WebTechTuts

Getting Started With MongoDB

Deepak Airy — Tue, 06 Dec 2011 17:07:10 +0000

MongoDB is a document-oriented database. The main reason for not choosing relational model is said to be able to make scaling out easier. MongoDB has retain the most useful features of relational databases, such as secondary indexes, range queries, sorting etc. and has added some more features such as built-in support for MapReduced-style aggregation and geospatial indexes.

Performance is the major goal for MongoDB. MongoDB attempts to keep many features from relational systems, but it is not intended to do everything that a relational dababase does.

MongoDB uses BSON(Binary JSON) format to store data. This is same as JSON or JavaScript object literal.

1	{“name”:”MongoDB”}.

An entry like this is known as document in MongoDB.

Now before we dive deeper into documents, collection and database lets us first install MongoDB. Its very simple and we will be done with in just 5 mins.

We just have to download the MongoDB from http://www.mongodb.org/downloads based on the operating system we are using. One thing to know here is a 32-bit builds are limited to around 2GB of data, there is no such restriction with 64-bit builds.

For Windows

Download the DB.
Unzip it and save it in c:/. I have saved it c:/ you can save it any place of your liking. And I have also changed the name of the folder to mongodir.
Create a folder data/db in c:/. This is the default directory where MongoDB stores data. But MongoDB doesn’t create it , so we will have to. We can choose any place and name for this too but for that we will to start MongoDB server with an –dbpath option which tell MongoDB the path for storing and fetching data. For now we will go with the default location.

For Linux

Same goes for linux too. The only difference is instead of c:/ we will use root directory.

That’s it we are done with installation.

Now as we have MongoDB with us lets do some exploring. First start the MongoDB server, for that open the command promt and go to c:/mongodir/bin and execute mongod.

1 2	cd /mongodir/bin/ mongod

If all goes well we will something like

See the last two line they tell us that MongoDB is listening to us through two ports

for command prompt :- 27017
for web :- 28017

To check if its telling the truth you can put the “localhost:28018″ in the address bar if you see something like the image below its telling the truth.

Server has started and working fine. Now to start actual work open another command prompt and enter the following.

1 2	cd /mongodir/bin/ mongo

this will give you the MongoDB console. This is javascript based console and can run any thing that is javascript.

Now if you open c:/data/db/ folder[we created it for MongoDB to store all our data here. If you forgot than check the installation step 3 again.] you will see only one file “mongod.lock”.

We will discuss this file in next blog. My point here is on console MongoDB displays “Connecting to test”, but there is no such file created in our default data folder. why?

This is because MongoDB wants to connect to a database whenever user open the client and by default it always connects to “test” database. But if its not present it will not create one, it will just assign the database name “test” to the variable “db” that is used to reffer to the current database in MongoDB.

If we write db and press enter on console it will show the current db that is “test”.

Now in MongoDB a database and a collection[some what same as tables in relational database] gets created when we insert some data in them. That is with insert commands.

1	db.contacts.insert({'name':'joy', 'email':'joy@ymail.com','phone':'123456789'})

when we execute this a database named “test” and a collection named “contacts”will get created.

Go to c:/data/db/, now you will see two more files “test.0” and “test.ns”.

Every database is stored in its own .0 and .ns files. Now these files will store all the details and data related to the respective database. If you look at the size of the files its quite large for the data we just have entered, this is just to deal with the space problem that can occurs while doing some admin task or some queries that require extra space.

That’s all for the day. We will dig deeper into the CRUD operations in MongoDB in my next blog.

HTC unveils its first Mango handset

Vijay Gupta — Wed, 12 Oct 2011 17:48:45 +0000

HTC unveiled its first Windows Phone OS 7.5 (codenamed ‘Mango’) powered smartphone the HTC Radar in the Indian mobile market on Tuesday. Powered by a 1GHz processor, the phone has an internal storage space of 8GB and has 512MB of RAM.

