Header only retrieval in php via curl

You are passing $header to curl_getinfo(). It should be $curl (the curl handle). You can get just the filetime by passing CURLINFO_FILETIME as the second parameter to curl_getinfo(). (Often the filetime is unavailable, in which case it will be reported as -1).

Your class seems to be wasteful, though, throwing away a lot of information that could be useful. Here's another way it might be done:

class URIInfo {    public $info;    public $header;    private $url;    public function __construct($url)    {        $this->url = $url;        $this->setData();    }    public function setData()     {        $curl = curl_init();        curl_setopt($curl, CURLOPT_URL, $this->url);        curl_setopt($curl, CURLOPT_FILETIME, true);        curl_setopt($curl, CURLOPT_NOBODY, true);        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);        curl_setopt($curl, CURLOPT_HEADER, true);        $this->header = curl_exec($curl);        $this->info = curl_getinfo($curl);        curl_close($curl);    }    public function getFiletime()     {        return $this->info['filetime'];    }    // Other functions can be added to retrieve other information.}$uri_info = new URIInfo('http://www.codinghorror.com/blog/');$filetime = $uri_info->getFiletime();if ($filetime != -1) {    echo date('Y-m-d H:i:s', $filetime);} else {    echo 'filetime not available';}

Yes, the load will be lighter on the server, since it's only returning only the HTTP header (responding, after all, to a HEAD request). How much lighter will vary greatly.

Why use CURL for this? There is a PHP-function for that:

$headers=get_headers("http://www.amazingjokes.com/img/2014/530c9613d29bd_CountvonCount.jpg");print_r($headers);

returns the following:

Array(    [0] => HTTP/1.1 200 OK    [1] => Date: Tue, 11 Mar 2014 22:44:38 GMT    [2] => Server: Apache    [3] => Last-Modified: Tue, 25 Feb 2014 14:08:40 GMT    [4] => ETag: "54e35e8-8873-4f33ba00673f4"    [5] => Accept-Ranges: bytes    [6] => Content-Length: 34931    [7] => Connection: close    [8] => Content-Type: image/jpeg)

Should be easy to get the content-type after this.

You could also add the format=1 to get_headers:

$headers=get_headers("http://www.amazingjokes.com/img/2014/530c9613d29bd_CountvonCount.jpg",1);    print_r($headers);

This will return the following:

Array(    [0] => HTTP/1.1 200 OK    [Date] => Tue, 11 Mar 2014 22:44:38 GMT    [Server] => Apache    [Last-Modified] => Tue, 25 Feb 2014 14:08:40 GMT    [ETag] => "54e35e8-8873-4f33ba00673f4"    [Accept-Ranges] => bytes    [Content-Length] => 34931    [Connection] => close    [Content-Type] => image/jpeg)

More reading here (PHP.NET)

(1) Yes. A HEAD request (as you're issuing in this case) is far lighter on the server because it only returns the HTTP headers, as opposed to the headers and content like a standard GET request.

(2) You need to set the CURLOPT_RETURNTRANSFER option to true before you call curl_exec() to have the content returned, as opposed to printed:

curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);

That should also make your class work correctly.