Overview

As the Wikipedia definition says:

The strategy pattern is useful for situations where it is necessary to dynamically swap the algorithms used in an application. The strategy pattern is intended to provide a means to define a family of algorithms, encapsulate each one as an object, and make them interchangeable. The strategy pattern lets the algorithms vary independently from clients that use them.

Or in simpler terms, Instead of hardcoding an implementation that can vary according to the various classes. We on runtime inject the appropriate algorithm/behaviour that the class will need.

Big-O Notation

Section 1: What is it?

Big-O Notation helps us talk about the time taken by an algorithm to run given a particular input size.

Section 2: Why do we need it?

Imagine there are multiple solutions to a single problem but with different approaches/data structure, how do you know which one is better? Do you choose the solution that was the easiest to code or the solution you wrote and not the one your colleague did. Do we run both of them and decided by what is finished quicker? But what if one of the solutions is in a low-level/faster language than the other??

1. Overview

One of the most common administrative tasks while using Linux is finding out the disk space usage in our system. The most common command-line utilities to find the free disk space usage are the df (Disk Free) and du (Disk Usage commands).

In this tutorial, we will have a look at the common scenarios and usage of the du and df commands.

2. Common Usage Scenarios

We will be using the df and du commands interchangeably based on the information we are seeking, to check the amount of space used and free on our filesystem and partitions the df command is used additionally to check for space usage on a directory level the command du is used.

Introduction

The most mundane task a developer can be asked to do is creating new lang files (adding support for Spanish,German ) in your app. Unless you are using a library for dynamic translation in your app or browser capabilities,the whole process to convert the base language file (say English) to other languages is just time-consuming also if the software you are working on is huge, say 5k lines of text on the base language file. Converting the file manually will take you days.

Introduction

Being a Linux user and not coming across Regular Expressions or regex is next to impossible. I kept seeing the cryptic little set of characters everywhere and the people who could use it looked like ninjas to me. They are everywhere text editor's, JavaScript, Python, JAVA , Bash……and the list goes on.

What Exactly is a Regular Expression?

A regular expression is a string containing a combination of normal characters and special meta-characters or meta-sequences. The normal characters match themselves. Meta-characters and meta-sequences are characters or sequences of characters that represent ideas such as quantity, locations,or types of characters.

Do you have dreams about writing C shells by the sea shore? That makes two of us.

One of the many cool projects you can make while learning to program in the Linux environment is to make a command-line interpreter like the Bash shell or the command prompt in windows. In the process you will learn how to handle fork + exec calls and the various system calls associated with the working of a shell.