Permissions and users · Lesson 5 of 33 · 7 minutes

Directory modes

Review why private directories use tighter modes.

Open the lab Course map

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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
Set SSH folder mode
Run chmod 700 ~/.ssh.
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 700 ~/.ssh
```
Remember: Do not use 777 as a blanket fix. Grant the smallest access needed.
2
Inspect SSH folder
Run stat ~/.ssh.
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 ~/.ssh
```
Remember: Metadata and file contents answer different questions.
3
List SSH folder
Run ls -la ~/.ssh.
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 -la ~/.ssh
```
Remember: A listing is not proof that you can read or modify every listed file.

Understand the pattern

Sensitive config folders should not be casually readable.

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.
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

$ chmod 700 ~/.ssh

(no output; exit 0)

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

$ stat ~/.ssh

Path: /home/learner/.ssh
Type: dir
Mode: drwx------
Owner: learner
Group: learners
Size: 3 items

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

$ ls -la ~/.ssh

--rw------- learner learners    40 authorized_keys
--rw------- learner learners    87 config
--rw------- learner learners    84 known_hosts

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 modes”, which interpretation is safe?A successful first check guarantees that every dependent service is healthy.Metadata and file contents answer different questions.A command appearing in history proves it completed successfully.

Apply it elsewhere

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

Keep the momentum.

Complete the lab, then explain and apply the pattern.

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