Here's a short and sweet how-to from O'Reilly: "In today's article, I'd like to take a look at utmp, wtmp, and lastlog. These
three files are read and updated whenever a user logs in to your FreeBSD
system. However, you can't read these files directly, so we'll also look at the
various utilities you can use to garner the information contained within these files.
We'll then finish off the article with some utilities that deal with logins and
February 19, 2001