Day 1 Summary
This summary outlines the key concepts from the first day, focusing on Linux fundamentals, the graphical environment, and basic command-line proficiency.
Course Introduction
- Course Goal: To provide the fundamental skills required for Red Hat Enterprise Linux (RHEL) administration.
- Target Audience: Professionals new to Linux, including Windows system administrators, network administrators, and anyone needing core Linux skills.
Getting Access to RHEL for Free
A no-cost Red Hat Developer Subscription for Individuals is available at developers.redhat.com. This free program provides access to Red Hat Enterprise Linux Server, software collections, and developer tools, making it perfect for learning.
Session 1: An Introduction to Linux
This session covers the history of Linux, its core components, and the basic principles of interacting with the system.
Core Concepts
- History: Linux is a UNIX-like operating system kernel created by Linus Torvalds in 1991. It was combined with GNU project utilities to form a complete, free, and open-source operating system.
- The Linux Model: The system is viewed as layers, with the Hardware at the center, followed by the Kernel (manages hardware and processes), Utilities (commands), and the Shell (user interface).
- The Shell: The command-line interpreter that allows users to interact with the kernel. The default shell in RHEL is the Bash Shell.
- Login Sessions: Users log in with a username and password. Linux is a multi-user, multi-tasking system, allowing multiple users to be logged in and run programs simultaneously.
Session 2: The Graphical Environment
This session explores the graphical user interface (GUI) available in RHEL, which provides an intuitive desktop experience for managing files and system settings.
GNOME Desktop
RHEL uses the GNOME desktop environment. Key features include:
- Activities Overview: The main entry point for launching applications, managing workspaces, and searching.
- The Dock: A bar for launching favorite and running applications.
- File Manager (Nautilus): A graphical tool for navigating the filesystem, copying, moving, and deleting files.
- Terminal: The application used to access the command-line shell from within the GUI.
- System Settings: A centralized panel for configuring networking, displays, users, and other system properties.
Session 3: Basic Commands and Bash Environment
This session introduces the fundamental syntax for using the command line, getting help, and performing basic tasks.
Command Syntax
Commands follow a standard structure: command [options] [arguments]. Options modify a command's behavior, while arguments specify what the command acts upon.
Getting Help
Linux provides extensive built-in documentation.
| Command | Description |
|---|---|
man <command> | Displays the manual page for a command. |
<command> --help | Shows a brief usage summary for a command. |
Essential Commands
| Command | Description |
|---|---|
who | Shows who is currently logged into the system. |
date | Displays the current date and time. |
cal | Displays a calendar for the current month. |
passwd | Changes the current user's password. |
clear | Clears the terminal screen. |
echo "text" | Prints text to the terminal. |
Input/Output Redirection
- Piping (
|): Sends the output of one command as the input to another. Example:ls -l | less - Output Redirection (
>,>>): Redirects a command's output to a file, overwriting (>) or appending (>>).