gistfile1.php

<?php

if ($utf8) {
  if (function_exists('mb_strtolower')) {
    $strtolower = function ($string) { return mb_strtolower($string); }
  } else {
    require_once($sourcedir . '/Subs-Charset.php');
    $strtolower = function ($string) { return utf8_strtolower($string); }
  }
} else {
  $strtolower = function ($string) { return strtolower($string); }
}

...


'strtolower' => $strtolower