WordPress里要实现文章自动提取tag方法有很多，最方便的使用插件。今天分享一个不用插件来实现文章的自动提取tag并添加链接的方法。
登录博客后台，打开博客主题的function.php功能函数，在这个文件里面添加如下代码：

[prism lang=""]//连接数量
$match_num_from = 1; //一个关键字少于多少不替换
$match_num_to = 10; //一个关键字最多替换
//连接到WordPress的模块
add_filter('the_content','tag_link',1);
//按长度排序
function tag_sort($a, $b){
if ( $a->name == $b->name ) return 0;
return ( strlen($a->name) > strlen($b->name) ) ? -1 : 1;
}
//改变标签关键字
function tag_link($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;
//连接代码
$cleankeyword = stripslashes($keyword);
$url = "";
$limit = rand($match_num_from,$match_num_to);
//不连接的 代码
$content = preg_replace( '|(]+>)(.*)('.$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;
}[/prism]