Perl Programming

Duration:	3 days
Type:	beginner

Description

This course provides a complete introduction to the Perl scripting language. It includes both the latest features in Perl 5.10 and details of how the language is being redesigned in Perl 6. As the course progresses delegates learn to read data from files, filter it using regular expressions and store the result in data structures built from anonymous arrays and hashes. Best practises for Perl coding are introduced in each chapter, including techniques for creating reusable modules, classes and CPAN libraries.

Prerequisites

Delegates should have some previous programming experience, ideally in C, C++, C#, Java or JavaScript. By default the course is delivered on Windows using ActivePerl and the Komodo IDE, but other configurations are possible if required.

List of Modules

Introduction to Perl

The evolution of Perl from Sed, Awk and Shell Scripting

Installing Perl and downloading modules from CPAN

Understanding how the Perl interpreter runs your script

Differences between versions 5 and 6 of Perl

Comparing Perl to Python and Ruby

Key Characteristics of Perl

Sigils are used to denote variables

How barewords are interpreted

Packages, symbol tables and typeglobs

Strings, comments and using heredoc

Printing to and reading from the console

Basic Procedural Programming

Declaring and initializing scalar variables

Operators for strings and numbers

What values count as true in Perl

Variables created by the interpreter

Performing tests using if and unless

Different types of loops supported by Perl

File Access in Perl

Creating handles and testing file paths

Storing file handles in scalar variables

Reading lines, characters and binary data

Different techniques for slurping files

File globbing and changing permissions

Arrays and Lists

Initializing arrays based on lists

Initializing arrays implicitly

Initializing list values based on arrays

Slicing, expanding and shrinking arrays

Built-in functions for manipulating arrays

Introducing anonymous arrays

Working With Hashes

Initializing hashes based on lists

Initializing hashes implicitly

Using the 'fat comma' notation

Built-in functions for manipulating hashes

Initializing an array based on a hash

Using slices to add and retrieve multiple values

Creating hashes of anonymous arrays

The Perl Regular Expression Syntax

How a Regular Expression Engine operates

Creating character classes and specifying multiplicities

Shortcuts for character classes provided by Perl and POSIX

Meta-characters for specifying positions in the input

Using parenthesis for grouping and submatches

Running Regular Expressions in Perl

Using the =~ operator for pattern matching

Iterating over all the matches for an expression

Modifiers that can be used during matching

Using the extended regular expression syntax

Using the =~ operator for making substitutions

Using the e modifier to run code during substitutions

Regular Expressions - Advanced Concepts

The non greedy versions of *, + and ?

Using parenthesis that do not capture

Applying modifiers only to part of the expression

Using look-around assertions to match without capturing

Building regular expressions dynamically

Using Unicode properties in expressions

Named submatches in Perl 5.10

Subroutines in Perl

Declaring subroutines and passing parameters

Using hashes to implement named parameters

Creating local variables with my, our and local

Using anonymous subroutines for meta-programming

Perl Error Handling

Using eval to catch and handle errors

Enhanced error handling provided by Carp

References in Perl

Introducing references as memory addresses

Declaring references to named and anonymous variables

The different syntaxes available for working with arrays

Using references to create complex data structures

Best practises for navigating complex data structures

Creating Perl Modules

Understanding how packages work in Perl

The relationship between packages and modules

How the Exporter module exports symbols

Using the EXPORT, EXPORT_OK and EXPORT_FAIL arrays

Implementing versioning in your modules

Publishing modules to CPAN

Object Orientation in Perl

Reviewing the key concepts of OO

The effect of the bless keyword in Perl

Declaring classes with fields and methods

Creating class hierarchies and overriding methods

Using Perl Libraries (Optional)

Manipulating XML with SAX/DOM/XPath

Database access with DBI

Creating Web Applications

New Features in Perl 6 (Optional)

Sigils are now invariant

Better syntax for indexing

Modifications to operators

Changes to regular expressions

Changes to Object Orientation

Changes to references