I'm an analog IC designer moonlighting as a linux hacker (I'm actually addicted). I try to build software, write shell scripts and customize my desktop to death. I picked up this book a year or two back and I think I've probably used it almost every single day to look up something or the other. I probably own about 20 linux related books (more than my engineering books) but this is the one that I would run out with when the firealarm sounds. Here is my short summary of my feelings about this book.- this book (primarily) caters to intermediate to advanced users- I would still recommend this for linux beginners as a reference to check up when every other beginner book fails. There are introductory chapters on shell scripting which could put some of the dedicated shell scripting books to shame- One of the fundamental holy grail that linux books try to achieve (and in which they often fail) is to find a good balance between breadth and depth - both qualities which the subject of Unix do not shy away from. So a Linux beginner picks up an introductory book which addresses just one linux issue and before he knows it-he has gathered enough knowledge and the book just picks up dust. Or he could pick up a book that claims to be a reference and skims over all the items with little depth and boom when he really needs information about a particular topic he finds that the book is too shallow.The "Unix Power Tools" book, I'm happy to say achieves this good balance between depth and breadth in very good measure. Ex. When I was confused about the intricacies of bash quoting or I/O redirecition, this book came to my rescue. The Unix command "find" which was buried under a 4-year old alias for me owing to it's complexities, suddenly developed a fascination for me after I discovered it's myriad use and value from the multiple pages that this book devoted to it's demystifcation.- I bought the O'Reilly books - "Linux in a Nutshell" and "Essential system Administration" with the purpose of using them as references - The first one was just too shallow for my requirements and taste and I use it basically as a replacement for online man pages. The second one has it's very niche, but only in specific circumstances. So they have been put to use probably just 1/10th of what the "Power Tools" book has been put to- I'm not a guy who is driven to write reviews i.e unless I am totally ecstatic or totally disgusted with a product and you probably have guessed where I stand with this one. I waited 1 or two years and I somehow felt that I owe this review to this book.