Magento Shell

product.php

    // Change product attribute value
    public function run()
    {
        // --edit 1-10,color,5
//        $default = array(
//            'product_ids' => array(1, 10),
//            'attribute_code' => 'color',
//            'attribute_value' => 5
//        );
        if (isset($this->_args['edit'])) {
            $params = explode(',', $this->_args['edit']);
            $default['product_ids'] = explode('-', $params[0]);
            $default['attribute_code'] = $params[1];

            $default['attribute_value'] = explode('-', $params[2]);
            if (count($default['attribute_value']) < 2) {
                $default['attribute_value'] = $default['attribute_value'][0];
            }
            $default['product_ids'] = array_map('intval', $default['product_ids']);
            $productId = $default['product_ids'][0];
            if (!isset($default['product_ids'][1])) {
                $default['product_ids'][1] = $productId;
            }
            while (true) {
                $product = Mage::getModel('catalog/product')->load($productId);
                $product->setData($default['attribute_code'], $default['attribute_value']);
                $product->save();
                if ($productId === $default['product_ids'][1]) {
                    break;
                } else {
                    $productId++;
                }
            }

        } else {
            echo $this->usageHelp();
        }
    }
    /**
     * Get products collection by category ID
     * @param array $categoryIds
     * @return null|object
     */
    public function getProductsCollectionByCatIds($categoryIds = array())
    {
        if (empty($categoryIds)) {
            return null;
        }
        $collection = Mage::getModel('catalog/product')
        ->getCollection()
        ->joinField('category_id', 'catalog/category_product', 'category_id', 'product_id = entity_id', null, 'left')
        ->addAttributeToSelect('*')
        ->addFieldToFilter('visibility', Mage_Catalog_Model_Product_Visibility::VISIBILITY_BOTH)
        ->addAttributeToFilter('status', array('eq' => 1))
        ->addAttributeToFilter('category_id', array('in' => $categoryIds));

        return $collection;
    }