WordPress自动给文章添加nofollow属性方法

add_filter( 'the_content', 'cn_nf_url_parse');
 
function cn_nf_url_parse( $content ) {
 
 $regexp = "]*href=("??)([^" >]*?)\1[^>]*>";
 if(preg_match_all("/$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 = '';
 
    $pattern = '/targets*=s*"s*_blanks*"/';
    preg_match($pattern, $tag2, $match, PREG_OFFSET_CAPTURE);
    if( count($match) < 1 )
     $noFollow .= ' target="_blank" ';
 
    $pattern = '/rels*=s*"s*[n|d]ofollows*"/';
    preg_match($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;
 
}

function nofollow_cat_posts($text) {
global $post;
        if( in_category(1) ) { // 修改这里的分类ID
                $text = stripslashes(wp_rel_nofollow($text));
        }
        return $text;
}
add_filter('the_content', 'nofollow_cat_posts');