For example, one of the more confusing aspects of the Unix command line for beginners is piping. He writes “A mnemonic for remembering which is which is to remember that, just as in English, Unix works from left to right, so a character that points to the left (<) changes input, whereas a character that points right (>) changes the output.” In one sentence he clarifies what originally took me hours to sort out and learn on my own. The book contains many such places of learning.

Most of the book focuses on the command line in Unix. As Taylor points out, these commands work not only in the commercial versions of Unix, but also in the *nix clones like Linux and BSD. He often works to include other versions by writing things like “if you work in this other shell, you need to type ... instead”. The command line is the tool which provides users with greater flexibility and control over the operating system than using a graphical user interface (GUI). The command line can be intimidating however, particularly in Unix when there is usually no confirmation that an action has succeeded. Time and again Taylor points out what results to expect and how to check if the desired action has been performed.

Because Unix has such a great variety of command line tools, Taylor had to make some choices about what to discuss in an introductory book. "awk" and "sed" get a few pages each, emacs one chapter, but vi (the classic Unix text editor) has two chapters. The book also has four chapters about shells and shell programming. As experienced Unix users know, each shell requires at least one book on its own. Still, his introductions to these tools are well worth reading. There is also a chapter about backup including a very practical shell script for personal backups. The last hour of the twenty-four hours introduces users to the Gnome GUI environment.

Each chapter includes a list of key words and some additional exercises to attempt. There are two appendices called “extra hours”. One is a what Taylor calls common Unix questions with answers. While I have never needed to ask these questions, I understand why others might. The second appendix is a brief look at the Apache Web Server including discussion of Common Gateway Interface (CGI), server-side scripting and the log files. The few pages in this appendix will not replace one or more of the good Apache books on the market, but the appendix is still worthwhile. I am impressed by Taylor's depth of knowledge and the seeming ease with which he writes. He communicates clearly and concisely, he seems to anticipate what the learner's next question might be and what the next difficulty will be. If I were teaching Unix I would seriously consider using this book as the course text. If I were writing an instructional manual I would try to emulate Taylor's writing style. Recommended.