Practical Perl Programming A. D. Marshall 1999 HTML PERL NOTES ● Contents ● Introduction to Perl ❍ What is Perl? ■ Origins ■ Similar to C? ■ Cost and Licensing ❍ Installing Perl Installed ■ Getting and Installing Perl ❍ Writing Perl Programs ■ Creating the Program ■ Invocation ■ Comments in Your Program ❍ Further Reading/Information ● Numeric and String Literals ❍ Numeric Literals ■ Example: Numbers ❍ String Literals ■ Example: Single-Quoted Strings ■ Example: Double-Quoted Strings ■ Example: Back-Quoted Strings ● Variables ❍ Scalar Variables ■ Defining Scalar Variables ■ String Scalar Variables ● Arrays ❍ What is an Array? ❍ Literal Arrays ❍ Indexed Arrays ❍ Some Useful Array Functions ❍ Associative Arrays ■ Associative Array Operators ● Operators ❍ The Binary Arithmetic Operators ❍ The Unary Arithmetic Operators ❍ The Logical Operators ❍ The Bitwise Operators ■ Comparison operators for numbers and strings ❍ The Range Operator (..) ❍ The String Operators (. and x) ❍ Order of Precedence ● Perl Statements ❍ Understanding Expressions ❍ Statement Blocks ❍ Statement Blocks and Local Variables ❍ If/Unless statement ■ The for statement ■ The while/until statement ■ The foreach statement ● Functions ❍ Using the Parameter Array (@_) ❍ Passing Parameters by Reference ❍ Scope of Variables ❍ Using a List as a Function Parameter ❍ Nesting Function Calls ❍ Using a Private Function ❍ String Functions ❍ Array Functions ❍ Summary ● References ❍ Reference Types ❍ Passing Parameters to Functions ❍ The ref() Function ❍ Example: Creating a Data Record ❍ Interpolating Functions Inside Double-Quoted Strings ❍ Summary ● Files -- Input and Output in Perl ❍ Some Files Are Standard ■ Using the Diamond Operator (<>) ❍ File Test Operators ❍ File Functions ■ Reading Directories ■ Reading and Writing Files ■ Binary Files ■ Getting File Statistics ■ Printing Revisited ● Regular Expressions ❍ What are regular Expressions ❍ Using Regular Expressions ■ Special pattern matching character operators ❍ Backtracking ❍ Setting the Target Operator (Binding) ❍ Substitution ❍ The Matching Operator (m//) ■ The Matching Options ❍ The Translation Operator (tr///) ■ The Translation Options ❍ The Binding Operators ❍ Character Classes ❍ Quantifiers ❍ Pattern Memory ❍ Pattern Precedence ❍ Extension Syntax ❍ Pattern Examples ❍ Some Practical Examples ■ Using the Match Operator ■ Using the Substitution Operator ■ Example: Using the Translation Operator ■ Example: Using the Split() Function ● Reports ❍ Format Statements ❍ Field Lines ❍ Report Headings ● Special Variables ❍ What Are the Special Variables? ❍ Example: Using the DATA File Handle ❍ Example: Using the %ENV Variable ● Handling Errors and Signals ❍ Checking for Errors ❍ Using errno ❍ Using the || Logical Operator ❍ Using the die() Function ❍ Using the warn() Function ❍ Trapping Fatal Errors ■ Using the eval() Function ❍ Signals ■ How to Handle a Signal ● Objects in Perl ❍ What are objects? ❍ Classes ❍ Abtraction ❍ Polymorphism:Overriding Methods ❍ Encapsulation:Keeping Code and Data Together ❍ Objects in Perl ■ Bless the Hash and Pass the Reference ■ Initializing Properties ■ Using Named Parameters in Constructors ■ Inheritance: Perl Style ■ Polymorphism ■ One Class Can Contain Another ❍ Static Versus Regular Methods and Variables ● Perl Modules ❍ Module Constructors and Destructors ■ The BEGIN Block ■ The END Block ❍ Symbol Tables ❍ The require Compiler Directive ❍ The use Compiler Directive ❍ Pragma in Perl ❍ The strict Pragma ❍ The Standard Modules ❍ strict, my() and Modules ❍ Module Examples ■ The Carp Module ■ The English Module ■ The Env Module ● Debugging Perl ❍ Syntax Errors ❍ Common Syntax Errors ❍ Logic Errors ■ Using the -w Command-Line Option ■ Being Strict with Your Variables ■ Stepping Through Your Script ■ Displaying Information ■ Examples: Using the n Command ■ Using Breakpoints ■ Creating Command Aliases ■ Using the Debugger as an Interactive Interpreter ❍ Summary ● Perl Command-Line Options ❍ How Are the Options Specified? ❍ The Command-line Options ❍ Example uses of command-line options ■ Using the -0 Option ■ Using the -n and -p Options ■ Using the -i Option ■ Using the -s Option ❍ Summary ● Networking with Perl ❍ Sockets ❍ Clients and Servers ■ The Server Side of a Conversation ■ The Client Side of a Conversation ❍ Some Network Examples ■ Using the Time Service ■ Sending Mail (SMTP) ■ The MAIL Command ■ The RCPT Command ■ The DATA Command ■ Reporting Undeliverable Mail ■ Using Perl to Send Mail ❍ Receiving Mail (POP) ■ Checking for Upness (Echo) ❍ Transferring Files (FTP) ■ The World Wide Web (HTTP) ● CGI Programming in Perl ❍ CGI Scripting ■ What is a CGI Script? ■ Writing and Running CGI Scripts ■ Why Use Perl for CGI? ■ CGI Apps versus Java Applets ■ Should You Use CGI Modules? ❍ How Does CGI Work? ❍ Calling Your CGI Program ❍ Beginning CGI Programming in Perl ■ CGI Script Output ■ A First Perl CGI Script ■ Exectiion of CGI Programs ■ Why Are File Permissions Important in UNIX? ❍ HTTP Headers ■ CGI and Environment Variables ❍ URL Encoding ❍ Security ■ CGIwrap and Security ● The Other Side of CGI:Input -- HTML Forms ❍ A Brief Overview of HTML ❍ Server-Side Includes ❍ Forms: Facilitating User Input and Interaction ■ Forms and CGI: What are they? ■ Some Example Forms ■ The FORM Tag ■ Entering Data ■ The Submit Button ■ Text Input ■ Password ■ Associating labels with text and password input ■ Radio Buttons ■ Checkboxes ■ Assigning Initial Input Values to ■ Select ■ Textarea ■ Hidden Input ■ An Example Form ■ HTML Forms as an Interface to Databases ■ Further Information ❍ CGI Script Input: Accepting Input To Perl Scripts ■ Accepting Input from the Browser ■ Passing Data to a CGI Script ■ A Simple Form CGI Script Call ■ The Other Side -- receiving and processing information in CGI ( Perl) script ■ cgi-lib.pl ■ The cgi.pm module ■ A Minimal Form Response CGI Perl Script ■ Multiple argument input to a Perl CGI script ● Some Example Perl CGI Scripts ❍ Red, Green and Blue to Hexadecimal Converter ❍ An Address Book Search Engine ❍ Creating a Guest Book ❍ A Web Page Counter ● Using Perl with Web Servers ❍ Server Log Files ❍ Reading a Log File In Perl ❍ Listing Access by Document ❍ Looking at the Status Code ❍ Existing Log File Analyzing Programs ❍ Creating Your Own CGI Log File ● Internet Resources ❍ Web Sites ❍ Usenet Newsgroups ● A Quick Quide to HTML ❍ Basic HTML Programming ■ HTML ■ Hypertext Terminology ■ Creating HTML Documents ■ Learning HTML ■ Anatomy of Any HTML Document ■ HTML Tags ■ Basic HTML Page Structure ■ Summary of Basic HTML Tags ■ Bare-bones example of HTML ■ Basic HTML Coding ■ Head elements ■ The Body Element ■ Headings ■ Paragraphs ■ Comments ■ Links and Anchors ■ Linking to Other Documents ■ Relative, Absolute and remote Links ■ Anchors ■ Lists ■ Unordered or Bulleted lists ■ Ordered or Numbered lists ■ Glossary or Definition Lists ■ Nesting Lists ■ Preformatted Text ■ In-Line Images ■ External Images, Sounds, Video ■ Things to remember when HTML programming ❍ Text Formatting with HTML ■ Logical Character Formatting ■ Physical Character formatting ■ Special Characters ■ Horizontal rules and Line breaks ■ Fonts and Font Sizes ❍ Recommended Reading ● About this document ... next up previous Next: Introduction to Perl Up: Practical Perl Programming Previous: Practical Perl Programming Contents ● Contents ● Introduction to Perl ❍ What is Perl? ■ Origins ■ Similar to C? ■ Cost and Licensing ❍ Installing Perl Installed ■ Getting and Installing Perl ❍ Writing Perl Programs ■ Creating the Program ■ Invocation ■ Comments in Your Program ❍ Further Reading/Information ● Numeric and String Literals ❍ Numeric Literals ❍ String Literals ■ Example: Double-Quoted Strings ● Variables ❍ Scalar Variables ■ Defining Scalar Variables ■ String Scalar Variables ● Arrays ❍ What is an Array? ❍ Literal Arrays ❍ Indexed Arrays ❍ Some Useful Array Functions ❍ Associative Arrays ■ Associative Array Operators ● Operators ❍ The Binary Arithmetic Operators ❍ The Unary Arithmetic Operators ❍ The Logical Operators ❍ The Bitwise Operators ■ Comparison operators for numbers and strings ❍ The Range Operator (..) ❍ The String Operators (. and x) ❍ Order of Precedence ● Perl Statements ❍ Understanding Expressions ❍ Statement Blocks ❍ Statement Blocks and Local Variables ❍ If/Unless statement ■ The for statement ■ The while/until statement ■ The foreach statement ● Functions ❍ Using the Parameter Array (@_) ❍ Passing Parameters by Reference ❍ Scope of Variables ❍ Using a List as a Function Parameter ❍ Nesting Function Calls ❍ Using a Private Function ❍ String Functions ❍ Array Functions ❍ Summary ● References ❍ Reference Types ❍ Passing Parameters to Functions ❍ The ref() Function ❍ Example: Creating a Data Record ❍ Interpolating Functions Inside Double-Quoted Strings ❍ Summary ● Files -- Input and Output in Perl ❍ Some Files Are Standard ■ Using the Diamond Operator (<>) ❍ File Test Operators ❍ File Functions ■ Reading Directories ■ Reading and Writing Files ■ Binary Files ■ Getting File Statistics ■ Printing Revisited ● Regular Expressions ❍ What are regular Expressions ❍ Using Regular Expressions ■ Special pattern matching character operators ❍ Backtracking ❍ Setting the Target Operator (Binding) ❍ Substitution ❍ The Matching Operator (m//) ■ The Matching Options ❍ The Translation Operator (tr///) ■ The Translation Options ❍ The Binding Operators ❍ Character Classes ❍ Quantifiers ❍ Pattern Memory ❍ Pattern Precedence ❍ Extension Syntax ❍ Pattern Examples ❍ Some Practical Examples ■ Using the Match Operator ■ Using