PHP filesize() 函数是什么？相信很多没有经验的人对此束手无策，为此本文总结了问题出现的原因和解决方法，通过这篇文章希望你能解决这个问题。

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

<?phpfunction 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 ($size >= 0) {//Check if it really is a small file (< 2 GB) if (fseek($file, 0, SEEK_END) === 0) {//It really is a small file fclose($file); return $size; } } //Quickly jump the first 2 GB with fseek. After that fseek is not working on 32 bit php (it uses int internally) $size = PHP_INT_MAX - 1; if (fseek($file, PHP_INT_MAX - 1) !== 0) { fclose($file); return false; } $length = 1024 * 1024; while (!feof($file)) {//Read the file until end $read = fread($file, $length); $size = bcadd($size, $length); } $size = bcsub($size, $length); $size = bcadd($size, strlen($read)); fclose($file); return $size;}

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