#!/usr/bin/perl

$| = 1;

use strict;

my ($qs, $ref) = @ENV{'QUERY_STRING','HTTP_REFERER'};

if ($qs eq 'check') {
	if (defined $ref) {
		print <<OKAY;
Connection: close
Content-type: text/html

Okay, the referer was: $ref

OKAY
	} else {
		print <<DENIED;
Status: 403 Forbidden
Connection: close
Content-type: text/html

Your client has not sent the Referer header.

DENIED
	}
} else {
	$ref = defined $ref ? "= $ref" : "not present";
	print <<HELLO;
Connection: close
Content-type: text/html

<pre>
Referer $ref.

Use this <a href=$ENV{SCRIPT_URL}?check>link</a> to check.
</pre>
HELLO
}