Author: Rahul

The tail command in Linux is a powerful tool used for displaying the end of a file. By default, it displays the last 10 lines of a file, but this can be modified by specifying a different number of lines to display. The tail command is often used to monitor log files, debug applications, or view the contents of a file in real time. Syntax The basic syntax for using the tail command is as follows:

where options are any optional flags or parameters that modify the behavior of the tail command, and the file is the name of…

An Orphan Process is a process that has lost its parent process, which normally takes care of cleaning up the process’s resources. In Unix/Linux, when a parent process terminates, its child processes become Orphan processes and are adopted by the init process, which becomes the new parent. Here’s a step-by-step guide to understanding and handling Orphan processes in Unix/Linux: Identifying Orphan Processes: To identify Orphan processes, you can use the ps command and look for processes with a parent process ID (PPID) of 1, which is the init process. For example: ps -eo pid,ppid,cmd | grep ‘^[ ]*[0-9]*[ ]*1’ Understanding…

Secure Shell (SSH) is a protocol used to remotely log into a Linux system and execute commands on it. It provides a secure encrypted connection between two untrusted hosts over an insecure network. System administrators often use SSH to remotely manage servers. Displaying a warning message to unauthorized SSH access is an important step in securing your Linux system. A warning message can inform users of security policies, warn them of the consequences of unauthorized access, and provide important information about the system they are accessing. In this article, we will guide you through the process of setting a custom…

Secure Shell (SSH) is a protocol used to remotely log into a Linux system and execute commands on it. SSH provides a secure encrypted connection between two untrusted hosts over an insecure network. It is commonly used by system administrators to remotely manage servers. One way to secure an SSH connection is by setting a custom SSH warning banner and Message of the Day (MOTD) in Linux. A warning banner is displayed when a user logs into the system using SSH, and the MOTD is displayed after the user logs in. In this article, we will guide you through the…

Reverse DNS, also known as rDNS, is a system that maps an IP address to a hostname. Unlike traditional DNS (Domain Name System), which maps a hostname to an IP address, rDNS performs the reverse process, providing an extra layer of information about the owner and location of a particular IP address. In this article, you will understand reverse DNS records, and why it is useful. Why Does Reverse DNS Matter? A reverse DNS record plays an important role in email delivery, security, network management, and many others: Email delivery: Reverse DNS is an important aspect of email delivery as…

Journalctl is a command-line utility for viewing system logs in Linux distributions that use Systemd. It’s an essential tool for system administrators to diagnose problems, monitor system performance, and track changes to the system. However, journal logs can consume large amounts of disk space, especially if they are not managed properly. In this article, we will explain how to automate the process of cleaning up journal logs in Linux systems using journalctl and cron. Before proceeding, it’s important to understand that journal logs contain important information that can help diagnose problems. It’s recommended to keep a few weeks’ worth of…

The Mate desktop is a popular and lightweight graphical user interface (GUI) for Linux systems. It provides a traditional and easy-to-use interface that can run on both high-end and low-end computers. If you’re looking to install the Mate desktop on Debian 11, this guide will walk you through the process step by step. Before getting started, it is recommended to back up any important data and files as the installation process may cause changes to your system. Additionally, ensure that your system is updated to the latest version and that you have administrative access to the computer. Step 1: Install…

When it comes to hosting a website, two of the most common options are virtual private server (VPS) hosting and shared hosting. Both have their pros and cons, and the right choice for your website will depend on your specific needs and budget. Shared hosting is the most basic and affordable type of hosting. With shared hosting, your website is hosted on the same server as other websites, and you share the server’s resources with these other websites. This means that your website will be subject to the same performance limitations as the other websites on the server. On the…

In a Linux system, the cron daemon is used to execute scheduled commands or scripts. By default, cron jobs run as the root user. However, sometimes it is necessary to run cron jobs as a non-root user, such as the www-data user. The www-data user is often used by web servers to run web applications and is usually used for security reasons to limit the damage that could be done by a malicious cron job. In this article, we will discuss the proper way to run crontab as the www-data user in a Linux system. Step 1: Determine the User…

The uptime command in Linux is a simple utility that displays the system uptime or the amount of time that the system has been running since its last reboot. The uptime command is commonly used to monitor the stability and availability of a system, as well as to determine the amount of time a user has been logged into the system. When the uptime command is run, it displays information about the system’s uptime, the number of currently logged-in users, the system load average, and the current time. Uptime Command Output Explained The output of the uptime command can be…