human readable file size

Question

function humanFileSize($size)
{
    if ($size >= 1073741824) {
      $fileSize = round($size / 1024 / 1024 / 1024,1) . 'GB';
    } elseif ($size >= 1048576) {
        $fileSize = round($size / 1024 / 1024,1) . 'MB';
    } elseif($size >= 1024) {
        $fileSize = round($size / 1024,1) . 'KB';
    } else {
        $fileSize = $size . ' bytes';
    }
    return $fileSize;
}

... works great except: I can't manually choose in what format I need to display, say i want to show in MB only whatever the file size is. Currently if its in the GB range, it would only show in GB.

Also, how do I limit the decimal to 2?

Answer 1

I'm using this method:

function byteConvert($bytes)
{
    if ($bytes == 0)
        return "0.00 B";

    $s = array('B', 'KB', 'MB', 'GB', 'TB', 'PB');
    $e = floor(log($bytes, 1024));

    return round($bytes/pow(1024, $e), 2).$s[$e];
}

works great in o(1).

Answer 2

Try something like this:

function humanFileSize($size,$unit="") {
  if( (!$unit && $size >= 1<<30) || $unit == "GB")
    return number_format($size/(1<<30),2)."GB";
  if( (!$unit && $size >= 1<<20) || $unit == "MB")
    return number_format($size/(1<<20),2)."MB";
  if( (!$unit && $size >= 1<<10) || $unit == "KB")
    return number_format($size/(1<<10),2)."KB";
  return number_format($size)." bytes";
}

Answer 3

Here is a working function managing till Yottabyte:

function DisplayFileSize($size, $unit = false, $precision = 2){

$b = $size;
$kb = round($size / 1024, $precision);
$mb = round($kb / 1024, $precision);
$gb = round($mb / 1024, $precision);
$tb = round($gb / 1024, $precision);
$pb = round($tb / 1024, $precision);
$eb = round($pb / 1024, $precision);
$zb = round($eb / 1024, $precision);
$yb = round($zb / 1024, $precision);

if((!$unit && floor($kb) == 0) || $unit == "b") {
    return array("value" => FormatNumber($b), "unit" => "bytes");
} else if((!$unit && floor($mb) == 0) || $unit == "kb") {
    return array("value" => FormatNumber($kb, 2), "unit" => "Kb");
} else if((!$unit && floor($gb) == 0) || $unit == "mb") {
    return array("value" => FormatNumber($mb, 2), "unit" => "Mb");
 } else if((!$unit && floor($tb) == 0) || $unit == "gb") {
     return array("value" => FormatNumber($gb, 2), "unit" => "Gb");
 } else if((!$unit && floor($pb) == 0) || $unit == "tb") {
     return array("value" => FormatNumber($tb, 2), "unit" => "Tb");
 } else if((!$unit && floor($eb) == 0) || $unit == "pb") {
    return array("value" => FormatNumber($pb, 2), "unit" => "Pb");
 } else if((!$unit && floor($zb) == 0) || $unit == "eb") {
     return array("value" => FormatNumber($eb, 2), "unit" => "Eb");
 } else if((!$unit && floor($yb) == 0) || $unit == "zb") {
     return array("value" => FormatNumber($zb, 2), "unit" => "Zb");
} else {
    return array("value" => FormatNumber($yb, 2), "unit" => "Yb");
}

}

Answer 4

To expand on Vaidas' answer, here's how you should do it to account for the new IEC standards:

function human_readable_bytes($bytes, $decimals = 2, $system = 'binary')
{
    $mod = ($system === 'binary') ? 1024 : 1000;

    $units = array(
        'binary' => array(
            'B',
            'KiB',
            'MiB',
            'GiB',
            'TiB',
            'PiB',
            'EiB',
            'ZiB',
            'YiB',
        ),
        'metric' => array(
            'B',
            'kB',
            'MB',
            'GB',
            'TB',
            'PB',
            'EB',
            'ZB',
            'YB',
        ),
    );

    $factor = floor((strlen($bytes) - 1) / 3);

    return sprintf("%.{$decimals}f%s", $bytes / pow($mod, $factor), $units[$system][$factor]);
}

Technically, according to the specifications for storage devices and such you should use the metric system as default (that's why Google converter shows kB -> MB as mod 1000 instead of 1024).

Answer 5

There is great example by Jeffrey Sambells:

function human_filesize($bytes, $dec = 2) 
{
    $size   = array('B', 'kB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB');
    $factor = floor((strlen($bytes) - 1) / 3);

    return sprintf("%.{$dec}f", $bytes / pow(1024, $factor)) . @$size[$factor];
}

print human_filesize(filesize('example.zip'));

Answer 6

I wanted a function that returned filesizes like Windows does, and surprisingly I could find none at all. Even worse, some here and elsewhere are broken in that they assume 1KB = 1000B.

So I coded one! Plus two helper functions. Here they are:

// Returns a size in a human-readable form from a byte count.
function humanSize($bytes)
{
    if ($bytes < 1024) return "$bytes Bytes";

    $units = ['KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];

    foreach ($units as $i => $unit)
    {
        // The reason for this threshold is to avoid e.g., "1000 KB",
        // instead jumping from e.g., "999 KB" to "0.97 MB".
        $multiplier = pow(1024, $i + 1);
        $threshold = $multiplier * 1000;

        if ($bytes < $threshold)
        {
            $size = formatToMinimumDigits($bytes / $multiplier, false);
            return "$size $unit";
        }
    }
}

// Efficiently calculates how many digits the integer portion of a number has.
function digits($number)
{
    // Yes, I could convert to string and count the characters,
    // but this is faster and cooler.
    $log = log10($number);
    if ($log < 0) return 1;
    return floor($log) + 1;
}

// Formats a number to a minimum amount of digits.
// In other words, makes sure that a number has at least $digits on it, even if
// that means introducing redundant decimal zeroes at the end, or rounding the
// ones present exceeding the $digits count when combined with the integers.
// For example:
//     formatToMinimumDigits(10)           // 10.0
//     formatToMinimumDigits(1.1)          // 1.10
//     formatToMinimumDigits(12.34)        // 12.3
//     formatToMinimumDigits(1.234)        // 1.23
//     formatToMinimumDigits(1.203)        // 1.20
//     formatToMinimumDigits(123.4)        // 123
//     formatToMinimumDigits(100)          // 100
//     formatToMinimumDigits(1000)         // 1000
//     formatToMinimumDigits(1)            // 1.00
//     formatToMinimumDigits(1.002)        // 1.00
//     formatToMinimumDigits(1.005)        // 1.01
//     formatToMinimumDigits(1.005, false) // 1.00
// This is primarily useful for generating human-friendly numbers.
function formatToMinimumDigits($value, $round = true, $digits = 3)
{
    $integers = floor($value);

    $decimalsNeeded = $digits - digits($integers);

    if ($decimalsNeeded < 1)
    {
        return $integers;
    }
    else
    {
        if ($round)
        {
            // This relies on implicit type casting of float to string.
            $parts = explode('.', round($value, $decimalsNeeded));
            // We re-declare the integers because they may change
            // after we round the number.
            $integers = $parts[0];
        }
        else
        {
            // Again, implicit type cast to string.
            $parts = explode('.', $value);
        }

        // And because of the implicit type cast, we must guard against
        // 1.00 becoming 1, thus not exploding the second half of it.
        $decimals = isset($parts[1]) ? $parts[1] : '0';
        $joined = "$integers.$decimals".str_repeat('0', $digits);
        return substr($joined, 0, $digits + 1);
    }
}

Usage is as simple as humanSize(123456789).