filesize
作用：函数返回指定文件的大小
语法：
filesize(filename)
参数：
filename：必需。规定要检查的文件。
返回值：
返回文件大小的字节数，如果出错返回 FALSE 并生成一条 E_WARNING 级的错误。
filesize 示例
示例一
<?php // 输出类似：somefile.txt: 1024 bytes $filename = 'somefile.txt'; echo $filename . ': ' . filesize($filename) . ' bytes'; ?>
示例二
<?php function human_filesize($bytes, $decimals = 2) {
$sz = 'BKMGTP';
$factor = floor((strlen($bytes) - 1) / 3);
return sprintf("%.{$decimals}f", $bytes / pow(1024, $factor)) . @$sz[$factor];
}
?>
示例三
<?php /**
* Converts bytes into human readable file size.
*
* @param string $bytes
* @return string human readable file size (2,87 Мб)
* @author Mogilev Arseny
*/
function FileSizeConvert($bytes)
{
$bytes = floatval($bytes);
$arBytes = array(
0 => array(
"UNIT" => "TB",
"VALUE" => pow(1024, 4)
),
1 => array(
"UNIT" => "GB",
"VALUE" => pow(1024, 3)
),
2 => array(
"UNIT" => "MB",
"VALUE" => pow(1024, 2)
),
3 => array(
"UNIT" => "KB",
"VALUE" => 1024
),
4 => array(
"UNIT" => "B",
"VALUE" => 1
),
);
foreach($arBytes as $arItem)
{
if($bytes >= $arItem["VALUE"])
{
$result = $bytes / $arItem["VALUE"];
$result = str_replace(".", "," , strval(round($result, 2)))." ".$arItem["UNIT"];
break;
}
}
return $result;
}
?>
示例四
<?php /**
* Return file size (even for file > 2 Gb)
* For file size over PHP_INT_MAX (2 147 483 647), PHP filesize function loops from -PHP_INT_MAX to PHP_INT_MAX.
*
* @param string $path Path of the file
* @return mixed File size or false if error
*/
function realFileSize($path)
{
if (!file_exists($path))
return false;
$size = filesize($path);
if (!($file = fopen($path, 'rb')))
return false;
if ($size >= 0)
{//Check if it really is a small file (<p>推荐教程：《<a href="https://www.php.cn/php-weizijiaocheng.html" target="_blank">PHP</a>》<br></p>
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