VI, VIM Commands , Cheat Sheet

Vi is a default editor in Linux operating systems. Vim is basically the improved version of the Vi editor. In this tutorial, We will learn Vi commands.
If you are new to Linux operating system and you don’t know how to start with Vi, Vim editor then in this tutorial we’ll important commands and their usage .

vi,vim editor beginners guide

Top ten most useful Linux commands for beginners

I already mentioned Vi is a default editor in Linux , Ubuntu and all other flavors of Unix operating system. To use Vim editor you need to installed it first.

php.ini File Location in Ubuntu – How to Find, Open & Edit php.ini

php.ini file location in ubuntu

What is the php.ini file, why we use it ? Where do I find this file on  Ubuntu ? How I open and edit the php.ini file on a terminal. This is the most common questions asked by beginners who are either new to PHP or Linux.

php.ini File

The php.ini file is a default configuration file used when your PHP application runs. When PHP starts it reads the configuration setting from the php.ini file.

If you have installed LAMP on a Ubuntu operating system and unable to find and edit this file then this tutorial is for you.

Recursion Concept with Example

What is recursion and how to use recursion in programming. If you are new to programming, then recursion concept is tough to understand. In this post, i’ll explain the concept of recursion with example.

What is Recursion ?

In Recursion, function call itself repeatedly, until the base condition is reached.  It’s a much preferred way to write cleaner and shorter code for many complex problems.

Through recursion, you can reduce complex problem into smaller version.

How to check system configuration on Ubuntu using command


How to check the system configuration on Ubuntu 12.04 using terminal command.

I am using Ubuntu 12.04 but the command i am going to write it’s working on previous version also.
If you are new to Ubuntu then you find difficulty to check the system configuration of Ubuntu.

How to check

Open the terminal and write the folowing command

cat  /proc/meminfo

cat  /proc/cpuinfo



It will show all the information. If you want specific thing to show like if you want to check only the Model then use the command written below.

cat /proc/cpuinfo | grep -i ‘Model’

It will show information like this


model        : 42
model name    : Intel(R) Pentium(R) CPU G630 @ 2.70GHz
model        : 42
model name    : Intel(R) Pentium(R) CPU G630 @ 2.70GHz

How to extract .rar files in ubuntu/Linux



Extract .RAR files in Ubuntu



While working on ubuntu i tried to extract .rar file but it failed to extract and shows the error that archive type not supported.

So how to extract .rar files on Linux

Go to terminal and type following command

sudo apt-get install unrar 


After installing unrar on your system right click on rar file and extract them it will easily extract there.

Extract .RAR file in linux

How to Enable/Install apache mod_rewrite and mod_headers in ubuntu

Last week while i was working on url rewriting i face the problem. I had written the rule in .htaccess but forget to enable the mod_rewrite. Remember your .htaccess rule will not work until you enable the mod_rewrite.

How to install apache2 on ubuntu

Go to terminal (ctrl+Alt+T) and write the following command

Once apache2 installation is complete. Write the command mentioned below to enable mod_rewrite

After enable the mod_rewrite do the changes on following file

After done the changes restart the apache.

To restart apache2

Enable mod_headers in apache

Remember to restart apache 

So to restart apache2 write through terminal

Find Duplicate Elements in an Array – Java Program

Write a java program to find duplicate elements in an array. There are multiple ways through which we can find duplicate elements in an array. In this tutorial, I’ll discuss three ways to find duplicate elements in an array.
This question is also very important in terms of technical interviews.

Selection Sort Program in C – Sorting Algorithm

Write a selection sort program in C. How selection sort algorithm works and what’s their time complexity.

What is Selection Sort

Selection sort is an in-place comparison sort. Like bubble sort time complexity of Selection sort is also O(n^2). It is not suitable for large elements.