checkUploadSize.php

<?php
/*
	2012/05/15		taichunmin
	
	用途：
		計算出最大可用的檔案上傳大小。 ( 以設定檔中之 upload_max_filesize 和 post_max_size 來判定 )
		此函式是參考 phpMyAdmin 寫出
		
	參考：
		phpMyAdmin - phpMyAdmin\libraries\Config.class.php (checkUploadSize)
		php官方網站 - http://php.net/manual/en/function.ini-get.php
*/
	function tai_checkUploadSize_returnBytes($val)
    {
        if(empty($val))return 0;
        $val = trim($val);
        preg_match('#([0-9]+)[\s]*([a-z]+)#i', $val, $matches);
        $last = '';
        if(isset($matches[2]))
            $last = $matches[2];
        if(isset($matches[1]))
            $val = (int) $matches[1];
        switch (strtolower($last))
        {
            case 'g':
            case 'gb':
                $val *= 1024;
            case 'm':
            case 'mb':
                $val *= 1024;
            case 'k':
            case 'kb':
                $val *= 1024;
        }
        return (int) $val;
    }
	function tai_checkUploadSize()
	{
		global $cfg;
		
        if (! $filesize = ini_get('upload_max_filesize'))
            $filesize = "5M";
		if(! $postsize = ini_get('post_max_size'))
			$postsize = $filesize;
		$filesize = tai_checkUploadSize_returnBytes($filesize);
		$postsize = tai_checkUploadSize_returnBytes($postsize);
		$cfg['MAX_FILE_SIZE'] = min($filesize,$postsize);
	}
	tai_checkUploadSize();
?>