php obtient des balises html de la chaîne
$html = '<div><p>Some text</p><iframe src="http://www.source.com"></iframe></div>';
$start = strpos($html, 'src="') + 5;
$length = strpos($html, '"></iframe') - $start;
$src = substr($html, $start, $length);
echo $src;
or
var_dump(simplexml_load_string($rss_feed));
or
$rssFeed = '<div>
<p>
Some text
</p>
<iframe src="http://www.source.com"></iframe>
</div>';
$rssArray = explode('"', $rssFeed);
echo $rssArray[1];
SECRET MYSTERY