<?php

function php_to_bytes($value)
{
  $value = trim($value);
  if (is_numeric($value)) {
    return $value;
  } else {
    $value_length = strlen($value);
    $qty = substr($value, 0, $value_length - 1);
    $unit = strtolower(substr($value, $value_length - 1));
    switch ($unit) {
    case 'k':
      $qty *= 1024;
      break;
    case 'm':
      $qty *= 1048576;
      break;
    case 'g':
      $qty *= 1073741824;
      break;
    }
    return $qty;
  }
}

function php_round($qty)
{
  if ($qty - intval($qty) != 0)
    $qty = sprintf('%.2f', $qty);
  return $qty;
}

function bytes_to_php($value)
{
  if ($value > 1073741824)
    return php_round($value / 1073741824) . 'GB';
  elseif ($value > 1048576)
    return php_round($value / 1048576) . 'MB';
  elseif ($value > 1024)
    return php_round($value / 1024) . 'KB';
  else
    return $value . 'B';
}

function upload_max_filesize($limit=false)
{
  $values = array(php_to_bytes(ini_get('upload_max_filesize')),
		  php_to_bytes(ini_get('post_max_size')),
		  php_to_bytes(ini_get('memory_limit')));
  if ($limit) $values[] = $limit;

  return min($values);
}

?>