Permissions and users · Lesson 29 of 33 · 8 minutes

Directory traversal modes

Set and inspect a directory mode that supports controlled traversal.

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 report directory
Run mkdir -p lab/private-reports.
Hint & worked example
Create a directory. -p also creates missing parent directories and accepts an existing directory.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
mkdir -p lab/private-reports
```
Remember: Creating a folder does not change the current directory.
2
Set controlled traversal mode
Run chmod 750 lab/private-reports.
Hint & worked example
Change permissions using an octal mode or a symbolic adjustment. Each rwx bit belongs to owner, group, or other.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
chmod 750 lab/private-reports
```
Remember: Do not use 777 as a blanket fix. Grant the smallest access needed.
3
Inspect the directory mode
Run stat lab/private-reports.
Hint & worked example
Inspect a file or directory metadata record, including ownership, permissions, and size.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
stat lab/private-reports
```
Remember: Metadata and file contents answer different questions.

Understand the pattern

Reasoning about read, write, and execute bits on directories helps operators explain what they know before they change anything.

mkdir: Create a directory. -p also creates missing parent directories and accepts an existing directory.
Creating a folder does not change the current directory.
chmod: Change permissions using an octal mode or a symbolic adjustment. Each rwx bit belongs to owner, group, or other.
Do not use 777 as a blanket fix. Grant the smallest access needed.
stat: Inspect a file or directory metadata record, including ownership, permissions, and size.
Metadata and file contents answer different questions.

Worked example and expected result

$ mkdir -p lab/private-reports

(no output; exit 0)

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

$ chmod 750 lab/private-reports

(no output; exit 0)

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

$ stat lab/private-reports

Path: /home/learner/lab/private-reports
Type: dir
Mode: drwxr-x---
Owner: learner
Group: learners
Size: 0 items

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 “Directory traversal modes”, which interpretation is safe?A command appearing in history proves it completed successfully.A successful first check guarantees that every dependent service is healthy.Do not use 777 as a blanket fix. Grant the smallest access needed.

Apply it elsewhere

Before adapting the chmod workflow from “Directory traversal modes” 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: Shared group directory Try an incident drill

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