php5以上でCall to undefined function domxml_new_doc()

domxml_new_docがundefinedと出てしまった。

[vagrant@localhost map]$ php -v
PHP 5.6.27 (cli) (built: Oct 14 2016 14:06:54)

phpのversionは、5.6

php4.0からサポートされているのに何で？と思ったが、以下のようにphp5以上はDOM extensionを使えとのこと。
It will, however, never be released with PHP 5, and will only be distributed with PHP 4. If you need DOM XML support with PHP 5 you can use the DOM extension. This domxml extension is not compatible with the DOM extension.

こちらのDom Object Model
http://us3.php.net/manual/ja/book.dom.php

new DOMDocument(), createElement, appendChild, setAttribute, saveXMLに修正したら問題なく表示されました。

<?php
require("phpsqlajax_dbinfo.php");

$doc = new DOMDocument("1.0");

$node = $doc->createElement("makers");
$parnode = $doc->appendChild($node);

$connection =mysql_connect('localhost', $username, $password);
if (!$connection){
	die('Not connected : ' . mysql_error());
}

$db_selected = mysql_select_db($database, $connection);
if (!$db_selected){
	die ('Can\'t use db:' . mysql_error());
}

$query = "SELECT * FROM markers WHERE 1";
$result = mysql_query($query);
if(!$result){
	die('Invalid query:' . mysql_error());
}

header("Content-type: text/xml");

while ($row = @mysql_fetch_assoc($result)){
	$node = $doc->createElement("marker");
	$newnode = $parnode->appendChild($node);
	$newnode->setAttribute("name", $row['address']);
	$newnode->setAttribute("lat", $row['lat']);
	$newnode->setAttribute("lng", $row['lng']);
	$newnode->setAttribute("type", $row['type']);
}

$xmlfile = $doc->saveXML();
echo $xmlfile;
?>

<makers>
<marker name="580 Darling Street, Rozelle, NSW" lat="-33.861034" lng="151.171936" type="restaurant"/>
<marker name="76 Wilford Street, Newtown, NSW" lat="-33.898113" lng="151.174469" type="bar"/>
<marker name="Greenwood Plaza, 36 Blue St, North Sydney NSW" lat="-33.840282" lng="151.207474" type="bar"/>
<marker name="7A, 2 Huntley Street, Alexandria, NSW" lat="-33.910751" lng="151.194168" type="bar"/>
<marker name="16 Foster Street, Surry Hills, NSW" lat="-33.879917" lng="151.210449" type="bar"/>
<marker name="43 Macpherson Street, Bronte, NSW" lat="-33.906357" lng="151.263763" type="restaurant"/>
<marker name="60-64 Reservoir Street, Surry Hills, NSW" lat="-33.881123" lng="151.209656" type="restaurant"/>
<marker name="60 Riley Street, Darlinghurst, NSW" lat="-33.874737" lng="151.215530" type="restaurant"/>
</makers>