Safely run Magento 1.x upgrade scripts via CLI

upgrade.php

<?php
/**
 * Set global/skip_process_modules_updates to '1' in app/etc/local.xml and
 * then use this script to apply updates and refresh the config cache without
 * causing a stampede on the config cache.
 *
 * It should be placed in the shell/ directory, and must be run via CLI.
 */
if(strtolower(php_sapi_name()) != 'cli'){
  exit;
}

umask(0);
set_time_limit(0);

set_include_path(
    get_include_path() . PATH_SEPARATOR .
    dirname(dirname(__FILE__))
);

require_once('app/Mage.php');

// Init without cache so we get a fresh version
Mage::app('admin','store', array('global_ban_use_cache' => TRUE));

echo "Applying updates... ";
Mage_Core_Model_Resource_Setup::applyAllUpdates();
Mage_Core_Model_Resource_Setup::applyAllDataUpdates();
echo "done.\n";

// Now enable caching and save
Mage::getConfig()->getOptions()->setData('global_ban_use_cache', FALSE);
Mage::app()->baseInit(array()); // Re-init cache
Mage::getConfig()->loadModules()->loadDb()->saveCache();
echo "Saved config cache. Refresh all caches to finish the upgrade.\n";