#! /usr/local/bin/perl

$url = http://○.com;
$host_name = &GetHostName($ENV{'REMOTE_ADDR'});
if (host_name = *******) {
print "Location: $url";
exit;

sub GetHostName {
my($ip_address) = @_;
my(@addr) = split(/\./, $ip_address);
my($packed_addr) = pack("C4", $addr[0], $addr[1], $addr[2], $addr[3]);
my($name, $aliases, $addrtype, $length, @addrs);
($name, $aliases, $addrtype, $length, @addrs) = gethostbyaddr($packed_addr, 2);
return $name;
}