Copyright © 2003 ProsoftTraining. All rights reserved. Perl Fundamentals

Copyright © 2003 ProsoftTraining. All rights reserved. Lesson 1: Introduction to Perl

Objectives Describe the benefits of Perl Explain the role of the Perl interpreter Identify the characteristics of Perl’s basic syntax Describe the use of the print function Create and execute a simple Perl script Define scalar variables Use scalar variables to manipulate numerical and string data Use expression operators Retrieve data from STDIN

Practical Extracting and Reporting Language Why use Perl? –Innate flexibility –Simple syntax –Relaxed compiler instructions –Free

Getting Started with Perl The shebang line Creating a simple Perl script

Scalar and Numerical Variables Assignment Expressions

String Variables Second type of scalar variable The print function

Retrieving Data from STDIN The chomp() function

Summary Describe the benefits of Perl Explain the role of the Perl interpreter Identify the characteristics of Perl’s basic syntax Describe the use of the print function Create and execute a simple Perl script Define scalar variables Use scalar variables to manipulate numerical and string data Use expression operators Retrieve data from STDIN

Copyright © 2003 ProsoftTraining. All rights reserved. Lesson 2: Flow Control in Perl

Objectives Evaluate Boolean expressions Construct an if statement Discuss else and elsif branches Construct a while loop, a do {} while loop, and a for loop Use loop-control commands Describe the I/O redirection paradigm

Boolean Expressions in Perl Numeric Boolean expressions String Boolean expressions Logical operators

The if Statement The else branch The elsif branch

The while Statement Second type of control structure Defines a block of code that will be executed repeatedly as long as some Boolean expression evaluates as true

The do { } while Statement Similar to the while loop except that the condition is not evaluated until the code block has already been executed once

The for Statement Includes three expressions separated by semicolons Incorporates facilities for initializing a counter and incrementing it on each turn through the code block

Loop-Control Commands last next redo

I/O Redirection Many Perl scripts use I/O redirection in place of more complicated file-handling subroutines

Summary Evaluate Boolean expressions Construct an if statement Discuss else and elsif branches Construct a while loop, a do {} while loop, and a for loop Use loop-control commands Describe the I/O redirection paradigm

Copyright © 2003 ProsoftTraining. All rights reserved. Lesson 3: Regular Expressions in Perl

Objectives Define regular expressions Perform pattern matching Define and use metacharacters, quantifiers and assertions Explain character classes Perform substitution Use the binding operator

Introduction to Regular Expressions Pattern binding operators Escape sequences and metacharacters

Character Classes Indicate a list of characters that one element in a string will match

Pattern Matching and Substitution Back references

Summary Define regular expressions Perform pattern matching Define and use metacharacters, quantifiers and assertions Explain character classes Perform substitution Use the binding operator

Copyright © 2003 ProsoftTraining. All rights reserved. Lesson 4: Arrays in Perl

Objectives Describe the purpose of arrays Define arrays using lists Access array elements Use the sort function to sort an array alphabetically Use a foreach loop to traverse an array Use the push, pop, shift, unshift, split and join functions

Introduction to Perl Arrays Initializing arrays Accessing array elements

The sort Function Accepts an array as an argument, alphabetizes the elements within the array, and returns the resultant array

The foreach Statement A special control structure designed to iterate through an array or list

The push and pop Functions The push function adds values to the top of a stack The pop function removes values from a stack

The shift and unshift Functions The unshift function adds a value to the front of an array and shifts the rest of the array by one The shift function removes values from an array Using an array as a queue

The split and join Functions The split function accepts two arguments, a regular expression and a string The join function accepts a list of values and combines them into a single string

Summary Describe the purpose of arrays Define arrays using lists Access array elements Use the sort function to sort an array alphabetically Use a foreach loop to traverse an array Use the push, pop, shift, unshift, split and join functions

Copyright © 2003 ProsoftTraining. All rights reserved. Lesson 5: Hashes in Perl

Objectives Describe the purpose of hashes Define hashes using lists Access hash elements Use the delete, keys, values, each, and reverse functions

Introduction to Perl Hashes Hashes are collections of scalar values that can be accessed individually Hash elements are accessed using an arbitrary scalar value, called a key Also known as associative arrays

Adding and Deleting Hash Elements The delete function The keys function The values function The each function The reverse function

Summary Describe the purpose of hashes Define hashes using lists Access hash elements Use the delete, keys, values, each, and reverse functions

Copyright © 2003 ProsoftTraining. All rights reserved. Lesson 6: Subroutines in Perl

Objectives Define and use a subroutine Call subroutines directly and indirectly Pass values to a subroutine Pass references to a subroutine Explain variable scope Return a value from a subroutine

Introduction to Perl Subroutines Defining subroutines Calling subroutines Passing arguments Returning values The sort function and subroutines

