A Tech Blog about PHP, Javascript, JQuery, Phone Unlocks, Apps and IT Service Management

How to create a virtual host in ubuntu?

2013-06-10T15:25:00.001+01:00

When you are used to running your websites in windows envirnment, it can be a bit of pain to suddenly switch in to linux. This post will guide you towards setting up a virtual host in ubuntu.

1. Enable the virual host module and restart apache.

      sudo a2enmod vhost_alias
      sudo /etc/init.d/apache2 restart

2. Goto to /etc/apache2/sites-available directory and create a copy of the default file with the name of the virtual host you would like to create. In this case the virutal host is "my-first-host.com".

      cd /etc/apache2/sites-available/
      sudo cp default my-first-host.com

3. Customize the my-first-host.com file and point the target folder to your content directory. If the content directory is /var/www/first_host, the file will has to look something like this:

<VirtualHost *:80>
    ServerAdmin webmaster@localhost

    DocumentRoot /var/www/first_host
    <Directory />
        Options FollowSymLinks
        AllowOverride None
    </Directory>
    <Directory /var/www/first_host/>
        Options Indexes FollowSymLinks MultiViews
        AllowOverride None
        Order allow,deny
        allow from all
    </Directory>

    ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
    <Directory "/usr/lib/cgi-bin">
        AllowOverride None
        Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
        Order allow,deny
        Allow from all
    </Directory>

    ErrorLog /var/log/apache2/error.log

    # Possible values include: debug, info, notice, warn, error, crit,
    # alert, emerg.
    LogLevel warn

    CustomLog /var/log/apache2/access.log combined

    Alias /doc/ "/usr/share/doc/"
    <Directory "/usr/share/doc/">
        Options Indexes MultiViews FollowSymLinks
        AllowOverride None
        Order deny,allow
        Deny from all
        Allow from 127.0.0.0/255.0.0.0 ::1/128
    </Directory>

</VirtualHost>

4. Enable the virtual host setup file and reload apache.

   sudo a2ensite my-first-host.com
   sudo /etc/init.d/apache2 reload

5. You are almost done now. The only thing left is point your virtual site to the right IP address. In this case you will need to point it to your local IP which is 127.0.0.1. Edit the /etc/hosts file by typing

sudo gedit /etc/hosts

6. Add the IP 127.0.0.1 to your virtual site you have created. The file should look like below:

127.0.0.1   localhost
127.0.0.1   my-first-host.com
127.0.1.1   manishpc-vm

# The following lines are desirable for IPv6 capable hosts
::1     localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts

7. Finally restart apache and you are done.

sudo /etc/init.d/apache2 restart

Enjoy your virtual host :)

How to enable mod_rewrite in ubuntu?

2012-10-16T10:14:00.001+01:00

Simply run the following command in the command line to enable mod_rewrite.

sudo a2enmod rewrite

The command simply adds the rewrite module to the apache configuration file as mod_rewrite is a part of apache. Now we need to restart apache to make the command take effect.

sudo /etc/init.d/apache2 restart

The command automatically adds file rewrite.load to the folder /etc/apache2/mods-enabled/

How to enable curl in PHP ubuntu?

2012-10-16T10:02:00.002+01:00

To enable curl in PHP in ubuntu we simply need to install it. The following command can be used to install curl in ubuntu.

sudo apt-get install php5-curl

Now the next step would be restart apache using the following command

sudo /etc/init.d/apache2 restart

Enjoy!

Getting latitude, longitude, timezone using ip address.

2012-04-18T15:51:00.001+01:00

This is a post to find the latitude, longitude, timezone, country, city and so on using the web services/api by ipinfodb. The ipinfodb provides api in both xml and json format. We can use either of them. I will show you how to use it for both formats.

Using XML format:

You can either register for api key from ipinfodb. I am using mine in this example.

