$re = '/<a href="([^"]*?\/n\/\?confirm\.php)">.*?<\/a>/m';
$str = '<a href="https://www.website.com/n/?noconfirm.php">SSD</a>
<div>How are you</div>
<a href="https://www.website.com/n/?confirm.php">HDD</a>
<h2>Being Sunny</h2>
<a href="https://www.website.com/n/?noconfirm.php">MSD</a>
<div>How are you</div>
<a href="https://www.website.com/n/?confirm.php"></a>
<h2>Being Sunny</h2>
<a href="https://www.website.com/n/?noconfirm.php">GSD</a>
<div>How are you</div>
<a href="https://www.website.com/n/?confirm.php">LSD</a>
<h2>Being Sunny</h2>';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php