dhcp-lease-list --help (return code: 0)
Prints active DHCP leases.
Usage: /usr/sbin/dhcp-lease-list [options]
--help shows this help
--parsable machine readable output with full dates
--last prints the last (even if end<now) entry for every MAC
--all prints all entries i.e. more than one per MAC
--lease uses the next argument as the name of the lease file
the default is to try /var/db/dhcpd.leases then
/var/lib/dhcp/dhcpd.leases then
/var/lib/dhcp3/dhcpd.leases