Files and paths · Lesson 27 of 36 · 8 minutes

Glob safety preview

List and find targets before deleting broad patterns.

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
Preview text files
Run find /home/learner/lab -name txt.
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/lab -name txt
```
Remember: Quote wildcard patterns so find receives them instead of the shell expanding them first.
2
List lab
Run ls lab.
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 lab
```
Remember: A listing is not proof that you can read or modify every listed file.
3
See wildcard guardrail
Run rm lab/*.
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 lab/*
```
Remember: Simulator protections are not a promise that a real shell will protect the same target.

Understand the pattern

Junior operators build confidence by gathering evidence before changing systems.

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.
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.
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

$ find /home/learner/lab -name txt

(no output; exit 0)

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

$ ls lab

(no output; exit 0)

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

$ rm lab/*

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

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 “Glob safety preview”, which interpretation is safe?A listing is not proof that you can read or modify every listed file.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 ls workflow from “Glob safety preview” 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: Temp cleanup review Try an incident drill

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