$key="9dcde915a1a065fbaf14165f00fcc0461b8d0a6b43889614e8acdb8343e2cf15";
$ip= "208.115.219.10";

$url = "http://api.ipinfodb.com/v3/ip-city/?key=$key&ip=$ip&format=xml";

// load xml file
$xml = simplexml_load_file($url);
// print the name of the first element
echo $xml->getName() . "<br />";
// create a loop to print the element name and data for each node
foreach($xml->children() as $child)
{
echo $child->getName() . ": " . $child . "<br />";
}

Output

Response
statusCode: OK
statusMessage:
ipAddress: 208.115.219.10
countryCode: US
countryName: UNITED STATES
regionName: NEW JERSEY
cityName: FLEMINGTON
zipCode: 08822
latitude: 40.5207
longitude: -74.8671
timeZone: -05:00

Using JSON format

$key="9dcde915a1a065fbaf14165f00fcc0461b8d0a6b43889614e8acdb8343e2cf15";
$ip=$_POST['address'];

$url = "http://api.ipinfodb.com/v3/ip-city/?key=$key&ip=$ip&format=json";

$cont = file_get_contents($url);
$data = json_decode($cont , true);

if(strlen($data['latitude']))
    {
    $result = array(
        'ip' => $data['ipAddress'] ,
        'country_code' => $data['countryCode'] ,
        'country_name' => $data['countryName'] ,
        'region_name' => $data['regionName'] ,
        'city' => $data['cityName'] ,
        'zip_code' => $data['zipCode'] ,
        'latitude' => $data['latitude'] ,
        'longitude' => $data['longitude'] ,
        'time_zone' => $data['timeZone'] ,
    );
    }
    print_r($result);

Output

Array ( [ip] => 208.115.219.10 [country_code] => US [country_name] => UNITED STATES [region_name] => NEW JERSEY [city] => FLEMINGTON [zip_code] => 08822 [latitude] => 40.5207 [longitude] => -74.8671 [time_zone] => -05:00 )

How to parse a XML file using SimpleXML in PHP5?

2012-04-08T14:32:00.003+01:00

SimpleXML is a very simple function introduced in PHP5 to parse a XML file. It is very simple to use and implement as compared to other bulky codes to parse a XML file. The steps are pretty simple. Let us use a simple XML file as below naming it as xmltest.xml.

<?xml version="1.0" encoding="UTF-8"?><Response>

<countryName>UNITED STATES</countryName>

<regionName>GEORGIA</regionName>

<cityName>ATLANTA</cityName>

</Response>

Now you can use the following php code to parse the above xmltest.xml file.

<?php

// load xml file
$xml = simplexml_load_file("xmltest.xml");
// print the name of the first element
echo $xml->getName() . "<br />";
// create a loop to print the element name and data for each node
foreach($xml->children() as $child)
{
echo $child->getName() . ": " . $child . "<br />";
}
?>

The above code will print the output as follows:

Response
statusCode: OK
statusMessage:
ipAddress: 173.200.52.93
countryCode: US
countryName: UNITED STATES
regionName: GEORGIA
cityName: ATLANTA
zipCode: 30339
latitude: 33.809
longitude: -84.3548
timeZone: -05:00

Changing file permissions of a folder and all of its subfolders and files in Ubuntu.

2012-03-30T16:41:00.000+01:00

Changing file permissions in Ubuntu is a very essential thing. If proper file permissions are not set to folders or files, it is not possible to execute any PHP or HTML files from the browser using localhost. The following command can be used to set file permission for any file or folder.

sudo chmod 755 /var/www/myfolder

In the above example

7 – Owner(current user)
5 – Group(set by owner)
5 – anyone else

To change the file permission for all the files and subfolders inside a folder the following command can be used:

sudo chmod 755 -R /var/www/myfolder

0 – no permission, this person cannot read, write or execute
1 – execute only
2 – write only
3 – execute and write only (1 + 2)
4 – read only
5 – execute and read only (1 + 4)
6 – write and read only (2 + 4)
7 – execute, write and read (1 + 2 + 3)

How to fix "url /phpmyadmin was not found in this server" problem in Ubuntu (linux)?

2012-03-28T16:03:00.000+01:00

Sometimes after installing LAMP, when you try to open the phpmyadmin in your browser you might get the error like this:
"Not Found
The requested URL /phpMyAdmin was not found on this server.
Apache/2.2.12 (Ubuntu) Server at localhost Port 80"

This is likely to be caused by not checking apache2 during installation. To reinstall you can use the following command:

sudo dpkg-reconfigure -plow phpmyadmin

If the above code does not work you can include the phpMyadmin-shipped Apache configuration into Apache using the command below:

sudo ln -s /etc/phpmyadmin/apache.conf /etc/apache2/conf.d/phpmyadmin.conf
sudo /etc/init.d/apache2 reload

How to install LAMP in Ubuntu (linux)

2012-03-17T13:56:00.002+00:00

LAMP stands for Linux, Apache, MySQL and PHP/Python. Installing and configuring LAMP is not a very complicated thing in Ubuntu, its just a matter of few lines of commands via the command line. This post will show you how to install PHP5, Apache2, MySQL and phpMyAdmin in Ubuntu.

