PHP: DIsplay the content type of a file with PHP and cURL

<?php
//googles small gif logo
$curl = curl_init('http://www.google.com/images/logo_sm.gif');
curl_setopt($curl, CURLOPT_RETURNTRANSFER, TRUE);
curl_exec($curl);
//get the content type
print("Content type: " . curl_getinfo($curl, CURLINFO_CONTENT_TYPE) .'<br>');
?>