Perl in a Nutshell, Second Edition by Nathan Patwardhan, Ellen Siever, and Stephen Spanbour

Reviewed by: Greg Leffler, send e-mail Published by: O'Reilly and Associatesl, go to the web site Requires: N/A MSRP: US$39.95, CA$61.95 Perl is often called the "Swiss Army Chainsaw" of languages. Perl (as it's nickname implies) is quite possibly the most flexible programming/scripting language in existence. It is a standby in any UNIX system, and interpreters for Perl are available for nearly any other platform including Macintosh and Windows. Perl in a Nutshell offers a valuable guide to the Perl language in an easy to access format. The book is divided into 5 main sections: an introduction, the basics of Perl, a modules reference, using Perl on the Web, and advanced topics. Of these three sections, the module reference is by far the most valuable portion of the book. The first section describes what Perl can be used for (almost anything), installing Perl, CPAN, and Perl's documentation and other forms of help for learning the language. In the second section, the reader is introduced to the rudiments of Perl, including command-line argument handling, Perl program structure, variables, file handling and debugging. This section also contains a valuable (if terse) reference for Perl's built-in functions, including usage tips and some examples.

The third and by far largest section of this book consists of the modules reference. This is a very comprehensive reference, taking up around 200 pages and providing a quick glance at what the module does, what it is and sometimes offering some syntax or examples. No, this section of the book will not be enough to assist in you writing your next OS in Perl, but it is an excellent start for someone who needs a refresher about what modules are available and how to use them. It is certainly better than having to look at CPAN for module information every time you need to remember what module Foo::Bar does.

Perl is one of the premiere scripting languages used for Internet services. Specifically, most CGI scripts (enabling interactivity such as shopping carts and e-mail forms) are written in Perl, mainly due to Perl's superior text-handling functions. The 4th part of this book deals with CGI, the CGI.pm module, and setting up and using mod_perl for Apache to accelerate Perl on an Apache web server. This information is a good overview, but for more detailed information and for usable/specific examples, you'll have to look elsewhere.

The rest of the book provides great overviews of a wide array of topics to introduce readers to more advanced functions that Perl can handle. These include XML, Simple Object Access Protocol (SOAP - a protocol to enable easy data interchange among applications), network programming (sockets, e-mail, Usenet, FTP and LDAP), LWP (tools to write Perl scripts that handle information retrieved from the Internet), Perl/Tk (a system to add a GUI to a Perl application) and special information for Windows (OLE automation, Windows-specific modules, and ODBC database handling). All of these topics aren't covered in exhaustive detail, but they provide a very solid background for further development and work in Perl.

Overall, the book is excellent for two types of people: those who already have a basic knowledge of Perl (possibly with some knowledge of structured programming), and people with an intermediate knowledge of Perl. Advanced Perl users might find this book handy to refresh some details, but there really isn't enough detail to provide a canonical reference of the language. Beginners with no programming knowledge would probably be better off picking up a book specifically geared to someone just starting to learn Perl. This book provides most of what you will need to know on a day-to-day basis without getting bogged down in minutiae like so many other technical books seem to do.

Cons: Detail is weak on some points, examples are lacking in many instances, coverage on some subjects is spottier than on others, CGI information seems insufficient for the depth of the subject.

Pros: Excellent overview of the language, excellent index, sufficient depth of coverage to provide resources for more information on subjects that aren't covered. Very useful information on parts of Perl that are often overlooked and how to use them.

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