Priced at Rs 25,490, the phone has a 3.8-inch touchscreen with 480×800 resolution. It sports a 5 megapixel rear camera with f/2.2 aperture lens and a front VGA camera. With 28mm wide-angle lens, it allows users to capture more of the scene, while the panoramic feature lets users create dramatic pictures of skylines and landscapes.

HTC Radar make the user interface more interactive with the new ‘People Hub’ from Windows Phone. The People Hub keeps users updated with their friends’ latest news and also shows all communication history with each person, as well as their recent social network updates and photos.

HTC’s another Mango powered phone – HTC Titan, which is already available in the global market, is expected to hit the Indian market by the end of this year, said Faisal Siddiqui, country manager, HTC India.

The Acer Allegro, another ‘Mango’ powered phone, was also unveiled at the Windows Phone OS event at New Delhi. However, the company has not yet announced its price. When asked about the price, Ravi Desai, head – telecom, Acer India said, “It will be within the bracket of Rs 18,000-20,000.”

How To Reset Password in Ubuntu?

Vijay Gupta — Mon, 10 Oct 2011 07:51:25 +0000

If you just installed Ubuntu and forgot what password you selected during the installation process or you have too many passwords in your life and can’t keep track of them all.

This small tutorial will help you to reset your password.

First you have to reboot your system in recovery mode. If you have a single boot then hold down shift key during the boot-up. In dual boot you get the menu to select the boot option from the menu.
After you select recovery mode and wait for all the boot-up processes to finish, you’ll be presented with a few options. In this case, you want the Drop to root shell prompt option so press the Down arrow to get to that option, and then press Enter to select it.

The root account is the ultimate administrator and can do anything to the Ubuntu installation (including erase it), so please be careful with what commands you enter in the root terminal.

Once you’re at the root shell prompt, if you have forgotten your username as well, type
To reset password type

1
# passwd username

You’ll then be prompted for a new password.Just type the password and hit Enter when you’re done. You’ll be prompted to retype the password. Do so and hit Enter again.
Now Your Password is reset.Type exit to return to the recovery mode

1
# exit

In recovery mode select resume normal boot.

Reset MySQL root Pasword – Ubuntu 11.04

Vijay Gupta — Sat, 08 Oct 2011 11:06:54 +0000

If you forgot your mysql root password and you want to recover this here are the steps to Set / change / reset the password.

First stop your mysql
1
# sudo /etc/init.d/mysql stop
Start Mysqld Configuration
1
# sudo mysqld --skip-grant-tables &
Login to mysql as root
1
# mysql -u root mysql

4.Replace YOURNEWPASSWORD with your new password!

1
2
3
4
5
6
7
8
9
10

mysql> UPDATE user SET Password=PASSWORD('YOURPASSWORD') WHERE User='root'; FLUSH PRIVILEGES; exit;
Query OK, 3 rows affected (0.00 sec)
Rows matched: 3 Changed: 3 Warnings: 0

Query OK, 0 rows affected (0.00 sec)
li>
<li>
5. Now Start Your Mysql.
[cc lang="bash"]
# /etc/init.d/mysql start

6. Try to connect with new password with root user.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 35
Server version: 5.1.54-1ubuntu4 (Ubuntu)

Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
This software comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to modify and redistribute it under the GPL v2 license

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
+--------------------+
2 rows in set (0.00 sec)

Convert 2D videos to 3D with YouTube

Vijay Gupta — Fri, 30 Sep 2011 15:23:56 +0000

September seems to be the month where many of Internet’s biggest services are rolling out improvements and tools. After Facebook, Google Plus and Twitter’s turn to add some new frills and functionality, it’s now YouTube’s turn.

In a bid to foster the creation of video content, YouTube has introduced three new features to empower YouTubers and to facilitate video content creation.

The world’s largest video sharing service now allows users to convert 2D videos into 3D with a single click. However, it has currently introduced it in a beta stage. Users don’t need to go through a long journey to create 3D videos which requires them to set up two cameras, combine the footage from each, and use special software to make the effect look just right.

