Below are the few steps :-

1) Open /etc/hosts.allow

Use the following command to open the hosts.allow file:

Once this file is open, add the following line:

2) Open /etc/hosts.deny

Use the following command to open the hosts.deny file:

Once it opens, add the following line to the file:

Save and exit, and you have successfully limited SSH access by IP address.

Dropbox is a free service that lets you bring all your photos, docs, and videos anywhere. Dropbox provides users with 2 GB of space for free, and they can pay for more. Dropbox  support Windows, Mac OS X, Fedora, Ubuntu, iPad, iPhone, Android and Blackberry.

After you install Dropbox on your computer, any file you save to your Dropbox will automatically save to all your computers, your iPhone and iPad and even the Dropbox website.

To know more about Dropbox, click HERE to visit Dropbox web site.

To download Dropbox, just click HERE to download.

You will see the installation guide on the download page. Just follow the instruction to install it.

Recently i downloaded a eBook in EPUB format. I failed to open it using Adobe Reader (PDF reader) and Chmox (.chm reader). How to open it?? What is EPUB?? After i google it, i know that ePub format is an open standard for ebooks by the International Digital Publishing Forum. All the ePub files have the extension .epub.

There are several software programs support the ePub format. Below are the few software allow you to read .ePub file on your computer. You can just click the following link to download it.

• Adobe Digital Editions (Support Windows and OS X)
• EPUBReader (Firefox Add-on)
• Lucidor (Supports Windows, OS X, and Linux)
• Openberg (plug-in for Firefox,)
• FBReader (Windows, Linux, OS X)

Among all the software that i mention above, i tried to read .epub ebook using Adobe Digital Edition on my Mac OS X machines. It work fine for me.

Below are the few step to show how to install Adobe Digital Edition :-

• Download Adobe Digital Edition

• Just follow the on screen instruction to download the installer files.
• After that, just follow the on screen instruction to install the application. Below are the screen shoot: -

• Try to open .epub format e-book

Besides Adobe Digital Editions, i tried to install Firefox add-on called EPUBReader to read ePub-files in the browser. With this Firefox add-on, you can read ePub files on multiple Operating System (Windows, Linux, Mac OS X, FreeBSD) without install additional software.

To install this Firefox Add-on, it is very easy to do it. Below are the few simple steps to show how to install it:-

• Click HERE to download the EPUBReader add-on

• Click Add to Firefox button to begin the installation

• After download, click Install Now

• Restart the Firefox application

How to use EPUBReader? Just view the following video:-

If you others way to read .epub files, please share with me by leave a comment.

Ubuntu 11.04 is the version of the Ubuntu operating system released on 28 April 2011. The common name given to this release is “Natty Narwhal“. Last release of ubuntu was ubuntu 10.10 (Maverick Meerkat). According to Ubuntu official web site (http://www.ubuntu.com/ubuntu/features), there are lots of visible improvement in ubuntu 11.04 compare with ubuntu 10.10.

What’s new in Ubuntu 11.04? from Canonical Design on Vimeo.

Now you can download Ubuntu for free on Ubuntu Web site. Click HERE to download.

I would like to sync my iPod’s media file on Linux Machine, is it possible?  As i know iTunes does not support on Linux platform. I found 1 of the open source software called gtkpod. Gtkpod is a platform independent GUI for Apple’s iPod using GTK2. It allows you to upload songs and playlists to your iPod. It supports ID3 tag editing, multiple charsets for ID3 tags, detects duplicate songs, allows offline modification of the database with later synchronisation, and more.

Installing GTKPod

Before you start sync your iPod, you should install GTKPod 1st. I going to install GTKPod on my Ubuntu Machine.

• Launch your terminal (Applications > Accessories > Terminal)
• type following command to install GTKPod

sudo apt-get install gtkpod

How to use GTKPod

First plug in your iPod into your desktop system using the iPod USB cable. The iPod should be mounted automatically, and you should find an iPod icon on your desktop.

Now start your gtkpod (on Ubuntu 10.10, it’s under Sound & Video> Sound > gtkpod iPod Manager)

How To Add Songs To Your iPod

In this post, I going to show you how to  install WordPress on Ubuntu 10.10 Linux Desktop. I going to install WordPress on my Ubuntu Machine as my development environment for edit and testing my new WordPress theme.To make wordpress running on local host over Linux, you must setup a LAMP server first. . I already posted a tutorial on how to setup LAMP on Ubuntu. You just view my previous post on LAMP installation on Ubuntu.

