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. To enable IP2Location support you will need to install the optional dependency ip2location-c first, and then pass: IP2LOCATION=yes to this Slackbuild.