$url = 'http://www.baidu.com';

$ch = curl_init(); 
curl_setopt($ch, CURLOPT_URL, $url); 
curl_setopt($ch, CURLOPT_VERBOSE, true); 
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_NOBODY, true);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'GET');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); 
curl_setopt($ch, CURLOPT_TIMEOUT, 20); 
curl_setopt($ch, CURLOPT_AUTOREFERER, true); 
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true); 
$ret = curl_exec($ch); 
$info = curl_getinfo($ch); 
curl_close($ch);

curl_setopt($curl, CURLOPT_CUSTOMREQUEST, 'GET');