Files and paths · Lesson 11 of 36 · 7 minutes

Wildcard safety

See why broad delete patterns are blocked in the lab.

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
Find note paths
Run find /home/learner -name note.
Hint & worked example
Search directory trees by criteria rather than relying on one shallow listing.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
find /home/learner -name note
```
Remember: Quote wildcard patterns so find receives them instead of the shell expanding them first.
2
Try blocked wildcard
Run rm "*".
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 "*"
```
Remember: Simulator protections are not a promise that a real shell will protect the same target.
3
List home
Run ls /home/learner.
Hint & worked example
List directory entries; -a includes hidden names and -l adds ownership and permission detail.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
ls /home/learner
```
Remember: A listing is not proof that you can read or modify every listed file.

Understand the pattern

A wrong wildcard can destroy real files quickly.

find: Search directory trees by criteria rather than relying on one shallow listing.
Quote wildcard patterns so find receives them instead of the shell expanding them first.
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.
ls: List directory entries; -a includes hidden names and -l adds ownership and permission detail.
A listing is not proof that you can read or modify every listed file.

Worked example and expected result

$ find /home/learner -name note

/home/learner/archive/old-note.txt
/home/learner/notes

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

$ rm "*"

Wildcard deletion is not simulated. Name one lab file directly.

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

$ ls /home/learner

archive  backups  data  lab  notes  projects  README.txt  restore  scripts

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

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

Apply it elsewhere

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

Keep the momentum.

Complete the lab, then explain and apply the pattern.

Next: Path normalization Try an incident drill

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