Implementation of two kinds of file downloads in php

1. Directly add file links

<button> <a href = "http://localhost/down.zip"> 下载文件 </button>

2. Pass parameters to find and jump to the download link

Pass parameters:

<button>
    <a href = "http://localhost?f='down'">
    下载文件
</button>

Find the file and challenge to the download link:

<?php

$down = $_GET['f'];   //获取文件参数
$filename = $down.'.zip'; //获取文件名称
$dir ="down/";  //相对于网站根目录的下载目录路径
$down_host = $_SERVER['HTTP_HOST'].'/'; //当前域名

//判断如果文件存在,则跳转到下载路径
if(file_exists(__DIR__.'/'.$dir.$filename)){
    header('location:http://'.$down_host.$dir.$filename);
}else{
    header('HTTP/1.1 404 Not Found');
}