Perl Training Course

Course Outline

Perl is a mature, extremely flexible, general-purpose programming language, which is especially well-suited to textual manipulation. In addition to its brilliant built-in-facilities, there are vast freely-accessible libraries of Perl code to help build almost every conceivable application. And it’s available free-of-charge.

The capabilities of Perl have been applied by a wide range of professionals in both systems support and programming fields for various applications including manipulating text and data, database access, CGI programming, HTML generation, and parsing and generating XML files.

This five-day course provides a comprehensive examination of the major aspects of the Perl programming language and an overview of selected applications, with an emphasis on database and web server processing.

It covers basic through intermediate and advanced techniques and programming structures provided by Perl5. A number of mainly advanced topics are normally self-study, or as time allows.

This is a ‘hands-on’ course with many practical examples of everyday use of Perl, as well as some more substantial exercises.

Course Content

All exercises and examples are designed to achieve the maximum benefit for delegates. They aim to effectively demonstrate the concepts covered in the course and provide an opportunity to experiment with them; many of the exercises develop custom code which encapsulate complex functionality that can be used in numerous real world applications.

This course has been developed for real-world, commercial scenarios by our expert instructors. See below for detailed syllabus.

What you will learn

• Fundamental principals behind Perl.
• Data Types, Expressions, operators, and scalar data functions
• String processing & Manipulation
• Control Structures, Normal Arrays & Lists
• Functions and Subroutines
• Hashes (associative arrays)
• Handling Text Files
• Regular expressions
• Packages and modules
• Web Server Programming.

Perl with CGI Training Course Outline

Introduction

• Perl as a practical language
• Perl applications and capabilities
• Perl flavours, including Perl 6
• The CPAN
• Compiling and invoking Perl

Basics

• Program structure, including comments
• Standard input, output and error
• Input and output functions and constructs

Data types, expressions, operators

• Integers, floats, strings
• Scalars, variables, assignment and scope
• Creating expressions using operators
• Conversion functions

String processing and manipulation

• Unicode support
• Simple string functions
• More advanced string functions
• Regular expression basics
• Transliteration operator

Basic control structures

• Relational expressions
• Conditional processing: if , else, unless, elsif
• Logical operators
• Looping: while, until, for
• List constructor
• foreach with lists
• Simple subroutines

Other control structures

• The conditionasl operator
• Statement modifiers
• Using logical operators as control structures
• Labels and other loop constructs

Arrays and lists

• Defining normal (ordered) arrays
• Assigning and extracting values
• foreach with arrays
• Array dimensions
• Extending and reducing arrays
• Conversion functions: split, join
• List interpolation; slices
• Array functions: pop, shift, push, unshift, splice
• List functions: sort, reverse, map, grep

Functions and subroutines

• Creating your own functions and subroutines
• return value(s)
• Passing (and localising) arguments: the @_ array
• my, local, and state functions
• defined function

Hashes (associative arrays)

• Defining hashes
• Assigning and extracting hash elements
• keys function
• Hash element functions: exists, delete
• Accessing values: values, each
• Hashes in list/scalar context
• Hash dimensions; hash slices

Special variables

• Global special arrays
• Array and hash special variables
• Regular and per-filehandle special variables

Reading and writing text files

• Filehandles; open and close functions
• Opening files for input, output and appending
• Reading/writing individual/multiple lines
• die, warn, exit and the special variable $!

Format and the Write Function

• Declaring and defining formats
• Fieldline and fieldholder definition
• Invoking a format...the write function
• Changing the filehandle using select
• Top-of-page format

Introduction to references

• Creating references to anonymous data
• ‘Multidimensional’ arrays
• Reference types and ref function
• Referencing/dereferencing existing data
• Passing array and hash references to subroutines
• Hashes of arrays
• Arrays of hashes
• Sorting arrays of references
• Symbolic references
• Variables or blocks as variable names

More complex data structures

• Selecting the appropriate data structure
• Complex and nested data structures
• Data serialisation
• Data::Dumper
• Storable

Packages and module basics

• Package scope and symbol tables
• my, our, use vars;
• use and require keywords
• Module location: @INC and %INC; use lib
• Module invocation variations
• Standard library modules and examples
• Implementing simple modules
• Exporter standard module

