Permissions: Beyond owner, group, and everyone else

The standard way of assigning file permissions on Unix systems is so tied into how people think of Unix that many of us seem to forget that this scheme was expanded many years ago to accomodate more than just file owners, groups, and everyone else. The setfacl (set file access control lists) and getfacl (get file access control list) commands were designed to allow more than the traditional limited assignment of privileges.