wordpress纯代码实现文章自动添加内链、提升SEO效果

效果见本站，将以下代码加入主题的function.php文件即可，根据需要可以设置同一关键词tag添加内链数量
/* 自动为文章内的标签添加内链 */
$match_num_from = 1; //一篇文章中同一个标签少于几次不自动链接,根据自己需求修改
$match_num_to = 1; //一篇文章中同一个标签最多自动链接几次,根据自己需求修改
function tag_sort($a, $b){
if ( $a->name == $b->name ) return 0;
return ( strlen($a->name) > strlen($b->name) ) ? -1 : 1;
}
function tag_link($content){
global $match_num_from,$match_num_to;
$posttags = get_the_tags();
if ($posttags) {
usort($posttags, "tag_sort");
foreach($posttags as $tag) {
$link = get_tag_link($tag->term_id);
$keyword = $tag->name;
$cleankeyword = stripslashes($keyword);
$url = "";
$limit = rand($match_num_from,$match_num_to);
$content = preg_replace( '|(]+>)(.*)('.$ex_word.')(.*)(]*>)|U'.$case, '$1$2%&&&&&%$4$5', $content);
$content = preg_replace( '|()|U'.$case, '$1$2%&&&&&%$4$5', $content);
$cleankeyword = preg_quote($cleankeyword,'\'');
$regEx = '\'(?!((<.*?)|(]*?)>)|([^>]*?))\'s' . $case;
$content = preg_replace($regEx,$url,$content,$limit);
$content = str_replace( '%&&&&&%', stripslashes($ex_word), $content);
}
}
return $content;
}
//激活钩子内链
add_filter('the_content','tag_link',1);