教你如何为wordpress dux主题文章站外链接自动添加nofollow属性

// 文章外部链接加上nofollow
add_filter( 'the_content', 'cn_nf_url_parse');
function cn_nf_url_parse( $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;
 
}