<?php

$html = <<<DATA
<html>
    <title>Random Website</title>

    <body>

    Click <a href="http://d...content-available-to-author-only...z.com">here</a> for foobar

    Another site is http://w...content-available-to-author-only...n.com
    <a href="http://w...content-available-to-author-only...n.com/test">Test 1</a>
    <a href="http://w...content-available-to-author-only...n.com/test">Test 2</a>
    <Strong>NOT A LINK</strong>
    </body>

    </html>
DATA;

$dom = new DOMDocument;
$dom->loadHTML($html);
$xpath = new DOMXPath($dom);
$arr = array();
$links = $xpath->query('//a[contains(@href, "www.domain.com")]');

foreach($links as $link) { 
   array_push($arr, $link->getAttribute("href"));
}

print_r($arr);
