WordPress 技巧：用户注册时候不能含有非法关键字

function wpjam_blacklist_check($str){
    $moderation_keys = trim(get_option('moderation_keys'));
    $blacklist_keys = trim(get_option('blacklist_keys'));

    $keys = $moderation_keys ."\n".$blacklist_keys;

    $words = explode("\n", $keys );

    foreach ( (array) $words as $word) {
        $word = trim($word);

        // Skip empty lines
        if ( empty($word) )
            continue;

        // Do some escaping magic so that '#' chars in the
        // spam words don't break things:
        $word = preg_quote($word, '#');

        $pattern = "#$word#i";
        if ( preg_match($pattern, $str) ) return true;
    }

    return false;
}

add_filter( 'sanitize_user', 'wpjam_sanitize_user',3,3);
function wpjam_sanitize_user($username, $raw_username, $strict){
    if(wpjam_blacklist_check($username)){
        $username = '';
    }

    return $username;
}