“We are launching 2D to 3D conversion. Once people have uploaded their 2D videos to YouTube, they can convert them to 3D with the click of a button. Converted videos will be viewable by everyone in 3D,” said the company in a blog post. Users can find this feature by selecting “Edit Info”, then “3D Video” on a video they have uploaded to YouTube. But experiencing the 3D effect will need the aid of special glasses.

YouTube is also allowing all “verified users in good standing” to upload long-form videos, that are longer than the current limit of 15 minutes for most users. To help people get those longer videos online, YouTube has also launched ‘resumable uploads’, which ensures that users will able to continue their uploads from the point from where the upload failed due to connectivity faults or any other reason.

YouTube has also added two additional video creation platforms – Vlix and Magisto – to help its users make better videos. Vlix lets users add effects to their videos and text to the video introduction and closing, while Magisto takes their unedited video and automatically edits it into short, fun clips.

Get Google+ Publicly Shared Profile information

Vijay Gupta — Thu, 29 Sep 2011 12:12:10 +0000

How to get the profile information which are shared publicly on Google+ using PHP and Google+ API? For that you first need Google API Key.

Please open Google API Key Console.
Generate an API key on the API Access pane.

After Getting API Key you can get publicly shared profile information on Google+ using below HTTP Request as shown in the example. Please replace the yourAPIKey with the key you have generated.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

$strUrl="https://www.googleapis.com/plus/v1/people/112063946124358686266?key=yourAPIKey";

$str = fetchURLPageData($strUrl);

print_r(get_object_vars(json_decode($str)));

function fetchURLPageData($vURL) {
$cu = curl_init();
curl_setopt($cu, CURLOPT_URL,$vURL);
curl_setopt($cu, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($cu,CURLOPT_CONNECTTIMEOUT,3);
curl_setopt($cu, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.13)');
curl_setopt($cu, CURLOPT_HEADER, 0); // set to 0 to eliminate header info from response
$res = curl_exec($cu);
return $res;
}
?>

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68

Array
(
[kind] => plus#person
[id] => 112063946124358686266
[displayName] => Tom Anderson
[gender] => male
[aboutMe] => I might be your friend.
[url] => https://plus.google.com/112063946124358686266
[image] => stdClass Object
(
[url] => https://lh5.googleusercontent.com/-IKJaEaE8GgY/AAAAAAAAAAI/AAAAAAAAAao/PNoLYQ0f3sw/photo.jpg
)

[urls] => Array
(
[0] => stdClass Object
(
[value] => http://www.twitter.com/myspacetom
)

[1] => stdClass Object
(
[value] => http://www.facebook.com/myspacetom
)

[2] => stdClass Object
(
[value] => http://about.me/myspacetom
)

[3] => stdClass Object
(
[value] => https://plus.google.com/112063946124358686266
[type] => profile
)

[4] => stdClass Object
(
[value] => https://www.googleapis.com/plus/v1/people/112063946124358686266
[type] => json
)

)

[organizations] => Array
(
[0] => stdClass Object
(
[name] => University of California at Berkeley
[type] => school
)

[1] => stdClass Object
(
[name] => University of California at Los Angeles
[type] => school
)

[2] => stdClass Object
(
[name] => MySpace
[title] => former President
[type] => work
)

)

)

Similarly, you can get a list of someone’s most recent public posts by using the below HTTP Request.
1
https://www.googleapis.com/plus/v1/people/112063946124358686266/activities/public?key=yourAPIKey

Install LAMP (Linux-Apache-MySQL-PHP) Server on Fedora 13

Vijay Gupta — Fri, 23 Sep 2011 08:47:28 +0000

If you have Fedora 13 on installed on your machine and you want to install LAMP server, then follow simple three steps shown below. This guide provides step-by-step instructions for installing a full-featured LAMP stack on a Fedora 13 system. In this guide, you will be instructed on setting up Apache, MySQL, and PHP

Install and Configure the Apache Web Server
Install and Configure MySQL Database Server
Installing and Configuring PHP

But first of all check wheather yum is install on your machine or not. To check this use below command.

