Coding With Cody

Hidden Images in Email to Confirm Receipt, Part 2.5

Cody Snider — Wed, 01 Sep 2010 07:44:27 +0000

In part 1 of this series, we discussed how to track email views using an image. In part 2, we setup the tables and functions necessary to record the emails. Before we start building the reporting and campaign tracking mechanisms for step 3, we will need to adjust the code so it will be more maintainable in the future. Based on the traffic and emails I’ve received regarding this script, we are going to develop this into an easy-to-use, quick-to-deploy solution that can adapt to a variety of existing content management systems and web frameworks but still work as a standalone system.

This is simply a cleanup step and the code below is the revised version of the functionality from step 2. Please update the constants in the Config class to use this script.

Requests to this new version also have an argument change and the URL should now look like this (where ID is the id for the user that will receive the email):

http://YOUR-SITE.com/signup_complete.php?userId=ID

View Code PHP


 
// SCRIPT CONFIGURATION
class Config {
 
    const EMAIL_ADDRESS = 'you@site.com'; // YOUR EMAIL ADDRESS
 
    const SITE_DOMAIN = 'site.com'; // YOUR DOMAIN
    const IMG_PATH = '/images/email/'; // PATH TO PNG IMAGE AND TRACK.PHP
 
    const DB_HOST = 'localhost'; // YOUR DB HOST
    const DB_USERNAME = 'username'; // YOUR DB USERNAME
    const DB_PASSWORD = 'password'; // YOUR DB PASSWORD
    const DB_SCHEMA = 'database'; // YOUR DATABASE/SCHEMA NAME
 
}
 
// PRESISTENT DB CONNECT
mysql_pconnect(Config::DB_HOST, Config::DB_USERNAME, Config::DB_PASSWORD);
mysql_select_db(Config::DB_SCHEMA);
 
// USER MODEL
class User {
 
    public $id;
    public $emailAddress;
    public $status = 0; // WE'LL USE THIS AS AN ACTIVE/CAN-BE-EMAILED FLAG
 
    // STATIC METHODS
 
    public static function addUser($emailAddress) {
	$result = mysql_query('INSERT IGNORE INTO `user` SET `email_address` = "' . mysql_escape_string($emailAddress) . '";');
    }
 
    // PUBLIC METHODS
 
    public function __construct($userId){
	$this->id = $userId;
 
	if($this->fetchDetails()){
	    $this->status = 1;
	} else {
	    $this->status = 0;
	}
    }
 
    // PRIVATE METHODS
 
    private function fetchDetails(){
	$result = mysql_query('SELECT * FROM `user` WHERE `user_id` = ' . $this->id . ';');
	if(mysql_num_rows($result) == 1){
	    $row = mysql_fetch_array($result);
	    $this->emailAddress = $row['email_address'];
	    return true;
	} else {
	    return false;
	}
    }
}
 
// EMAIL MODEL
class Email {
 
    public static function send(User $user){
	if($user->status === 1){
	    $subject = 'Test email from ' . Config::SITE_DOMAIN;
	    $body = 'Test Email
 . Config::SITE_DOMAIN . Config::IMG_PATH . 'image' . $user->id . '-' . rand(0, 9999) . '.png" />';
	    $headers  = "From: " . Config::EMAIL_ADDRESS . "\r\n";
	    $headers .= "Content-type: text/html\r\n";
	    return mail($user->emailAddress, $subject, $body, $headers);
	} else {
	    return false;
	}
    }
 
}
 
$user = new User($_REQUEST['userId']);
Email::send($user);
 
?>

Hidden Images in Email to Confirm Receipt, Part 2

Cody Snider — Sat, 21 Aug 2010 12:07:12 +0000

In a previous post, we discussed how to track the viewing of an email using a 1x1px image, PHP and htaccess. Now we’ll see how to generate the ID that is associated with the email and update a database to record the action.

