If you are running jail hosts you no doubt have a large number of aliases on your boxes. And when you need to add and remove aliases it can be a pain if you have to renumber the list.
Here is a method of dynamically numbering the aliases so that that you don't have to remember to do it. (Unless you change alias0).
For non consecutive addresses:
ifconfig_bce0="inet 192.168.0.1/24" ifconfig_bce0_alias0="inet 192.168.0.2/32" eval ifconfig_bce0_alias$(( bce0_alias += 1))=\"inet 192.168.0.3/32\" eval ifconfig_bce0_alias$(( bce0_alias += 1))=\"inet 192.168.0.8/32\" eval ifconfig_bce0_alias$(( bce0_alias += 1))=\"inet 192.168.0.10/32\" eval ifconfig_bce0_alias$(( bce0_alias += 1))=\"inet 192.168.0.20/32\"
For consecutive addresses:
ipv4_addrs_bce0="192.168.0.1-5/24"