Secure Shell

Now that we have a good understanding of users and the shell, we’re ready to tackle the concept of a remote terminal. A foundational advantage of Linux is easy access to the Secure Shell daemon, known as sshd. This service allows a user to establish an encrypted shell session from anywhere in the world. On top of basic remote shell access, sshd provides a few nice perks: Secure file transfer over the same encrypted protocol. [Read More]

Navigating the CLI

The purpose of this post is to provide a general overview of the command line interface (CLI), and how to interact with it. So far, I have shown many things that you can do from the CLI, but haven’t covered exactly what the CLI is, what options it presents you, and how you can use it powerfully to save time. What Is the CLI, Anyway? The technical term for the CLI in Linux is a shell. [Read More]

Text Streams and Redirection

In my very first Linux Learning Series post, I outlined one of the guiding philosophies of UNIX: Write programs to handle text streams, because that is a universal interface. This post will cover how to work with text streams of different forms. Text Editors The first and most obvious form of text is a file with a text stream saved inside. This is the form most of us are used to, so we will start here. [Read More]

Daemons at your Service

In the days of UNIX, there were programs, users, and daemons. The Devil doth decreed the daemon was good! A daemon is so-named after a thought experiment known as Maxwell’s Demon, in which a hypothetical demon worked in the background in such a way to theoretically violate the 2nd law of thermodynamics. The thermodynamics are not relevant here, but the concept of an autonomous “background operator” is. A UNIX daemon typically ends with a “d”, to signify its intended operation. [Read More]

Users and Permissions

Building off the previous post, we now explore the dual topics of users and permissions. Multiple Users Linux is inherently a multi-user operating system. This can be quite confusing for desktop users of Windows or MacOS, and completely foreign to smartphone/table users. Using Windows as an example, it’s common for someone to have a username that matches their real name. Once they open the computer and type their password, that’s about as far as they get. [Read More]

File System Structure

If you successfully followed the tutorial in the previous post, you now have a fully-functional VM running Ubuntu 20.04 LTS. Nice! Going forward, I will dedicate each new post in the Linux Learning Series to a narrow topic. This allows me to keep the post frequency high, and allows you to take small manageable bites from an otherwise unmanageable topic. In these early posts I may present some information that seems out of place. [Read More]

Virtual Machines

A Brief History of CPU Clock Speeds In the last decade, the concept of a virtual machine (VM) has really come into prominence. Until roughly the mid 2000s, the benchmark of any good central processing unit (CPU) was its clock speed. Measured in Hz, clock speed represents the number of times per second that a CPU can execute a full instruction cycle. The very first computer I ever owned had an Intel Pentium processor, clocked at 60 MHz. [Read More]

Linux — Introduction

I’m a big Linux junkie, this is known. I will speak highly of it until blue in the face. The critical question, dear reader, is why should you care? My previous post was highly philosophical — fond memories of childhood, seasoned lightly with a dose of paranoia and distrust of the modern panopticon. A unique flavor profile! This will be a brief primer, intended to list a few important points. [Read More]

But First…

An Origin Story I remember the first time I encountered Linux in the wild. It was a summer afternoon between my Freshman and Sophomore year in high school. I lived two blocks from a downtown shopping center, and often walked there to get out of the house. Before I got a sandwich at the barbecue place, I would stop at the bookstore and browse the magazine section. I was learning how to play guitar, and I could learn a new song by flipping through the latest issues of Guitar Player and Guitar World. [Read More]
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