WordPress外部链接自动添加nofollow标签

WordPress外部链接自动添加nofollow标签，目的是为了减少权重流失，我们只需将下面代码，添加到当前WordPress主题 Functions.php 文件中即可。

//外部链接添加nofollow
add_filter('the_content','zhuige_the_content_nofollow',999);
function zhuige_the_content_nofollow($content){
  preg_match_all('/href="(.*?)" rel="external nofollow" /',$content,$matches);
  if($matches){
    foreach($matches[1] as $val){
      if( strpos($val,home_url())===false ) $content=str_replace("href=\"$val\"", "href=\"$val\" rel=\"nofollow\" ",$content);
    }
  }
  return $content;
}