rtprio(1) on FreeBSD

The text 55b5939556b9, as FreeBSD 4.11-RELEASE, FreeBSD 4.10-RELEASE, FreeBSD 4.9-RELEASE, FreeBSD 4.8-RELEASE, FreeBSD 4.7-RELEASE shipped it.

execute, examine or modify a utility's or process's realtime or idletime scheduling priority