// LINUX_FUNDAMENTALS.START_HERE

LINUX FUNDAMENTALS

The Start Here track — a free, hands-on introduction to Linux for someone who has never opened a terminal. Ten modules take you from “what even is Linux?” to writing your first scripts, then a helpdesk capstone puts the whole toolkit to work on one real (fictional) shift. Every module: a pre-read, a bite-sized lecture, a self-graded concept check, a follow-along guided lab, an unguided challenge lab, a printable cheatsheet and a mastery check. You cannot break anything — your sandbox is yours. No account needed to read everything; create a free one to save progress and earn points.
DOMAIN 1 Getting Oriented start here
🐧M1 · OS, kernel, distros, your own labOPEN →
📖 Lecture 1 — Full Lecture — What Is Linux, Really?LESSON 1 1. What an operating system actually doesLESSON 2 2. The kernel, the shell, and everything betweenLESSON 3 3. A "distro" is Linux dressed for a jobLESSON 4 4. Where Linux actually runs (almost everywhere, it turns out)LESSON 5 5. Open source, in one pageLESSON 6 6. Your safe playground — getting a Linux of your ownLESSON 7 7. First contact — proving there's a Linux in there
📄 📄 Pre-read — the vocabulary📄 ❓ Concept Check — self-graded📄 🧪 Guided Lab — follow along📄 🎯 Challenge Lab — no guardrails📄 📋 Cheatsheet📄 🏁 Mastery Check
⌨️M2 · prompt, commands, help, errorsOPEN →
📖 Lecture 1 — Full Lecture — Meet The TerminalLESSON 1 1. Why the terminal beats clicking for real workLESSON 2 2. Command grammar — how every command is builtLESSON 3 3. Tab completion — let the shell type for youLESSON 4 4. History — never type anything twiceLESSON 5 5. Panic buttons — clearing, cancelling, closingLESSON 6 6. Error messages — the machine is helping, read it aloudLESSON 7 7. The help system — why you never need to memorize
📄 📄 Pre-read — the vocabulary📄 ❓ Concept Check — self-graded📄 🧪 Guided Lab — follow along📄 🎯 Challenge Lab — no guardrails📄 📋 Cheatsheet📄 🏁 Mastery Check
DOMAIN 2 Files & the Filesystem the map & the files
🗺️M3 · the filesystem map, cd, ls, findOPEN →
📖 Lecture 1 — Full Lecture — Finding Your Way AroundLESSON 1 1. Everything is a file, and it all hangs from /LESSON 2 2. The grand tour — what lives where (and why you'd look there)LESSON 3 3. Addresses — absolute, relative, and the three magic namesLESSON 4 4. Moving — pwd and every flavor of cdLESSON 5 5. Looking — ls, properly decodedLESSON 6 6. Hunting — find and which (the search party)LESSON 7 7. The tree in your head — putting the map to work
📄 📄 Pre-read — the vocabulary📄 ❓ Concept Check — self-graded📄 🧪 Guided Lab — follow along📄 🎯 Challenge Lab — no guardrails📄 📋 Cheatsheet📄 🏁 Mastery Check
📁M4 · touch, cp, mv, less, wildcardsOPEN →
📖 Lecture 1 — Full Lecture — Making, Moving, Reading FilesLESSON 1 1. Making things — touch and mkdirLESSON 2 2. Copying — cp and the -r lessonLESSON 3 3. Moving and renaming — one command, mvLESSON 4 4. Writing — your first real editing session with nanoLESSON 5 5. Reading — cat, less, head, tailLESSON 6 6. Deleting — rm, respected properlyLESSON 7 7. Patterns — wildcards, and knowing what a thing is
📄 📄 Pre-read — the vocabulary📄 ❓ Concept Check — self-graded📄 🧪 Guided Lab — follow along📄 🎯 Challenge Lab — no guardrails📄 📋 Cheatsheet📄 🏁 Mastery Check
DOMAIN 3 The System Underneath users · processes · software
🔐M5 · rwx, chmod, chown, sudoOPEN →
📖 Lecture 1 — Full Lecture — Users, Groups & PermissionsLESSON 1 1. Who am I, really — whoami, id, groupsLESSON 2 2. Root and you — the two-class systemLESSON 3 3. sudo — borrowing power properlyLESSON 4 4. The ID cards — /etc/passwd and /etc/shadowLESSON 5 5. Making users and teams — adduser, groupadd, usermodLESSON 6 6. Permissions, finally decoded — rwx and chmodLESSON 7 7. Ownership and the shared-space trick — chown, chgrp, sticky bit
📄 📄 Pre-read — the vocabulary📄 ❓ Concept Check — self-graded📄 🧪 Guided Lab — follow along📄 🎯 Challenge Lab — no guardrails📄 📋 Cheatsheet📄 🏁 Mastery Check
⚙️M6 · ps, top, kill, systemctl, journalctlOPEN →
