/system/helpers/download_helper.php CI下载助手

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package		CodeIgniter
 * @author		ExpressionEngine Dev Team
 * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license		http://codeigniter.com/user_guide/license.html
 * @link		http://codeigniter.com
 * @since		Version 1.0
 * @filesource
 */

// ------------------------------------------------------------------------

/**
 * CodeIgniter Download Helpers
 * CI下载助手
 * 
 * @package		CodeIgniter
 * @subpackage	Helpers
 * @category	Helpers
 * @author		ExpressionEngine Dev Team
 * @link		http://codeigniter.com/user_guide/helpers/download_helper.html
 */

// ------------------------------------------------------------------------

/**
 * Force Download
 * 强制下载
 * Generates headers that force a download to happen
 * 生成头发生强制下载
 * @access	public
 * @param	string	filename
 * @param	mixed	the data to be downloaded
 * @return	void 
 * force_download()
 */
if ( ! function_exists('force_download'))
{
	function force_download($filename = '', $data = '')
	{
		if ($filename == '' OR $data == '')
		{
			return FALSE;
		}

		// Try to determine if the filename includes a file extension.
		// We need it in order to set the MIME type
		// 尝试来确定，如果文件名中包含文件扩展名。
		// 我们需要它以设置的MIME类型
		
        //如果文件没有扩展名，直接返回空
		if (FALSE === strpos($filename, '.'))
		{
			return FALSE;
		}

		// Grab the file extension 获取文件的扩展名
		$x = explode('.', $filename);
		$extension = end($x);

		// Load the mime types 加载MIME类型
		if (defined('ENVIRONMENT') AND is_file(APPPATH.'config/'.ENVIRONMENT.'/mimes.php'))
		{
			include(APPPATH.'config/'.ENVIRONMENT.'/mimes.php');
		}
		elseif (is_file(APPPATH.'config/mimes.php'))
		{
			include(APPPATH.'config/mimes.php');
		}

		// Set a default mime if we can't find it
		// 设置一个默认的哑剧，如果我们不能找到它
		if ( ! isset($mimes[$extension]))
		{
			$mime = 'application/octet-stream';
		}
		else
		{
			$mime = (is_array($mimes[$extension])) ? $mimes[$extension][0] : $mimes[$extension];
		}

		// Generate the server headers 生成服务器头
		if (strpos($_SERVER['HTTP_USER_AGENT'], "MSIE") !== FALSE)
		{
			header('Content-Type: "'.$mime.'"');
			header('Content-Disposition: attachment; filename="'.$filename.'"');
			header('Expires: 0');
			header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
			header("Content-Transfer-Encoding: binary");
			header('Pragma: public');
			header("Content-Length: ".strlen($data));
		}
		else
		{
			header('Content-Type: "'.$mime.'"');
			header('Content-Disposition: attachment; filename="'.$filename.'"');
			header("Content-Transfer-Encoding: binary");
			header('Expires: 0');
			header('Pragma: no-cache');
			header("Content-Length: ".strlen($data));
		}

		exit($data);
	}
}


/* End of file download_helper.php */
/* Location: ./system/helpers/download_helper.php */