- preg_match: documentation ( source)
- print_r: documentation ( source)
<?php
$string = '<div><a href=%http://link1%><img></a><a href=%http://link2%><img></a><a href=%http://link3%><img></a></div>';
$re = '|<div>(<a((?!href)(?!<).)+?href=%([^%]+?)%((?!</a>).)+?</a>){2}</div>|';
$matches = array();
echo('result='.intval(preg_match($re, $string, $matches))."\n");
echo('$matches='); print_r($matches);