<?php
          //I haven't changed this file from it's original state to make it easier for you
          //  to skim code, please change the email addreses, I don't really want notification
          // from your test system when stuff fails... :)
          
  //Process the IPN
    //Step 0. Record the transaction
      ob_start();
      echo date("D M j G:i:s T Y") . "\n"; 
      print_r($\_SERVER);\; print\_r($_POST);
      $body\; =\; ob\_get\_clean();\; file\_put\_contents("/tmp/IPN.txt",$body, FILE_APPEND);
      
    //Step 1. Verify IPN With PayPal 
    $result=verifyIPN($_POST); 
    if ($result\; ==\; 0)\; \{$subject = "FAKE IPN RECEIVED";
      $address\; =\; "paul@preinheimer.com";$headers = 
         "From: ipn_processor@example.com\r\n" .
         "Reply-To: donotreply@example.com\r\n" .
         "X-Mailer: PHP/" . phpversion();
      mail($address,$subject, $body,$headers);
      exit;
    }else if($result\; !=\; 1)\; \{$subject = "Unable to validate IPN";
      $body\; =\; "If\; this\; is\; payment\; notification\; is\; valid\; it\; will\; need\; to\; be\; manually\; processed\backslash n$result\n $body";$address = "paul@preinheimer.com";
      $headers\; =\; "From:\; ipn\_processor@example.com\backslash r\backslash n"\; .\; "Reply-To:\; donotreply@example.com\backslash r\backslash n"\; .\; "X-Mailer:\; PHP/"\; .\; phpversion();\; mail($address, $subject,$body, $headers);\; exit;\; \}$//Step 1.5 Check payment status
    switch (_POST['payment_status']) 
    {
      case "Completed":
        break;
      case "Pending":
        paymentPendingThankYou($\_POST[\text{'}payer\_email\text{'}]);\; break;\; default:$body = "Hi, an IPN was received that wasn't a completed payment or 
          a pending payment. Please confirm this transaction against our records.";
        $body\; .=$post;
        $subject\; =\; "IPN\; Received";$address = "paul@preinheimer.com";
        $headers\; =\; "From:\; ipn\_processor@example.com\backslash r\backslash n"\; .\; "Reply-To:\; donotreply@example.com\backslash r\backslash n"\; .\; "X-Mailer:\; PHP/"\; .\; phpversion();\; mail($address, $subject,$body, $headers);\; exit;\; break;\; \}$//Step 2. Confirm Product Information
    result = confirmProduct($\_POST[\text{'}item\_number\text{'}],$_POST['item_name'],$\_POST[\text{'}payment\_gross\text{'}]);\; if\; ($result == false)
    {
      $subject\; =\; "Product\; Name/ID/Price\; mis-match";$address = "paul@preinheimer.com";
      $headers\; =\; "From:\; ipn\_processor@example.com\backslash r\backslash n"\; .\; "Reply-To:\; donotreply@example.com\backslash r\backslash n"\; .\; "X-Mailer:\; PHP/"\; .\; phpversion();\; mail($address, $subject,$body, $headers);\; exit;\; \}$//Step 3. Process the order
    subject = "VALID IPN Received";
    $address\; =\; "paul@preinheimer.com";$headers = 
     "From: ipn_processor@example.com\r\n" .
     "Reply-To: donotreply@example.com\r\n" .
     "X-Mailer: PHP/" . phpversion();
    mail($address,$subject, $body,$headers);
    file_put_contents("/tmp/IPN.txt", "\ngood ipn\n", FILE_APPEND);
    exit;
  
  function verifyIPN($data)\; \{$postdata = "";
    $response\; =\; array();\; foreach($data as $i=>$v) 
    { 
      $postdata\; .=$i . "=" . urlencode(postdata.="cmd=_notify-validate"; 
    $fp=@fsockopen("ssl:$//www.sandbox.paypal.com" ,"443",errnum,$errstr,30);$
    
    if(!fp) 
    { 
        return "$errnum:$errstr";
    } else 
    { 
      
      fputs($fp,\; "POST\; /cgi-bin/webscr\; HTTP/1.1\backslash r\backslash n");\; fputs($fp, "Host: www.sandbox.paypal.com\r\n"); 
      fputs($fp,\; "Content-type:\; application/x-www-form-urlencoded\backslash r\backslash n");\; fputs($fp, "Content-length: ".strlen($postdata)."\backslash r\backslash n");\; fputs($fp, "Connection: close\r\n\r\n"); 
      fputs($fp,$postdata . "\r\n\r\n"); 
      while(!feof($fp))\; \{$response[]=@fgets($fp,\; 1024);\; \}\; fclose($fp); 
      
    }
    $response\; =\; implode("\backslash n",$response);
    if(eregi("VERIFIED",$response))\; \{\; return\; true;\; \}else\; \{$//Remember, You're likely going to want to set this to a real location
      file_put_contents("/tmp/IPN.txt", "Failed, response", FILE_APPEND); 
      return false;
    }
  }
  
  function confirmProduct($id,$name, $amount)\; \{\; if\; (!(ctype\_digit($id) && is_numeric($amount)))\; \{\; return\; false;\; \}else\; \{$name = mysql_escape_string($name);\; \}$query = "SELECT id FROM products WHERE `id` = '$id\text{'}\; AND\; `p\_name`\; =\; \text{'}$name' AND `cost` = '$amount\text{'}\; LIMIT\; 1";\; if\; (rowCount($query) == 1)
    {
      return true; 
    }else
    {
      return false;
    }
  }
  
  function processOrder($data)\; \{\; \}\; function\; paymentPendingThankYou($address)
  {
    $subject\; =\; "Order\; Received";$body = "Thanks for your order with Example.com!\n
      This message confirms that we have received notification from
      PayPal regarding your order. However, PayPal is still processing
      your payment at this time. Once PayPal confirms that they have completed
      processing your payment we will contact you again to confirm payment and
      include shipping details.\n\n
      If you have any questions please do not hesitate to contact us at
      support@example.com.\n\n
      We apreciate your business!";
    $headers\; =\; "From:\; OrderConfirmation@example.com\backslash r\backslash n"\; .\; "Reply-To:\; support@example.com\backslash r\backslash n"\; .\; "X-Mailer:\; PHP/"\; .\; phpversion();\; mail($address, $subject,$body, $headers);\; exit;\; \}\; function\; unknownIPNReceived($post)
  {
     $body\; =\; "Hi,\; an\; IPN\; was\; received\; that\; wasn\text{'}t\; a\; completed\; payment\; or\; a\; pending\; payment.\; Please\; confirm\; this\; transaction\; against\; our\; records.";$body .= $post;$subject = "IPN Received";
     $address\; =\; "paul@preinheimer.com";$headers = 
         "From: ipn_processor@example.com\r\n" .
         "Reply-To: donotreply@example.com\r\n" .
         "X-Mailer: PHP/" . phpversion();
      mail($address,$subject, $body,$headers);
      exit;
  }
  
  function rowCount($query)\; \{\; return\; 1;\; \}\; ?>$