Sockaddr is a command-line utility that makes it easy to query network
address information from the local server.  With sockaddr it is possible
to create a list of the RFC 1918 addresses on a server, obtain the
default gateway, or public IP addresses and use this information in other
shell scripts.  See the website for additional templating and IP math
functions.

WWW: https://github.com/hashicorp/go-sockaddr/tree/master/cmd/sockaddr