First, we’ll need a table to record the information. The following are two SQL queries to create the tables we need. The first query is for the table we’ll use for the tracking event and the second is a query to create the user table to identify each unique user (if you use some type of user login/account system, feel free to adjust the table parameters to work with that system):

View Code SQL

CREATE TABLE `user` (
  `user_id` int(3) NOT NULL AUTO_INCREMENT,
  `email_address` varchar(40) DEFAULT NULL,
  PRIMARY KEY (`user_id`),
  UNIQUE KEY `email` (`email_address`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8

View Code SQL

CREATE TABLE `email_tracker_event` (
  `event_id` int(3) NOT NULL AUTO_INCREMENT,
  `user_id` int(3) DEFAULT NULL,
  `event_timestamp` datetime DEFAULT NULL,
  PRIMARY KEY (`event_id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8

Next, in the document root folder for your site, add a file named signup_complete.php. This file will be the last step to your user signup form (which goes beyond the scope of this tutorial) and requires only that the user’s email address be passed as the first argument to the addUser() function we’re creating. If you are using a framework, consider adding a static method similar to this to your user model:

View Code PHP


 
mysql_connect('YOUR-DB-HOSTNAME', 'YOUR-USERNAME', 'YOUR-PASSWORD');
mysql_select_db('YOUR-DB');
 
function addUser($emailAddress){
 
    // PREPARE QUERY
    $query = 'INSERT IGNORE INTO `user` SET `email_address` = "' . mysql_escape_string($emailAddress) . '";';
 
    // EXECUTE QUERY
    $resultResource = mysql_query($query);
 
    // IF IT EXECUTED
    if($resultResource !== false){
 
	//  AND AFFECTED ONE ROW
	if(mysql_affected_rows() === 1){
 
	    // RETURN THE ID
	    return mysql_insert_id();
	} else if(mysql_affected_rows() === 0){
 
	    // OOPS! THIS ADDRESS IS ALREADY IN THE TABLE, RETURN THE ID
	    $result = mysql_query('SELECT `user_id` AS `id` FROM `user` WHERE `email_address` = "' . mysql_escape_string($emailAddress) . '";');
	    $row = mysql_fetch_array($result);
	    return $row['id'];
	}
    }
 
    // SOMETHING MUST HAVE GONE WRONG, RETURN FALSE
    return false;
}
 
function sendEmail($emailAddress, $id){
    $subject = 'Test email from your site';
    $body = 'Test Email
 . $id . '-' . rand(0, 9999) . '.png" />';
    $from = 'YOUR-EMAIL-ADDRESS';
    $headers  = "From: " . $from . "\r\n";
    $headers .= "Content-type: text/html\r\n";
 
    return mail($emailAddress, $subject, $body, $headers);
}
 
// KILL ANY REQUEST THAT HAS NEWLINE/RETURN IN THE EMAIL ADDRESS, THEY'RE TRYING TO PULL A FAST ONE ON YA
if (eregi("(\r|\n)", $_REQUEST['email'])) {
    die();
}
 
// ADD THE USER AND GET THE ID
$userId = addUser($_REQUEST['email']);
 
if($userId !== false){
    echo 'USER ID: ' . $userId;
    if(sendEmail($_REQUEST['email'], $userId)){
	echo 'Email sent!';
    } else {
	echo 'Email NOT sent!';
    };
} else {
    echo 'Something went wrong, check DB connection.';
}
 
?>

Using the following URL, this script will add a user to the user table we created earlier and return the new user’s ID. This ID is what we will use for the image to track emails from the system that they have viewed.

http://YOUR-SITE.com/signup_complete.php?email=name@site.com

Last but not least, we’ll need to modify the /images/email/track.php we created in the previous post to record the viewing of the email:

View Code PHP


 
mysql_connect('YOUR-DB-HOSTNAME', 'YOUR-USERNAME', 'YOUR-PASSWORD');
mysql_select_db('YOUR-DB');
 
$trackingNumber = $_REQUEST['x'];
mysql_query('INSERT INTO `email_tracker_event` SET `user_id` = ' . mysql_escape_string($trackingNumber) . ', `event_timestamp` = NOW();');
 
header('Content-Type:image/png');
echo file_get_contents('track.png');
 
?>

In part 3 of this tutorial series, we’ll look at how to create campaigns and reports.

