In General the task looks like this:
To configure access rights to the directory library and tests, so that the users in the group teachers can modify and create files there and users group students had read access.
I asked the owner using chown
and group owners with chgrp
It is clear that it is now possible to set permissions: chmod 124 filename
But it turns out that the owner and one group of owners one! How to give privileges to 2m different groups?
I understand several owners can not be. Or am I wrong?