Introduction

If you've used Unix for any length of time, you've probably found yourself starting to push the envelope, tweak how things work, change the default flags for commands you use a lot, and even create rudimentary shell scripts that automate simple tasks in a coherent fashion. Even if all you've done is to create an alias or two, you've taken the first step on the road to being a shell script hacker extraordinaire, as you'll soon see.

I've been using Unix for more years than I want to think about, and it's a great OS, especially because I can tweak, tune, and hack it. From simply automating common tasks to creating sophisticated, user-friendly versions of existing Unix commands, and creating brand-new utilities that serve a useful purpose, I've been creating spiffo little shell scripts for quite a while.

This book is about making Unix a friendlier, more powerful, and more personal computing environment by exploiting the remarkable power and capabilities of the shell. Without writing a single line of C or C++, without invoking a single compiler and loader, and without having to take any classes in program design and methodology, you'll learn to write dozens of wicked cool shell scripts, ranging from an interactive calculator to a stock ticker monitor, and a set of scripts that make analyzing Apache log files a breeze.

This Book Is for You If...

As with any technical book, an important question for Wicked Cool Shell Scripts is whether this book is for you. While it's certainly not a primer on how to use the Unix, Linux, or Mac OS X shell to automate tasks, and it doesn't list all the possible conditional tests that you can utilize with the test command, this book should nonetheless be engaging, exciting, and stimulating for anyone who has ever delved into the murky world of shell scripting. If you want to learn how to write a script, well, there are lots of great references online. But they all have one thing in common: They offer dull, simple, and uninteresting examples. Instead, this book is intended to be a cookbook, a sort of "best of" hacks compendium that shows the full and remarkable range of different tasks that can be accomplished with some savvy shell script programming. With lengths ranging from a few dozen lines to a hundred or more, the scripts in this book should not just prove useful, but will hopefully inspire you to experiment and create your own shell scripts too. And if that sounds interesting, well, this book is definitely for you.