It's been a while since the first version of the book came out (2004) and a lot has changed in the world of UNIX since that time so though many of the ideas from the first version are still valid, it has been updated to take into account systems like macOS and even Windows.
The book is broken into the following sections
- Chapter 0: A Shell Scripts Crash Course
- Chapter 1: The Missing Code Library
- Chapter 2: Improving on User Commands
- Chapter 3: Creating Utilities
- Chapter 4: Tweaking Unix
- Chapter 5: System Administration: Managing Users
- Chapter 6: System Administration: System Maintenance
- Chapter 7: Web and Internet Users
- Chapter 8: Webmaster Hacks
- Chapter 9: Web and Internet Administration
- Chapter 10: Internet Server Administration
- Chapter 11: OS X Scripts
- Chapter 12: Shell Script Fun and Games
- Chapter 13: Working with the Cloud
- Chapter 14: ImageMagick and Working with Graphics Files
- Chapter 15: Days and Dates
- Appendix A: Installing Bash on Windows 10
- Appendix B: Bonus Scripts
It's a long book at 305 pages, and it's probably more of a reference book for ideas on shell scripting and what you can do rather than reading it from start to finish - though if you're new to the subject, it's probably worth reading Chapter 0 before moving to other chapters.
If you want to get more out of using the command line (on pretty much any UNIX like OS) this could be the book for you.
It's available for purchase direct from No Starch Press for $34.95 Print Book and FREE Ebook or $27.95 Ebook (PDF, Mobi, and ePub), slightly more through O'Reilly (but you can get it through their Safari service) and considerably cheaper through Amazon.