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Security is paramount in any GNU/Linux environment. One common concern is the visibility of passwords, especially when using sudo. By default, when you type your password for sudo, nothing is displayed on the screen. This "blank" input is a security measure, but some users prefer to see asterisks (*) or other characters as they type to confirm that something is being entered. This guide will explore how to configure your GNU/Linux system to display asterisks or other masking characters when typing your sudo password, along with important security considerations. But Why Mask Passwords? Actually, The primary reason for masking ... Read More
The power and flexibility of Linux is deeply intertwined in its shell environment. Understanding how shell initialization files and user profiles work is crucial for customizing your Linux experience and optimizing your work-flow. These files control everything from your command prompt appearance to the environment variables available to your shell sessions. In this tutorial, we will explore the intricacies of shell initialization files, explaining their purpose, differences, and how to effectively use them. What are Shell Initialization Files? Shell initialization files, often referred to as "dotfiles" because of their leading dot (making them hidden by default in file managers), are ... Read More
The Linux boot process, while seemingly complex, is a well-defined sequence of events that brings your system from a powered-off state to a fully functional operating system. Understanding this process is crucial for troubleshooting boot issues, customizing your system, and gaining a deeper understanding of Linux internals. In this tutorial, we will provide a basic overview of the Linux boot process, explaining each stage in detail. The Stages of the Linux Boot Process The Linux boot process can be broadly divided into the following stages − BIOS / UEFI − Basic I/O System or Unified Extensible Firmware Interface. MBR ... Read More
The Linux command line is a powerful environment for automating tasks and managing your system. While the built-in commands are highly versatile, creating custom shell functions and libraries can significantly enhance your work-flow, allowing you to encapsulate complex operations into reusable and easily accessible units. Read this tutorial to learn how to write, use, and manage custom shell functions and libraries in Linux. Why Use Custom Shell Functions and Libraries? Before we dive into the "how, " let's understand the "why." Custom shell functions and libraries offer several key advantages − Automation − Automate repetitive sequences of commands, saving ... Read More
Have you ever wondered how to accelerate your daily Linux system administration tasks in an efficient and simpler way? If yes, then you might probably heard that Bash (Your Daily Linux Shell) and as any interpreter out there has a lot which can be used to automate various Linux-related tasks. In this tutorial, we will explain how to use one of the built-ins in Bash (Functions) to get your task quickly done. Table of Contents What are Bash Functions? Benefits of using Bash Functions Getting started with ... Read More
A bytestring in Python is a sequence of bytes, represented using the bytes data type in Python 3. Bytestrings are primarily used to handle binary data or data that doesn't conform to the ASCII or Unicode encodings, such as images, audio files, and more. They are crucial for tasks that require low-level data manipulation. Creating a Bytestring To create a bytestring in Python, prefix a string literal with the letter b. This indicates to Python that the string should be interpreted as a sequence of bytes. Example In this example, we create a bytestring with the contents "This is a ... Read More
In Python, there are several methods to check if a given character in a string is an alphabetic letter. Here, we'll explore three effective techniques: using the isalpha() method, the string module, and regular expressions. Using the isalpha() method The isalpha() method is a built-in method in Python that returns True if all the characters in a string are alphabets (letters) and False otherwise. Example In this example, we have a string "Hello World" and we want to check if the character at index 1 is a letter. We use the isalpha() method to check if the character is ... Read More
In this article, we will discuss how to count the maximum number of disjoint pairs in an array, where for each pair (x, y), one element is not less than K times the other. The goal is to find the number of such valid pairs in the array using C++. Given an array of integers, the task is to find all pairs (i, j) such that: arr[i] > K * arr[j] or arr[j] > K * arr[i] holds true for a given constant K. The condition is that no element ... Read More
In this article, we will learn how to count pairs of numbers from a given array where the bitwise AND of the two numbers is greater than the bitwise XOR. Bitwise operations work on the individual bits of numbers. The AND operation results in 1 only when both bits are 1, while XOR gives 1 when the bits are different. Given an array of integers, we need to count how many pairs (i, j) exist such that the bitwise AND of the pair is greater than the bitwise XOR. In other words, for each pair of elements in the ... Read More
In this article, we will discuss how to create a C++ program to generate the mirror image of a matrix across its diagonal. The diagonal mirror of a matrix means that we swap the elements at symmetric positions with respect to the diagonal. Let's break down the problem step by step and then look at the code that solves this problem. Understanding the Problem For any given matrix, the mirror image across the diagonal means that the element at position (i, j) will be swapped with the element at position (j, i). This operation is also known as transposing ... Read More