MAGENTO : EXPORT CATEGORIES AND IDS TO CSV

<?php
require_once 'app/Mage.php';
Mage::app();
$allCategories = Mage::getModel ( 'catalog/category' );
$categoryTree = $allCategories->getTreeModel();
$categoryTree->load();
$categoryIds = $categoryTree->getCollection()->getAllIds();
if ($categoryIds) {
$outputFile = "var/export/categories-and-ids.csv";
$write = fopen($outputFile, 'w');
foreach ( $categoryIds as $categoryId ) {
$data = array($allCategories->load($categoryId)->getName(), $categoryId);
fputcsv($write, $data);
}
}
fclose($write);
?>