12. Logs, Reports, and Evidence Files

This chapter applies text processing to logs, timestamped reports, hashes, and evidence-conscious file handling.

• Logs: Read records of system and application events.

• Reports: Produce clear output for humans.

• Hashes: Record file integrity facts.

• Timestamps: Make automation auditable.

• Evidence habits: Prefer read-only inspection and reproducible output.

• Templates: Use here-documents to produce repeatable reports and notes.

Chapter Video

Linux Crash Course - Understanding Logging (29:09) by Learn Linux TV

Hosted on YouTube; property of its original creator, embedded here for educational reference only.

Learning Objectives

By the end of this chapter, you will be able to:

1. Inspect logs without modifying original files.

2. Generate timestamped text reports.

3. Use here-documents to create repeatable report templates.

4. Use hashes to document file identity.

5. Separate notes, raw data, and summaries.

6. Explain evidence-safe habits for beginner incident work.

Chapter Flow

1. Reports and Logs

2. Here-Documents and Templates

3. Evidence Files and Hashes

Glossary

#	Term	Explanation
1	log	Record of events.
2	report	Human-readable summary.
3	timestamp	Recorded date and time.
4	hash	Fixed-length file digest.
5	checksum	Value used to detect changes.
6	audit trail	Record of actions and results.
7	evidence copy	Copy preserved for analysis.
8	read-only inspection	Examining without modifying.
9	summary	Condensed result.
10	raw data	Unmodified collected output.
11	Here-document	A multi-line input block introduced with <<, useful for generated reports.
12	Here-string	A one-line string passed to standard input with <<<.
13	Delimiter	The marker that starts or ends a here-document.
14	Template	A reusable text pattern filled with variable values.