Get the feed informations using xpath.

getfeed.php

<?php

$dom = @DOMDocument::loadHTMLFile( $url );
$xpath = new DOMXpath( $dom );

$query = "//link[ @rel='alternate' and ( @type='application/x.atom+xml' or "
	. "@type='application/atom+xml' or @type='application/xml' or @type='text/xml' or "
	. "@type='application/rss+xml' or @type='application/rdf+xml' ) ]";

$elements = $xpath->query( $query );
foreach( $elements as $element ){
	echo "{$element->getAttribute('href')} ({$element->getAttribute('type')})";
	echo "<br />";
}