GNU AWK

Example based guide to mastering GNU awk.

The book also includes exercises to test your understanding, which is presented together as a single file in this repo - Exercises.md

For solutions to the exercises, see Exercise_solutions.md.

See Version_changes.md to keep track of changes made to the book.

E-book

You can purchase the pdf/epub versions of the book using these links:

• https://learnbyexample.gumroad.com/l/gnu_awk
• https://leanpub.com/gnu_awk

You can also get the book as part of these bundles:

• Magical one-liners bundle from https://learnbyexample.gumroad.com/l/oneliners or https://leanpub.com/b/oneliners
• Awesome Regex bundle from https://learnbyexample.gumroad.com/l/regex or https://leanpub.com/b/regex
• All books bundle bundle from https://learnbyexample.gumroad.com/l/all-books
  • Includes all my programming books

See https://learnbyexample.github.io/books/ for list of other books

For a preview of the book, see sample chapters

The book can also be viewed as a single markdown file in this repo. See my blogpost on generating pdf from markdown using pandoc if you are interested in the ebook creation process.

For web version of the book, visit https://learnbyexample.github.io/learn_gnuawk/

Testimonials

Step up your cli fu with this fabulous intro & deep dive into awk. I learned a ton of tricks!

— feedback on twitter

I consider myself pretty experienced at shell-fu and capable of doing most things I set out to achieve in either bash scripts or fearless one-liners. However, my awk is rudimentary at best, I think mostly because it's such an unforgiving environment to experiment in.

These books you've written are great for a bit of first principles insight and then quickly building up to functional usage. I will have no hesitation in referring colleagues to them!

— feedback on Hacker News

Feedback

Open an issue if you spot any typo/errors.

⚠️ ⚠️ Please DO NOT submit pull requests. Main reason being any modification requires changes in multiple places.

I'd also highly appreciate your feedback about the book.

Twitter: https://twitter.com/learn_byexample

Table of Contents

1. Preface
2. Installation and Documentation
3. awk introduction
4. Regular Expressions
5. Field separators
6. Record separators
7. In-place file editing
8. Using shell variables
9. Control Structures
10. Built-in functions
11. Multiple file input
12. Processing multiple records
13. Two file processing
14. Dealing with duplicates
15. awk scripts
16. Gotchas and Tips
17. Further Reading

Acknowledgements

• GNU awk documentation — manual and examples
• stackoverflow and unix.stackexchange — for getting answers to pertinent questions on bash, awk and other commands
• tex.stackexchange — for help on pandoc and tex related questions
• LibreOffice Draw — cover image
• pngquant and svgcleaner for optimizing images
• softwareengineering.stackexchange and skolakoda for programming quotes
• Warning and Info icons by Amada44 under public domain
• arifmahmudrana for spotting an ambiguous explanation
• mdBook — for web version of the book
  • mdBook-pagetoc — for adding table of contents for each chapter
  • minify-html — for minifying html files

Special thanks to all my friends and online acquaintances for their help, support and encouragement, especially during these difficult times.

License

The book is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License

The code snippets are licensed under MIT, see LICENSE file