WordPress 网站外链纯代码自动添加nofollow和blank属性

// 站外链接自动添加nofollow属性
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;

}