Linux: The Operating System That Powers the World

# Check your kernel version
uname -r
# Output: 6.6.10-arch1-1

# The kernel manages:
# - Memory allocation
# - CPU scheduling
# - Hardware drivers
# - File systems
# - Network protocols

# Want to change your login screen? Easy.
sudo systemctl enable lightdm

# Prefer a different one?
sudo systemctl enable gdm

# Don't want a graphical interface at all?
sudo systemctl set-default multi-user.target

# Minimal and lightweight (~200MB RAM)
sudo pacman -S i3-wm

# Feature-rich and modern (~500MB RAM)
sudo pacman -S plasma-desktop

# Beautiful and intuitive (~700MB RAM)
sudo pacman -S gnome

# Arch Linux (pacman)
sudo pacman -S firefox vlc gimp

# Ubuntu/Debian (apt)
sudo apt install firefox vlc gimp

# Fedora (dnf)
sudo dnf install firefox vlc gimp

# One command installs everything
# Updates ALL software at once
sudo pacman -Syu

# Check what's already installed
python --version
git --version
gcc --version
ssh -V

# Install development tools instantly
sudo pacman -S base-devel nodejs npm docker postgresql

# Set up a web server in seconds
sudo pacman -S nginx
sudo systemctl start nginx
# Your server is running!

# Check system uptime
uptime
# 237 days, 14:23 - Common for Linux servers!

# Security features:
# - Built-in firewall (iptables/nftables)
sudo ufw enable

# - SELinux/AppArmor for access control
# - Regular security patches
# - No built-in telemetry or tracking
# - Encrypted home directory support

# Check your RAM usage
free -h
#               total        used        free
# Mem:           16Gi       2.1Gi       12Gi

# See what's using resources
htop

# Linux runs smoothly on:
# - 15-year-old computers
# - Raspberry Pi ($35 computer)
# - Servers with minimal resources

# Pros:
# - Massive community support
# - Works out of the box
# - Great hardware compatibility
# - Regular LTS (Long Term Support) releases

# Best for:
# - Linux newcomers
# - Users who want it to "just work"
# - People transitioning from Windows

# Installation:
# Download Ubuntu ISO → Burn to USB → Boot → Install
# Total time: 20 minutes

# Pros:
# - Familiar desktop layout
# - Based on Ubuntu (stable)
# - Includes media codecs
# - Beginner-friendly

# Best for:
# - Former Windows users
# - People who want stability
# - Non-technical users

# Pros:
# - Latest software versions
# - Red Hat backed
# - Great for developers
# - Excellent security features

# Best for:
# - Software developers
# - People who want new features
# - Red Hat/CentOS ecosystem users

# Pros:
# - Made by System76 (hardware company)
# - Auto-tiling windows
# - NVIDIA support out of box
# - Clean, modern interface

# Best for:
# - Developers and creators
# - Machine learning practitioners
# - Gaming on Linux

# Philosophy: "Keep It Simple, Stupid" (KISS)
# You build the system from scratch

# Pros:
# - Rolling release (always up-to-date)
# - AUR (Arch User Repository) - 80,000+ packages
# - Bleeding-edge software
# - Complete control
# - Legendary documentation (Arch Wiki)

# Cons:
# - Requires manual installation
# - Steeper learning curve
# - Can break if you don't read update notes

# Best for:
# - Experienced users
# - Those who want to learn Linux deeply
# - People who love customization

# Arch-based but user-friendly

# Pros:
# - Arch benefits without manual installation
# - Tested updates (more stable than pure Arch)
# - Multiple desktop environments
# - Hardware detection tools

# Best for:
# - Users who want Arch but easier
# - Intermediate Linux users

# Pros:
# - Declarative configuration
# - Atomic upgrades and rollbacks
# - Perfect for DevOps
# - Reproducible builds

# Best for:
# - DevOps engineers
# - Advanced users
# - Those who value reproducibility

# One update command keeps EVERYTHING current
sudo pacman -Syu

# No version upgrades (18.04 → 20.04 → 22.04)
# No reinstallation needed
# Always have the latest software

# Install anything with yay (AUR helper)
yay -S spotify          # Music streaming
yay -S visual-studio-code-bin  # VS Code
yay -S google-chrome    # Chrome browser
yay -S discord          # Discord
yay -S slack-desktop    # Slack

# Over 80,000 packages
# Community-maintained
# If software exists, it's probably in AUR

# Arch installs ONLY what you need
# No bloatware
# No pre-installed software you'll never use

# My base system installation:
# - Kernel + essential tools
# - Package manager
# - Network manager
# Total size: ~1GB

# Then I add exactly what I want:
sudo pacman -S i3-wm kitty firefox neovim
# Perfect development environment: ~2GB total

# Need to set up:
# - Dual boot? → wiki.archlinux.org/title/Dual_boot
# - NVIDIA drivers? → wiki.archlinux.org/title/NVIDIA
# - Sound system? → wiki.archlinux.org/title/PulseAudio