Installing Apache

1. Open the terminal and type the following command.

sudo apt-get install apache2

2. Type the password when asked and press enter key.
3. To test if apache is installed in your system or not. Open the browser and type localhost. If you see a message saying "it works" then its installed.

Installing PHP5

1. Open the terminal and type the following command.

sudo apt-get install php5 libapache2-mod-php5

2. Restart apache by typing the following command.

sudo /etc/init.d/apache2 restart

3. Now test if PHP is installed in your system or not. Type the following command in the terminal to edit a PHP file.

sudo gedit /var/www/myfirstphp.php

4. Type the following code in the editor and save it.

<?php echo "hello world";?>

5. Open the browser and type the following URL.

http://localhost/myfirstphp.php

6. If it displays hello world then it works.

Installing MySQL

1. Open the terminal and type the following command.

sudo apt-get install mysql-server

2. It will ask you for the MySQL password. Enter and remember the password. You can change the password by typing the following command.

mysql -u root

mysql> SET PASSWORD FOR 'root'@'localhost' = PASSWORD('yourpassword');

Installing phpMyAdmin

1. Type the following command in the terminal to instal phpMyAdmin.

sudo apt-get install libapache2-mod-auth-mysql php5-mysql phpmyadmin

2. Now we need to configure php.ini file to make PHP work with mysql. So type the following command.

gksudo gedit /etc/php5/apache2/php.ini

3. Search for ';extension=mysql.so' and remove the semicolon(;) which is in the beginning of the line. It must look like this.

extension=msql.so

4. Save the file and restart Apache by typing the following command and you are done.

sudo /etc/init.d/apache2 restart

Adding facebook comment box to your blogger

2012-03-09T15:40:00.000+00:00

Few days ago I wrote about adding facebook comment box to your website. To add similar comment box to your blogger a few more steps are required. Adding this box helps users to comment to your posts easily in one click without having the blogger account. Let us see how we can embed it.

1. Create a Facebook application. (Click here to follow the steps).
2. Go to your Blogger->Design->Edit HTML.
3. Proceed to edit HTML and check Expand Widget Templates check-box (Back up your code before editing anything).
4. Search for <html and enter the following code just after it leaving a space.

xmlns: fb='http://www.facebook.com/2008/fbml'

5. Search for <body expr:class='"loading" + data:blog.mobileClass'> and copy the following code just below it.

<div id='fb-root'/>
<script>
    window.fbAsyncInit = function() {
    FB.init({
      appId : 'APP_ID',
      status : true, // check login status
        cookie : true, // enable cookies to allow the server to access the   session
      xfbml : true // parse XFBML
    });
};
    (function() {
    var e = document.createElement('script');
      e.src = document.location.protocol +   '//connect.facebook.net/en_US/all.js';
    e.async = true;
      document.getElementById('fb-root').appendChild(e);
    }());
</script>

Replace APP_ID with your facebook application ID.

6. Search for </head> and copy paste the following code just above it.

Replace YOUR BLOG TITLE, IMAGE-URL, APP_ID and http://www.facebook.com/manishgubaju with your facebook profile link.

7. Search for <b:includable id='comment-form' var='post'> and just below it copy the following code.

<b:if cond='data:blog.pageType == "item"'>

<div style='color:#fff; background-color:#3B5998;border: solid 1px #ddd; font-size:10px; padding:3px; width:510px;'>Facebook Blogger Plugin: Bloggerized by <b><a alt='blogger templates' href='http://www.allblogtools.com/' style='text-decoration:underline; color:#fff;' target='_blank' title='blogger templates'>AllBlogTools.com</a></b> Enhanced by <b><a alt='blogger widgets' href='http://www.mybloggertricks.com/' style='text-decoration:underline; color:#fff;' target='_blank' title='Blogger Widgets'>MyBloggerTricks.com</a></b></div></div>

</b:if>

You can choose your colorscheme as light or dark and also vary the width of the comment box as shown above.