Regular expressions

• Match and pattern-binding operators
• Metacharacters
• Alternation and grouping
• Character classes including special classes
• Anchors and word boundaries
• Quantifiers and greediness
• Capturing
• Backreferences
• Regular expression special variables
• qr operator and study function
• Use of modifiers
• Advanced and cloistered modifiers
• Substitution operator
• Global and Perl-expression substitution
• Extended regular expression sequences

Further file and storage features

• File tests, eg -e FILENAME
• Using @ARGV for multi-file processing
• In-place editing
• open modes

Emulating OS commands

• chmod, mkdir, rmdir, chdir functions
• link (Unix), unlink and rename functions
• stat and lstat functions, and module equivalents
• Cwd module
• system function

Directory contents

• glob function and alternatives
• Opening and closing directory handles
• Reading directory contents…readdir
• File::Find module

Time functions

• gmtime, localtime, time, times
• Time-related modules

Object-oriented programming

• Background to object-orientation
• Accessing object methods
• Class methods and attributes
• bless function
• The -> notation and variations
• Object-oriented wrappers for complex data
• Perl-style inheritance, @ISA special array
• Polymorphism

Ties and closures

• Introduction to the tie command
• Tied scalars, arrays and hashes
• Unix-like DBM databases and DBM hashes
• SDBM_File and similar modules
• Pseudo databases
• Tied handles
• Private data via closures
• Perl 5.10 state declaration

More on modules and packages

• Specialised import lists
• import function
• Multiple packages in a module
• Pragmas
• BEGIN, END and similar blocks
• eval blocks and eval function
• Default functions and methods
• AUTOLOAD functions
• UNIVERSAL package

Database processing

• RDBMS connectivity from Perl
• ‘Standard’ DBI/DBD approach
• ODBC and DBD::ODBC
• Other possibilities, eg Win32::ODBC
• Non-RDBMS data sources

Database interaction via DBI module

• Database modules: DBI and DBD::...
• Installing DBD modules
• Connecting to databases via DBI/DBD
• DBI->connect method; connection descriptors
• prepare and execute
• Fetching and retrieving data...fetchrow_array
• Other fetch..._... methods
• select... methods
• Standard error handling
• Updating data: INSERT, UPDATE, DELETE

Perl & web server programming

• The CGI specification
• Using Perl with a web server program
• Preparing a Perl program for web server use
• CGI.pm, related and alternative modules
• Unbundling data from the client
• Sending dynamic HTML documents

The CGI.pm module

• Function-oriented and object-oriented approaches
• The param function
• The header and start_html functions
• HTML output functions
• Handling forms
• Handling tables
• CGI with DBI (or Win32::ODBC)
• Alternatives, eg CGI::Lite

Other web server issues

• General Perl security issues
• Security issues in outline
• Redirection
• Serving exception and alternative output
• Maintaining state
• Persistent connections and scripts

Following are self-study or as time allows

• Miscellaneous functions
• srand, rand
• pack and unpack
• Other bitwise operators and functions

Typeglobs

• Typeglobs, local() and my()
• Applying typeglob aliasing
• Typeglobs and references
• Typeglobs and filehandles

The Standard Library

• Time modules
• Bechmark.pm
• Config.pm

The CPAN; example CPAN modules

• Installing CPAN modules
• Mime::Lite
• Net::SMTP
• HTML::Template
• GD

AUTOLOAD uses

• AUTOLOADing modules
• SelfLoader, AutoLoader and related modules
• The autouse pragma

Distributing modules

• h2xs utility
• The blib pragma
• Contributing to CPAN

Further DBI module features

• DBI metadata
• Transactions
• Customised error handling

CGI security in more detail

• General and specific security issues
• Security problem avoidance
• Denial of service attacks
• Restricting CGI permissions

Other applications

• XML parsing and processing
• Perl/TK introduction
• HTML parsing
• Perl and AJAX

Who Should Attend

Experienced developers who need a firm comprehensive foundation in the language and a succinct appreciation of the capabilities of Perl in selected application areas. Systems administrators, database administrators and testers; developers working with Perl applications of all types.