<?php

	header("Content-type=html/text;charset=utf-8");

 	function download($file_name,$file_sub_dir)

	{

		$file_name = iconv("utf-8","gb2312",$file_name);

		$file_path = $_SERVER['DOCUMENT_ROOT'].$file_sub_dir.$file_name;

		if(!file_exists($file_path))

		{

			echo "文件不存在";

			return;

		}

		$fp = fopen($file_path,"rb");

		$file_size = filesize($file_path);

		header("Content-type: application/octet-stream");

		header("Accept-Ranges: bytes");

		header("Accept-Length: $file_size");

		header("Content-Disposition: attachment;filename=".$file_name);

		$buffer = 1024;

		$file_count = 0;

		while(!feof($fp) && $file_size-$file_count>0)

		{

			$file_data = fread($fp,$buffer);

			$file_count+=$buffer;

			echo $file_data;

		}

		fclose($fp);

	}

	download("picture1.jpg","/txt/");

?>