This three- or four-day course provides a thorough introduction to the Perl programming language.

• Participants learn how to develop and maintain portable scripts useful for system management, data manipulation, and Web CGI programming.
• Emphasis is placed on built-in subroutines that can be used to help conveniently build fast, portable and efficient scripts.
• Extensive hands-on exercises provide practice in report creation, pattern matching, string manipulation, file I/O, command line processing, and debugging.
• Participants are shown how to extend Perl's basic functionality with packages and loadable modules.
• The final day encompasses CGI scripting with Perl as well as database access using the DBI module.
• Participants are shown how to validate form data, how to perform robust database access, and how to generate HTML output in order to create a dynamic web site.

Participants who do not need or want in-depth coverage of CGI scripting and DBI should attend for just the first three days.

Knowledge of HTML is required to benefit fully from attendance on the fourth day. Otherwise, basic computer knowledge is all that is required, although some programming experience would be advantageous. .

Course Content

Introduction to Perl

• Origin and Design Goals of Perl
• Overview of Perl Features
• Getting and Installing Perl
• Accessing Documentation via perldoc
• HTML-Format Reference Documentation
• Perl Strengths and Limitations

Getting Started With Perl

• Explicit Invocation of the Perl Interpreter Running Perl on UNIX vs. Windows
• Running Perl from the Command Line
• Using Command Line Options
• Using Debug Mode
• Implicit Invocation of the Perl Interpreter
• Running and Debugging Perl Scripts
• Simple and Compound Statements
• Fundamental Input Techniques
• Using the print Function to Generate Standard Output

Using Variables

• Scalar Variables
• Introduction to Standard Data Types
• Retrieving Standard Input Using the Default Variable $_
• Assigning Strings and Numbers to Scalar Variables
• Declaring Constants for Persistent Values
• Using strict to Declare Variables

Pattern Matching in Perl

• Regular Expressions in Perl
• Using Pattern Matching Operators
• Altering Data with Substitutions in Regular Expressions
• Using Backreferences to Capture Data from Regular Expression Matching
• Global and Case-Insensitive Matches
• Altering Data with Character Translation
• Using Variables in Patterns

Operators

• Introduction to Fundamental Operators
• Operator Precedence and Associativity
• Using the Ternary Operator ?: as a Shortcut for the if Statement
• Using <FILEHANDLE> and <> File I/O Operators for Standard Input/Output
• Using the Shortcut Operators +=, -=, *=, /=

String Manipulation

• String Comparison
• String Relations
• Concatenation
• Substring Manipulation
• Using chomp and chop to Eliminate EOL Characters
• Escape Characters for Formatting
• String Manipulation Functions

Flow Control: Conditional Statements and Looping

• Conditional Expressions and Logical Operators
• if/else/elsif and unless
• Constructing switch/case Equivalent Expressions
• while Loops and do Loops
• for and foreach Loops
• Labels
• Altering Program Flow with next, last, and redo
• Trapping Errors with the eval Function
• Terminating a Script with exit

Subroutines and Parameters

• Simplifying Scripts with Subroutines
• Defining and Calling a Subroutine
• Passing Arguments by Value
• Passing Arguments by Reference
• Using return to Return a Value
• Controlling Variable Scope using my and local Keywords

Arrays and Hashes

• Defining Numeric Index Arrays
• Defining Associative Arrays
• Sorting Arrays with the sort Function
• Adding and Deleting Items Using push, pop, shift, and unshift
• Using slice, splice, and reverse
• Other Array Manipulation Techniques
• Looping through an Array
• Merging Arrays
• Introduction to Hashes
• Preallocating Memory to Optimize Hash Performance

Packages and Modules

• The Power of Packages and Modules
• Introduction to Standard Modules
• Where to Find Modules on the Internet
• Installing a Module on UNIX or Windows
• Creating Packages for Portability
• Using Packages to Create Isolated Namespaces and to Separate Code

File Manipulation

• Using open and close
• Difference Between print and write
• Reading and Writing Arrays
• Directory Manipulation Using opendir, closedir, readdir, chdir, mkdir and rmdir

Input/Output Processing

• Parsing Input
• Using Standard Input, Standard Output, and Standard Error
• String and Field Processing
• Using Streams and Pipes
• Using die to Quit with an Error
• Redirecting Standard Output and Standard Error to a File
• Getting Standard Input from a File

Implementing Command Line Arguments

• Reading Command Line Arguments from @ARGV
• Manipulating Positional Parameters with push, pop, shift
• Processing Command Line Options with getopt or getopts
• Analyzing Command Line Argument Values with the Getopt::Std and Getopt::Long Modules
• Reserved Variables
• Manipulating Identifiable Options Using GetOptions

Perl Report Formatting

• Defining Report Formats
• Justifying Text (Left, Right, Center)
• Using write to Generate Reports
• Defining here Documents for Report Customization
• Creating Report Headers
• Using Built-in Variables to Control Report Appearance
• Printing Line Numbers on a Report
• Formatting Multi-Line Output
• Writing Formatted Text to a File

Debugging In Perl

• Using the Built-in Perl Debugger
• Starting the Debugger
• Debugger Command Syntax
• Checking for Script Syntax Errors
• Solving Compile-Time Errors
• Single-Stepping through a Script
• Executing to Breakpoints
• Setting Global Watches
• Printing Values of Variables
• Listing All Variables Used in the Script
• Using strict Error Checking
• Quitting the Debugger

Web Architecture and CGI Scripting Overview

• Evolution of the World Wide Web
• The WWW as a Computing Platform
• Perl’s Role in Distributed Web Applications
• Client and Server Interaction
• How Server-Side CGI Scripts Work
• Differences between Client-Side and Server-Side Script Environment
• Strengths and Weaknesses of Web Programming Languages
• Maintaining State in the Web Architecture Using Cookies and QueryString Variables
• Using Environment Variables to Control CGI Scripts

CGI Scripting with Perl

• Communicating with the Web Server
• Perl CGI Script Instantiation and Invocation
• Generating Output for the Browser
• Understanding the Differences between the Get and Post Methods in an HTML Form
• Using Form Data Validation to Check Data Values
• Storing and Retrieving Form Data
• Using Cookies and QueryString Variables to Maintain State Across Invocations
• CGI Security Mechanisms

Using the CGI.pm Module

• Overview of HTML Generation Using CGI.pm
• Creating HTML Using CGI.pm Methods
• Using HTML Elements Built into the CGI.pm Module Headers
• Hyperlinks
• Images
• Forms
• Form Elements
• Retrieving Form Data Using the param Method

Using the DBI Module

• Fundamental Characteristics of Relational Databases
• Using DBI and DBD to Connect to a Database
• Fundamental Data Storage and Retrieval Strategies
• Using SQL Statements to Communicate with the Database
• DBI Query Syntax
• Using DBI Methods to Retrieve Database Information
• Initializing and Connecting to a Database
• Preparing a SQL Statement
• Executing the SQL Statement Against the Database
• Fetching the Result Set to Achieve Workable Data in the Perl Script
• Useful Utilities to Aid in Database Development
• Using Other Modules to Access Databases on the Web

Web Programming Optimization Using ModPerl

• Overview of Apache Web Server Functionality
• Comparing the Speed of CGI Scripting vs. ModPerl
• Configuring Apache with Perl and ModPerl
• Apache Strengths and Limitations
• Using the Apache::Registry Module
• Extending and Enhancing Apache Functionality
• Using High-Level Packages to Help Develop Scalable and Easily Managed Web Applications