Based on their official website memcached is defined as:

Free & open source, high-performance, distributed memory object caching system, generic in nature, but intended for use in speeding up dynamic web applications by alleviating database load.

Memcached is an in-memory key-value store for small chunks of arbitrary data (strings, objects) from results of database calls, API calls, or page rendering.

Memcached is simple yet powerful. Its simple design promotes quick deployment, ease of development, and solves many problems facing large data caches. Its API is available for most popular languages.

— memcached.org

MemCached Server

This is how I installed(a simple installation) my memcached server that can be accessed by a webserver on our local area network. The server is running Ubuntu as its operating system. Caution: The version on ubuntu’s repository could not be the latest version. Refer to memcached’s website for the latest version. If you want to install the latest version from the source you can refer to memcached’s wiki page

Open synaptic package manager and install memcached and php5-memcached. After the installation restart the webserver using the command:

Start memcached by using the command:

By default memcached is running on port 11211 and is accessible by the machine with IP 127.0.0.1 which is the machine’s local IP address with 64MB memory allocation

To try if memcached is working use this simple PHP code

< ?php
$m = new Memcached();
$m->addServer('localhost', 11211);

$m->set('int', 99);
$m->set('string', 'a simple string');
$m->set('array', array(11, 12));
$m->set('object', new stdclass, time() + 300);

var_dump($m->get('int'));
var_dump($m->get('string'));
var_dump($m->get('array'));
var_dump($m->get('object'));
?>

Open the script on the browser. Try opening the cli and telnet to memcached using the command:

The image below shows how the cli would look like after the command

Check memcached’s status by using the command

We can get a cached value using the command:

It should return “a simple string” as assigned on the script.

To explore more, commands can be seen on this page http://lzone.de/articles/memcached.htm

To allow another machine (local web server) to store data on the memcached server we need to edit the configuration file using the command:

In my case I changed the allotted memory to 256MB and allowed IP of 191.168.1.254 which is our windows webserver as seen on the image below:

After the configuration I restarted memcached using the command:

The Webserver (XAMPP)

To quickly test the memcached server I used xampp portable version which can be downloaded on their official website www.apachefriends.org.

As stated earlier the webserver is already allowed to use the memcached server. As an information memcached is a daemon which runs like the mysql server, so we need PHP to connect to the memcached server.

1. To start, download memcached on code.jellycan.com/memcached which is win32 binary.
2. After downloading extract the file (recommended: C:\memcached). You should have the file memcached.exe
3. We can install memcached as a service on the command line using the command:
   C:\memcached\memcached.exe -d install
4. Start memcached using the command:
   C:\memcached\memcached.exe -d start
5. After running memcached we need to tie it with PHP using the php_memcached.dll. You should have this file on your PHP’s ext folder, if not download the file at these links http://downloads.php.net/pierre/, http://www.pureformsolutions.com/pureform.wordpress.com/2008/06/17/php_memcache.dll or on our server: php_memcached.dll.rar
6. enable the use of php_memcached.dll by editing your php.ini and uncomment the line extension=php_memcache.dll if it does not exist add this line. After editing the file restart the webserver.

You can access the data on the memcached server by using the code below:

< ?php
        $memcache = new Memcache();
        if(!$memcache->connect('191.168.1.7', 11211))
                die("Couldn't connect to memcached!");

        $key="string";

        $result = $memcache->get($key);

        if($result)
        {
                echo "$key is $result";
        }
        else
        {
            echo 'There is no data saved named '. $key;
        }
?>

You should have an output of “a simple string”. I hope this helped you set up the server. Happy coding!

Sources:

http://pureform.wordpress.com/2008/01/10/installing-memcache-on-windows-for-php/

http://memcached.org

http://blogs.oracle.com/oswald/entry/cache_cache_cache_part_1

One of the things I find hard in developing a web application is using a library for sending email such as PHPMailer. I find it hard when used to send emails. Another thing I find hard is when sending emails in a localhost webserver. It would also cost me more and would take much time in setting up my own mail server. PHP’s mail function is also very useless in such testing ground.

If you are using a gmail account and want to use PHP’s mail function in your local webserver, here is a better way to relay an email to gmail. I am using backtrack 5 Gnome and the steps will also work for debian based distros. Follow the steps below,

Install ssmtp,

After installing ssmtp, open the configuration file.

Append the configuration at the bottom

After the changes, you can now use PHP’s mail function

< ?php
$message = "This is a test";
$message = wordwrap($message, 70);
mail('icpep.org@gmail.com', 'My Subject', $message);
?>

I installed Apache, MySQL and PHP on windows 7.  I tried to install drupal version 7.9 and went through an error as shown in the image below:

The error “Your web server does not appear to support any common PDO database extensions.” can be fixed by following these steps:

1. Open your php.ini file
2. Around line 966 uncomment the line “extension=php_pdo_mysql.dll”
3. Make sure you have php_pdo_mysql.dll on your ext folder or download it here php_pdo_mysql
4. Restart Apache and you can continue with the installation of drupal

I created a web application that managers collected links.  The web application was called duplicate checker where premium links collected are being stored in a mysql database.  Previously they are doing it on an excel file which automatically highlights the duplicate entry but as months pass by the file is running so slow and so I came up to a solution which is the duplicate checker.

Its been almost 5 months and the system was running without any problem, its running on a LAMP server with slackware as the chosen distro until a time came when the system errors an insert query.  The error is Duplicate entry ’129577′ key 1‘.  I tried to check the data but there is no duplicate entry.  I search the net and found out that SQL is corrupted which happens when MyISAM is used for tables where data is constantly changing.

