Nano and editing · Lesson 5 of 27 · 9 minutes

Nano SSH config copy

Copy SSH config to the lab and inspect it after opening nano.

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

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1
Copy config
Run sudo cat /etc/ssh/sshd_config > lab/sshd_config.
Hint & worked example
Read one or more files to standard output without editing their contents.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
sudo cat /etc/ssh/sshd_config > lab/sshd_config
```
Remember: Reading a source file should precede changing it; avoid printing real secrets.
2
Open copy
Run nano lab/sshd_config. Save a nonempty note using the worked example below. Required evidence: PasswordAuthentication no; # reviewed training copy.
Hint & worked example
Edit a virtual text file using the browser editor and explicitly save it.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
nano lab/sshd_config
```
Save this example in the editor:
```
PasswordAuthentication no
PubkeyAuthentication yes
PermitRootLogin no
# reviewed training copy
```
Remember: Opening the editor does not complete a write task. Save and verify the contents.
3
Verify setting
Run grep PasswordAuthentication lab/sshd_config.
Hint & worked example
Select input lines that match a pattern; -i ignores case, -n adds line numbers, and -v inverts selection.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
grep PasswordAuthentication lab/sshd_config
```
Remember: No matches is exit status 1, which is different from a malformed invocation.

Understand the pattern

Working on a copy reduces risk when learning.

cat: Read one or more files to standard output without editing their contents.
Reading a source file should precede changing it; avoid printing real secrets.
nano: Edit a virtual text file using the browser editor and explicitly save it.
Opening the editor does not complete a write task. Save and verify the contents.
grep: Select input lines that match a pattern; -i ignores case, -n adds line numbers, and -v inverts selection.
No matches is exit status 1, which is different from a malformed invocation.

Worked example and expected result

$ sudo cat /etc/ssh/sshd_config > lab/sshd_config

(no output; exit 0)

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

$ nano lab/sshd_config

Opening simulated nano for /home/learner/lab/sshd_config. Save or cancel in the browser.

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

$ Save the editor buffer

PasswordAuthentication no
PubkeyAuthentication yes
PermitRootLogin no
# reviewed training copy

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

$ grep PasswordAuthentication lab/sshd_config

PasswordAuthentication no

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 “Nano SSH config copy”, which interpretation is safe?A successful first check guarantees that every dependent service is healthy.Opening the editor does not complete a write task. Save and verify the contents.A command appearing in history proves it completed successfully.

Apply it elsewhere

Before adapting the nano workflow from “Nano SSH config copy” 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.

Next: Nano env example Try an incident drill

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