php中HTTP_REFERER函数用法实例

<?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>

<?php 
$host = "www.vevb.com"; 
$referer = "http://".$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";
}

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

<?php 
$host = '127.0.0.1'; 
$target = '/2.php'; 
$referer = 'http://www.vevb.com'; //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); 
} 
?>

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