Redis - Copy hash with members

<?php
/**
composer.json

{
    "name": "predis-copy-keys",
    "require": {
        "predis/predis": "^1.1"
    },
    "authors": [
        {
            "name": "Gabriel C.",
            "email": "eu@lazycoder.ro"
        }
    ]
}
/*
require 'vendor/autoload.php';

$redis = new Predis\Client('tcp://redis');

$source = 'SOURCE';
$destination = 'DESTINATION';
$keys = [2, 3, 4, 5, 6, 7, 8]; // keys to copy - applies for hashes

$script = <<<LUA
    local hash = redis.call('hgetall', KEYS[1]);
    if #hash == 0 then
        return { err = 'Unknown key "'..KEYS[1]..'" 1' }
    end
    return redis.call('hmset', KEYS[2], unpack(hash));
LUA;

foreach ($keys as $memberToCopy) {
	$redis->eval($script, 2, $source, $destination);
}

$copiedKey = $redis->hgetall($destination);

echo sprintf('-- Copied %s over %s\n\n\n', $source, $destination);
var_dump(array_keys($copiedKey));