Method getFileSizeReadable

/*
 * http://aidanlister.com/repos/v/function.size_readable.php
 */
public static function getFileSizeReadable($size, $retstring = null, $onlyMB = false)
{
    if ($onlyMB) {
        $sizes = array('B', 'kB', 'MB');
    } else {
        $sizes = array('B', 'kB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB');
    }
    if ($retstring === null) {
        $retstring = '%01.2f %s';
    }
    $lastsizestring = end($sizes);
    foreach ($sizes as $sizestring) {
        if ($size < 1024) {
            break;
        }
        if ($sizestring != $lastsizestring) {
            $size /= 1024;
        }
    }
    if ($sizestring == $sizes[0]) {
        $retstring = '%01d %s';
    }
    // Bytes aren't normally fractional
    return sprintf($retstring, $size, $sizestring);
}