Nano and editing · Lesson 3 of 27 · 9 minutes

Edit and verify

Create a runbook, count its lines, and inspect metadata after saving.

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Your objectives

Hints are always available. Wrong turns never cost XP.

1
Open a runbook
Run mkdir -p lab, then nano lab/runbook.txt. Save a nonempty note using the worked example below. Required evidence: status=reviewed; evidence=recorded; rollback=ready.
Hint & worked example
Create a directory. -p also creates missing parent directories and accepts an existing directory. 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.
```
mkdir -p lab
nano lab/runbook.txt
```
Save this example in the editor:
```
# Edit and verify
status=reviewed
evidence=recorded
rollback=ready
```
Remember: Creating a folder does not change the current directory. Opening the editor does not complete a write task. Save and verify the contents.
2
Count the runbook
After saving, run wc -l lab/runbook.txt.
Hint & worked example
Count input. -l counts newline characters, -w counts whitespace-delimited words, and -c counts bytes.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
wc -l lab/runbook.txt
```
Remember: Text without a final newline may have fewer counted lines than visible rows.
3
Inspect metadata
Run stat lab/runbook.txt.
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/runbook.txt
```
Remember: Metadata and file contents answer different questions.

Understand the pattern

Verification catches wrong paths, failed saves, and stale assumptions.

mkdir: Create a directory. -p also creates missing parent directories and accepts an existing directory.
Creating a folder does not change the current directory.
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.
wc: Count input. -l counts newline characters, -w counts whitespace-delimited words, and -c counts bytes.
Text without a final newline may have fewer counted lines than visible rows.
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

(no output; exit 0)