1 2	shell> which yum /usr/bin/yum

Please read this article, Yum installation on Fedora .

Install and Configure the Apache Web Server

The Apache Web Server is a very popular choice for serving web pages. While many alternatives have appeared in the last few years, Apache remains a powerful option that we recommend for most uses.

Make sure your system is up to date by issuing the following command:

1	shell> yum update

To install the current version of the Apache web server (in the 2.x series) use the following commands:

1 2	shell> yum install httpd shell> /sbin/chkconfig --levels 235 httpd on

The main configuration directives for Apache are contained in the httpd.conf file, which is located at /etc/httpd/conf/httpd.conf. We advise you to make a backup of this file into your home directory, like so:

1	shell> cp /etc/httpd/conf/httpd.conf ~/httpd.conf.backup

By default, all files ending in the .conf extension in /etc/httpd/conf.d/ are treated as configuration files, and we recommend placing your non-standard configuration options in files in these directories. Regardless of how you choose to organize your configuration files, making regular backups of known working states is highly recommended.

Now we’ll configure virtual hosting so that we can host multiple domains (or subdomains) with the server. These websites can be controlled by different users, or by a single user, as you prefer.

Before we get started, we suggest that you combine all configuration on virtual hosting into a single file called vhost.conf located in the /etc/httpd/conf.d/ directory. Open this file in your favorite text editor, and we’ll begin by setting up virtual hosting.
Configure Virtual Hosting

There are different ways to set up virtual hosts, however we recommend the method below.

By default, Apache listens on all IP addresses available to it. We must configure it to listen only on addresses we specify. Even if you only have one IP, it is still a good idea to tell Apache what IP address to listen on in case you decide to add more.

Begin by adding the following line to the virtual hosting configuration file:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

File excerpt:/etc/httpd/conf.d/vhost.conf

NameVirtualHost 0.0.0.0:80

Be sure to replace 13.34.56.78 with your own IP address.
Configure Virtual Hosts

Now we will create virtual host entries for each site that we need to host with this server. Here are two examples for sites at "example.com" and "example.org".

File excerpt:/etc/httpd/conf.d/vhost.conf

ServerAdmin webmaster@example.com
ServerName example.com
ServerAlias www.example.com
DocumentRoot /srv/www/example.com/public_html/
ErrorLog /srv/www/example.com/logs/error.log
CustomLog /srv/www/example.com/logs/access.log combined

ServerAdmin webmaster@example.org
ServerName example.org
ServerAlias www.example.org
DocumentRoot /srv/www/example.org/public_html/
ErrorLog /srv/www/example.org/logs/error.log
CustomLog /srv/www/example.org/logs/access.log combined

Notes regarding this example configuration:

All of the files for the sites that you host will be located in directories that exist underneath /srv/www. You can symbolically link these directories into other locations if you need them to exist in other places.
ErrorLog and CustomLog entries are suggested for more fine-grained logging, but are not required. If they are defined (as shown above), the logs directories must be created before you restart Apache.

Before you can use the above configuration, you’ll need to create the specified directories. For the above configuration, you can do this with the following commands:

1
2
3
4
5
6
7
8
9

shell> mkdir -p /srv/www/example.com/public_html
shell> mkdir /srv/www/example.com/logs

shell> mkdir -p /srv/www/example.org/public_html
shell> mkdir /srv/www/example.org/logs

After you've set up your virtual hosts, issue the following command to run Apache for the first time:
[cc lang="bash"]
shell> service httpd start

Assuming that you have configured the DNS for your domain to point to your Linode’s IP address, virtual hosting for your domain should now work. Remember that you can create as many virtual hosts with Apache as you need.

