我正在尝试创建一个基本的附属系统插件，目前将执行以下操作：

如果存在，请在任何页面中读取$\\u GET URL参数（例如http://mysite.com/about/?affid=1234). 如果没有，请跳过以下两个步骤

将其保存在cookie中，重定向到干净的URL(http://mysite.com/about/)

我的问题在于第一部分和最后一部分（读取参数并重定向）。我不这么认为add_query_var 是正确的方法，因为我只想跟踪引用，而不是在查询中使用参数。有什么想法吗？

编辑：以下是我目前拥有的：

add_action( \'template_redirect\', \'test_redirect\' );
function test_redirect() {
  global $wp;
  $wp->add_query_var(\'aff_id\');
  //cookie related stuff goes here
  $current_url = add_query_arg( $wp->query_string, \'\', home_url( $wp->request ) );
  //strip the URL parameter aff_id from $current_url???
  wp_redirect( $current_url ); exit;
}

Edit: Working code, thanks to all of you and specifically @Max who helped a lot.

<?php add_action(\'init\', \'affiliate_redirect\');
function affiliate_redirect() {
  $varname = \'aff_id\';
  $weeks = \'4\';
    if( isset($_GET[$varname]) && \'\' != $_GET[$varname] ) {
    setcookie(\'wp_affiliate\', $_GET[$varname], time()+648000*$weeks, \'/\');
    $pageURL = \'http\';
    if ( isset( $_SERVER["HTTPS"] ) && strtolower( $_SERVER["HTTPS"] ) == "on" ) {
      $pageURL .= "s";
    }
    $pageURL .= "://";
    if ($_SERVER["SERVER_PORT"] != "80") {
      $pageURL .= $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];
    } else {
      $pageURL .= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];
    }
    $url = preg_replace(\'/([?&])\'.$varname.\'=[^&]+(&|$)/\',\'$1\',$pageURL);
    $last = $url[strlen($url)-1];
    if ($last == \'?\') {
      $url = substr_replace($url ,"",-1);
    }
    wp_redirect($url);
    exit;
  }
} ?>

<?php
add_action(\'send_headers\', \'affiliate_redirect\');
function affiliate_redirect() {
    // it\'s possible to use \'if( !empty( $_GET[\'affid\']) )\'
    if( isset($_GET[\'affid\']) && \'\' != $_GET[\'affid\'] ) {
        if( empty($_COOKIE[\'affid\']) )
            setcookie(\'affid\', $_GET[\'affid\'], time()+2592000, \'/\');
        header(\'Location: http://mysite.com/about/\');
        exit;
    }
}

add_action( \'send_headers\', \'wpse85540_affiliate_redirect\' );
function wpse85540_affiliate_redirect()
{
    // Maybe even more elegant than simple $_GET, depending on if it was added:
    // $affid = get_query_arg( \'affid\' );

    if (
        isset( $_GET[\'affid\'] )
        AND ! empty( $_GET[\'affid\'] ) 
        )
    {
        empty( $_COOKIE[\'affid\'] ) AND setcookie(
             \'affid\'
            ,$_GET[\'affid\']
            ,time() +4 * WEEK_IN_SECONDS
            ,\'/\'
        );
        $path = user_trailingslashit( \'/about\' );
        $scheme = is_ssl() ? \'https://\' : \'http://\';
        $url = is_multisite()
            ? network_site_url( $path, $scheme )
            : site_url( $path, $scheme );
        wp_redirect( $url ); // 302
        exit;
    }
}