问题
I'm asking how to convert KB MB GB TB & co. into bytes.
For example:
byteconvert("10KB") // => 10240
byteconvert("10.5KB") // => 10752
byteconvert("1GB") // => 1073741824
byteconvert("1TB") // => 1099511627776
and so on...
EDIT: wow. I've asked this question over 4 years ago. Thise kind of things really show you how much you've improved over time!
回答1:
Here's a function to achieve this:
function convertToBytes(string $from): ?int {
$units = ['B', 'KB', 'MB', 'GB', 'TB', 'PB'];
$number = substr($from, 0, -2);
$suffix = strtoupper(substr($from,-2));
//B or no suffix
if(is_numeric(substr($suffix, 0, 1))) {
return preg_replace('/[^\d]/', '', $from);
}
$exponent = array_flip($units)[$suffix] ?? null;
if($exponent === null) {
return null;
}
return $number * (1024 ** $exponent);
}
$testCases = ["13", "13B", "13KB", "10.5KB", "123Mi"];
var_dump(array_map('convertToBytes', $testCases));
Output:
array(5) { [0]=> int(13) [1]=> int(13) [2]=> int(13312) [3]=> int(10752) [4]=> NULL } int(1)
回答2:
function toByteSize($p_sFormatted) {
$aUnits = array('B'=>0, 'KB'=>1, 'MB'=>2, 'GB'=>3, 'TB'=>4, 'PB'=>5, 'EB'=>6, 'ZB'=>7, 'YB'=>8);
$sUnit = strtoupper(trim(substr($p_sFormatted, -2)));
if (intval($sUnit) !== 0) {
$sUnit = 'B';
}
if (!in_array($sUnit, array_keys($aUnits))) {
return false;
}
$iUnits = trim(substr($p_sFormatted, 0, strlen($p_sFormatted) - 2));
if (!intval($iUnits) == $iUnits) {
return false;
}
return $iUnits * pow(1024, $aUnits[$sUnit]);
}
回答3:
Here's what I've come up with so far, that I think is a much more elegant solution:
/**
* Converts a human readable file size value to a number of bytes that it
* represents. Supports the following modifiers: K, M, G and T.
* Invalid input is returned unchanged.
*
* Example:
* <code>
* $config->human2byte(10); // 10
* $config->human2byte('10b'); // 10
* $config->human2byte('10k'); // 10240
* $config->human2byte('10K'); // 10240
* $config->human2byte('10kb'); // 10240
* $config->human2byte('10Kb'); // 10240
* // and even
* $config->human2byte(' 10 KB '); // 10240
* </code>
*
* @param number|string $value
* @return number
*/
public function human2byte($value) {
return preg_replace_callback('/^\s*(\d+)\s*(?:([kmgt]?)b?)?\s*$/i', function ($m) {
switch (strtolower($m[2])) {
case 't': $m[1] *= 1024;
case 'g': $m[1] *= 1024;
case 'm': $m[1] *= 1024;
case 'k': $m[1] *= 1024;
}
return $m[1];
}, $value);
}
回答4:
I use a function to determine the memory limit set for PHP in some cron scripts that looks like:
$memoryInBytes = function ($value) {
$unit = strtolower(substr($value, -1, 1));
return (int) $value * pow(1024, array_search($unit, array(1 =>'k','m','g')));
}
A similar approach that will work better with floats and accept the two letter abbreviation would be something like:
function byteconvert($value) {
preg_match('/(.+)(.{2})$/', $value, $matches);
list($_,$value,$unit) = $matches;
return (int) ($value * pow(1024, array_search(strtolower($unit), array(1 => 'kb','mb','gb','tb'))));
}
回答5:
<?php
function byteconvert($input)
{
preg_match('/(\d+)(\w+)/', $input, $matches);
$type = strtolower($matches[2]);
switch ($type) {
case "b":
$output = $matches[1];
break;
case "kb":
$output = $matches[1]*1024;
break;
case "mb":
$output = $matches[1]*1024*1024;
break;
case "gb":
$output = $matches[1]*1024*1024*1024;
break;
case "tb":
$output = $matches[1]*1024*1024*1024;
break;
}
return $output;
}
$foo = "10mb";
echo "$foo = ".byteconvert($foo)." byte";
?>
回答6:
Wanting something similar to this and not quite liking the other solutions posted here for various reasons, I decided to write my own function:
function ConvertUserStrToBytes($str)
{
$str = trim($str);
$num = (double)$str;
if (strtoupper(substr($str, -1)) == "B") $str = substr($str, 0, -1);
switch (strtoupper(substr($str, -1)))
{
case "P": $num *= 1024;
case "T": $num *= 1024;
case "G": $num *= 1024;
case "M": $num *= 1024;
case "K": $num *= 1024;
}
return $num;
}
It adapts a few of the ideas presented here by Al Jey (whitespace handling) and John V (switch-case) but without the regex, doesn't call pow(), lets switch-case do its thing when there aren't breaks, and can handle some weird user inputs (e.g. " 123 wonderful KB " results in 125952). I'm sure there is a more optimal solution that involves fewer instructions but the code would be less clean/readable.
回答7:
One more solution (IEC):
<?php
class Filesize
{
const UNIT_PREFIXES_POWERS = [
'B' => 0,
'' => 0,
'K' => 1,
'k' => 1,
'M' => 2,
'G' => 3,
'T' => 4,
'P' => 5,
'E' => 6,
'Z' => 7,
'Y' => 8,
];
public static function humanize($size, int $precision = 2, bool $useBinaryPrefix = false)
{
$base = $useBinaryPrefix ? 1024 : 1000;
$limit = array_values(self::UNIT_PREFIXES_POWERS)[count(self::UNIT_PREFIXES_POWERS) - 1];
$power = ($_ = floor(log($size, $base))) > $limit ? $limit : $_;
$prefix = array_flip(self::UNIT_PREFIXES_POWERS)[$power];
$multiple = ($useBinaryPrefix ? strtoupper($prefix) . 'iB' : $prefix . 'B');
return round($size / pow($base, $power), $precision) . $multiple;
}
// ...
}
Source:
https://github.com/mingalevme/utils/blob/master/src/Filesize.php https://github.com/mingalevme/utils/blob/master/tests/FilesizeTest.php
回答8:
I know this is a relative old topic, but here's a function that I sometimes have to use when I need this kind of stuff; You may excuse for if the functions dont work, I wrote this for hand in a mobile:
function intobytes($bytes, $stamp = 'b') {
$indx = array_search($stamp, array('b', 'kb', 'mb', 'gb', 'tb', 'pb', 'yb'));
if ($indx > 0) {
return $bytes * pow(1024, $indx);
}
return $bytes;
}
and as compact
function intobytes($bytes, $stamp='b') {$indx=array_search($stamp,array('b','kb','mb','gb','tb','pb','yb'));if($indx > 0){return $bytes * pow(1024,$indx);} return $bytes;}
Take care!
Brodde85 ;)
来源：https://stackoverflow.com/questions/11807115/php-convert-kb-mb-gb-tb-etc-to-bytes