Download WordPress

After setup LAMP on Ubuntu, you need to download WordPress from WordPress official website into your Ubuntu desktop.

root@techkakiCompaq6910:~# cd /tmp

root@techkakiCompaq6910:/tmp# wget http://wordpress.org/latest.tar.gz

Extract your WordPress archieve into your server directory

After downloading WordPress , extract it on your desktop and move the WordPress folder to  /var/www/ directory. (You should have all the files inside /var/www/wordpress/). Your installation url will become http://localhost/wordpress/ where you can have access to your WordPress.

root@techkakiCompaq6910:/tmp# tar zxvf latest.tar.gz

root@techkakiCompaq6910:/tmp# mv wordpress/ /var/www

Create MySQL Database for WordPress

Because of i not i not install phpMyAdmin on my Ubuntu Machine. I going to use the commands to create the database. First i will create dababase: wordpress and then create a new user: wordpress with password: wordpresspassword

Just follow below steps:-

• In the linux terminal, type command mysql -u root -p and enter mysql’s root password when prompted

root@techkakiCompaq6910:/var/www# mysql -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 45
Server version: 5.1.49-1ubuntu8.1 (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> CREATE DATABASE wordpress;
Query OK, 1 row affected (0.00 sec)

mysql> CREATE USER wordpress;
Query OK, 0 rows affected (0.00 sec)

mysql> SET PASSWORD FOR wordpress = PASSWORD(“wordpresspassword”);
Query OK, 0 rows affected (0.00 sec)

mysql> GRANT ALL PRIVILEGES ON wordpress.* TO “wordpress”@”localhost” IDENTIFIED BY “wordpresspassword”;
Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

mysql> EXIT

Configure WordPress Setting

Now, is time for us to configure WordPress. We must manually create and edit wordpress Configuration file. To create the configuration file manually, just opy the wp-config-sample.php file to wp-config.php. After that, open and edit wp-config.php file. Below are steps:-

root@techkakiCompaq6910:/var/www# cd /var/www/wordpress/

root@techkakiCompaq6910:/var/www/wordpress# cp wp-config-sample.php wp-config.php

root@techkakiCompaq6910:/var/www/wordpress# vi wp-config.php

Edit the content of wp-config.php:

define('DB_NAME', 'wordpress');    // The name of the database

define('DB_USER', 'username');     // Your MySQL username

define('DB_PASSWORD', 'password'); // ...and password

define('DB_HOST', 'localhost');

Here is my wp-config.php setting

// ** MySQL settings – You can get this info from your web host ** //
/** The name of the database for WordPress */
define(‘DB_NAME’, ‘wordpress’);

/** MySQL database username */
define(‘DB_USER’, ‘wordpress’);

/** MySQL database password */
define(‘DB_PASSWORD’, ‘wordpresspassword’);

/** MySQL hostname */
define(‘DB_HOST’, ‘localhost’);

Install WordPress

Before start the installation, please make sure the folder (/var/www/wordpress) and all its files and subfolders must be owned by www-data. If not, just type the following command to change it

 chown -R www-data /var/www/wordpress

Now, open your browse to “http://localhost/wordpress” to install it. Just follow the on screen instruction. You will be given an initial user named admin.You just give your wordpress title, admin password and email address. After that, click Install WordPress button to install it.

That’s it! You can login to wordpress backend at http://localhost/wordpress/wp-admin/ and to preview your new wordpress http://localhost/wordpress.

LAMP (Linux, Apache, MySQL and PHP) is an open source Web Server. To develop my new WordPress theme, i need to setup LAMP on my Ubuntu 10.10 Machine. In this post,  I will show you how to install a LAMP on Ubuntu 10.10. system..

To start the installation:-

1. Open up the Terminal (Applications > Accessories > Terminal).

2. Before you start setup the LAMP, please make sure you’re logged in as root:

sudo su -

3. Installing MySQL

apt-get install mysql-server mysql-client

A screen that asked to provide a password for the MySQL root user will be prompt out. Just enter the password for MySQL root user

Note: this password is valid for the user root@localhost

4. Installing Apache2

apt-get install apache2

In order to ensure your Apache is working fine. Just test your apache by open up any of your web browser and enter the following address into your browser address bar:

http://localhost/

If your apache run successful, you will see a web page with “It works!”  message.

