get file size funcation in php

function Size($path)
{
    $bytes = sprintf('%u', filesize($path));

    if ($bytes > 0)
    {
        $unit = intval(log($bytes, 1024));
        $units = array('B', 'KB', 'MB', 'GB');

        if (array_key_exists($unit, $units) === true)
        {
            return sprintf('%d %s', $bytes / pow(1024, $unit), $units[$unit]);
        }
    }

    return $bytes;
}