Nano and editing · Lesson 10 of 27 · 9 minutes

Nano config backup

Back up a config copy before editing it.

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Your objectives

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1
Copy config
Run cp /etc/nginx/sites-available/learn.conf lab/learn.conf.
Hint & worked example
Copy a file to a new location, leaving the original in place.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
cp /etc/nginx/sites-available/learn.conf lab/learn.conf
```
Remember: Confirm the destination before replacing a file. This lab supports file copies, not every cp option.
2
Copy backup
Run cp lab/learn.conf lab/learn.conf.bak.
Hint & worked example
Copy a file to a new location, leaving the original in place.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
cp lab/learn.conf lab/learn.conf.bak
```
Remember: Confirm the destination before replacing a file. This lab supports file copies, not every cp option.
3
Compare backup
Run diff lab/learn.conf lab/learn.conf.bak.
Hint & worked example
Compare two text files; a difference is a meaningful nonzero status, not necessarily an execution error.
Inspect the differences. diff exits 1 when files differ and 0 when they match.
```
diff lab/learn.conf lab/learn.conf.bak
```
Remember: Status 1 means differences for diff; shell status must be interpreted in command context.

Understand the pattern

Diffing against a backup shows exactly what changed.

cp: Copy a file to a new location, leaving the original in place.
Confirm the destination before replacing a file. This lab supports file copies, not every cp option.
diff: Compare two text files; a difference is a meaningful nonzero status, not necessarily an execution error.
Status 1 means differences for diff; shell status must be interpreted in command context.

Worked example and expected result

$ cp /etc/nginx/sites-available/learn.conf lab/learn.conf

(no output; exit 0)

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

$ cp lab/learn.conf lab/learn.conf.bak

(no output; exit 0)

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

$ diff lab/learn.conf lab/learn.conf.bak

(no output; exit 0)

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 config backup”, which interpretation is safe?A successful first check guarantees that every dependent service is healthy.Confirm the destination before replacing a file. This lab supports file copies, not every cp option.A command appearing in history proves it completed successfully.

Apply it elsewhere

Before adapting the cp workflow from “Nano config backup” 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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