Preface (Perl in a Nutshell, 2nd Edition)

Perl is a programming language that is useful. By this, we mean that people don't learn Perl just because they think they should, they learn Perl because they want to get something done.

This book is for Perl programmers who need to get things done. It's for readers who have dabbled a little in Perl and want a single reference for all their needs. This book is part reference, part guide to the world of Perl. We cover the language itself, but also the Perl modules that are most popular—modules for CGI, database manipulation, XML processing, network programming, graphical interfaces, and Win32 integration.

In this second edition of the book, we added several new chapters, included some topics that we neglected in the first edition and new technologies that have emerged, and updated the material to Perl 5.8.

0.1. How This Book Is Organized

This book has 10 parts, as follows:

Part I, "Getting Started"

Chapter 1, "Introduction to Perl" gets you oriented to Perl and the Perl community.

Chapter 2, "Installing Perl" gives you some pointers on installing Perl and its modules on your machine. This chapter introduces you to the CPAN archive and discusses using the CPAN module to retrieve the latest versions of Perl modules.

Part II, "Language Basics"

Chapter 3, "The Perl Executable" is about using the perl program itself. It covers environment variables, command-line options, and the differences in executing the Unix and Win32 versions of Perl.

Chapter 4, "The Perl Language" is the turbo-charged tutorial/reference to the Perl language. If you've never programmed before, then you might need a tutorial that goes more slowly. But if you have some experience with other programming languages, this chapter should teach you enough to start writing Perl programs.

Chapter 5, "Function Reference" is a reference chapter for each of the built-in functions of Perl.

Chapter 6, "Debugging" is about using the Perl debugger to help locate the rare errors in your programs.

Part III, "Modules"

Chapter 7, "Packages, Modules, and Objects" gives a quick introduction to Perl packages, Perl modules, and object-oriented programming in Perl.

Chapter 8, "Standard Modules" is a reference to each of the modules included in the standard Perl distribution.

Part IV, "CGI"

Chapter 9, "CGI Overview" is a brief introduction to the concepts behind CGI programming.

Chapter 10, "The CGI.pm Module" covers the very popular CGI.pm module, which is deemed essential by many CGI programmers.

Chapter 11, "Web Server Programmingwith mod_perl" is about mod_perl, the Apache module that can be used to significantly improve CGI performance and allows you to embed Perl code into the Apache server itself.

Part V, "Databases"

Chapter 12, "Databases and Perl" gives a brief introduction to DBM databases in Perl and provides a reference to DBI, the Database Independence package that gives you a consistent interface to many different database packages.

Part VI, "XML and SOAP"

Chapter 13, "XML and Perl" covers the modules for XML processing with Perl.

Chapter 14, "SOAP" gives an introduction to SOAP and web services in general, and to the SOAP::Lite module for SOAP programming with Perl.

Part VII, "Network Programming"

Chapter 15, "Sockets" explains socket programming and how to use the IO:Socket module.

Chapter 16, "Email Connectivity" covers the Net::SMTP and Net::POP3 modules for sending and reading email, and the Mail modules for manipulating email messages.

Chapter 17, "Usenet News" explains the NNTP protocol and the Net::NNTP module for reading and posting Usenet news, and the News::Newsrc module for managing .newsrc files.

Chapter 18, "FTP" explains the FTP protocol, the Net::FTP module for transferring files by FTP, and the Net::Netrc module for managing .netrc files.

Chapter 19, "Lightweight Directory Access with Net::LDAP" covers the Net::LDAP module for using LDAP directory services within Perl applications.

Part VIII, "LWP"

Chapter 20, "The LWP Library" covers the most commonly used parts of the huge LWP library of modules for HTTP transactions.

Part IX, "Perl/Tk"

Chapter 21, "Perl/Tk" is a reference to the Tk extension to Perl, which creates graphical user interfaces from within a Perl program.

Part X, "Win32"

Chapter 22, "Win32 Modules and Extensions" talks about the many Perl modules for working with the Win32 operating systems.

Chapter 23, "OLE Automation" covers the Win32::OLE modules for OLE automation.

Chapter 24, "ODBC Extension for Win32" covers the Win32::ODBC module.