Smarty Modifier: readable_filesize - displays a filesize in an easier to read format/ best units available.

modifier.readable_filesize.php

<?php
/**
 * Smarty plugin
 *
 * @package App
 * @subpackage SmartyPluginsModifier
 */

/**
 * Smarty number modifier
 *
 * Type:     modifier
 * Name:     readable_filesize
 * Purpose:  allows you to present a filesize in the best possible units
 * Useage:   {$nFilesize|readable_filesize}  or by specifiying a unit {$nFilesize|readable_filesize:'MB'}
 *
 * @link
 * @author Tim Swann <https://github.com/faffyman/>
 * @param int $nFilesize
 * @param string $sUnits preferred units specified  'KB','MB','GB' This will over-ride the default
 * @param int $decimals number of decimal places to work to.
 * @return string
 */
function smarty_modifier_readable_filesize($nFilesize, $sUnits=null, $decimals = null)
{


    // if user specified bytes just return the same number input
    if($sUnits=='KB') {
      return number_format($nFilesize, $decimals) . ' KB';
    }



    $aAllowedUnits =  array('KB','MB','GB','TB','PB','EB','ZB','YB');


    if ( empty($sUnits) || !in_array($sUnits, $aAllowedUnits )) {

      if ($nFilesize < 1000) {
        return $nFilesize . ' KB';
      } else {

        //$nFilesize = $nFilesize / 1024;

        if ($nFilesize < 1024) {
          $decimals = is_null($decimals) || !is_numeric($decimals) ? 0 : intval($decimals);
          return number_format($nFilesize, $decimals) . ' KB';
        } else {

          if ($nFilesize < pow(1024,2) ) {
            $decimals = is_null($decimals) || !is_numeric($decimals) ? 2 : intval($decimals);
            $nFilesize = $nFilesize / 1024;
            return number_format($nFilesize, $decimals) . ' MB';
          } else {
            $decimals = is_null($decimals) || !is_numeric($decimals) ? 2 : intval($decimals);
            $nFilesize = $nFilesize / pow(1024,2);
            return number_format($nFilesize, $decimals) . ' GB';
          }

        }

      }
    } else {
      switch ($sUnits) {
        // DEFAULT IS KB
      	case 'KB':
      		$nDivideBy = 1;
      		break;
      	case 'MB':
      	  $nDivideBy = 1024;
      	  break;
      	case 'GB':
      	  //$nDivideBy = 1024 * 1024 * 1024;
      	  $nDivideBy = pow(1024,2);
      	  break;
      	case 'TB':
      	  //$nDivideBy = 1024 * 1024 * 1024 * 1024;
      	  $nDivideBy = pow(1024,3);
      	  break;
      	case 'PB':
      	  //$nDivideBy = 1024 * 1024 * 1024 * 1024 * 1024;
      	  $nDivideBy = pow(1024,4);
      	  break;
      	case 'EB':
      	  //$nDivideBy = 1024 * 1024 * 1024 * 1024 * 1024 * 1024;
      	  $nDivideBy = pow(1024,5);
      	  break;
      	case 'ZB':
      	  //$nDivideBy = 1024 * 1024 * 1024 * 1024 * 1024 * 1024 * 1024;
      	  $nDivideBy = pow(1024,6);
      	  break;
      	case 'YB':
      	  //$nDivideBy = 1024 * 1024 * 1024 * 1024 * 1024 * 1024 * 1024 * 1024;
      	  $nDivideBy = pow(1024,7);
      	  break;
      	default:
      	  $nDivideBy = 1;
      		break;
      }

      $decimals = is_null($decimals) || !is_numeric($decimals) ? 2 : intval($decimals);

      $nFilesize = $nFilesize / $nDivideBy;
      return number_format($nFilesize, $decimals) . $sUnits;

    }

  }