php中HTTP_REFERER函数用法实例

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 = '//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。