function downserver($file_name){


$file_path = “./img/”.$file_name;


//转码，文件名转为gb2312解决中文乱码


$file_name = iconv(“utf-8″,”gb2312”,$file_name);


$file_path = iconv(“utf-8″,”gb2312”,$file_path);


$fp = fopen($file_path,”r”) or exit(“文件不存在”);


//定义变量空着每次下载的大小


$buffer = 1024;


//得到文件的大小


$file_size = filesize($file_path);


//header(“Content-type:text/html;charset=gb2312”);


//会写用到的四条http协议信息


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


header(“Accept-Ranges:bytes”);//可以忽略


header(“Content-Length: “.$file_size);//原文这里是Accept-Length经查阅http协议无此项


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


//字节技术器，纪录当前现在字节数


$count = 0;


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


//从$fp打开的文件流中每次读取$buffer大小的数据


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


$count+=$buffer;


//将读取到的数据读取出来


echo $file_data;


}


//关闭文件流


fclose($fp);


    }

   }


?>