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0.2. What's New in This Edition
The book you're holding is thicker than its previous edition of five
years ago—about 200 pages thicker. New material is spread
across more than 80 entirely new recipes plus over 100 existing
recipes that were substantially updated since the first edition.
You'll also find two new chapters: one on mod_perl, Perl's interface
to the popular Apache web server; the other on XML, an increasingly
important standard for exchanging structured data.Growth in this book reflects growth in Perl itself, from Version
5.004 in the first edition to v5.8.1 in this one. Syntactic changes
to the core language are nevertheless comparatively few. Some include
the spiffy our keyword to replace the crufty
use vars construct for declaring global variables,
fancier forms of open to disambiguate filenames
with strange characters in them, and automatic allocation of
anonymous filehandles into undefined scalar variables. We've updated
our solutions and code examples to reflect these changes where it
made sense to make use of the new features.Several of Perl's major subsystems have been completely overhauled
for improved functionality, stability, and portability. Some of these
are relatively isolated, like the subsystems for threading (see
Recipe 17.14) and for safe signals (see Recipe 16.17). Their applications are usually
confined to systems programming.More sweeping are the changes to Perl and to this book that stem from
integrated support for Unicode characters. The areas most profoundly
affected are strings (now with multibyte characters) and I/O (now
with stackable encoding layers), so Chapter 1 and Chapter 8 include new
introductory material to orient you to these sometimes confusing
topics. These chapters also provide the bulk of recipes dealing with
those specific topics, but this fundamental shift touches many more
recipes throughout the book.Another growth area for this book and Perl has been the welcome
proliferation of many highly used and highly useful modules now
released standard with the Perl core. Previously, these modules had
to be separately located, downloaded, configured, built, tested, and
installed. Now that they're included in the standard distribution,
that's all taken care of when installing Perl itself.Some new core modules are really pragmas that alter Perl's
compilation or runtime environment, as demonstrated in
Recipe 1.21, Recipe 12.3, and Recipe 12.15. Some are
programmer tools to aid code development and debugging, like modules
shown in Recipe 11.11, Recipe 11.13, Recipe 11.15, and Recipe 22.2. Others augment basic operations available
on core data types, like those shown in Recipe 2.1, Recipe 4.13, Recipe 4.18, Recipe 5.3, Recipe 8.7, and Recipe 11.15. Finally, the
networking modules have at last made their way into the core
distribution, as seen throughout Chapter 18. We've
probably not seen the last of this inward migration of modules.
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| Preface |  | 0.3. Platform Notes |
Copyright © 2003 O'Reilly & Associates. All rights reserved.
