2025-04-28 (3 UE): The Shell, And The OS

OS Concepts

From Introduction: Concepts and Terminology

• Overview

• Everything Is A File (Live Demo)

• Processes, Scheduling, Address Spaces

• Process Hierarchy (Parent, Child Process)

Shell Usage

From The Shell (Bash - “Bourne Again Shell”)

• Commandline

• Absolute and Relative Paths

• Special Paths

• Directory Listings: The ls Command

• Current Working Directory

• Creating And Removing Files and Directories

• Copying: cp

• Moving and Renaming: mv

• Symbolic Links, Hard Links

• Shell Configuration File: ~/.bashrc

Permissions

From File System Permissions

• Permissions: Mode, User and Group Ownership

SSH Setup

From SSH: Secure Shell

• SSH: Basics

• SSH: Public Key Authentication

• SSH: Secure Copy (scp)