Rating: 

This book is one of my all-time favourites, and I recommend it again and again to people working with UNIX. This is one of the most important books if you are an administrator in charge of various UNIX based systems.

I come from a UNIX environment at the beginning of 1990's and have used UNIX systems like HP-UX, SunOS/Solaris, Linux (SLS to Kubuntu), OpenBSD and AIX - about 15+ years of UNIX.

During this time UNIX tools and scripting has evolved tremendously and I have been caught sometimes using "yesterdays" ways of doing things.

This book immediately taught me how to do things in better ways and told me why some of my old habits should go out the door ASAP.

This book does go from beginner, having the basics of how to create a script using #! but is very dense and could be combined with some introductory stuff - another book on your favourite shell perhaps.

Over the years you will enjoy this book when working with UNIX and researching how to do a shell script task in an efficient AND portable way. To me it is an instant classic!