UPDATE:

Part 2.5 has been posted to clean up the code above and prepare it for the next step in creating a more complex email tracking system. Please review this step before proceeding to step 3 (you can still use the code above, but we’ll be building something much more complex by the end of this series).

Hidden Images in Email to Confirm Receipt

Cody Snider — Sun, 25 Jul 2010 01:56:27 +0000

It’s a little rude to ask someone to confirm they read an email, isn’t it? Well, there’s a way to get a confirmation without them knowing it using PHP and htaccess.

First, create a directory in your images folder called ‘email’ (/images/email/ for this tutorial). Inside that folder, create an .htaccess file. Be sure that your Apache directive for AllowOverride is set to All.

In this .htaccess file, add the following:

View Code HTACCESS

RewriteEngine On
ReWriteRule ^image(.*?)\-\d{4}\.png$ track.php?x=$1 [L]

Next, create a 1x1px PNG image in the same folder and name it track.png. This will be the image loaded in the email.

Finally, in the same folder create a file named track.php and add the following:

View Code PHP


 
$trackingNumber = $_REQUEST['x'];
// logic here for updating your database tables
 
header('Content-Type:image/png');
echo file_get_contents('track.png');
 
?>

Inside the email you are sending, include the following line. This will allow the system to track the ID ’1234′ when that image is loaded. Additionally, as we are using htaccess to mask the script being used, the image will appear to be a regular PNG without any extra parameters.

View Code HTML

In part 2 of this tutorial, we’ll discuss where the ID is generated and how it is used.

Stopping Non-Essential Services on CentOS

Cody Snider — Thu, 22 Jul 2010 04:55:23 +0000

Under an out-of-the-box installation of CentOS, many services are running that are non-essential for a LAMP stack to run effectively. Running the following (either individually or as a script) will remove these services from the boot.

Original post from VPS.net

View Code BASH

#Shut down non essential services:
 
# 1. sendmail
# Purpose: sending mail, most use another
/etc/init.d/sendmail stop
chkconfig sendmail off
 
# 2. nfs
# Purpose: mount a disk from another machine
/etc/init.d/portmap stop
/etc/init.d/nfs stop
chkconfig portmap off
chkconfig nfs off
 
