man fdnsnamep (Commandes) - resolve an IPv4 or IPv6 address to a hostname with paranoid checking
NAME
fdnsnamep - resolve an IPv4 or IPv6 address to a hostname with paranoid checking
SYNOPSIS
fdnsname <IP address>
DESCRIPTION
fdnsname will attempt to look up a single hostname for IP address (which is an IPv4 address in dotted-quad format or an IPv6 address in colon-seperated format). If one is found, the program checks to make sure that the hostname has a corresponding A or AAAA record pointing back to the supplied IP. If so, the hostname is printed to standard output and the program exits with return code 0. If the paranoid check fails, nothing is printed and the program exits with return code 3. If no hostname is found, nothing is printed and the program exits with return code 1.
AUTHOR
Ian Gulliver <ian@penguinhosting.net>