Dynamically adding a file type custom option to multiple products (IDs 100, 101, and 102) in Magento.

file_custom_option_script.php

<?php
require_once 'app/Mage.php';
Mage::app('default');

$productIds = array(100, 101, 102);

$option = array(
    'title' => 'Test Option',
    'type' => 'file',
    'is_require' => 1,
    'price' => 10,
    'price_type' => 'fixed',
    'sku' => 'testsku',
    'file_extension' => 'png,jpg',
    'image_size_x' => '100',
    'image_size_y' => '200'
);


foreach ($productIds as $productId) {
    $product = Mage::getModel('catalog/product')->load($productId);
    $optionInstance = $product->getOptionInstance()->unsetOptions();

    $product->setHasOptions(1);
    if (isset($option['is_require']) && ($option['is_require'] == 1)) {
        $product->setRequiredOptions(1);
    }
    $optionInstance->addOption($option);
    $optionInstance->setProduct($product);
    $product->save();

}

Can you suggest where to add this code .. !! In Magento directory .. !! Do I need to create a separate module and use this logic or this script alone will work.

Thanks

@shalintripathi
Create a new file names xxx.php under Magento root directory and copy the content into the file.

I created a new file and named it test.php under Magento root directory and copy the content into the file. After that I run www.mysite.com/test.php. Its not working. Custom options didnt added to multiple products.
Can you suggest where I did mistake?

Thanks.

$product->save();
is not working

Anyone know how to programmatically create add to cart with custom option type file with params.?
Note problem in send file