我开发了自己的功能，将人类可读的内存大小转换为不同的大小。

function convertMemorySize($strval, string $to_unit = 'b')
{
    $strval    = strtolower(str_replace(' ', '', $strval));
    $val       = floatval($strval);
    $to_unit   = strtolower(trim($to_unit))[0];
    $from_unit = str_replace($val, '', $strval);
    $from_unit = empty($from_unit) ? 'b' : trim($from_unit)[0];
    $units     = 'kmgtph';  // (k)ilobyte, (m)egabyte, (g)igabyte and so on...


    // Convert to bytes
    if ($from_unit !== 'b')
        $val *= 1024 ** (strpos($units, $from_unit) + 1);


    // Convert to unit
    if ($to_unit !== 'b')
        $val /= 1024 ** (strpos($units, $to_unit) + 1);


    return $val;
}


convertMemorySize('1024Kb', 'Mb');  // 1
convertMemorySize('1024', 'k')      // 1
convertMemorySize('5.2Mb', 'b')     // 5452595.2
convertMemorySize('10 kilobytes', 'bytes') // 10240
convertMemorySize(2048, 'k')        // By default convert from bytes, result is 2

这个函数接受任何内存大小的缩写，比如“Megabyte, MB, MB, MB, m, kilobyte, K, KB, b, Terabyte, T....”，所以它是拼写安全的。

如果需要短代码，请使用此函数

BCDIV（）

$size = 11485760;
echo bcdiv($size, 1048576, 0); // return: 10

echo bcdiv($size, 1048576, 2); // return: 10,9

echo bcdiv($size, 1048576, 2); // return: 10,95

echo bcdiv($size, 1048576, 3); // return: 10,953

下面是Drupal format_size函数的简化实现:

/**
 * Generates a string representation for the given byte count.
 *
 * @param $size
 *   A size in bytes.
 *
 * @return
 *   A string representation of the size.
 */
function format_size($size) {
  if ($size < 1024) {
    return $size . ' B';
  }
  else {
    $size = $size / 1024;
    $units = ['KB', 'MB', 'GB', 'TB'];
    foreach ($units as $unit) {
      if (round($size, 2) >= 1024) {
        $size = $size / 1024;
      }
      else {
        break;
      }
    }
    return round($size, 2) . ' ' . $unit;
  }
}

我的方法

    function file_format_size($bytes, $decimals = 2) {
  $unit_list = array('B', 'KB', 'MB', 'GB', 'PB');

  if ($bytes == 0) {
    return $bytes . ' ' . $unit_list[0];
  }

  $unit_count = count($unit_list);
  for ($i = $unit_count - 1; $i >= 0; $i--) {
    $power = $i * 10;
    if (($bytes >> $power) >= 1)
      return round($bytes / (1 << $power), $decimals) . ' ' . $unit_list[$i];
  }
}

function byte_format($size) {
    $bytes = array( ' KB', ' MB', ' GB', ' TB' );
    foreach ($bytes as $val) {
        if (1024 <= $size) {
            $size = $size / 1024;
            continue;
        }
        break;
    }
    return round( $size, 1 ) . $val;
}

function convertToReadableSize($size)
{
  $base = log($size) / log(1024);
  $suffix = array("B", "KB", "MB", "GB", "TB");
  $f_base = floor($base);
  return round(pow(1024, $base - floor($base)), 1) . $suffix[$f_base];
}

只需要调用函数

echo convertToReadableSize(1024); // Outputs '1KB'
echo convertToReadableSize(1024 * 1024); // Outputs '1MB'