The best way to learn something is by doing it. Kindly practice the programs and verify or contradict what we say. All the examples in this text are actual, runnable code tested on UNIX system. As a reader of this book, you are the most important critic and commentator. You can email or write to us directly to let us know what you did or didnĂt like about this book as well as what we can do to make our book stronger.