//文章自动nofollowadd_filter( 'the_content', 'tin_seo_wl');function tin_seo_wl( $content ) {    $regexp = "<a\s[^>]*href=(\"??)([^\" >]*?)\\1[^>]*>";    if(preg_match_all("/$regexp/siU", $content, $matches, PREG_SET_ORDER)) {        if( !empty($matches) ) {               $srcUrl = get_option('siteurl');            for ($i=0; $i < count($matches); $i++)            {                   $tag = $matches[$i][0];                $tag2 = $matches[$i][0];                $url = $matches[$i][0];                   $noFollow = '';                $pattern = '/target\s*=\s*"\s*_blank\s*"/';                preg_match($pattern, $tag2, $match, PREG_OFFSET_CAPTURE);                if( count($match) < 1 )                    $noFollow .= ' target="_blank" ';                   $pattern = '/rel\s*=\s*"\s*[n|d]ofollow\s*"/';                preg_match($pattern, $tag2, $match, PREG_OFFSET_CAPTURE);                if( count($match) < 1 ) $noFollow .= ' rel="nofollow" '; $pos = strpos($url,$srcUrl); if ($pos === false) { $tag = rtrim ($tag,'>');                    $tag .= $noFollow.'>';                    $content = str_replace($tag2,$tag,$content);                }            }        }    }       $content = str_replace(']]>', ']]>', $content);    return $content;}

添加到当前主题Funcions.php 文件中，当然目前一些wordpress主题设置有这个nofollow标签功能。