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rootnode-academy/content/root/root-01-computing-linux-foundations/m04-files-and-text/04-guided-exercise-choosing-the-right-tool.md
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ced4568andClaude Sonnet 5 15b616274b feat(root01): author Computing & Linux Foundations, and the real 01->05 prerequisite chain
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]>
2026-08-26 12:59:52 -05:00

1.2 KiB

Guided Exercise: Which Tool Actually Answers the Question?

This is a paper exercise — commit to an answer before checking it in the Lab.

Your task

For each situation, name the ONE command (or short pipeline) you'd reach for first:

  1. You want to see just the last 20 lines of a 50,000-line log file.
  2. You want to know how many lines in a file contain the word "timeout."
  3. You want to watch a log file update live while a process is running.
  4. You want to see a file's full contents but it's too long for one screen and you want to scroll through it interactively.

A worked shape to check yourself against

  1. tail -n 20 file.log
  2. grep -c timeout file.log
  3. tail -f file.log
  4. less file.log

Notice: cat would technically "work" for #4 too, but it dumps everything at once with no way to scroll back — less is the actual right tool once a file is longer than one screen.

Instructor Notes

Facilitation: Item 4 is worth discussing explicitly — "it works" isn't the same bar as "it's the right tool for this situation," and that distinction matters more as commands compose into real troubleshooting workflows.

Approximate timing: 8-10 minutes live discussion; 5 minutes self-paced.