This question is related to Planck units (also called natural units, absolute units or God's units).
I'm wondering which constant is the most fundamental and should be normalized to 1. I would like as much explanation as possible please.


Question: How to get <img> src from CDATA in RSS?
Answer: You would better not to use regular expressions where you can use proper tools. Something which comes to my mind (although maybe it can be done easier):

$descr = $rss[description]; // String. You have extracted description part from your feed

$dom = new DOMDocument();
$dom-&gt;loadHTML($descr); // or you can use loadXML
if (!$dom) {
    die('Error loading HTML string.');
}

$xml = simplexml_import_dom($dom);
$imgSrc = (string)$xml-&gt;body-&gt;div-&gt;a-&gt;img['src'];


Here we go. Based on the your example CDATA $imgSrc will be equal to img_url.