#!/usr/bin/perl

##########################################################
# ipkur.pl, v.1.01
# Scans for DNS hostnames of a group of IP addresses.
# Useful, if you do not remember on which address was
# the web server or mail server, for example.
# (C) Ansis Ataols Bērziņš <ataols@latnet.lv>, 2004-2006
# http://ansis.lv/ipkur/
# Public domain, can be used and modified as wanted.
##########################################################

use IO::Socket;

($userfile,$arglist) = split(/\\\[/,"@ARGV");

($addr) = split(/ /,$userfile);

print "Host names scanner for a group of IP addresses.\n";

if ($addr !~ /\d+\.\d+\.\d+/) {
	print "Usage: ipkur.pl [XX]X.[XX]X.[XX]X\n";
	exit(0);
}

for ($i=0; $i<=255; $i++) {
	$ip = $addr.'.'.$i;
	$hn = &addr2host($ip);
	if ($hn) {
		print "$ip - $hn\a\n";
	}
}
print "\n\n";

exit(1);


sub addr2host {
	local($IP_address) = $_[0];
	local(@bytes) = split(/\./, $IP_address);
	local($packaddr) = pack("C4",@bytes);
	local($host_name) = (gethostbyaddr($packaddr, 2))[0];
	return($host_name);
}