Linux File & Folder Permissions

File & folder security is a big part of any operating system and Linux is no exception!

These permissions allow you to choose exactly who can access your files and folders, providing an overall enhanced security system. This is one of the major weaknesses in the older Windows operating systems where, by default, all users can see each other's files (Windows 95, 98, Me).

For the more superior versions of the Windows operating system such as NT, 2000, XP and 2003 things look a lot safer as they fully support file & folder permissions, just as Linux has since the beginning.

Together, we'll now examine a directory listing from our Linux lab server, to help us understand the information provided. While a simple 'ls' will give you the file and directory listing within a given directory, adding the flag '-l' will reveal a number of new fields that we are about to take a look at:

Creating Simple RSS Reader as an Android Application

RSS is a family of web feed formats used to publish frequently updated works. Such as blog entries, news headlines,audio and video in a standardized format. - wikipedia-

Basically RSS are xml files. We can read RSS files using applications called RSS Readers. In this post, I am going to write about how to create a simple RSS Reader application in Android platform.

In this example, I have used an external 'xml'(RSS) of the website.

RSS Link: http://www.mobilenations.com/rss/mb.xml

Installing Nodejs in Ubuntu

Simply execute the following commands in Ubuntu Terminal


sudo apt-get install python-software-properties python g++ make
sudo add-apt-repository ppa:chris-lea/node.js
sudo apt-get update

sudo apt-get install nodejs

Introduction to shell script

Before going to start the shell script programming we mush know what is kernel? , what is shell?, what is process?, and what is redirection, pipe and filter?

What is kernel?
Kernel is heart of Linux OS. It manages resources in Linux OS. The resources means the facilities available in Linux. For example, facility to store the data,  print data on printer, memory and file management and etc.Kernel decides who will use this resource, for how long and when.

What is Linux Shell?
In early days of computing, instructions are provided using binary language, which is difficult for all of us to read and write. So, in Linux, there is a special program called Shell. Shell accepts our instruction or commands in English and translate it into computers native binary language.

What is Process?
Process is a kind of program or task carried out by our PC. For example, $ ls is the command to list files and folders in current directory. It a kind of process. A process is a program to perform some job.

What is Redirection?
Mostly all commands gives output on screen or takes input from keyboard, but in Linux it is possible to send output to file or to read from file. This is called redirection.

For example,

Logging Levels

In software development, logging is refers to recording the activities. There are several logging framework for java platform. 

Logging is divided into three pieces. 
1.Logger 
2. Formatter
3. Handler (Appender)

Logger is responsible for capturing the message to be  logged along with the initial meta-data. After receiving the message the framework calls the formatter with the message. The formatter formats it for the output.
Then the framework handle the formatted message to the appropriate appender for disposition. this might include in a console display.

The messages are logged in certain level. The following are the six logging levels used by log (in order).

1. FATAL : (Highest level) shows messages at a FATAL level only. This level is straightforward and you don't get it quite often. Once you get this level and it indicates application death. This shows the error messages that cause premature termination.

2. ERROR: This shows messages classified as ERROR and FATAL. This level gives information about a serious error which needs to be addressed and may result in unstable state. This level is one level higher than WARN.

3. WARN: This level shows messages classified as WARN, ERROR, and FATAL. This level gives a warning about an unexpected event to the user. This warning messages may not halt the progress of the system.

4. INFO: This level shows messages classified as INFO, WARN, ERROR, and FATAL. This level gives the progress and chosen state information. This level will be useful for end user. 

5. DEBUG: This shows messages classified as DEBUG, INFO, WARN, ERROR, and FATAL. This level helps developer to debug the application. This logged message will be focused on providing support to application developer.

6. TRACE :(Lowest level) Actually we don't use this level often. But this would be extremely for more detailed and potentially high volume logs. So you don't need typically enabled even during normal development.

 

Yarl Geek Challenge

Yarl Geek Challenge is a kind of competition organized by Yarl IT Hub. I decided to participated this competition. We formed a team with the team member Lukshica, Vanaja, Vijay and me. The team lead is lukshica.
But there are some topics we have thought.
1. பல்லாங்குழி

This is a traditional game played by Sri Lankan and Indian Tamils. I think when I was at 10 year old I have played this game. This game is also one of the most interesting game that I have played. The rules and regulations are differ by different peoples.

Therefore we had interested to develop this game as a mobile app.After that we google it weather it is already exist or not. But there was an application we have found.
https://play.google.com/store/apps/details?id=com.nrace.android.pallankuli&hl=en

So, we decided to change our ideas.

Now I would like to write other ideas on another posts.

Today i created a blogs