Variable Scope Variables can be created within subroutines that are private (specific) to just that subroutine using the my operator –The my operator takes a scalar, array, or hash name and instantiates local versions inside a subroutine

References Creating and referencing anonymous arrays Creating and referencing anonymous hashes Passing references to subroutines

Summary Define and use a subroutine Call subroutines directly and indirectly Pass values to a subroutine Pass references to a subroutine Explain variable scope Return a value from a subroutine

Copyright © 2003 ProsoftTraining. All rights reserved. Lesson 7: File Input and Output

Objectives Define and use filehandles Obtain a filehandle using the open function Output data to a file Close a file using the close function Open a file for reading Use the stat and lstat functions to obtain information about a file

Perl File Input and Output What is a filehandle? The open function Outputting data to a file Opening files for reading Other file-related functions Determining information about files The stat and lstat functions

Summary Define and use filehandles Obtain a filehandle using the open function Output data to a file Close a file using the close function Open a file for reading Use the stat and lstat functions to obtain information about a file

Copyright © 2003 ProsoftTraining. All rights reserved. Lesson 8: Environment Variables and Command Line Arguments

Objectives Access and use environment variables Use command line arguments Define options when handling command line arguments

Environment Variables What are environment variables? –Shells

Command Line Arguments Arguments entered at the command line can be used in Perl programs

Summary Access and use environment variables Use command line arguments Define options when handling command line arguments

Copyright © 2003 ProsoftTraining. All rights reserved. Lesson 9: Packages and Modules in Perl

Objectives Describe the purpose of packages Use the package keyword Use BEGIN and END blocks Describe the purpose of modules Create a module to facilitate code reuse Incorporate a module into your Perl scripts using the use and require statements Use the Exporter module

Using Packages in Perl Namespace The package keyword Package symbol tables

BEGIN and END Blocks Special blocks of code defined within a package

Using Modules in Perl Specially designed Perl scripts that package functionality for reuse by other Perl scripts

The use and require Statements The require statement takes a single argument (the name of the module to include) The use statement adds symbols directly to the including package’s symbol table

Summary Describe the purpose of packages Use the package keyword Use BEGIN and END blocks Describe the purpose of modules Create a module to facilitate code reuse Incorporate a module into your Perl scripts using the use and require statements Use the Exporter module

Copyright © 2003 ProsoftTraining. All rights reserved. Lesson 10: Object-Oriented Perl

Objectives Describe the purpose of objects Define objects for use in your Perl scripts Access object data Define and use object methods Use inheritance to expand the functionality of a class

Introduction to Object-Oriented Perl Creating objects Object data Object methods

array Destructor methods

Summary Describe the purpose of objects Define objects for use in your Perl scripts Access object data Define and use object methods Use inheritance to expand the functionality of a class

Copyright © 2003 ProsoftTraining. All rights reserved. Lesson 11: Database Connectivity and Perl

Objectives Define database programming Explain the benefits of using a database Define and use the DBI, the DBD, and SQL Open a database connection Query a database Return records from a database Insert records into a database Close a connection to a database

Introduction to Database Connectivity Database programming Database Interface Module Database Driver Module

Interacting with Databases 1. Connect to the database 2. Query the database 3. Display the results 4. Close the connection

Connecting to Databases The connect method

Structured Query Language Data Definition Language –CREATE –DROP Data Query Language Data Manipulation Language –INSERT –DELETE –UPDATE

Quoting Operators Perl includes quoting operators that can be used instead of single or double quotation marks

Summary Define database programming Explain the benefits of using a database Define and use the DBI, the DBD, and SQL Open a database connection Query a database Return records from a database Insert records into a database Close a connection to a database

Copyright © 2003 ProsoftTraining. All rights reserved. Lesson 12: Debugging Perl Programs

Objectives Debug Perl programs Use the –w switch Use the strict module Issue commands to the Perl debugger Trace the execution of a Perl script Design Perl scripts to minimize bugs

Introduction to Debugging Perl Scripts Using the print command Using the –w switch Using the strict module

The Perl Debugger Traps and fixes errors in a Perl script An interactive Perl environment wherein the user is prompted for debugger commands

Writing Bug-Free Perl Code Preventing errors Common Perl errors

Summary Debug Perl programs Use the –w switch Use the strict module Issue commands to the Perl debugger Trace the execution of a Perl script Design Perl scripts to minimize bugs

Perl Fundamentals Introduction to Perl Flow Control in Perl Regular Expressions in Perl Arrays in Perl Hashes in Perl Subroutines in Perl File Input and Output in Perl

Perl Fundamentals Environment Variables and Command Line Arguments Packages and Modules in Perl Object-Oriented Perl Database Connectivity and Perl Debugging Perl Programs