I have a number of users (23) but I want to create another user that can be accessed only from one of the user account to do some specific task. How can I do it. And obviously this user cannot be root. Nobody else must see or have access to this user.
I don't have any idea how to do it, any attempt I did yesterday doesn't satisfy my conditions.
Update (explanation) :
It's like a user inside other user. A user (hiddenUser in the graph) that can't only be accessed if you are user2 (graph). Graph : - user1 | - user2 | | | - hiddenUser | - user3