Question: There is a function in Drupal 5 (`_phptemplate_variables()`) that has been deprecated in Drupal 6.
Is there a similar function in Drupal 6?

Answer: 
well, i'm not totally sure what you mean, but according to the title of the post, you want a redirect function ?

something like the drupal\_goto(); function?

<http://api.drupal.org/api/drupal/includes--common.inc/function/drupal_goto/6>
```
function phptemplate_preprocess_page(&$variables) {
  if (isset($variables['node'])) {
    $variables['template_files'][] = 'page-' . str_replace('_', '-', $variables['node']->type);
  }
  return $variables;
}

```