Nano and editing · Lesson 13 of 27 · 8 minutes

Nano checklist

Create a checklist and search it for a completion marker.

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
Edit checklist
Run nano lab/checklist.txt. Save a nonempty note using the worked example below. Required evidence: status=reviewed; evidence=recorded; rollback=ready.
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/checklist.txt
```
Save this example in the editor:
```
# Nano checklist
status=reviewed
evidence=recorded
rollback=ready
```
Remember: Opening the editor does not complete a write task. Save and verify the contents.
2
Search reviewed
Run grep reviewed lab/checklist.txt.
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 reviewed lab/checklist.txt
```
Remember: No matches is exit status 1, which is different from a malformed invocation.
3
Read checklist
Run cat lab/checklist.txt.
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.
```
cat lab/checklist.txt
```
Remember: Reading a source file should precede changing it; avoid printing real secrets.

Understand the pattern

Checklists protect against skipped steps.

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.
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.

Worked example and expected result

$ nano lab/checklist.txt

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

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

$ Save the editor buffer

# Nano checklist
status=reviewed
evidence=recorded
rollback=ready

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

$ grep reviewed lab/checklist.txt

status=reviewed

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

$ cat lab/checklist.txt

# Nano checklist
status=reviewed
evidence=recorded
rollback=ready

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 checklist”, which interpretation is safe?A successful first check guarantees that every dependent service is healthy.No matches is exit status 1, which is different from a malformed invocation.A command appearing in history proves it completed successfully.

Apply it elsewhere

Before adapting the grep workflow from “Nano checklist” 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 script stub Try an incident drill

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