared session.
Shared sessions are very useful if you want to see what the other person is doing, typing, etc...
The software I am going to describe here is screen: a powerful screen manager and terminal emulator.
Actually screen is almost a window manager but in text-mode, if you can imagine that.
This How-To uses standard GNU/Linux commands, therefore it is not specific to openSUSE.
First, make sure that screen package is installed, by issuing rpm -q screen.
If not, then install via Yast. Fortunetaly, it is included with openSUSE.
Both users must be logged in via the same account. Either remotely (telnet or ssh), or from local terminal, doesn't matters. Create a separate account, if must with Yast.
The first user must type screen to create a session
The second user must type screen -x to join a session
Excellent ! Now you have your shared session, and now, what the first guy types, the second guy sees instantly on his "screen" :)
To exit screen use: “ctrl+a”, then “ctrl+\”, “y”