hook_menu - setting a variable to use in page.tpl.php
Just as an option, you could use a specific page template for your path, and sub-paths.

/**
 * Implements hook_preprocess_page
**/
function HOOK_preprocess_page(&amp;$variables) {
  // Optional logic to check path condition
  // e.g arg(), request_uri(), current_path() etc..
  $some_condition = FALSE;
  if(arg(0) == 'base' || $some_condition) {
    // Set single page--base.tpl.php template, for /base and /base/subpath
    // Note: this overrides theme_hook_suggestions[]
    $variables['theme_hook_suggestion'] = 'page__base';
    // Sample template variable
    $variables['foo'] = 'bar';
  }

}


Then, in your theme, you can copy page.tpl.php to page--base.tpl.php and add whatever page specific markup you need in the template.

You could also add logic and template variables to hook_preprocess_page.  They would be available in your custom template. They can also be added there for the default page.tpl.php template. In any case, you will need some condition check for the specific target path match there.

Some relevant API functions to check the URL path include:


arg
current_path
request_uri


Note: arg() is also used by core template_preprocess_page to set the theme suggestions.


  Uses the arg() function to generate a series of page template suggestions based on the current path.