This is an object oriented perl interface to the FreeBSD jail subsystem. Here's a replica of the 'jls' utility in just a few lines of perl: use BSD::Jail::Object 'jids'; print " JID IP Address Hostname Path\n"; printf "%6d %-15.15s %-29.29s %.74s\n", $_->jid, $_->ip, $_->hostname, $_->path foreach jids( instantiate => 1 ); And here's 'jexec': my $j = BSD::Jail::Object->new( $ARGV[0] ) or die $@; $j->attach && chdir('/') && exec $ARGV[1] or exit; For more info please use 'perldoc' on the module. WWW: https://metacpan.org/release/BSD-Jail-Object