8. Save your template and you are done.

Adding facebook comment box to your website

2012-03-06T12:46:00.000+00:00

Adding Facebook comment box to your website is not as difficult as it used to be about an year ago. When I first used Facebook comment in one of my website about an year ago, I first had to use facebook connect and then write a lot of complicated fbml codes. It was a hell full of complications. But now it has become very easy all because of the Facebook Social Plugins. It just copy paste of some html codes and you are done. The following steps will guide you through using it.

1. Create a Facebook application for your website by using the following link:
http://developers.facebook.com/setup

2. Fill the details like app name and captcha as shown below.

3. You will be able to see your app page now where you can add the domain name of your website and will be able to see your app ID and app secrect key.

4. Now go to the following facebook comments website using the link http://developers.facebook.com/docs/reference/plugins/comments/.

5. Enter your url that you created, no. of comments that you would like to display, width, colour and get the code. Simply put the code inside your body tag and you are done.

SQL Injection and its prevention in PHP

2012-03-02T16:10:00.002+00:00

What is SQL injection?

SQL injection is one of the common attacks in web industry which uses SQL statements in the web form to execute a query in the wrong way and make attacks like making an unauthorised login or making wrong access to the data in the database. SQL injection usually occurs when users are asked for inputs through the HTML forms.

Let us see a common example of SQL injection. Suppose we have a user login form that asks for their username and password. We use select statement for validating the username which is stored in the database.

Code:

Proper user input:

$uname= "Harry";

$query= "SELECT * from tbl_users where username='$uname'";

//query that is executed

$query= "SELECT * from tbl_users where username='Harry'";

SQL injected user input:

$uname="' or '1=1";

$query= "SELECT * from tbl_users where username='$uname'";

//query that is executed

$query= "SELECT * from tbl_users where username='' or '1=1'";

The above SQL statement satisfies the where condition and will allow the intruder to make an unauthorised login into your application.

How to prevent SQL injection?

The root cause for all SQL injection attacks are quotes (' '); therefore it is very important to escape these quotes while getting string inputs from the users. In PHP 4, there were no such functions to escape these quotes apart from setting magic_quotes_gpc ON in the PHP configuration file which does the same task as done by addslashes() function does. Since, the setting was for all files, it would cause a big problem during other tasks as each and every quote would be escaped.

To fix this problem, PHP removed magic quotes from PHP 5.4.0 and introduced a new function called mysql_real_escape_string(). This function replaces troublesome single quote (') with slash and quote (\').

Therefore we can use this function in our above code to prevent SQL injection as follows:

$uname="' or '1=1";

$uname=mysql_real_escape_string($uname); // value of $uname will be \' or \'1=1

$query= "SELECT * from tbl_users where username='$uname'";

//query that is executed

$query= "SELECT * from tbl_users where username='\' or \'1=1'";

This is one of the easiest solution to prevent SQL injection and make your website safe.

How to jailbreak and unlock iPhone 4 IOS 4.3.3

2012-02-27T17:40:00.002+00:00

To unlock iPhone running on IOS 4.3.3, it should be first jailbroken using redsnow 0.9.6rc15 which was developed by the Dev team in May 2011 and then unlocked by installing UltraSnow 1.2.3 via cydia. Below are the detail steps for jailbreaking and unlocking iPhone IOS 4.3.3:

Note: Try at your own risk.

A. JAILBREAK IPHONE

1. Download redsnow 0.9.6rc15 (Mac, Windows).
2. Download IOS 4.3.3 for iPhone 4.
3. Connect your iPhone with your computer.
4. Run redsnow 0.9.6rc15 that you had downloaded using the steps given below:

Step 1: Launch redsnow.
Step 2: Click browse and find the corresponding IOS 4.3.3 (.ipsw file) that you had downloaded earlier.

Step 3: After selecting the .ipsw file a rapid process will start for patching the kernel into your iphone. Now a window will appear for selecting applications. Select cydia only in the options as shown below:

Step 4: The phone will now go into DFU mode. Follow the steps as guided by the software. If you are not able to set your phone into DFU mode please refer to a video tutorial for setting your iPhone into DFU mode.

When the process is completed cydia application will be installed in your iPhone.

B. Unlock your iPhone

Step 1: Open the Cydia installed in your iPhone.
Step 2: Goto Search Tab and search for ultrasnow.
Step 3: Install ultrasnow.

Installing ultrasnow and rebooting your phone will unlock your iPhone.

