Pull the http-equiv attribute out of an html meta element
function _openid_meta_httpequiv($equiv, $html) {
preg_match('|<meta\\s+http-equiv=["\']' . $equiv . '["\'](.*)/?>|iUs', $html, $matches);
if (isset($matches[1])) {
preg_match('|content=["\']([^"]+)["\']|iUs', $matches[1], $content);
if (isset($content[1])) {
return $content[1];
}
}
return FALSE;
}