tools:

ipgen: generates IPs based on IP and netmask.
example: ipgen 192.168.0.4 255.255.255.252
outputs:
192.168.0.4
192.168.0.5
192.168.0.6
192.168.0.7

cidr: converts cidr notation to IP and netmask.
example: cidr 192.168.0.4/30
outputs:
192.168.0.4 255.255.255.252

these two programs were made to be used together like:

ipgen $(cidr 192.168.0.4/30)