Getting city name using real IP address

2012-02-26T14:01:00.000+00:00

Getting the name of the city using IP address is quite simple. This tutorial shows how we can get real IP address of the server and find the city name using the IP address with the help of API from GEOBYTES.
Following are the steps to do this:

1. Find the real IP address using the following function.

function getRealIpAddr()

{

if (!empty($_SERVER['HTTP_CLIENT_IP'])) //check ip from share internet

{

$ip=$_SERVER['HTTP_CLIENT_IP'];

}

elseif (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) //to check ip is pass from proxy

{

$ip=$_SERVER['HTTP_X_FORWARDED_FOR'];

}

else

{

$ip=$_SERVER['REMOTE_ADDR'];

}

return $ip;

}

$ip=getRealIpAddr();

2. Get the city name using the API from GEOBYTES.

$tags = get_meta_tags("http://www.geobytes.com/IpLocator.htm?GetLocation&template=php3.txt&IpAddress=$ip");
$city= ucfirst($tags['city']); // $tags is an array that contains city name for the supplied IP Address

echo $city; // prints the city name

LightBox for displaying contents and image using a common jquery plugin

2012-02-23T20:57:00.000+00:00

Displaying contents using a sexy lightBox has become a kind of fashion in the web industry. I have seen many scripts to do this but most of them are complex and bulky. I have come up with a very simple way to do this. Following are the steps to do this.

Download jquery-1.7.1.min.js, thickbox.js, thickbox.css and loading image.
Insert the following code between the <head></head> tag.

<script type="text/javascript" src="path-to-file/jquery.js"></script>
<script type="text/javascript" src="path-to-file/thickbox.js"></script>

<link rel="stylesheet" href="path-to-file/thickbox.css" type="text/css"

  media="screen" />

3. To display any image in lightBox simply use the following code.

4. To display your content in lightBox , first create a page for the contents you wish to display e.g. test.php then use the following code.

<a href="test.php?TB_iframe=true&height=180&width=390&modal=true" class="thickbox">CLICK HERE</a>

In the Image lightBox the close window button appears automatically but for the content lightBox you need to add it manually using the code

<a href="javascript:void(0)" onClick="self.parent.tb_remove();">Close</a>

I hope this tutorial will be helpful for many developers. Enjoy.

Experience an Ajax based ecommerce solution with PrestaShop

2012-02-20T16:10:00.003+00:00

Last week I was asked by my client to develop an ecommerce site using prestashop. When I used it I found it amazing. The best thing I liked about it is its smooth AJAX based functionality in both backend and frontend. PrestaShop can be downloaded from the following link:

http://www.prestashop.com

Another best thing about PrestaShop is that it supports wide range of payment gateways such as paypal, google checkout, moneybookers, ideal and athorize.net. Developers will no longer have to download api for each payment gateway and waste their time on testing. PrestaShop is based on Smarty templates and the script are written in MVC architecture. PrestaShop was named the Best Open Source E-Commerce Application in the Packt 2010 Open Source Awards and the Best Open Source Business Application in the 2011 Open Source Awards. PrestaShop supports about 41 languages and has plenty of addons and templates.

My MSc Research

2012-02-10T16:16:00.000+00:00

Research Question: Why do programmers avoid frameworks in favor of ad hoc program development and how can they be motivated towards using frameworks to minimize the risks of projects?

The research results will be published soon

What is ITIL?

2012-02-08T13:11:00.000+00:00

Information in organisations is critical and always has been. However, due to the increase in scale of organisations; managing and organising information has become far more complex. To handle the increase in volume and complexity of this information and the systems that manage it, standards and frameworks have been developed. The aim of these frameworks is to provide consistency in an attempt to simplify processes and establish and share methods of ‘best practice’. This topic will focus on the current dominant framework that exists in the domain of IT service management.

Information Technology Infrastructure Library (ITIL) was developed in the late 1980s by The Office of Government Commerce in conjunction with private sector organisations worldwide. It provides guidance on the planning, delivery and management of quality IT services to support organisational needs. ITIL provides a comprehensive, consistent and coherent set of processes for IT management and is underpinned by formal qualifications and an associated training scheme. ITIL is still owned by the UK government.

ITIL v3 was released in May 2007 and is bases around 5 key areas that translate into 5 five books:

Service Strategy
Service Design
Service Transition
Service Operation
Continual Service Improvement

ITIL v3 is recognised as an international standard ISO/IEC20000.