Files are paths
Learn absolute and relative paths, working directories and why pwd, ls and cd fit together.
pwd
ls
cd /tmp
pwdLinux tutorials that make the terminal click.
Short, original lessons built around one idea at a time. Read the mental model, try the tiny experiment, then mark the skill complete.
Build a file safely
Understand creation, copying, moving and removal as separate operations instead of memorized commands.
mkdir -p lab/notes
touch lab/notes/today.txt
cp lab/notes/today.txt lab/notes/backup.txtThink in streams
Standard output, standard error and pipelines let small programs cooperate. Learn to inspect evidence instead of guessing.
printf 'alpha\nbeta\n' | grep betaFind information, then filter it
Use find for paths and grep for text. Combine them only after each step is understandable on its own.
find . -type f
find . -type f | grep notesRead permission bits
Translate user, group and other permissions into an access model before changing anything.
ls -l notes.txt
chmod 640 notes.txt
ls -l notes.txtA process is a running program
Connect process IDs, command lines and exit status. Learn why observation should come before intervention.
ps
ps aux
# inspect before deciding what to changeRead disk usage as evidence
Distinguish filesystem capacity from directory usage and learn which question df versus du answers.
df -h
du -sh .Predict before you execute
A strong shell habit is to predict stdout, stderr and the exit status before pressing Enter.
printf '%s\n' hello
echo $?Separate connectivity from application health
Learn what a network command can prove—and what it cannot. In the browser Linux lab, networking is intentionally disabled.
ip addr
# observe the environment before drawing conclusionsMake repetition explicit
Use simple pipelines and scripts when repetition is clear, while keeping each step observable and reversible.
printf '%s\n' one two three | wc -lRead the error, not just the failure
Errors contain evidence: command, target, reason and sometimes a suggested correction. Build the habit of reading stderr.
cat does-not-exist.txt
# inspect stderr and exit statusExplain what you just did
Finish by explaining the command, input, output and side effect in plain language. Understanding is more durable than memorization.
command
# What changed? What evidence proves it?Ready for practice?
After the tutorials, use challenges for deliberate practice, the quiz for recall, and the verified assessment when you want a server-graded credential.
Open challenges →