让系统自动把外链都加上nofollow属性,修改方法如下：   1. 打开目录source/function/function_discuzcode.php文件，查找parseurl函数，对照以下代码进行修改： function parseurl($url, $text, $scheme) { global $_G; if(!$url && preg_match("/((https?|ftp|gopher|news|telnet|rtsp|mms|callto|bctp|thunder|qqdl|synacast){1}:\/\/|www\.)[^\[\"']+/i", trim($text), $matches)) { $url = $matches[0]; $length = 65; if(strlen($url) > $length) { $text = substr($url, 0, intval($length * 0.5)).' ... '.substr($url, - intval($length * 0.3)); } $url = nofollow($url); return '<a href="'.(substr(strtolower($url), 0, 4) == '' ? ''.$url : $url).'" target="_blank">'.$text.'</a>'; } else { $url = substr($url, 1); if(substr(strtolower($url), 0, 4) == '') { $url = ''.$url; } $url = !$scheme ? $_G['siteurl'].$url : $url; return '<a href="'.nofollow($url).'" target="_blank">'.$text.'</a>'; } }  
复制代码   2. 在parseurl函数后面新增nofollow函数，代码如下： function nofollow($url = '') { $temp = array(); if( ! empty($url)) { $temp = parse_url($url); if(isset($temp['host']) && $temp['host'] != $_SERVER['HTTP_HOST']) { $url .= '" rel="nofollow"'; } } unset($temp); return $url; }