#!/usr/bin/perl
use strict;
use warnings;
use LWP::UserAgent;

my $ua = LWP::UserAgent->new();
my $req = HTTP::Request->new('GET', $ARGV[0]);

my $res = $ua->simple_request($req);
if($res->code == 401 && $res->header('WWW-Authenticate') =~ m/realm="([^"]+)"/) {
	print "Realm: " . $1;
}