I am part of a group called friends and we have a directory titled secrets. I have a rwx permissions, friends have rx permissions and others have w permissions. I want to explicitly ban members of a separate group called enemies from accessing my directory.
The only thing I could think of was changing the group to enemies and giving them no permissions but it would take away the rx permissions of friends.
I should mention this is for a project and it was explicitly stated in our spec to not use setfacl since it wasn't covered in the class. Is it possible using only commands like chmod, chown, chgrp? If it isn't possible, I may have just misinterpreted the question.