Linux is an essential skill in the toolbelt of any IT professional. Whether you're a Software Developer, Network Engineer, Cloud Engineer, or Security Analyst, Linux is a skill you'll need to have down to perform your job. Shell Samurai introduces Linux in a beginner-friendly format. It starts by introducing Linux and then invites users to dive head-first into the command-line. By the end of Shell Samurai, you'll be prepared to navigate the Linux shell like a boss. Preface 6 Book Changelog 7 Need Help? 8 Acknowledgements 9 Syntax Used In This Book 11 How this book is structured 12 Introduction and Thank You 13 Who Am I and Why Am I Worth Listening to? 14 Why You Should Learn Linux 14 What is a Shell Anyway? 15 Why You Should Use the Command-Line 16 Who This Book is For 17 What You Should Know Already 17 What is a Shell Samurai? 19 1. Setting Up a Lab Environment 20 Lab Setup Intro 20 Install Linux on an old Laptop or Desktop computer 20 Use Windows Subsystem for Linux or WSL 21 Use Virtualization Software 22 Dual Boot 22 Use a Server from A Cloud Host 22 Using Cloud Hosting Setup Tutorial 24 Setting up Digital Ocean VPS 24 Creating a Droplet 26 Connecting To Your VPS 31 Troubleshooting Key Errors 33 Other Methods of Connecting to your VPS 34 2. Linux Fundamentals 36 What is Linux? 36 Linux Distributions 38 Debian 38 Ubuntu 38 RHEL 39 Fedora 39 Arch 39 What is The Kernel? 39 Kernel Space vs User Space 40 Interrupts 40 What is a System Call? 41 Signals 42 Everything is a file? Always has been 44 Linux Directory Structure 46 An Overview of Filesystems 47 Devices 48 What is a daemon? 50 Boot Process and Init, systemd 50 What's a TTY? 56 inodes 56 3. White Belt Command Line Skills - The basics, file manipulation, etc 60 Intro to the Shell - pwd, cd and basic ls 60 more ls, mkdir, cat, touch, copy and move 66 Users, Groups, Root and Sudo 73 File Permissions 79 Flying Around the Command Line with Shortcuts 83 file 85 rm — Proceed with extreme caution 85 Helping Yourself with help, man and tldr 88 Installing Packages and Programs 93 Compressing Files and Uncompressing Them 96 The Environment 100 whereis and which 101 Shutting the System Down 102 Aliases - Not just for Criminals, Spies and Detectives 102 4. Black Belt Command Line Skills - Output Redirection, Text and More 104 Black Belt Intro 104 Compiling Code from Source 104 Managing Processes 107 stdout, stdin and stderr 115 Symlinks and Hardlinks 120 Chaining Commands in the Shell with ; and && Operators 122 Text Processing 124 Editing Text with Nano 124 Text Editing Like a Boss with Vim 125 Pipe -- Not Just for Plumbers 130 Tee -- Not just for Old English Ladies and Golfers 132 Grep - I will find you and I will grep you 133 Regular Expressions with Grep 134 cut 136 Counting Lines with Word Count 138 sed and awk 138 Uniq and Sort 143 Making Heads and Tails of it 145 Spying on syscalls with strace 147 Finding Files with Find 148 Swap Space 150 Scheduling tasks with cron 151 Secure Shell or SSH 154 CURL - Not just for Olympians and Hair Stylists 158 jq - Processing JSON 163 Tmux - Secret Background Windows 166 lsof 170 The /proc directory 174 troubleshooting low disk 176 Logs - Not Just for Lumberjacks 179 Log Rotate - Don’t let the disk fill up! 180 5. The Network 184 The Network 184 DNS - The Yellow Pages of the Internet 193 Transferring files with rsync and scp 198 6. Real World Samurai Skills and Interview Questions 202 Intro 202 Installing Nginx Web server 203 Using Git and Version Control 207 Interview Questions and Scenarios 223 Outro 231