5. Installing PHP5

Just enter following command to install PHP5 and the Apache PHP5 module:

apt-get install php5 libapache2-mod-php5

After install, you must restart Apache2 In order for PHP to work and be compatible with Apache

/etc/init.d/apache2 restart

6. Test PHP

To ensure PHP running fine, just do a quick test run by create a small PHP file (info.php) in document root of the default web site  /var/www directory .The file will display lots of useful details about our PHP installation, such as the installed PHP version.

vi /var/www/info.php

Now type (http://localhost/info.php) in a browser to verify PHP run on your

I hope this simple tutorial able to guide you setup basic web server in ubuntu

By default, most Linux distributions do not enable password aging. This means passwords do not expire and is it possible for a user to have the same password indefinitely. This situation is not secure. For security reasons, it is advisable to require users to change their passwords periodically.

Password aging is a mechanism that allows the system to enforce a certain lifetime for passwords. The chage command is used to modify password aging.

# chage [options] username

Here are the common options used with the chage command:

Below are few example on how to use chage command:-

a) Displays the help information

Just type chage command

[root@myopensos ~]# chage
Usage: chage [options] user

Options:
-d, –lastday LAST_DAY    set last password change to LAST_DAY
-E, –expiredate EXPIRE_DATE    set account expiration date to EXPIRE_DATE
-h, –help            display this help message and exit
-I, –inactive INACTIVE    set password inactive after expiration
to INACTIVE
-l, –list            show account aging information
-m, –mindays MIN_DAYS    set minimum number of days before password
change to MIN_DAYS
-M, –maxdays MAX_DAYS    set maximim number of days before password
change to MAX_DAYS
-W, –warndays WARN_DAYS    set expiration warning days to WARN_DAYS

List the password and its related details for an user

b) Show account aging information

Just type chage -l username or chage –list username

[root@myopensos ~]# chage -l techkaki
Last password change                    : Aug 19, 2010
Password expires                    : never
Password inactive                    : never
Account expires                        : never
Minimum number of days between password change        : 0
Maximum number of days between password change        : 99999
Number of days of warning before password expires    : 7

c) Set Password Expiry Date

Example, user techkaki password is set to expire 3 days from the last password change.

Note: both “Password expires” and “Maximum number of days between password change” entries as shown below.

[root@myopensos ~]# chage -M 3 techkaki
[root@myopensos ~]# chage -l techkaki
Last password change                    : Aug 19, 2010
Password expires                    : Aug 22, 2010
Password inactive                    : never
Account expires                        : never
Minimum number of days between password change        : 0
Maximum number of days between password change        : 3
Number of days of warning before password expires    : 7

d) To disable password aging for an user account

To turn off the password expiration for an user account, set the following:

• -m 0 will set the minimum number of days between password change to 0
• -M 99999 will set the maximum number of days between password change to 99999
• -I -1 (number minus one) will set the “Password inactive” to never
• -E -1 (number minus one) will set “Account expires” to never.

[root@myopensos ~]# chage -m 0 -M 99999 -I -1 techkaki
[root@myopensos ~]# chage –list techkaki
Last password change                    : Aug 19, 2010
Password expires                    : never
Password inactive                    : never
Account expires                        : never
Minimum number of days between password change        : 0
Maximum number of days between password change        : 99999
Number of days of warning before password expires    : 7

e) To set Account Expiry Date for an user

With option -E, You can set the account expiry date

[root@myopensos ~]# chage -E “2010-08-20″ techkaki
[root@myopensos ~]# chage -l techkaki
Last password change                    : Aug 19, 2010
Password expires                    : never
Password inactive                    : never
Account expires                        : Aug 20, 2010
Minimum number of days between password change        : 0
Maximum number of days between password change        : 99999
Number of days of warning before password expires    : 7

If you want to know more on how to use chage command, please type man chage to view the manual.

In Linux environment, we can view the calendar directly in the terminal. To do this, just simply use the “cal” command

cal command is used to display the calendar. Below are the syntax:-

cal [options] [month{1-12}] [year{1-9999}] 

OPTIONS:

Example:

To use this command, open a Terminal window and type the cal command:

By default, the command displays a calendar for the current month.

To display calendar for year 2010

To display calendar of the month Feburary 2010

If you wish to learn more how to use cal command, just type ‘man cal‘ for more details

In Windows XP/Vista/7, we can easily view the hidden files or folder by check the “view hidden file” option. How about linux? Linux do not have “view hidden file” option, any idea?

Here are the quick tip:-

# ls -a

or

# ls -la

Enjoy.