Any time you change an option in your vhost.conf file, or any other Apache configuration remember to reload the configuration with the following command:

1	shell> service httpd reload

Install and Configure MySQL Database Server

MySQL is a relational database management system (RDBMS) and is a popular component in contemporary web development tool chains. It is used to store data for many popular applications, including WordPress and Drupal.
Install MySQL

The first step is to install the mysql-server package, which is accomplished by the following command:

1	shell>yum install mysql-server

If you want to run MySQL by default when the system boots, which is a typical setup, execute the following command:

1	shell>/sbin/chkconfig --levels 235 mysqld on

Use the chkconfig command to setup runlevels as needed.

Now you can start the mysql daemon (mysqld) with the following command:

1	shell> service mysqld start

MySQL should be ready to configure and run. While you shouldn’t need to change the configuration file, note that it is located at /etc/my.cnf for future reference.
Configure MySQL and Set Up MySQL databases

After installing MySQL, it’s recommended that you run mysql_secure_installation, a program that helps secure MySQL. While running mysql_secure_installation, you will be presented with the opportunity to change the MySQL root password, remove anonymous user accounts, disable root logins outside of localhost, and remove test databases. It is recommended that you answer yes to these options. If you are prompted to reload the privilege tables, select yes. Run the following command to execute the program:

1 2	shell> mysql_secure_installation

Next, we’ll create a database and grant your users permissions to use databases. First, log in to MySQL:

1	shell> mysql -u root -p

Enter MySQL’s root password, and you’ll be presented with a prompt where you can issue SQL statements to interact with the database.

To create a database and grant your users permissions on it, issue the following command. The semi-colons (; characters) at the end of the lines are crucial for ending the commands. Your command should look like this:

create database test;

grant all on test.* to ‘foreman’ identified by ’5t1ck’;

In the example above, test is the name of the database, foreman is the username, and 5t1ck password. Note that database user names and passwords are only used by scripts connecting to the database, and that database user account names need not (and perhaps should not) represent actual user accounts on the system.

With that completed, you’ve successfully configured MySQL and you may now pass these database credentials on to your users. To exit the MySQL database administration utility issue the following command:

quit

With Apache and MySQL installed you are now ready to move on to installing PHP to provide scripting support for your web pages.

Installing and Configuring PHP

PHP makes it possible to produce dynamic and interactive pages using your own scripts and popular web development frameworks. Furthermore, many popular web applications like WordPress are written in PHP. If you want to be able to develop your websites using PHP, you must first install it.

Fedora includes packages for installing PHP from the terminal. Issue the following command:

1	shell> yum install php php-pear

Once PHP5 is installed, we’ll need to tune the configuration file located in /etc/php.ini to enable more descriptive errors, logging, and better performance. These modifications provide a good starting point if you’re unfamiliar with PHP configuration.

Make sure that the following values are set, and relevant lines are uncommented (comments are lines beginning with a semi-colon (; character)):

1
2
3
4
5
6
7
8
9

File excerpt:/etc/php.ini

error_reporting = E_COMPILE_ERROR|E_RECOVERABLE_ERROR|E_ERROR|E_CORE_ERROR
display_errors = Off
log_errors = On
error_log = /var/log/php.log
max_execution_time = 300
memory_limit = 64M
register_globals = Off

If you need support for MySQL in PHP, then you must install the php5-mysql package with the following command:

1	shell> yum install php-mysql

You can test PHP by creating a file with the following contents under your “public_html” directory:

File:/srv/www/example.com/public_html/test.php

1
2
3

echo phpinfo();
?>

When you view this page in your browser, you should be presented with detailed PHP configuration information.
Restart Apache

Finally, restart Apache to make sure everything is loaded correctly:

service httpd restart

Yum installation on Fedora 13

Vijay Gupta — Fri, 23 Sep 2011 07:57:10 +0000

If you have Fedora on your machine and you want install yum on your fedora machine then use below steps to install it.

