preg_match（）：编译失败：在偏移量1处不重复

Question

preg_match（）：编译失败：在偏移量1处不重复 我的代码

define("IN_MYBB", 1);
define('THIS_SCRIPT', 'safelink.php');

require_once("./global.php");

$lang->load("safelink");

// Add link in breadcrumb
add_breadcrumb($lang->safelink, "safelink.php");
if($mybb->settings['safelink_enabled'] == 1)
{
    if($mybb->input['url'])
    {

        if(!filter_var($mybb->input['url'], FILTER_VALIDATE_URL))
        {
            $error = $lang->badurl;
        }
        else
        {
            $v = substr($_SERVER['REQUEST_URI'], strpos($_SERVER['REQUEST_URI'], "safelink.php?url=")); // these 2 lines filter out the url to continue to
            $url = str_replace('safelink.php?url=', '', $v); // only problem with these is it will replace all occurrencesof 'safelink.php?url=' in the url, and I don't know how to fix this (preg_replace perhaps?)
            $group = $mybb->user['usergroup'];
            $groups = explode(",", $mybb->settings['safelink_groups']);
            $excludes = explode("\n", $mybb->settings['safelink_urls']);
            foreach($excludes as $exclude)
            {
                if(!preg_match("#^".trim($exclude)."+[\d\w]*#i", $url) && !in_array($group, $groups)) // not an excluded site, go to safelink page and link intended URL
                {
                    $warning = $lang->warning;
                    $continue = $lang->continue;
                }
                else // site excluded from safelink OR user is in excluded usergroup
                {
                    header("location:$url");
                }
            }
        }
    }
    else
    {
        $error = $lang->nourl;
    }
}
else
{
    $error = $lang->disabled;
}
eval("\$safelink = \"".$templates->get("safelink")."\";");

output_page($safelink);

exit;