使用php重定向到相同的路径减去文件名

So I want to redirect a page in a directory, for example auth/login.php, to another page, at auth/. The page is actually called auth/index.php but I don't want this to show up to the client. How can I do this using this PHP code:

header("Location: /auth/");

However, I want the filename to be relative, e.g. ../ instead of hard-coded as auth. Is this possible, and how?

To direct the users to your current directory, you should extract the script's directory from $_SERVER['SCRIPT_NAME'], and then compare it to the actual HTTP request ($_SERVER['REQUEST_URI']). If they're not the same - redirect to the current directory. If they're the same - you should start your actual script:

<?php

$currentScript = $_SERVER['SCRIPT_NAME'];
$pathInfo = pathinfo($currentScript);
$currentDir = $pathInfo['dirname'].'/';

if ($currentDir != $_SERVER['REQUEST_URI'])
{
  header('Location: '.$currentDir);
  return ;
}

// Here be real site data