<!DOCTYPE html>
<html>
<body>
<?php
$xml=<<<XML
<?xml version="1.0" standalone="yes"?>
<cars xmlns:c="http://w3schools.com/ns">
<c:car id="1">Volvo</c:car>
<c:car id="2">BMW</c:car>
<c:car id="3">Saab</c:car>
</cars>
XML;
$sxe=new SimpleXMLElement($xml);
$ns=$sxe->getDocNamespaces();
print_r($ns);
?>
</body>
</html>