WordPress不用插件实现关键词自动添加链接

文章页面的关键词自动添加内链，有利于SEO，方便读者查看所有相关关键词的所有文章。

建议最多替换3个重复的词！避免过度SEO。

在主题的 functions 文件中添加以下代码：

// 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 );

            $url = “<a href=\”$link\” title=\”” . str_replace ( ‘%s’, addcslashes ( $cleankeyword, ‘$’ ), __ ( ‘View all posts in %s’ ) ) . “\””;

            $url .= ‘ target=”_blank”‘;

            $url .= “>” . addcslashes ( $cleankeyword, ‘$’ ) . “</a>”;

            $limit = rand ( $match_num_from, $match_num_to );

            

            // 不连接的代码

            $content = preg_replace ( ‘|(<a[^>]+>)(.*)(‘ . $ex_word . ‘)(.*)(</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;

}