Found 572 Articles for Linux

Generating an SHA-256 Hash From Command Line

Satish Kumar
Updated on 14-Mar-2023 16:31:49
As technology becomes increasingly integrated into our daily lives, security concerns continue to grow. It's more important than ever to ensure that our data is secure and protected from cybercriminals. One way to help protect data is to use a hash function. SHA-256 is one such hash function that can be used to create a unique digital fingerprint for data. In this article, we'll explore how to generate an SHA-256 hash from command line. What is SHA-256? SHA-256 is a cryptographic hash function that takes input data and produces a fixed-length output, or hash, of 256 bits. function is designed ... Read More

Introduction to Iptables

Satish Kumar
Updated on 14-Mar-2023 16:31:19
Introduction to iptables Iptables is a Linux-based firewall application that controls incoming and outgoing traffic. It is a powerful tool that can be used to secure a server, limit access to specific applications or services, and mitigate risk of malicious attacks. This article will provide an introduction to iptables, its purpose, and its basic usage. What is iptables? Iptables is a firewall application that works with Linux kernel. It controls incoming and outgoing traffic and provides a mechanism to filter, block, or allow traffic based on various criteria, such as port number, IP address, protocol, and more. Iptables is designed ... Read More

Tracking Down Where Disk Space Has Gone on Linux

Satish Kumar
Updated on 14-Mar-2023 16:30:54
As a Linux user, you might have come across a situation where you ran out of disk space, but you are not sure where all space has gone. It can be frustrating, but fortunately, there are several tools and techniques you can use to track down where disk space has gone on Linux. In this article, we will cover following sub-headings to help you identify where your disk space has gone − Check Disk Usage The first thing to do is to check disk usage of your system. Linux has several command-line tools that can help you do that. most ... Read More

What does opt mean in Linux

Satish Kumar
Updated on 14-Mar-2023 16:30:28
Linux is a popular operating system that is widely used for its open-source nature and flexibility. Linux command line interface (CLI) is a powerful tool that allows users to control and manipulate their system. One of most commonly used commands in Linux CLI is "opt." In this article, we will explore what opt means in Linux, and how it can be used to optimize your system. What is opt in Linux? The opt command is a command-line option that is used to modify behavior of a command or utility. It is used to specify optional arguments that may or may ... Read More

What Does a Double-Dash in Shell Commands Mean

Satish Kumar
Updated on 14-Mar-2023 16:30:03
Introduction If you are familiar with command line interface, you have probably encountered a double-dash (--) in some of commands you use. This article seeks to explain what double-dash means and how it affects behavior of shell commands. What is a Double-Dash in Shell Commands? A double-dash is a syntax used in shell commands to signify end of command options and beginning of positional arguments. In other words, it separates command options from arguments that command operates on. Many shell commands allow you to specify options or flags that modify behavior of command. For example, ls command allows you to ... Read More

Append Lines to a File in Linux

Satish Kumar
Updated on 14-Mar-2023 16:29:30
Introduction In Linux, files are often used to store data that is either created by a program or generated by user. It is common for users to append new lines of data to existing files rather than creating new ones from scratch. This article will explain how to append lines to a file in Linux, including several subheadings and examples. Using echo command The easiest way to append new lines to a file is by using echo command. echo command allows you to display a message on screen, but it can also redirect message to a file. Here's how to ... Read More

Recursively List All Files in a Directory Including Symlinks

Satish Kumar
Updated on 14-Mar-2023 16:28:57
Introduction When it comes to managing files and directories in any operating system, being able to list all files in a directory is an essential task. However, it becomes a bit more complicated when you need to recursively list all files in a directory, including symlinks. This is particularly important for developers and system administrators who work with large, complex file systems. In this article, we will cover how to recursively list all files in a directory, including symlinks, with examples and subheadings. What is a symlink? A symlink, also known as a symbolic link or soft link, is a ... Read More

Repeat a Linux Command at a Given Interval

Satish Kumar
Updated on 14-Mar-2023 16:25:57
Linux is a powerful operating system that offers a wide range of command-line tools for executing various tasks. One of tasks that often need to be performed is repeating a command at a given interval. This feature can be useful for several reasons, such as monitoring system performance, running scheduled tasks, and performing backups. In this article, we will explore how to repeat a Linux command at a given interval. We will discuss various ways to achieve this, including using cron utility, watch command, and sleep command. Using Cron to Repeat a Command The cron utility is a time-based job ... Read More

Recursive Search and Replace in Text Files in Linux

Satish Kumar
Updated on 14-Mar-2023 16:25:11
One of most basic and frequently performed tasks in any operating system is search and replace. This becomes even more crucial when working with text files, where multiple instances of same word or phrase may be scattered throughout document. In such cases, manually editing each instance can be both time-consuming and error-prone. In this scenario, a tool like Recursive Search and Replace in Linux comes in handy. In Linux, Recursive Search and Replace can be done via various methods. most common one involves use of command-line tools like Sed, Awk, and Perl. These tools are efficient, lightweight, and have been ... Read More

Save Modifications In-Place with AWK

Satish Kumar
Updated on 14-Mar-2023 16:24:37
Introduction The awk command is a versatile tool used in Unix and Linux environments for text processing and manipulation. One of its key features is ability to modify files in-place, which is particularly useful when working with large datasets. In this article, we will explore how to save modifications in-place with awk, including examples and subheadings to aid understanding. Understanding Awk Before we delve into how to save modifications in-place with awk, it's important to understand what awk is and how it works. Awk is a programming language designed for processing text files, with primary focus on processing rows of ... Read More
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