This is dhcpd-pools which is made for ISC dhcpd pool range
analysis.

With this command you can check usage of pool addresses when
address space is great. Command is designed so that it will not
get slow even there is thousands of IPs in lease file. This kind
of huge dhcpd installation can be near by DSL DSLAMs or some other
public access connection points.

This command will not print nice to know information like
DHCPStatus does. Output is limited only to list only usage for
ranges, shared network and total address space. Limiting what is
printed is the right thing to do when there is thousands of
addresses. If your address space is small some other dhcp
analyzer might be more suitable for you.

Source code is pretty printed with this indent command
configuration.

-nbad -bap -nbc -bbo -bl -bli2 -bls -ncdb -nce -cp1 -cs -di2 -ndj
-nfc1 -nfca -hnl -i2 -ip5 -lp -pcs -psl -nsc -nsob

If you write patch please use indent and keep style constant.

Command home page is located at
  http://dhcpd-pools.sourceforge.net/