WordPress给文章标签自动添加内链

很多做SEO的朋友都应该知道文章内链的重要性。内部链接结构可以引导权值的传递，提高收录，提升内页排名。

如何给WordPress博客的文章关键词标签自动添加内链呢？其实我们只需要在主题目录下的functions.php文件中添加一段代码就可以实现了。

//WordPress 文章关键词自动内链
 
function tag_sort($a, $b){
  if ( $a->name == $b->name ) return 0;
  return ( strlen($a->name) > strlen($b->name) ) ? -1 : 1;
}
function tag_link($content){
  $match_num_from = 1;  //一个标签少于几次不链接
  $match_num_to = 1;  //一个标签最多链接几次
  $posttags = get_the_tags();
  if ($posttags) {
    usort($posttags, \"tag_sort\");
    foreach($posttags as $tag) {
      $link = get_tag_link($tag->term_id);
      $keyword = $tag->name;
      //链接代码
      $cleankeyword = stripslashes($keyword);
      $url = \"<a href=\\\"$link\\\" title=\\\"\".str_replace(\'%s\',addcslashes($cleankeyword, \'$\'),__(\'更多关于 %s 的文章\')).\"\\\"\";
      $url .= \' target=\"_blank\"\';
      $url .= \">\".addcslashes($cleankeyword, \'$\').\"</a>\";
      $limit = rand($match_num_from,$match_num_to);
      //不链接代码
      $content = preg_replace( \'|(<a[^>]+>)(.*)<pre.*?>(\'.$ex_word.\')(.*)<\\/pre>(</a[^>]*>)|U\'.$case, \'$1$2%&&&&&%$4$5\', $content);
      $content = preg_replace( \'|(<img)(.*?)(\'.$ex_word.\')(.*?)(>)|U\'.$case, \'$1$2%&&&&&%$4$5\', $content);
      $cleankeyword = preg_quote($cleankeyword,\'\\\'\');
      $regEx = \'\\\'(?!((<.*?)|(<a.*?)))(\'. $cleankeyword . \')(?!(([^<>]*?)>)|([^>]*?</a>))\\\'s\' . $case;
      $content = preg_replace($regEx,$url,$content,$limit);
      $content = str_replace( \'%&&&&&%\', stripslashes($ex_word), $content);
    }
  }
  return $content;
}
add_filter(\'the_content\',\'tag_link\',1);