ipv6calc is a small utility written in C to manipulate (not only) IPv6
addresses. It converts a given IPv6 address into compressed format, or
into the same format shown in /proc/net/if_inet6.

This utility was also used in the past to extend features on
network-functions-ipv6 library, used by initscripts-ipv6.

In addition to its internal databases, ipv6calc supports several
external databases. The following build options may be used to include
support for these:

  IP2LOCATION=yes  Enable IP2Location support (requires ip2location-c)
  GEOIP=yes        Enable GeoIP support (requires GeoIP)
  GEOIP2=yes       Enable GeoIP2 support (requires libmaxminddb)
  EXTERNAL=yes     Enable external db support

where each build option is passed to the slackbuild. Example of
enabling the IP2Location and GeoIP external database:

  IP2LOCATION=yes GEOIP=yes ./ipv6calc.SlackBuild

The ipv6calc Apache module can be built by passing MOD_IPV6CALC=yes to
the slackbuild as:

  MOD_IPV6CALC=yes ./ipv6calc.SlackBuild