# 3. chargen
# Purpose: testing char generation
/etc/init.d/chargen stop
chkconfig chargen off
 
# 4. ypbind
# Purpose: stores info on NIS domains
/etc/init.d/ypbind stop
chkconfig ypbind off
 
# 5. anacron
# Purpose: cron for systems that shut down a lot
/etc/init.d/anacron stop
chkconfig anacron off
 
# 6. atd
# Purpose: at cmd daemon
/etc/init.d/atd stop
chkconfig atd off
 
# 7. routed
# Purpose: Route packets, log tables
/etc/init.d/routed stop
chkconfig routed off
 
# 8. snmpd
# Purpose: network monitoring
/etc/init.d/snmpd stop
chkconfig snmpd off
 
# 9. gpm
# Purpose: mouse
/etc/init.d/gpm stop
chkconfig gpm off
 
# 10. smartd
# Purpose: disk health monitor
/etc/init.d/smartd stop
chkconfig smartd stop
 
# 11. hidd
# Purpose: bluetooth
/etc/init.d/hidd stop
chkconfig hidd off
 
# 12. pcscf
# Purpose: smart card reader
/etc/init.d/pcscd stop
chkconfig pcscf off
 
# 13. isdn
# Purpose: digital network
/etc/init.d/isdn stop
chkconfig isdn off
 
# 14. kudzu
# Purpose: watches for new hardware
/etc/init.d/kudzu stop
chkconfig kudzu off
 
# 15. cups
# Purpose: printing
/etc/init.d/cups stop
chkconfig cups off
 
# 16. xfs
# Purpose: serves x# 1# 1 fonts
/etc/init.d/xfs stop
chkconfig xfs off
 
# 17. nfslock
# Purpose: file sys lock
/etc/init.d/nfslock stop
chkconfig nfslock off
 
# 18. canna
# Purpose: Chinese chars
/etc/init.d/canna stop
chkconfig canna off
 
# 19. freeWnn
# Purpose: Japanese chars
/etc/init.d/FreeWnn stop
chkconfig FreeWnn off
 
# 20. cups-config-daemon
# Purpose: print config
/etc/init.d/cups-config-daemon stop
chkconfig cups-config-daemon off
 
# 21. iiim
# Purpose: internet language input
/etc/init.d/iiim stop
chkconfig iiim off
 
# 22. mDNSResponder
# Purpose: dns service discovery
/etc/init.d/mDNSResponder stop
chkconfig mDNSResponder off
 
# 23. nifd
# Purpose: monitors net interfaces
/etc/init.d/nifd stop
chkconfig nifd off
 
# 24. rpcimpad
# Purpose: used for nfs server
/etc/init.d/rpcimpad stop
chkconfig rpcimpad off
 
# 25. bluetooth
# Purpose: bluetooth devices
/etc/init.d/bluetooth stop
chkconfig bluetooth off
 
# 26. saslauthd
# Purpose: handles plaintext authentication requests
/etc/init.d/saslauthd stop
chkconfig saslauthd off
Notes: some systems use this for email auth!
 
# 27. avahi-daemon
# Purpose: instant network recognition
/etc/init.d/avahi-daemon stop
chkconfig avahi-daemon off
 
# 28. avahi-dnsconfd
# Purpose: instant network recognition
/etc/init.d/avahi-dnsconfd stop
chkconfig avahi-dnsconfd off
 
# 29. sbadm
# Purpose: rapid reboot
/etc/init.d/sbadm stop
chkconfig sbadm off
 
# 30. haldaemon
# Purpose: monitors for hardware changes
/etc/init.d/haldaemon stop
chkconfig haldaemon off
 
# 31. acpi
# Purpose: sleep/hibernate control
/etc/init.d/acpi stop
chkconfig acpi off
 
# 99. gamin
# Purpose: monitors file/dir changes
/etc/init.d/gamin stop
yum -y remove gamin

Using Symbolic Links

Cody Snider — Sat, 03 Jul 2010 22:41:59 +0000

Symbolic links (symlinks) are an extremely useful tool to every system admin and web application developer. They work a lot like a shortcut in Windows. Let’s say you were working with a web application that used a framework that held all Javascript, CSS and image files in a tucked-away location (for the sake of this example, that location is /var/www/html/production/clientside/, making /var/www/html/production/clientside/js/ the location of the Javascript files). And you, the developer working on creating these Javascript, CSS and image files, wanted to use /js/somefile.js instead of a longer name like /production/clientside/js/somefile.js in your public-facing code. To do this, use the following commands:

ln -s /var/www/html/production/clientside/js/ /var/www/html/js/

ln -s /var/www/html/production/clientside/css/ /var/www/html/css/

ln -s /var/www/html/production/clientside/images/ /var/www/html/images/

Bear in mind that if you are using a framework that has pretty URL rules in the .htaccess file, you will have to make exclusions (below is the basic /var/www/html/.htaccess in our example framework):

RewriteEngine on RewriteCond $1 !^(index\.php|images|robots\.txt|css|js) RewriteRule ^(.*)$ /index.php/$1 [L]

SERPSight Testers Needed!

Cody Snider — Thu, 24 Jun 2010 09:42:48 +0000

Visit SERPSight.com for the pre-beta tests. Free automated search engine result page tracking credits for the testers (this is open to anyone). Bonus credits for anyone who can find and report an exploit in the system.

