Common methods to prevent hotlinking in php

Today’s Internet has a lot of collection websites, and many websites like to hotlink/steal pictures from other people’s websites. This not only infringes on network rights, but also causes the websites to be hotlinked to consume a lot of traffic, giving rise to The server puts a lot of pressure on the server. This article introduces two methods on how to prevent image theft/hotlinking in PHP. Friends in need can refer to it.

What is the use of anti-hotlinking for pictures? It prevents other websites from stealing your pictures and wasting your precious traffic. This article introduces you to three methods in PHP to prevent image theft/hotlinking

1. Simple anti-hotlinking, code is as follows:

$ADMIN[defaulturl] = "http:/www.php.cn/404.htm";//盗链返回的地址 
$okaysites = array("http:/www.php.cn/","http:/www.php.cn"); //白名单 
$ADMIN[url_1] = "http:/www.php.cn/temp/download/";//下载地点1 
$ADMIN[url_2] = "";//下载地点2，以此类推 

$reffer = $HTTP_REFERER; 
if($reffer) { 
$yes = 0; 
while(list($domain, $subarray) = each($okaysites)) { 
if (ereg($subarray,"$reffer")) { 
$yes = 1; 
} 
} 
$theu = "url"."_"."$site"; 
if ($ADMIN[$theu] AND $yes == 1) { 
header("Location: $ADMIN[$theu]/$file"); 
} else { 
header("Location: $ADMIN[defaulturl]"); 
} 
} else { 
header("Location: $ADMIN[defaulturl]"); 
} 

?>

Usage method: Replace the above code Save it as dao4.php,
For example, the validatecode.rar I used for testing is in my site http://www.php.cn/temp/download,
use the following code to represent the download connection.

CODE: [Copy to clipboard]
File name?site=1&file=file

2. Server anti-hotlinking
IIS anti-hotlinking software is used. You can search it. There are many online.

3. How to prevent hotlinking when downloading software
The code is as follows:

//放置下载软件的根目录相对于当前脚本目录的相对目录 
$fileRelPath = "../../software"; 
//例外允许连接的网址，注意:自身域名不需要填入,设定为肯定可以下载, 
// 空字符串("")表示直接输入网址下载的情况 
$excludeReferArr = array(http:/www.php.cn", "php.cn"); 

chdir($fileRelPath); 
$fileRootPath = getcwd() ."/"; 

$filePath=$HTTP_GET_VARS["file"]; 

$url=parse_url($_SERVER["HTTP_REFERER"]); 

if($url[host]!=$_SERVER["HTTP_HOST"] && !in_array($referHost, $excludeReferArr)){ 
?>

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