A better solution is not to use MyISAM for tables where the data is constantly changing
- Simon Woolf

As a solution to the problem a repair query was performed instead of renaming tables.

The table was fixed after the query and everything no is back to normal.

With millions of websites in search engines we can never be sure that the sites we are visiting are not harmful.  Some search engines like Google helps us detect websites that can cause harm to out computer.  Some search engines do not have this feature which makes us vulnerable to to exploit attacks especially for those that are webmasters.  We must always make sure that we have computer protection such as anti spyware or even the basic antivirus software which can be downloaded for free on the internet such as avast and avira.

Just like the website virus I found on some of our sites a new one existed and was not even noticed by the webmaster of the site I recently modified.  There was a script injected along the php files, as seen on the images.  I never knew how the virus got into the site, what I saw when I opened the site’s files via FTP is that there are encrypted codes along the normal pages.  I had the pages scanned and found out that the encrypted codes is a virus.  I removed the lines on the php files and in a short while it was back again.  There I found out that there are 3 files that generates the virus, 1 is the index.php which has the iframe tag as seen on the image, 2nd was the file ncoyrl.htm which has the encrypted javascript codes and lastly a gif image named zcv.gif which also plays a role.

After I deleted the files the website no longer throws a threat warning coming from an antivirus.  We must always make sure that in an online business, security is an issue.  Let a programmer or anybody that is techie enough to check free scripts downloaded online.

MySQL is proprietary and some developers are now merging to Postgre SQL.  If you are running windows you might come across this error.  I am using windows 7 ultimate and encountered this error during installation.  I solved the problem using the command

You need to navigate to where you downloaded the installer using the command prompt then you can use the command above to run the installer w/o the error

My friend forgot his mysql password and the database needs to be accessed by the root user.  My friend is running MySQL 5.1 and as I browsed the MySQL manual the solution provided is not working though a slight change was made.  Just like the provided step in the manual:

1. Log on to your system as Administrator.
2. Stop the MySQL server if it is running. For a server that is running as a Windows service, go to the Services manager: From the Start menu, select Control Panel, then Administrative Tools, then Services. Find the MySQL service in the list and stop it.If your server is not running as a service, you may need to use the Task Manager to force it to stop.
3. Create a text file containing the following statements. Replace the password with the password that you want to use.
   

   UPDATE mysql.user SET Password=PASSWORD('MyNewPass') WHERE User='root';
   FLUSH PRIVILEGES;

   
   Write the UPDATE and FLUSH statements each on a single line. The UPDATE statement resets the password for allroot accounts, and the FLUSH statement tells the server to reload the grant tables into memory so that it notices the password change.
4. Save the file. For this example, the file will be named C:\mysql.txt.
5. Open a console window to get to the command prompt: From the Start menu, select Run, then enter cmd as the command to be run.
6. mysqld –init-file=C:\\mysql.txt

I used “mysqld –init-file=C:\\mysql.txt” instead of having mysql-nt which is the command provided on the manual. After the that you have now changed the root password.  You can delete the mysql.txt file you created and you can now log in using the new account details.

On the last day of our class for the first semester, our instructor gave us an assignment about infix, postfix and prefix.  The assignment was to create a program that converts infix equations to its postfix form and prefix form.  I search around the net and the resources are so few that it took me days to have a sample program in C.  I am not that good in C programming but I can create C++ or C programs.  The code provided here may not be that well optimized and the structures may not be that perfect but it works well.  I used Visual C++ in modifying the program(yes I just modified a program):).  You can download the files here

PHP has a function date where you can specify different ways on how to display the date.  How do you generate current date and display only month and date like ‘September 2010′.  Here is a simple php howto,

<div>function curDate() {</div>
<div id="_mcePaste">return date("Y-m-d",mktime(date("h")+8, date("i"), date("s"), date("m")  , date("d"), date("Y")));</div>
<div id="_mcePaste">}</div>
<div>$now = substr(curDate(),0,7);</div>
<div>echo date("F Y", strtotime($now));</div>
<div>?&gt;</div>

The code above will simply output September 2010, a simple code that will surely help you especially when coding PHP from scratch.

Lately I have been searching  this post on the net about graphics.h in dev c++ and found few resources about it .  So I decided to write how to use graphics.h in dev-c++.  I am expecting that you have already installed bloodshed dev-cpp on your machine.  Graphics.h is a header file found in borlan c but because of its late development devcpp is now the mostly used IDE and compiler in programming c++.

Below are the steps on how to get graphics.h running on your machine,

1. download graphics.h and save it to the include folder where you installed dev-cpp (C:\Dev-Cpp\include)
2. Download libbgi.a and save it in the lib folder where you installed dev-cpp (C:\Dev-Cpp\lib)
3. So when you have to create a program that needs the use of graphics.h  you must instruct the linker to link in certain libraries by going to projects > project options > parameters tab > linker column copy the lines below and paste it on that column.

-lbgi
-lgdi32
-lcomdlg32
-luuid
-loleaut32
-lole32

By then you should be able to use graphics.h. As a sample I created this bubble sort algorithm as an example on how to use graphics.h in c++.

The program will have scattered points on the screen and will form a line as the loop iterates and at the end it will display how many loops are needed to sort the randomly generated numbers.

If you have problems using the functions you can refer to this link.  I hope this helps in solving your problem about dev c++ graphics.h with the bubble sort algorithm.