Shell scripts offer an impressive means for creating powerful and portable applications. When coupled with utilities such as grep, sed, and the AWK programming language, the shell is more than adequate for resolving a wide range of programming tasks. I wrote this book to demonstrate these exciting capabilities and help you to learn shell scripting by providing hundreds of examples.

The opening chapter sets the stage for this collection, introducing many Unix shell features and helping familiarize you with the syntax in many of the examples. The following chapters present scripts and shell functions ranging from one-liners to multipage programs. These scripts and functions are capable of accomplishing commonplace tasks such as converting DOS-based text files to Unix and vice versa, maintaining financial ledgers (which can be easily imported to a spreadsheet program), extracting information from web pages, and more. To facilitate code reuse, the book offers numerous function libraries that you can use to build even more programs quickly.

Some scripts in this book are taken from the hundreds I've written over the past 15 years, while others were written specifically for this book. I carefully selected each not only to demonstrate the breadth of problems that can be solved with shell scripts, but also to illustrate as many scripting techniques as possible.

I hope this book will help you solve the many problems illustrated by these scripts, and also encourage and help you to write your own.