Files and paths · Lesson 3 of 36 · 8 minutes

Safe deletion

Remove a single lab file and learn why wildcards, root, and force deletes are blocked.

Open the lab Course map

Mastery 0/3Run itExplain itApply it

learner@clairos:~ $

↑ history · Tab complete · Ctrl+C cancel · Esc, Tab to leaveExit 0

Your objectives

Hints are always available. Wrong turns never cost XP.

1
Create a delete target
Run mkdir -p lab, then touch lab/delete-me.txt.
Hint & worked example
Create a directory. -p also creates missing parent directories and accepts an existing directory. Create an empty file when absent, or update timestamps without truncating an existing file.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
mkdir -p lab
touch lab/delete-me.txt
```
Remember: Creating a folder does not change the current directory. touch is not a way to empty a file that already has content.
2
Remove one file
Run rm lab/delete-me.txt.
Hint & worked example
Remove the named file from the virtual workspace. The training root and system trees are guarded.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
rm lab/delete-me.txt
```
Remember: Simulator protections are not a promise that a real shell will protect the same target.
3
See the guardrail
Run rm -rf / and notice it is refused.
Hint & worked example
Remove the named file from the virtual workspace. The training root and system trees are guarded.
Observe the simulator safety refusal; no protected target is removed.
```
rm -rf /
```
Remember: Simulator protections are not a promise that a real shell will protect the same target.

Understand the pattern

Real rm mistakes can be destructive; the lab teaches narrow targets.

mkdir: Create a directory. -p also creates missing parent directories and accepts an existing directory.
Creating a folder does not change the current directory.
touch: Create an empty file when absent, or update timestamps without truncating an existing file.
touch is not a way to empty a file that already has content.
rm: Remove the named file from the virtual workspace. The training root and system trees are guarded.
Simulator protections are not a promise that a real shell will protect the same target.

Worked example and expected result

$ mkdir -p lab

(no output; exit 0)

Exit status: 0. The command completed successfully in the training fixture.

$ touch lab/delete-me.txt

(no output; exit 0)

Exit status: 0. The command completed successfully in the training fixture.

$ rm lab/delete-me.txt

(no output; exit 0)

Exit status: 0. The command completed successfully in the training fixture.

$ rm -rf /

That target is protected in the simulator.

Exit status: 1. This nonzero result is an expected part of this exercise.

Try a variation

Repeat this workflow in the sandbox with a different scratch filename. Keep the system fixtures unchanged and compare the observed output with your expectation before moving on.

Explain it

In “Safe deletion”, which interpretation is safe?A command appearing in history proves it completed successfully.A successful first check guarantees that every dependent service is healthy.Simulator protections are not a promise that a real shell will protect the same target.

Apply it elsewhere

Before adapting the rm workflow from “Safe deletion” to another server, what should you do?Skip output inspection whenever the command is familiar.Confirm the current directory, target identity, permissions, and the installed command behavior first.Paste the training paths unchanged into production.

Keep the momentum.

Complete the lab, then explain and apply the pattern.

Next: Find files Try an incident drill

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