Author: Rahul

I, Rahul Kumar am the founder and chief editor of TecAdmin.net. I am a Red Hat Certified Engineer (RHCE) and working as an IT professional since 2009..

In the vast expanse of the digital universe, every website visit begins with an unseen but crucial process, as integral to your online journey as a compass is to navigation. This process is powered by the Domain Name System (DNS), a foundational technology of the internet. Understanding how DNS works is like unveiling the wizard behind the curtain of the online world. This article demystifies the Domain Name System, explaining its function, how it works, and why it’s essential for your browser to find websites. What is the Domain Name System (DNS)? The Domain Name System is often likened to…

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In the world of Bash scripting and Unix-like operating systems, the expression /dev/null 2>&1 frequently appears, often leaving newcomers puzzled. This article aims to demystify this cryptic-looking command, breaking down its components and explaining its practical applications. By understanding what each part of /dev/null 2>&1 does, you’ll gain insights into its utility and learn how to use it effectively in your scripts. What is /dev/null? To comprehend /dev/null 2>&1, we first need to understand what /dev/null is. In Unix and Unix-like operating systems, /dev/null is a special file that discards all data written to it but reports that the write…

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To undo a pull request on GitHub, a fresh pull request is generated that includes a single reversal of the merge commit from the initially merged pull request. Having write access to the repository is a prerequisite for reverting pull requests. This tutorial will guide you through the steps to effectively revert a merged pull request directly from the GitHub dashboard, ensuring that you can quickly rectify any issues and keep your project on track. Reverting Pull Request in GitHub Navigate to the Merged Pull Request: Go to the pull request you want to revert on GitHub. Revert the Pull…

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Ubuntu 22.04 LTS, codenamed “Jammy Jellyfish”, introduces a plethora of updates and features, enhancing the Linux desktop experience for users worldwide. One of the key features of this release is the inclusion of Wayland as the default display server, replacing the traditional X.Org Server for many configurations. Wayland offers a more modern and secure approach to handling graphical input and output, promising smoother animations and a safer desktop environment. However, certain applications and drivers may not fully support Wayland yet, necessitating some users to switch back to X.Org. This guide will walk you through the process of enabling and disabling…

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In the realm of programming, understanding how to work with dates and times is crucial for a vast array of applications, from scheduling systems to historical data analysis. Among these tasks, determining whether a year is a leap year is a common challenge. Leap years, which have 366 days instead of the usual 365, add a day to February to keep our calendar in alignment with the Earth’s revolutions around the Sun. This article provides a comprehensive guide on how to master leap year calculations in Java, offering a deep dive into the logic behind leap years and showcasing how…

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In the realm of Linux, managing file systems and data storage efficiently is a fundamental skill for users and administrators alike. One particularly useful technique involves automounting remote shares, allowing for seamless access to network storage as if it were local. This guide will walk you through the process of using the /etc/fstab file to automate the mounting of remote shares, enhancing your Linux system’s connectivity and data management capabilities. Understanding /etc/fstab Before diving into the specifics of automounting remote shares, it’s crucial to understand what /etc/fstab is. The File System Table, or fstab, is a configuration file in Linux…

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In the world of programming, solving practical problems with efficient and elegant code is a skill highly prized. One such problem, seemingly simple but fundamental, is determining whether a given year is a leap year. This article will guide you through understanding leap years, the logic behind identifying them, and how to implement a Python program to automate this determination. By mastering this leap, you’ll not only add a useful tool to your coding arsenal but also deepen your understanding of calendar arithmetic and conditional logic in Python. What Is a Leap Year? A leap year is a year that…

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In the world of programming, understanding how to manipulate and work with dates is fundamental. One common challenge is determining whether a given year is a leap year or not. Leap years, which occur roughly every four years, add an extra day to the calendar year, making February 29 days long instead of 28. This adjustment helps synchronize the calendar year with the astronomical year. In this tutorial, we will guide you through the process of writing an efficient C program to determine if a year is a leap year. Understanding Leap Year Logic Before diving into coding, it’s essential…

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In modern software development, dealing with JSON data is inevitable, especially when handling user information in web applications. JSON’s ability to nest objects within objects makes it a powerful tool for representing complex data structures. However, this complexity can also present challenges, particularly when you need to process, filter, and manipulate data for multiple users. This article explores advanced Python techniques for working with such nested JSON data, focusing on handling input for two users, filtering data based on specific conditions, and ultimately, enhancing your data manipulation capabilities. 1. A Sample Nested JSON Objects File A nested JSON object is…

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SSH (Secure Shell) keys are a pair of cryptographic keys used to authenticate to an SSH server as an alternative to password-based logins. A key pair consists of a public key, which you can share freely, and a private key, which must be kept secure. The PEM format, standing for Privacy Enhanced Mail, is a widely used format for storing and sending cryptographic keys, certificates, and other data. It is recognizable by its “—–BEGIN CERTIFICATE—–” and “—–END CERTIFICATE—–” headers and footers. Its popularity stems from its compatibility and ease of use across different systems and software. Generate SSH Key in…

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