Clairos Learn

Play the terminal. Learn the server.

Practice Linux and Mac terminal basics in a simulated ops lab. Explore fake files, edit with nano, inspect logs, and learn file/security administration without touching a real machine.

Start lesson 1 Open sandbox

0/25 lessons 0/7 missions

New learnerrank 0XP 0%complete

learner@clairos:/home/learner $ Unix ops lab: type a command, press Enter

Fake server filesystem

Sandbox prompts

Use pwd, ls /, and cat /etc/hostname to map the fake server.
Create a new folder named lab and use nano lab/incident-notes.txt to save a note.
Use tail -n 3 /var/log/auth.log, then grep denied /var/log/auth.log.
Run ps and systemctl status nginx to inspect the fake service layer.
Run whoami, id, groups, and ufw status to practice security inspection.
Run nginx -t, df -h, free -h, and uptime to inspect fake operations health.
Try echo alpha beta beta | wc to practice a safe pipeline.

Mission board

Map the server

Find your location, list root, and read the fake hostname.

80 XP

Build a runbook

Create a lab note, edit it with nano, then read it back.

120 XP

Investigate logs

Tail the auth log and search for denied login attempts.

110 XP

Service check

Inspect fake processes and nginx service status.

100 XP

Security posture

Check identity, firewall status, and fake sudo boundaries.

130 XP

Validate nginx

Read the fake site config, search /api/, and run nginx -t.

120 XP

Pipeline practice

Use a safe text pipe and write one local note with redirection.

110 XP

Browser-only lab

Commands mutate only a fake filesystem saved in local browser storage.

Game-style missions

Complete small ops objectives and unlock practical command-line confidence.

Admin concepts

Practice logs, services, permissions, ownership, and firewall basics safely.

Course categories

Unix and server basics, grouped for steady progress.

Move through missions that start with navigation, then build toward editing files, reading logs, permissions, services, and safe security administration.

0/4 Terminal basics

Orientation, paths, hidden files, and command history.

4 short lessons 0/4 Files and paths

Create, copy, move, remove, and find files safely.

4 short lessons 0/4 Text and logs

Read files, search logs, and use safe text pipelines.

4 short lessons 0/3 Nano and editing

Use fake nano, edit config copies, and verify saved files.

3 short lessons 0/3 Permissions and users

Modes, owners, groups, and sensitive file review.

3 short lessons 0/4 Server operations

Processes, services, nginx validation, and capacity signals.

4 short lessons 0/3 Security administration

Identity, sudo boundaries, SSH hardening, firewall rules, and review notes.

3 short lessons

Browse all lessons

Sandbox objectives

A fake ops lab you can actually poke.

The mission board turns command practice into a small game loop: inspect, edit, verify, and reset.

Map the server

Find your location, list root, and read the fake hostname.

80 XP

Build a runbook

Create a lab note, edit it with nano, then read it back.

120 XP

Investigate logs

Tail the auth log and search for denied login attempts.

110 XP

Service check

Inspect fake processes and nginx service status.

100 XP

Security posture

Check identity, firewall status, and fake sudo boundaries.

130 XP

Validate nginx

Read the fake site config, search /api/, and run nginx -t.

120 XP

Pipeline practice

Use a safe text pipe and write one local note with redirection.

110 XP

Command reference

Small commands, clear jobs.

These are the first commands learners will practice in the fake terminal.

help

Show the simulated command list.

pwd

Print the current working directory.

ls [-la] [path]

List fake files and folders.

cd [path]

Change directories inside the fake filesystem.

echo <text>

Print text or write safe lab notes with >.

mkdir <name>

Create a folder.

touch <file>

Create an empty file.

nano <file>

Open a browser-only fake nano editor.

cat <file>

Print text file contents.

less <file>

Page through a file in simplified simulator output.

head|tail [-n N] <file>

Read the beginning or end of a file.

grep [-i] <text> <file>

Find literal text inside a file.

wc [-l] <file>

Count lines, words, and characters.

sort|uniq

Practice simple text pipelines.

find [path] [-name text]

Search fake filesystem paths.

cp <src> <dst>

Copy a file.

mv <src> <dst>

Move or rename a file.

rm <file>

Remove one fake file with safeguards.

chmod <mode> <path>

Change a fake numeric permission mode.

chown <user:group> <path>

Change fake owner/group labels.

chgrp <group> <path>

Change a fake file group label.

stat <path>

Show fake file details.

whoami|id|groups

Inspect the fake learner account.

ps

Show fake server processes.

systemctl status <service>

Inspect fake service status.

journalctl -u <service>

Read fake service journal entries.

nginx -t

Validate fake nginx configuration.

ufw status

Inspect fake firewall rules.

df|du|free|uptime

Inspect fake resource and system health.

history

Show recent simulated commands.

clear

Clear terminal output.

reset

Reset the simulated lab.

Safety model

Nothing runs outside the lesson.

The terminal is a deterministic browser simulation. It has no server execution path and no networked command bridge.

This is not a real shell.
Unsupported commands are explained instead of executed.
The simulator does not use network requests or server-side command execution.
Dangerous delete, sudo, ssh, and service actions are fake and guarded.