Size Readable

<?php
/**
* Return human readable sizes
*
* @author      Aidan Lister <[email protected]>
* @version     1.1.0
* @link        http://aidanlister.com/repos/v/function.size_readable.php
* @param       int    $size        Size
* @param       int    $unit        The maximum unit
* @param       int    $retstring   The return string format
* @param       int    $si          Whether to use SI prefixes
*/
function size_readable($size, $unit = null, $retstring = null, $si = true)
{
	// Units
	if ($si === true) {
		$sizes = array('B', 'kB', 'MB', 'GB', 'TB', 'PB');
		$mod   = 1000;
	} else {
		$sizes = array('B', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB');
		$mod   = 1024;
	}
	$ii = count($sizes) - 1;
 
	// Max unit
	$unit = array_search((string) $unit, $sizes);
	if ($unit === null || $unit === false) {
		$unit = $ii;
	}
 
	// Return string
	if ($retstring === null) {
		$retstring = '%01.2f %s';
	}
 
	// Loop
	$i = 0;
	while ($unit != $i && $size >= 1024 && $i < $ii) {
		$size /= $mod;
		$i++;
	}
 
	return sprintf($retstring, $size, $sizes[$i]);
}
 
?>