# Every topic is:
# - Comprehensive
# - Up-to-date
# - Written by experts
# - Useful for ALL Linux distros

# Installing Arch teaches you:
# - Disk partitioning
# - Bootloader configuration
# - System architecture
# - Package management
# - Network configuration

# After installing Arch, you UNDERSTAND Linux
# Not just USE it

# My development setup
# Window Manager: i3
# Terminal: kitty
# Editor: Neovim
# Browser: Firefox Developer Edition
# Version Control: Git

# Install everything:
sudo pacman -S i3-wm kitty neovim firefox-developer-edition git

# Total RAM usage: 400MB
# Compare to VS Code on Windows: 2GB+

# Linux dominates server infrastructure

# Install web server
sudo pacman -S nginx

# Database
sudo pacman -S postgresql

# Container platform
sudo pacman -S docker docker-compose

# Reverse proxy
sudo pacman -S nginx certbot

# Monitor everything
sudo pacman -S htop iotop nethogs

# Linux has professional creative tools

# Video editing
sudo pacman -S kdenlive

# Image editing
sudo pacman -S gimp inkscape

# 3D modeling
sudo pacman -S blender

# Audio production
sudo pacman -S ardour audacity

# Gaming has improved dramatically

# Steam with Proton (runs Windows games)
sudo pacman -S steam

# Lutris (game launcher)
sudo pacman -S lutris

# Wine (Windows compatibility layer)
sudo pacman -S wine

# Many games run as well or BETTER on Linux:
# - CS:GO, Dota 2, TF2 (native)
# - Cyberpunk 2077, Elden Ring (Proton)
# - Thousands more via Steam Deck compatibility

# Use a Live USB to test Linux
# No installation needed!

1. Download Ubuntu ISO
2. Use Rufus/Etcher to create bootable USB
3. Boot from USB
4. Try Linux without changing your system

# Test:
# - Hardware compatibility
# - Desktop environments
# - Basic software
# - Network connectivity

# Steps:
1. Shrink Windows partition (leave 50GB+ for Linux)
2. Boot Linux USB
3. Install alongside Windows
4. GRUB bootloader lets you choose OS at startup

# Boot menu:
# > Arch Linux
#   Windows 11
#   Advanced options

# Install VirtualBox (free)
# Create virtual machine
# Install Linux inside VM

# Pros:
# - Zero risk to main system
# - Easy to experiment
# - Can run Windows and Linux simultaneously

# Cons:
# - Performance overhead
# - Limited hardware access

# Navigate directories
cd /home/user/Documents
pwd  # Print working directory
ls -la  # List all files (detailed)

# Create, copy, move, delete
mkdir my_project
cp file.txt backup.txt
mv file.txt /home/user/
rm unwanted.txt
rm -rf directory/  # Delete folder and contents

# Package management (Arch)
sudo pacman -Syu  # Update system
sudo pacman -S package_name  # Install
sudo pacman -R package_name  # Remove

# System information
uname -a  # Kernel info
lsb_release -a  # Distro info
df -h  # Disk usage
free -h  # Memory usage

# View processes
ps aux  # All processes
top  # Live process monitor
htop  # Better process monitor

# Manage processes
kill PID  # Stop process
killall firefox  # Stop all Firefox processes

# Network info
ip addr  # IP addresses
ping google.com  # Test connectivity
curl https://api.example.com  # HTTP requests

# Network tools
nmcli device wifi list  # List WiFi networks
nmcli device wifi connect SSID password PASSWORD

# View permissions
ls -l file.txt
# -rw-r--r-- 1 user user 1234 Jan 24 file.txt

# Change permissions
chmod 755 script.sh  # Make executable
chmod 644 document.txt  # Read/write for owner

# Change ownership
chown user:group file.txt

# Installing software:
# Windows: Google → Download → Run installer → Next, Next, Next
# Linux: sudo pacman -S firefox

# Updates:
# Windows: Windows Update + Manual updates for each app
# Linux: sudo pacman -Syu (updates EVERYTHING)

# Check hardware compatibility
lspci  # List PCI devices
lsusb  # List USB devices

# Most hardware works out of box
# Exception: Some WiFi cards and NVIDIA GPUs
# Solution: Install proper drivers (easy with wiki)

# Check hardware before buying
# Look for "Linux compatible" or check online forums

# Snapshots (Timeshift)
sudo pacman -S timeshift
# Take snapshot before major changes
# Rollback if something breaks

# Separate /home partition
# OS can be reinstalled without losing personal files

# Live USB
# Boot from USB to fix broken system

# Even hardware is accessed as files
cat /proc/cpuinfo  # Read CPU info
echo "Hello" > /dev/usb/lp0  # Print to USB printer

# Small tools that do one job perfectly
ls  # List files
grep  # Search text
cat  # Display file contents

# Combine them with pipes
ls -la | grep "\.txt" | wc -l
# Count .txt files

# You own your computer
# Change anything
# No telemetry
# No forced updates
# No vendor lock-in