Adds all 6 ROOT 01 modules (how computers run software, the shell, filesystem navigation, files & text, processes, users & permissions foundations), each with a real lesson, demonstration/guided exercise, knowledge check where warranted, a hands-on Lab, and a reflection — 35 activities, 29 new content files. Adds 6 new hands-on Linux scenarios (linux-inspect-hardware, linux-shell-basics, linux-filesystem-navigation, linux-files-and-text, linux-process-management, linux-permissions-foundations) plus 2 MCQ scenarios, using the existing generic scenario/ validation engine (docs/ROOT_FOUNDATIONS_LAB_STRATEGY.md §1) — every one tested end-to-end via the real scenario setup/validate API, including negative tests confirming they correctly FAIL when not actually solved (e.g. the process-management scenario fails while the target process is still running; the permissions scenario is tested against a real `su - labuser` denial). Wires rootnode-linux-foundations-assessment (2 required + 4 random-draw scenarios) using the existing Phase 3B assessment engine. Adds a real, server-side ROOT 01->02->03->04->05 course prerequisite chain (courses.prerequisites) — verified live on two students: one who completed ROOT 01 sees ROOT 02 unlock; a fresh student sees ROOT 02 correctly locked while 03/04/05 stay vacuously satisfied (their own prerequisite courses are still empty). ROOT 06+ and the Capstone are unaffected. Co-Authored-By: Claude Sonnet 5 <[email protected]>
2.6 KiB
Navigating the Filesystem
Everything is one tree, starting at /
Linux has exactly one filesystem tree, rooted at / (pronounced "root," unrelated to your
username). Every file and directory, no matter what physical disk it's actually on, appears
somewhere under this one tree — there's no separate "C:" and "D:" the way Windows shows
multiple drives.
Absolute vs. relative paths
An absolute path starts with / and always means the same location no matter where you
currently are: /home/student/notes.txt. A relative path is interpreted relative to your
CURRENT directory: notes.txt means something different depending on where you're standing
when you type it. . means "this directory," .. means "one directory up" — cd .. moves up
one level, cd ../.. moves up two.
Key commands
pwd— print your current directory (where am I?)ls— list what's in a directory (ls -lashows hidden files and details)cd <path>— change directory (absolute or relative)
Hidden files
A file or directory starting with . (like .bashrc or .config) is "hidden" — ls skips it
by default, ls -a shows it. This isn't a security feature, just a convention to keep
configuration/metadata files out of the way of normal directory listings.
The important top-level directories (conceptually, not memorized)
You don't need to memorize the entire Filesystem Hierarchy Standard, but recognizing these by purpose will save you real confusion later:
/etc— system-wide configuration files (nginx's config lives at/etc/nginx/nginx.conf)/var— variable data that changes while the system runs: logs (/var/log), among others/home— personal directories for regular users/tmp— temporary files, safe to assume anything here can disappear on reboot/usr— most installed programs and their supporting files live somewhere under here/proc— not real files on disk at all — a live, kernel-generated view into running processes and system state (you'll use this again in Module 5)
Instructor Notes
Lesson goal: Give students a working mental model of "one tree, absolute vs. relative paths" plus just enough top-level-directory recognition to not be lost later — not FHS memorization.
Approximate timing: 15 minutes read; 10 minutes live.
Common misconception to watch for: students coming from Windows sometimes expect separate drives/roots — emphasize the single unified tree explicitly.
Demo idea: cd / then ls, narrating what each top-level directory is for as you see it,
rather than listing them in the abstract.