PHP simple anti-theft chain verification implementation method Original

Here we analyze the simple anti-theft chain implementation method of php. Share with you for your reference. The details are as follows:

The page is as follows:

&lt;html&gt;
&lt;head&gt;
&lt;meta http-equiv="Content-Language" content="en" /&gt;
&lt;meta name="GENERATOR" content="PHPEclipse 1.0" /&gt;
&lt;meta http-equiv="Content-Type" content="text/html; charset=gb2312" /&gt;
&lt;title&gt;Anti-theft chain&lt;/title&gt;
&lt;/head&gt;
&lt;body&gt;
 &lt;form action="" method="post"&gt;
 Submit information：&lt;input type="text" name="name" value=""/&gt;
 &lt;input type="submit" name="submit" value="submit"/&gt;
 &lt;/form&gt;
&lt;/body&gt;
&lt;/html&gt;

The page is as follows:

$urlar=parse_url($_SERVER['HTTP_REFERER']);
 print("&lt;pre&gt;");
 print_r($urlar);
 print_r($_SERVER['HTTP_REFERER']);
 if($urlar['host']!="localhost"){//This can be replaced with the currently used domain name echo "Verification error!";
 echo "&lt;script&gt;alert('Connection failed');='';&lt;/script&gt;";
 exit;
 }
 print("&lt;/pre&gt;");

I hope this article will be helpful to everyone's PHP programming.