So you want to see what each user has done? You can parse the .bash_history file... But it will only show you command line stuff. There are other history files specific to some apps also. As root,
Code:
locate history | less
or for a specific user:
Code:
locate history | grep user_name | less
and replace user_name with the user name.
If you are trying to find out if someone has done a su -, you can parse the /var/log/messages file(s). You will see something like this:
Code:
Aug 19 09:38:03 machinename su(pam_unix)[4095]: session opened for user root by (uid=500)