1. Login as root and go to your root directory.

1	shell> cd ~

2. Now create a directory called yum (or you can call it whatever you want)

1	shell> mkdir yum

3. Now change the directory to directory you just created.

1	shell> cd yum

4. please download the yum version of your choice, in my case, i downloaded the version 3.2.2 for my Fedora 13

1	shell> wget http://yum.baseurl.org/download/3.2/yum-3.2.4.tar.gz

5. Untar the package using tar command with necessary option.

1	shell> tar xvzf yum-3.2.4.tar.gz

6. Change the directory to the directory you untar.

1	shell> cd yum-3.2.4

7. Use below command to install the yum

1	shell> ./configure

then use make command

1	shell> make

make install

1	shell> make install

Facebook – all your news on one place

Vijay Gupta — Wed, 21 Sep 2011 07:49:56 +0000

Facebook come with the new look or features : All your news is now on one place.

All of your news is now in one place with the most interesting stories featured at the top. If you haven’t visited Facebook for a while, the first things you’ll see are top photos and status updates posted while you’ve been away. They’re marked with an easy-to-spot blue corner.

If you check Facebook more frequently, you’ll see the most recent stories first. Photos will also be bigger and easier to enjoy while you’re scrolling through.

You can see top stories at the top since you last checked news feed.
Each top stories are marked with a blue corner.
Recent stories are below, in order they were posted.

Ticker

Ticker, on the right-hand side of your account, lets you see all your friends’ activity in real-time. When you hover over an item on ticker, you can see the full story and join the conversation as it happens.

Ticker updates itself as as stories happen. This gives you a more complete picture of what your friends are doing, right now.

Motorola FIRE XT and Motorola FIRE launched in India

Vijay Gupta — Wed, 14 Sep 2011 16:16:33 +0000

In a bid to capture a large portion of the burgeoning Indian mobile market, Motorola Mobility has come up with two new Android powered smartphones – Motorola Fire XT and Motorola Fire. Both phones run Android 2.3 OS.

Featuring a 3.5-inch screen, the Motorola Fire XT sports a 5 megapixel auto-focus camera with built-in flash. The phone has an 800MHz processor, 1540mAh battery and 512MB of RAM. It is priced at Rs 13,890.

The lesser priced Motorola Fire is equipped with a 3 megapixel camera and has a 2.8-inch screen. Priced at Rs 9,990, it has a touch-screen display along with a full QWERTY keypad. Weighing 110g, its other features include 1420 mAh battery, 600 MHz processor, etc.

“With easy multitasking and contact management, faster and easier interactions, the Motorola FIRE XT and Motorola FIRE make for a great mobile experience at a great price for the young, fast-moving users who want everything from a top-quality smartphone,” said Rajan Chawla, Mobile Devices business country head-sales and operations, India and South West Asia, Motorola Mobility.

Specifications of Motorola FIRE XT

3.5 inch (480 x 320 pixels) extra bright capacitive multi-touch display
11.95 mm thick and weighs 114 g
Android 2.3 (Gingerbread)
5MP auto focus camera with flash and front-facing VGA camera
800MHz CPU
3G, Wi-Fi b/g/n, Bluetooth and aGPS
3.5 mm audio jack and FM Radio RDS
512MB RAM, 512MB ROM that is expandable up to 32GB with MicroSD
1540mAh battery that offers up to 8 hours talk time and up to 28 days in standby in 3G

Specifications of Motorola FIRE

2.8 inch (320 x 240 pixels) capacitive multi-touch display and full QWERTY keypad
13.45mm thick and weighs 110g
Android 2.3 (Gingerbread)
3MP camera
3G, Wi-Fi b/g/n, Bluetooth and aGPS
3.5 mm audio jack and FM Radio RDS
256MB RAM, 512MB ROM that is expandable up to 32GB with MicroSD
1420mAh battery that offers up to 8 hours talk time and up to 27 days in standby in 3G

Other common features include 2GB microSD card in box that is expandable up to 32GB, 3G3/WIFI4 enabled and supports 3G hotspot for connecting up to 5 devices, e-compass, proximity sensor, ambient light sensor, accelerometer, et al.

Reference

IBN Live