caching - how to check if a site has enabled Cache-Control for a file type

Question

I was wondering if there is any way to check if a website has enabled Cache-Control for a file type and its expiry time example for http://foo.com/foo.css how can i know if Cache-Control is enabled for it and whats is the expiry time set for it

Answer 1

Try this:

$ch = curl_init();
$url    = 'http://stackoverflow.com/questions/19320848/how-to-check-if-a-site-has-enabled-cache-control-for-a-file-type';

curl_setopt( $ch, CURLOPT_URL, $url );
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, 1 );
curl_setopt( $ch, CURLOPT_CONNECTTIMEOUT, 20 );
curl_setopt( $ch, CURLOPT_HEADER, true );
curl_setopt( $ch, CURLOPT_NOBODY, true );

$res    = explode( "\n", curl_exec( $ch ) );

foreach( $res as $line ) {
    if( strpos( $line, 'Expires:' ) !== false ) {
        $line = explode( ':', $line );

        array_shift( $line );
        echo 'Page expires on - ' . trim( implode( ':', $line ) );
    }
}

curl_close( $ch );

Hope this helps.

Answer 2

You can try this:

<?php
$temp = curl_init();
curl_setopt( $temp, CURLOPT_URL, 'http://foo.com/foo.css' );
curl_setopt( $temp, CURLOPT_RETURNTRANSFER, 1 );
curl_setopt( $temp, CURLOPT_CONNECTTIMEOUT, 20 );
curl_setopt( $temp, CURLOPT_HEADER, true );
curl_setopt( $temp, CURLOPT_NOBODY, true );
echo curl_exec( $temp );
curl_close( $temp );
?>

This will return an output like This:

HTTP/1.1 200 OK Server: Date: Current Date GMT Content-Type: text/css Content-Length: 2713 Connection: keep-alive Vary: Accept-Encoding Last-Modified: Date of file creation Accept-Ranges: bytes Cache-Control: max-age=expiry time in sec set for it Expires: Expiry Date GMT