Get size of directory

<?php

/**
 *
 * @get size of a directory in bytes
 *
 * @param string $directory
 *
 * @return int
 *
 */
function directorySize($directory)
{
    $size = 0;
    foreach(new RecursiveIteratorIterator(new RecursiveDirectoryIterator($directory)) as $file)
    {
        $size += $file->getSize();
    }
    return $size;
}

/*** example implementation ***/
$directory = '/home/foo';
$size = directorySize($directory);
echo $size;

?>