Method bytes

/**
 * Converts bytes to more distinguishable formats such as:
 * kilobytes, megabytes, etc.
 *
 * By default, the proper format will automatically be chosen.
 * However, one of the allowed unit types (viz. 'b', 'kB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB') may also be used instead.
 * IEC standard unit types ('KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB') can be used as well.
 *
 * @param   string   $bytes      The number of bytes. Can be either numeric or suffixed format: 32M, 60K, 12G or 812b
 * @param   string   $unit       The type of unit to return, few special values are:
 *                               Blank string '' for no unit,
 *                               'auto' to choose automatically (default)
 *                               'binary' to choose automatically but use binary unit prefix
 * @param   integer  $precision  The number of digits to be used after the decimal place.
 * @param   bool     $iec        Whether to be aware of IEC standards. IEC prefixes are always acceptable in input.
 *                               When IEC is ON:  KiB = 1024 B, KB = 1000 B
 *                               When IEC is OFF: KiB = 1024 B, KB = 1024 B
 *
 * @return  string   The number of bytes in the proper units.
 *
 * @since   1.6
 * @link    https://en.wikipedia.org/wiki/Binary_prefix
 */
public static function bytes($bytes, $unit = 'auto', $precision = 2, $iec = false)
{
    /*
     * Allowed 123.45, 123.45 M, 123.45 Mi, 123.45 MB, 123.45 MiB, 1.2345E+12MB, 1.2345E+12 MB , 1.2345E+12 MiB etc.
     * Meaning any number in decimal digits or in sci. notation, optional space, optional 1-3 letter unit suffix
     */
    if (is_numeric($bytes)) {
        $oBytes = $bytes;
    } else {
        preg_match('/(.*?)\\s?((?:[KMGTPEZY]i?)?B?)$/i', trim($bytes), $matches);
        list(, $oBytes, $oUnit) = $matches;
        if ($oUnit && is_numeric($oBytes)) {
            $oBase = $iec && strpos($oUnit, 'i') === false ? 1000 : 1024;
            $factor = pow($oBase, stripos('BKMGTPEZY', $oUnit[0]));
            $oBytes *= $factor;
        }
    }
    if (empty($oBytes) || !is_numeric($oBytes)) {
        return 0;
    }
    $oBytes = round($oBytes);
    // If no unit is requested return early
    if ($unit === '') {
        return (string) $oBytes;
    }
    $stdSuffixes = array('b', 'kB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB');
    $iecSuffixes = array('b', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB');
    // User supplied method
    if (in_array($unit, $iecSuffixes)) {
        $base = 1024;
        $i = array_search($unit, $iecSuffixes, true);
        $suffix = $unit;
    } elseif (in_array($unit, $stdSuffixes)) {
        $base = $iec ? 1000 : 1024;
        $i = array_search($unit, $stdSuffixes, true);
        $suffix = $unit;
    } elseif ($unit === 'binary') {
        $base = 1024;
        $i = (int) floor(log($oBytes, $base));
        $suffix = $iecSuffixes[$i];
    } else {
        // Default method
        $base = $iec ? 1000 : 1024;
        $i = (int) floor(log($oBytes, $base));
        $suffix = $stdSuffixes[$i];
    }
    return number_format(round($oBytes / pow($base, $i), (int) $precision), (int) $precision, Text::_('DECIMALS_SEPARATOR'), Text::_('THOUSANDS_SEPARATOR')) . ' ' . $suffix;
}