/**
* Delete any file that is older than 24 hours from the whole /cache folder (recursively)
* except index.html files and hiddenfiles (starting with .)
*
* @static
*
* @return string empty string on success, error message otherwise.
*/
function prune_page_cache()
{
global $cache_path;
load_funcs('tools/model/_system.funcs.php');
// check and try to repair cache folders
system_check_caches();
$path = trailing_slash($cache_path);
$first_error = '';
PageCache::deleteDirContent($path, $first_error);
return $first_error;
}
