run a command with a different MAC process label
setpmac utility forks a new process, attempts to set
the label to label and if successful, runs
This software was contributed to the FreeBSD Project by
Network Associates Labs, the Security Research Division of Network Associates
Inc. under DARPA/SPAWAR contract N66001-01-C-8035 (“CBOSS”), as
part of the DARPA CHATS research program.