10. Streams and Redirection

This chapter deepens the operational side of streams: file descriptors, redirection, append mode, pipeline status, tee, and failure-aware stream handling.

• Descriptors: Use numeric handles for streams.

• Redirection: Route output and errors intentionally.

• Pipelines: Connect commands while preserving failure information.

• Audit trails: Keep normal output, errors, and reports clear.

• Robustness: Avoid hiding failures in automation.

Chapter Video

Bash Scripting for Beginners: Complete Guide to Getting Started - Data Streams (Part 11) (28:15) 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. Redirect stdin, stdout, and stderr deliberately.

2. Use file descriptors in scripts.

3. Build pipelines that preserve failure information.

4. Use tee and append redirection for report capture.

5. Explain why stream separation matters for audit scripts.

Chapter Flow

1. Standard Streams

2. Advanced Redirection

Glossary

#	Term	Explanation
1	stdin	Standard input, file descriptor 0.
2	stdout	Standard output, file descriptor 1.
3	stderr	Standard error, file descriptor 2.
4	File descriptor	A numeric handle for an open stream.
5	Redirection	Shell syntax for routing streams.
6	Append	Adding output to the end of a file.
7	Pipeline	Commands connected with `
8	PIPESTATUS	Bash array of pipeline command statuses.
9	pipefail	Option that exposes pipeline failures.
10	tee	Command that writes output to both a file and stdout.
11	Null device	The special file /dev/null, which discards data written to it.