cache url file

<?php
set_time_error(0);
function readCacheFile($url, $file, $delay = 3600) {
    // @author: huyphungvan@gmail.com
    if(!file_exists($file)) {
        // first time
        $src = file_get_contents($url);
        file_put_contents($file, $src);
        return $src;
    } else {
        $now = time();
        $cached_time = filemtime($file);
        if ($now - $cached_time > $delay) {
            // re-cache
            $src = file_get_contents($url);
            file_put_contents($file, $src);
            return $src;
        } else {
            // read cached file
            return file_get_contents($file);
        }
    }
}


$src = readCacheFile("http://phungvanhuy.net", "cache/pvh.htm");
echo $src;
?>