This Book Will Show You How (Perl for System Administration)

1.3. This Book Will Show You How

In the 1966-68 "Batman" television show, the dynamic duo wore utility belts. If Batman and Robin had to scale a building, Batman would say, "Quick Robin, the Bat Grappling Hook! " Or Batman would say, "Quick Robin, the Bat Knockout Gas!" and they'd both have the right tool at hand to subdue the bad guys. This book aims to give you the utility belt you need to do good system administration work.

Every chapter attempts to provide you with three things.

Clear and concise information about a system administration domain.

In each chapter we discuss in depth one domain of the system administration world. The number of possible domains in multiplatform system administration is huge, far too many to be included in a single book. The best survey books on just Unix system administration, Essential System Administration, by Æleen Frisch (O'Reilly & Associates), and Unix System Administration Handbook, by Evi Nemeth, Garth Snyder, and Trent R. Hein (Prentice-Hall), are two and three times, respectively, the size of this book. We'll be looking at topics from three different operating systems: Unix, Windows NT, Windows 2000, and MacOS.

As a result, some hard choices were made on what to include and what to exclude. In general the topics that I believe will become even more important over the next five years made the cut. Important technologies like XML are explored because they are likely to have a significant impact on the field as time goes by. Unfortunately, these guidelines meant that some system administration stalwarts like backup and printing are edged out by newer topics like LDAP and SNMP. The skills and tools provided by this book can help with the domains I omit, but a direct treatment will have to be found elsewhere.

I've tried to put together a good stew of system and network administration information for people with varying levels of experience in the field. Seasoned veterans and new recruits may come away from this book having learned completely different material, but everyone should find something of interest to chew on. Each chapter ends with a list of references which can help you get deeper into a topic should you so choose.

For each domain or topic, especially the ones that have a considerable learning curve, I include appendixes with all of the information you need to come up to speed quickly. Even if you're familiar with a topic, you may find these appendixes can round out your knowledge about that matter (e.g., how something is implemented on a different operating system).

Perl techniques and approaches that can be used in system administration.

To get the most out of this book, you'll need some initial Perl background. Every chapter is full of Perl code that ranges in complexity from beginner to advanced levels of Perl knowledge. Whenever we encounter an intermediate-to-advanced technique, data structure, or idiom, I'll take the time to carefully step us through it, piece by piece. In the process, you should be able to pick up some interesting Perl techniques to add to your programming repertoire. The hope is that Perl programmers of all levels will be able to find something to learn from the examples presented in this book. And as your Perl skills improve over time, you should be able to come back to this book, learning new things each time.

To further enhance this learning experience, I will often present more than one way to accomplish the same task using Perl rather than showing a single limited answer. Remember the Perl motto, "There's More Than One Way To Do It." These multiple-approach examples are designed to better equip your Perl utility belt: the more tools you have at hand, the better the choices you can make when approaching a new task.

Sometimes it will be obvious that one technique is superior to the others. But this book only addresses a certain subset of situations you may find yourself in, and a solution that is woefully crude for one problem may be just the ticket for another. So bear with me. For each example I'll try to show you both the advantages and drawbacks of each approach (and often tell you which method I prefer).

System administration best practices and deep principles.

As I mentioned at the start of this chapter, there are better and worse ways to do system administration. I've been a system and network administrator for the last 15 years in some pretty demanding multiplatform environments. In each chapter I try to bring this experience to bear as I offer you some of the best practices I've learned and the deeper principles behind them. Occasionally I'll use a personal "war story from the front lines" as the starting point for these discussions. Hopefully the depth of the craft in system administration will become apparent as you read along.