Generate Random IP with Python

Cody Snider — Mon, 17 May 2010 18:09:13 +0000

In need of an IP address on-the-fly that appears to be valid? Try this:

View Code PYTHON

from random import randrange
 
def generateIP():
    blockOne = randrange(0, 255, 1)
    blockTwo = randrange(0, 255, 1)
    blockThree = randrange(0, 255, 1)
    blockFour = randrange(0, 255, 1)
    print 'Random IP: ' + str(blockOne) + '.' + str(blockTwo) + '.' + str(blockThree) + '.' + str(blockFour)
    if blockOne == 10:
        return self.__generateRandomIP__()
    elif blockOne == 172:
        return self.__generateRandomIP__()
    elif blockOne == 192:
        return self.__generateRandomIP__()
    else:
        return str(blockOne) + '.' + str(blockTwo) + '.' + str(blockThree) + '.' + str(blockFour)

We’re skipping 10.x.x.x, 172.x.x.x and 192.x.x.x due to the fact that these are reserved address. RFC 1918

Version 2:

An elegant solution to serve the purpose of generating a random IP provided by Ben (explanation of changes listed in the comments below):

View Code PYTHON

from random import randrange
if __name__=="__main__":
    not_valid = [10,127,169,172,192]
 
    first = randrange(1,256)
    while first in not_valid:
    first = randrange(1,256)
 
    ip = ".".join([str(first),str(randrange(1,256)),
    str(randrange(1,256)),str(randrange(1,256))])
    print ip

KEI and Competition Weight

Cody Snider — Wed, 31 Mar 2010 06:54:27 +0000

Normally, simple KEI is created using the following formula where P is popularity and C is competition:

KEI = P2/C

This will get you in trouble. Not all competitors are the same and looking at just the number of indexed sites using an allintitle operator does not take this into account. For example, a football game against 10 people would seem favorable to a game against 50 people, right? Would you change your mind if you discovered those 50 people were all amputees and the 10 were Olympic athletes?

How can we know the “physical conditioning” of our search competitors without extensive evaluation of each site? I suggest using PR distribution. Take the first 20 results and lookup the PR/MR of each URL (this is easier if you are or know a programmer) and get the average PR/MR value. This should be used in the existing formula in the following fashion where PR is PR/MR:

KEI = P2/(C*PR)

This may skew things a bit, so feel free to tinker with the weight till it meets your liking as in the following example:

KEI = P2/(C(PR*.25))

Ethical SEO

Cody Snider — Sat, 06 Mar 2010 07:34:31 +0000

Google and the other big players in search all hate SEO. This is completely understandable (coming from the Director of Search Engine Optimization at a large web development firm). SEO is riddled with bad advice, grey areas and misinformation to the engines. The problem is not the profession, it’s the approach.

Let’s step into the shoes of Google. Their mission is to organize the information for the entire globe into a single query line. They want to ensure what you type into that box results in what you want to understand. That’s one hell of a goal and I’d like to see it met with quickness. The problem lies in people trying to find an easy out, be it due to pressure from a marketing team or the lack of traffic they expected off their existing “tactics” or any number of other reasons.

We are not here to fight Google. We are here to help. First off, don’t take on a client that isn’t actually an authority in their market. If they are and should be an authority in the engines, then you have something to work with.

The biggest beef I have right now is social media. I talk to who I talk (or “friend”) to for a reason. I know a lot of you talk to 2k people but only do business with 10 and this is not ethical as an internet marketing practice. Additionally, I believe the goal of Google will shut you down. There is no truth in your methodology. If you believe relevance relies in any way on the number of people you connect with, Google has a big surprise waiting for you,

Bottom line is this: The best of the engines will show relevance and a trend when it actually is a trend. Don’t underhand them or try to make it what it isn’t. Play by the rules. By helping the master (Google) understand our world, we help ourselves.

Or…keep being cheap. You won’t last (just like the link farmers of ’97, who boasted big stats 13 years ago)

Disable yum-updatesd for better performance

Cody Snider — Sat, 15 Aug 2009 05:54:10 +0000

On a base server install for Centos 5.2, yum-updatesd is included and it seems like a fairly good idea to keep that running (keeps you updated). Not so and it’s safe to disable this (kill the process and disable it from starting up in the first place.

Here’s the process, I noticed an immediate speed increase in my VPS when I disabled it (among a few other thing like avahi):

/usr/bin/python -tt /usr/sbin/yum-updatesd