상대 경로를 절대 경로로 변환

相对路径转化成绝对路径

//相对路径转化成绝对路径
function relative_to_absolute($content, $feed_url) {
preg_match('/(http|https|ftp):///', $feed_url, $protocol);
$server_url = preg_replace("/(http|https|ftp|news):///", "", $feed_url);
//开源OSPhP.COM.CN
$server_url = preg_replace("//.*/", "", $server_url);
    if ($server_url == '') {
        return $content;
    }
    if (isset($protocol[0])) {
//开源代码OSPhP.COm.CN
$new_content = preg_replace('/href="//', 'href="'.$protocol[0].$server_url.'/', $content);
$new_content = preg_replace('/src="//', 'src="'.$protocol[0].$server_url.'/', $new_content);  //开源OSPhP.COM.CN
    } else {
$new_content = $content;
    }
    return $new_content;
}
?>