Author: Rahul

The $PATH variable in Linux is an environment variable that determines where the shell looks for executable files. By adding directories to this variable, you make it easier to run your scripts from anywhere without having to specify the full path to the script’s location. This guide will walk you through how to add a directory to your $PATH variable. Requirements You’ll need: Access to a Linux shell, either through a terminal emulator or by logging into a Linux-based server. Basic knowledge of command line operations. Permission to modify the .bashrc or .bash_profile file. Step-by-step Guide Locate the .bashrc or…

Python, as a flexible and intuitive language, introduces many constructs that enable the ease of coding. One such construct is the underscore ( _ ), a special character with multiple uses, ranging from variable naming to interpreter purposes, and more. For novice programmers, underscores might appear confusing, but understanding their purpose can significantly enhance your Python programming prowess. This article delves into an in-depth exploration of Python underscores, demystifying their diverse usages and significance. Single Underscore As a Throwaway Variable Often in Python, we come across a situation where we need to iterate over a range or any iterable, but…

In the vast landscape of the Linux operating system, understanding the intricacies of various system directories is key to effective system administration. The Linux directory structure holds a set of directories, each with a unique purpose, and among these is the “/etc/profile.d/” directory. This directory plays a crucial role in system configuration, providing a hub for script execution during system startup. What is the /etc/profile.d/ Directory? The “/etc/profile.d/” directory is an integral part of the Linux system, where shell-specific configuration scripts are kept. It’s associated with the “/etc/profile” file – a startup script that initializes an environment upon the start…

Apache CouchDB is a database management system that seamlessly takes the data to the edge and then back again. It’s known for its ease of replication and setup. If you want to install Apache CouchDB on your Ubuntu or Debian system, you’re at the right place. In this tutorial, we’ll guide you through the steps to install Apache CouchDB on your machine. Note: The instructions given below are for CouchDB version 3.x, and the system we are using is Ubuntu 22.04 LTS and Debian 11. You may need to adapt slightly if you are using a different version of either.…

Apache is a versatile, open-source HTTP server for modern operating systems including UNIX and Windows. It provides a secure, efficient, and extensible server that provides HTTP services in sync with the current HTTP standards. In this article, we’ll delve into the specifics of configuring Apache’s Userdir on Ubuntu and Debian. Userdir is a module that enables users to view their sites by entering a tilde (~) followed by their username. By configuring this module, you can set up Apache to serve files from a specific directory in the user’s home directory – typically public_html. Prerequisites Before we start, make sure…

Linux, the backbone of many computer systems around the world, is known for its versatility and robustness. An integral part of mastering Linux involves becoming familiar with its package management systems. In this guide, we’ll delve into DNF (Dandified YUM), a next-generation, powerful, and user-friendly software package manager for RPM-based Linux distributions. We’ll discuss how to use it effectively with practical examples and insights. Understanding the DNF Command DNF, introduced with Fedora 18, is the default package manager for Fedora, RHEL, and CentOS distributions. It replaced the older YUM (Yellowdog Updater, Modified) due to its superior dependency resolution and simpler…

In Bash scripting, a host of operators is available to manipulate, compare, and test data. One of the operators is the =~. Though not very frequently used, it is an extremely powerful operator that enables us to match string patterns using regular expressions. This article goes into the practical application of the =~ operator in Bash. Understanding the =~ Operator The =~ operator is unique to Bash, and used in conditional expressions. This operator will be used normally to compare a string with a given pattern in regular expressions. Whether the string matches with the pattern, it displays 0 for…

MySQL is one of the most popular open-source relational database management systems, relied upon by countless developers and companies worldwide. At its core, it operates on a simple concept – storing data in tables. As the volume of data increases, it becomes essential to optimize these tables for efficient storage and faster retrieval. This article will provide a comprehensive guide to optimizing MySQL tables, with practical examples for better understanding. Understanding Table Optimization Table optimization, in the context of MySQL, refers to the process of managing data storage effectively and enhancing the speed of data retrieval operations. By optimizing tables,…

Bash, the Bourne Again SHell, is one of the most widely used shell scripting languages due to its compatibility with Unix and Linux systems. It offers a host of built-in functions and variables that make scripting more efficient and less error-prone. One such variable is `$?`, an integral part of error handling in Bash scripting. This special variable holds the exit status of the last command that was executed, which is crucial for controlling the flow of scripts based on command success or failure. 1. Understanding Exit Statuses Before we delve into the specifics of `$?`, it’s essential to understand…

Secure File Transfer Protocol (SFTP) is a protocol that provides a secure and reliable mechanism for accessing, transferring, and managing files on remote systems over an SSH connection. In this article, we’ll walk you through the process of setting up an SFTP server on a CentOS/RHEL system. Prerequisites Before getting started, ensure that you have: A CentOS/RHEL system installed. Root or sudo user access to the system. An internet connection for downloading necessary packages. Step 1: Update your System First, make sure your system is up-to-date by executing the following command: sudo yum update -y Step 2: Install SSH Server…