SugarCRM user switching / login as another user

switch_user.php

<?php

if (!defined('sugarEntry')) {
    define('sugarEntry', true);
}
require_once('include/entryPoint.php');
require_once 'include/MVC/SugarApplication.php';
$app = new SugarApplication();
$app->startSession();
$app->loadUser();
$app->loadGlobals();
if (empty($current_language)) {
    $current_language = $sugar_config['default_language'];
}
$app_list_strings = return_app_list_strings_language($current_language);
$app_strings = return_application_language($current_language);


/**
 * Login as another user in SugarCRM and switch back to admin user
 *
 * Simply put this file into a custom entry point file and
 * browse to it with the parameters 'user_name' or 'back_to_sudo'
 *
 * Usage:
 *    http://xxxxxxxxx/index.php?entryPoint=my_awesome_entry_point&user_name=mylittlepony
 *    http://xxxxxxxxx/index.php?entryPoint=my_awesome_entry_point&back_to_sudo=1
 * 
 * @author Karl Metum <[email protected]>
 * @link http://www.codehacker.se
 */
if(!empty($_REQUEST['user_name']) && $GLOBALS['current_user']->is_admin)
{
  echo "Verified admin user...<br/>";
  $user_focus = BeanFactory::getBean('Users');
  $user_focus->retrieve_by_string_fields(array('user_name' => $_REQUEST['user_name']));
  if(!empty($user_focus->id))
  {
    echo "target user found...<br/>";
    if(empty($_SESSION['sudo_user_id'])) {
      $_SESSION['sudo_user_id'] = $GLOBALS['current_user']->id;
      echo "original user backed up...<br/>";
    }

    $GLOBALS['current_user'] = $user_focus;
    $_SESSION['authenticated_user_id'] = $user_focus->id;
    echo "Successfully logged in as " . $GLOBALS['current_user']->user_name;
    return;
  }
}
elseif(!empty($_REQUEST['back_to_sudo']) && !empty($_SESSION['sudo_user_id']))
{
  echo "original user backup found...<br/>";
  $user_focus = BeanFactory::getBean('Users');
  $user_focus->retrieve($_SESSION['sudo_user_id']);
  if($user_focus->is_admin)
  {
    echo "original user is admin...<br/>";
    $_SESSION['sudo_user_id'] = null;
    $GLOBALS['current_user'] = $user_focus;
    $_SESSION['authenticated_user_id'] = $user_focus->id;
    echo "Successfully logged back to sudo user: " . $GLOBALS['current_user']->user_name;
    return;
  }
}

die("No dice.");