问发送带有服务器缓存文件的头文件

EN

<?php
date_default_timezone_set('UTC');
$root=dirname(dirname(dirname(dirname(__FILE__))));
$filetime=filemtime(__FILE__);
if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) && (@strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']) == $filetime))
{
    header('Last-Modified: '.gmdate('D, d M Y H:i:s', $filetime).' GMT', true, 304);
}
else
{
    //Not yet cached on client

    $cachefile = $root.'/ayb_cache/'.preg_replace("/[^A-Za-z0-9 ]/", '', basename($_SERVER['REQUEST_URI']));
    $cachetime=60*60*24*14;

    if (file_exists($cachefile) && (time() - $cachetime < filemtime($cachefile)))
    {
        // Serve from the cache if it is younger than $cachetime
        include($cachefile);
        //echo "<!-- Cached ".date('jS F Y H:i', filemtime($cachefile))." -->";
        echo "/* Cached ".date('jS F Y H:i', filemtime($cachefile))." */";
    }

    else
    {
        //create new file
        ob_start();

        header( 'Content-type: text/javascript' ); //tell the browser we're returning JS
        header('Pragma: public');
        header('Cache-Control: public, maxage='.$cachetime);
        header('Expires: ' . gmdate('D, d M Y H:i:s', time()+$cachetime) . ' GMT');
        header('Last-Modified: '.gmdate('D, d M Y H:i:s', filemtime(__FILE__)).' GMT', true, 200);

        echo('alert("My Javascript");');

        $fp = fopen($cachefile, 'w'); // open the cache file for writing
        fwrite($fp, ob_get_contents()); // save the contents of output buffer to the file
        fclose($fp);
        ob_end_flush(); // Send the output to the browser
    }
}
?>