php header()函数实现文件下载的实例

/**
* 文件下载
**/
header("Content-type:text/html;charset=utf-8");
download('web/genban.txt', 'txt文件下载');
function download($file, $down_name){
$suffix = substr($file,strrpos($file,'.')); //获取文件后缀
$down_name = $down_name.$suffix; //新文件名，就是下载后的名字
//判断给定的文件存在与否
if(!file_exists($file)){
die("您要下载的文件已不存在，可能是被删除");
}
$fp = fopen($file,"r");
$file_size = filesize($file);
//下载文件需要用到的头
header("Content-type: application/octet-stream");
header("Accept-Ranges: bytes");
header("Accept-Length:".$file_size);
header("Content-Disposition: attachment; filename=".$down_name);
$buffer = 1024;
$file_count = 0;
//向浏览器返回数据
while(!feof($fp) && $file_count < $file_size){
$file_con = fread($fp,$buffer);
$file_count = $buffer;
echo $file_con;
}
fclose($fp);
}
?>