The chrootuid command combines chroot(8) and su(1) into one program,
so that there is no need to have commands such as /usr/bin/su in the
restricted environment.  Access to the file system is restricted to
the newroot subtree and privileges are restricted to those of the
newuser account (which must be a known account in the unrestricted
environment).

See also jail(8) in FreeBSD 4.0.

-- Don Lewis	(truckman@FreeBSD.org)