If you are a Linux programmer, you should get this book. It contains readable explanations of almost all aspects of the Linux API. Where there are multiple ways to do the same thing, it discusses the trade offs. It has plenty of examples. It has plenty of everything. I've seldom (maybe never) come across a better programming book in my 40 years as a professional programmer. At almost 1500 pages, it's not an introduction for the novice, but even a novice should have it on their shelf.