📖 Lecture 1 — Full Lecture — Processes & ServicesLESSON 1 1. What a process is (and the family tree it lives in)LESSON 2 2. The roster — ps and ps auxLESSON 3 3. Finding one process — the gentle pipe previewLESSON 4 4. The live dashboard — topLESSON 5 5. Signals — asking processes to stop (two levels of firmness)LESSON 6 6. Job control — multitasking in one terminalLESSON 7 7. Services — the permanent staff, and their manager
📄 📄 Pre-read — the vocabulary📄 ❓ Concept Check — self-graded📄 🧪 Guided Lab — follow along📄 🎯 Challenge Lab — no guardrails📄 📋 Cheatsheet📄 🏁 Mastery Check
📦M7 · apt, repositories, packagesOPEN →
📖 Lecture 1 — Full Lecture — Installing SoftwareLESSON 1 1. The trust flip — shelves, not downloadsLESSON 2 2. apt — the manager that remembersLESSON 3 3. The two-step — update then upgrade (the distinction that trips everyone)LESSON 4 4. Find, inspect, install — and the M06 payoffLESSON 5 5. Removing cleanly — remove, autoremove, purgeLESSON 6 6. Seeing what's there — dpkg and where things landLESSON 7 7. The other stores, and a reward for finishing
📄 📄 Pre-read — the vocabulary📄 ❓ Concept Check — self-graded📄 🧪 Guided Lab — follow along📄 🎯 Challenge Lab — no guardrails📄 📋 Cheatsheet📄 🏁 Mastery Check
DOMAIN 4 Power Tools & Connecting Out pipes · network · scripts
🔗M8 · pipes, > redirection, grep, sort, wcOPEN →
📖 Lecture 1 — Full Lecture — Pipes, Redirection & Text ToolsLESSON 1 1. The idea that makes Linux Linux — small tools, chainedLESSON 2 2. Three hoses — stdin, stdout, stderrLESSON 3 3. Redirection — aim a hose at a fileLESSON 4 4. The pipe — join the hosesLESSON 5 5. The toolbelt — six tools, one job eachLESSON 6 6. A first taste of regex — `^` means "starts with"LESSON 7 7. The showpiece — build a real one-liner, one pipe at a time
📄 📄 Pre-read — the vocabulary📄 ❓ Concept Check — self-graded📄 🧪 Guided Lab — follow along📄 🎯 Challenge Lab — no guardrails📄 📋 Cheatsheet📄 🏁 Mastery Check
🌐M9 · ip, ping, ssh, scp, portsOPEN →
📖 Lecture 1 — Full Lecture — Linux On The NetworkLESSON 1 1. Addresses and doors — IPs and ports in one screenLESSON 2 2. What's my address? — `ip a`LESSON 3 3. Are you there? — `ping`LESSON 4 4. Names into numbers — DNS and `/etc/hosts`LESSON 5 5. Who's listening? — `ss -tln`LESSON 6 6. Talk to the web from the terminal — `curl` and `wget`LESSON 7 7. The big one — reaching another machine with `ssh`
📄 📄 Pre-read — the vocabulary📄 ❓ Concept Check — self-graded📄 🧪 Guided Lab — follow along📄 🎯 Challenge Lab — no guardrails📄 📋 Cheatsheet📄 🏁 Mastery Check
📜M10 · bash scripts, cron, df/free/uptimeOPEN →
📖 Lecture 1 — Full Lecture — First Scripts & System HealthLESSON 1 1. Automation as earned lazinessLESSON 2 2. A script's identity: the shebang, chmod, and ./LESSON 3 3. Variables: naming the parts of your scriptLESSON 4 4. Arguments: scripts that take inputLESSON 5 5. Control flow: if statements and loopsLESSON 6 if: do something only when a condition holdsLESSON 7 for: do the same thing to every item in a listLESSON 8 6. Reading your system's vital signsLESSON 9 7. The showpiece: morning-check.shLESSON 10 8. Scheduling with cronLESSON 11 9. Where next
📄 📄 Pre-read — the vocabulary📄 ❓ Concept Check — self-graded📄 🧪 Guided Lab — follow along📄 🎯 Challenge Lab — no guardrails📄 📋 Cheatsheet📄 🏁 Mastery Check
🎫C01 · 5 tickets + a live incidentOPEN →
📄 📋 Capstone Brief — Your First Day📄 ☕ The Morning Tickets📄 🍽️ The Midday Tickets📄 🌇 The Afternoon Ticket📄 🚨 The Live Incident — circ-01 Is Frozen📄 📝 Answer Key & Rationale📄 📊 Scoring & Where Next
// WHERE_NEXT

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MODULE TITLE
▪ BEGINNER · 4 LESSONS · 0% COMPLETE
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SELECT A LESSON TO BEGIN

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LAB TITLE
LAB_01 · BEGINNER · ~20 MIN
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LAB COMPLETE — ALL OBJECTIVES CLEARED

Well executed. Review your commands above or proceed to the next lab.

LAB_01 // ACTIVE
root@lab:~$