Which output best matches ls -la?
Pick the main effect of this command.
Brush up on the CLI without leaving your browser
Quick quizzes and hands-on exercises to lock in shell reflexes: reading files, filters, permissions, and navigation.
Progress
Level 1 · Basics
Clear the first batch to unlock the rest.
0 / 12
Every correct answer unlocks a bit more of the path.
Level 1 · Basics
The essential commands, phrased to avoid overly obvious answers.
Which output best matches
What does grep -n "error" journal.log return?
Think about the output format, not just the filtering.
Print the absolute path of the current directory
Type the exact command in the field below.
Show the last 5 lines of rapport.log
Keep the syntax as classic as possible.
Level 2 · Filters and permissions
Moving on to commands that combine reading, filtering, and access control.
What does chmod 755 script.sh mean?
Interpret the permission mask precisely.
What does wc -l notes.txt do?
Pick the most accurate effect on the output.
Search for error case-insensitively in journal.log
Keep the syntax compact and readable.
Create projet/logs in a single command
The directory tree may not exist yet.
Level 3 · Automation
Last stretch: more realistic commands, useful for everyday work.
What does find /var/log -name "*.log" do?
Pay close attention to the search scope.
What does tar -czf archive.tar.gz dossier/ produce?
Focus on the command's end result.
Show the first 3 lines of config.conf
Keep the syntax short and direct.
Restrict secret.txt to read/write access for the owner only
You need to set a precise numeric mode.
Quick reference
Find your way around the tree
The minimal duo for knowing where you are and what's around you.
pwd ls -la
Filter logs
Perfect for hunting an error without opening the whole file.
grep -n "error" journal.log
Read the end of files
Very handy for following a running service's logs.
tail -n 5 rapport.log