$re = '/href="([^"]*+)"/m';
$str = '<a href="http:/my.domain/simple-product-2.html" class="product-image"><img src="http://my.domain/media/catalog/product/cache/1/small_image/75x/9df78eab33525d08d6e5fb8d27136e95/images/catalog/product/placeholder/small_image.jpg" width="75" height="75" alt="Simple Product 2" title="Simple Product 2"></a>
<div class="product-details">
<h3 class="product-name"><a href="http://my.domain/simple-product-2.html">Simple Product 2</a></h3>
<div class="price-box">
<span class="regular-price" id="product-price-2-related">
<span class="price">$42.00</span> </span>
</div>
<p><a href="http://my.domain/wishlist/index/add/product/2/form_key/PLOSE4N7mH4kcOgX/" class="link-wishlist">Add to Wishlist</a></p>
</div>';
preg_match_all($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