这篇文章主要介绍了php中HTTP_REFERER函数用法,以实例的形式分别讲述了判断用户来路与伪造来路地址等应用,需要的朋友可以参考下

本文实例分析了php中HTTP_REFERER函数用法。分享给大家供大家参考。具体分析如下：

利用php的http_referer函数来判断用户的来路,这是比较简单的,实例代码如下:

<?php 
   if (isset($_SERVER['HTTP_REFERER'])) { 
     print "The page you were on previously was {$_SERVER['HTTP_REFERER']}<br />"; 
   } else { 
     print "You didn't click any links to get here<br />"; 
      } 
    ?> 
<a href="refer.php">Click me!</a>

下面是我们让用户不知道我们的来路处理,实例代码如下:

<?php 
$host = "www.jb51.net"; 
$referer = "http://".$host; 
$fp = fsockopen ($host, 80, $errno, $errstr, 30); 
if (!$fp){ 
        echo "$errstr ($errno)<br>;n"; 
}else{ 
$request = " 
GET / HTTP/1.1 
Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/vnd.ms-powerpoint, application/vnd.ms-excel, application/msword, */"."* 
Referer: http://$host 
Accept-Language: zh-cn 
Accept-Encoding: gzip, deflate 
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1) 
Host: $host 
Connection: Close" 
."rnrn"; 
 
fputs ($fp, "$request"); 
while (!feof($fp)) 
{ 
   $res[] = fgets($fp,1024); 
} 
$html = join("",$res); 
fclose ($fp); 
$fp = file_put_contents("123cha.html",$html); 
echo "done";
}

这不就行了?

不过很奇怪的是,www.jb51.net 的页面抓下来是乱码(除了http头),这是为什么?难道是因为用了gzip之类压缩?

<?php 
$host = "www.jb51.net"; 
$html = file_get_contents("http://".$host); 
$fp = file_put_contents("hao123.html",$html); 
echo "done"; 
?>;

但这样抓的就没问题,再来分析开始抓的http头:

HTTP/1.1 200 OK Date: Wed, 31 Aug 2005 00:59:36 GMT Server: Apache/1.3.27 Cache-Control: max-age=1296000 Expires: Thu, 15 Sep 2005 00:59:36 GMT Last-Modified: Mon, 29 Aug 2005 13:56:00 GMT Accept-Ranges: bytes Connection: close Content-Type: text/html Content-Encoding: gzip Content-Length: 14567

果然有这句,Content-Encoding:gzip ,原来压缩了的,长度14567字节了,用第二种方法抓,原来没压缩的html是71143字节,原来file_get_contents还可以自动解压缩.

php实例二,代码如下:

<?php 
$host = '127.0.0.1'; 
$target = '/2.php'; 
$referer = 'http://www.jb51.net'; //伪造HTTP_REFERER地址 
$fp = fsockopen($host, 80, $errno, $errstr, 30); 
if (!$fp){ 
echo "$errstr($errno)<br />n"; 
}  
else{ 
$out = " 
GET $target HTTP/1.1 
Host: $host 
Referer: $referer 
Connection: Closernrn"; 
fwrite($fp, $out); 
while (!feof($fp)){ 
echo fgets($fp, 1024); 
} 
fclose($fp); 
} 
?>

另一个2.php文件很简单,只是写上一行读取当前的HTTP_REFERER服务器值的代码即可,如下:

<?php 
echo "<hr />"; 
echo $_SERVER["HTTP_REFERER"]; 
?>

希望本文所述对大家的php程序设计有所帮助。