Perl Programming

Contents Preparing to learn Perl Things you need to know and do in order to run Perl programs and learn Perl programming A module designed for complete beginners The perl compiler/interpreter Perl under Unix/Linux Perl under MS Windows 2000/NT/95/98/ME (perl.exe) ActiveState Perl Making programs executable (chmod +x) Perl from the command line (perl command) Specify the perl compiler/interpreter (#!) Using plain text for programs Writing a very simple program Running a very simple program Basic syntax Perl: the absolute minimum Enough of the language to get started The print function Variables Scalars numbers and strings Assignment Simple conditional tests if Lists Arrays for storing lists foreach loops Hashes Other loops: while, for, do, until Arrays the rest Simple input, e.g., while() Functions overview recognising, writing, using Simple file handling open, print Subroutines parameters in and out, listification, local variables (my) Help perldoc, books, web Regular expressions Text manipulation with regular expressions Matching strings Matching the default variable Case-sensitivity and matching Special characters Special characters: where Special characters: what Special characters: how many Built-in character classes Built-in character class examples Capturing Regular expression examples Substitution Global substitutions Perl: beyond the basics More flow control Statement modifiers Quoting mechanisms qq(), etc. Here documents Uppercase/lowercase conversion Splitting strings into lists Joining lists into strings Filtering lists with map Sorting lists The importance of context Assignment shortcuts Scoping rules Special variables Complex data structures & references Limits of flat lists Nesting arrays Array references Anonymous arrays Named array references Passing multiple arrays to/from functions Hashes of arrays Hash references Arrays of hashes Hashes of hashes Complex nested data structures Code references Dispatch tables Finding Out More For Yourself How to read Perl's documentation Where to find more information Knowing what's out there to look for FAQs Using Perl Modules from CPAN The Comprehensive Perl Archive Network (CPAN) Why effective Perl programmers are efficient CPAN users CPAN's philosophy Finding modules Installing Modules Using modules Some particularly useful modules The Perl debugger & debugging Perl Avoiding bugs Perl's built-in debugger Invoking the debugger What you can do with the debugger Understanding the debugger's command line interface Knowing the debugger's basic command set Exploring some extended functions Graphical debuggers Alternative debugging techniques Command-Line Perl General principles Using Perl as a filter Editing files in-place Many real world examples Command line flags Many examples using regular expressions A Whistle-Stop Tour of the World of Perl Wheels you don't need to re-invent Common recipes Common pitfalls Perl Style The Philosophy of Perl Why good style is important Good style Bad style Handling Databases with Perl Interacting with SQL databases from Perl Using DBI Connection/disconnection, log in/log out Retrieving a single record Retrieving multiple records Update/insert queries Place-holders and bind values Connecting through ODBC Advanced File Processing with Perl Types of open Filehandles Reading line by line Reading paragraph by paragraph Reading entire files Special variables The flip-flop operator (..) File test functions Pipes System interaction Connecting to other programs Unsafe pipes Using IO::Pipe Grabbing a program's output Other ways to run programs Perl Security Issues Potential security pitfalls Coding for security Taint checking Dangerous environment variables File input Set-user-id Perl programs Permissions and us Contents Finding Out More For Yourself How to read Perl's documentation Where to find more information Knowing what's out there to look for FAQs The Perl Cookbook Command Line Perl Writing Perl programs on the command line Using Perl as a filter Perl imitating other programs: Awk, grep, sed Perl editing files Command line flags Many real world examples Advanced File Processing with Perl Types of open Filehandles Reading line by line Reading paragraph by paragraph Reading entire files Special variables The flip-flop operator (..) File test functions Pipes Advanced Perl Regular Expressions Commenting regexps /x Back-references Alternation Quantifiers: ?, {} Non-greedy quantifiers Finding multiple matches Zero-width assertions: anchors, lookahead, lookbehind Dynamically making replacement text Object-Oriented Techniques in Perl Using object-orientation: classes and objects Constructors Object methods Destructors Dual-purpose class and object methods Inheritance An example class: CGI::Page Advanced Perl Miscellany Exception-handling: trapping run-time errors Executing code fragments in strings Secret subroutines Static variables Subroutine prototypes Benchmarking code Creating Perl Modules Modules Packages & files Creating a module Defining functions in modules Exporting functions from modules Variables in modules When you should create a module Using the Perl Debugger Avoiding bugs Perl's built-in debugger Invoking the debugger What you can do with the debugger Understanding the debugger's command line interface Knowing the debugger's basic command set Exploring some extended functions Graphical debuggers Alternative debugging techniques Perl Style The Philosophy of Perl Why good style is important Good style Bad style Reading Perl Reading well-written Perl programs Reading badly-written Perl programs Advanced Object-Oriented Techniques in Perl Multiple inheritance Method resolution algorithm Customizing method dispatch using AUTOLOAD Using tie to make instances simulate scalars, aggregates, or file handles Operator overloading Managing Dates and Times in Perl Time-keeping concepts Built-in time functions The DateTime modules