$re = '/[^<]*<(.*)>.*/s';
$str = '--------------------------3cbec9ce8f05
Content-Disposition: form-data; name="owServerData"; filename="details.xml"
Content-Type: text/plain
<?xml version="1.0" encoding="UTF-8"?>
<Devices-Detail-Response xmlns="http://www.example.com"
// Rest omitted
</Devices-Detail-Response>
------------------------------3cbec9ce8f05--';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($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