Perl Cookbook, Second Edition

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Perl Cookbook, Second Edition

By: Tom Christiansen, Nathan Torkington
Publisher:: O'Reilly Media
Released:: August 2003
Pages:: 976

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Description

Find a Perl programmer, and you'll find a copy of Perl Cookbook nearby. Perl Cookbook is a comprehensive collection of problems, solutions, and practical examples for anyone programming in Perl. The book contains hundreds of rigorously reviewed Perl "recipes" and thousands of examples ranging from brief one-liners to complete applications. The second edition of Perl Cookbook has been fully updated for Perl 5.8, with extensive changes for Unicode support, I/O layers, mod_perl, and new technologies that have emerged since the previous edition of the book. Recipes have been updated to include the latest modules. New recipes have been added to every chapter of the book, and some chapters have almost doubled in size.

Full Description

Table of Contents

Chapter 1 Strings
1. Introduction
2. Accessing Substrings
3. Establishing a Default Value
4. Exchanging Values Without Using Temporary Variables
5. Converting Between Characters and Values
6. Using Named Unicode Characters
7. Processing a String One Character at a Time
8. Reversing a String by Word or Character
9. Treating Unicode Combined Characters as Single Characters
10. Canonicalizing Strings with Unicode Combined Characters
11. Treating a Unicode String as Octets
12. Expanding and Compressing Tabs
13. Expanding Variables in User Input
14. Controlling Case
15. Properly Capitalizing a Title or Headline
16. Interpolating Functions and Expressions Within Strings
17. Indenting Here Documents
18. Reformatting Paragraphs
19. Escaping Characters
20. Trimming Blanks from the Ends of a String
21. Parsing Comma-Separated Data
22. Constant Variables
23. Soundex Matching
24. Program: fixstyle
25. Program: psgrep
Chapter 2 Numbers
1. Introduction
2. Checking Whether a String Is a Valid Number
3. Rounding Floating-Point Numbers
4. Comparing Floating-Point Numbers
5. Operating on a Series of Integers
6. Working with Roman Numerals
7. Generating Random Numbers
8. Generating Repeatable Random Number Sequences
9. Making Numbers Even More Random
10. Generating Biased Random Numbers
11. Doing Trigonometry in Degrees, Not Radians
12. Calculating More Trigonometric Functions
13. Taking Logarithms
14. Multiplying Matrices
15. Using Complex Numbers
16. Converting Binary, Octal, and Hexadecimal Numbers
17. Putting Commas in Numbers
18. Printing Correct Plurals
19. Program: Calculating Prime Factors
Chapter 3 Dates and Times
1. Introduction
2. Finding Today's Date
3. Converting DMYHMS to Epoch Seconds
4. Converting Epoch Seconds to DMYHMS
5. Adding to or Subtracting from a Date
6. Difference of Two Dates
7. Day in a Week/Month/Year or Week Number
8. Parsing Dates and Times from Strings
9. Printing a Date
10. High-Resolution Timers
11. Short Sleeps
12. Program: hopdelta
Chapter 4 Arrays
1. Introduction
2. Specifying a List in Your Program
3. Printing a List with Commas
4. Changing Array Size
5. Implementing a Sparse Array
6. Iterating Over an Array
7. Iterating Over an Array by Reference
8. Extracting Unique Elements from a List
9. Finding Elements in One Array but Not Another
10. Computing Union, Intersection, or Difference of Unique Lists
11. Appending One Array to Another
12. Reversing an Array
13. Processing Multiple Elements of an Array
14. Finding the First List Element That Passes a Test
15. Finding All Elements in an Array Matching Certain Criteria
16. Sorting an Array Numerically
17. Sorting a List by Computable Field
18. Implementing a Circular List
19. Randomizing an Array
20. Program: words
21. Program: permute
Chapter 5 Hashes
1. Introduction
2. Adding an Element to a Hash
3. Testing for the Presence of a Key in a Hash
4. Creating a Hash with Immutable Keys or Values
5. Deleting from a Hash
6. Traversing a Hash
7. Printing a Hash
8. Retrieving from a Hash in Insertion Order
9. Hashes with Multiple Values per Key
10. Inverting a Hash
11. Sorting a Hash
12. Merging Hashes
13. Finding Common or Different Keys in Two Hashes
14. Hashing References
15. Presizing a Hash
16. Finding the Most Common Anything
17. Representing Relationships Between Data
18. Program: dutree
Chapter 6 Pattern Matching
1. Introduction
2. Copying and Substituting Simultaneously
3. Matching Letters
4. Matching Words
5. Commenting Regular Expressions
6. Finding the Nth Occurrence of a Match
7. Matching Within Multiple Lines
8. Reading Records with a Separator
9. Extracting a Range of Lines
10. Matching Shell Globs as Regular Expressions
11. Speeding Up Interpolated Matches
12. Testing for a Valid Pattern
13. Honoring Locale Settings in Regular Expressions
14. Approximate Matching
15. Matching from Where the Last Pattern Left Off
16. Greedy and Non-Greedy Matches
17. Detecting Doubled Words
18. Matching Nested Patterns
19. Expressing AND, OR, and NOT in a Single Pattern
20. Matching a Valid Mail Address
21. Matching Abbreviations
22. Program: urlify
23. Program: tcgrep
24. Regular Expression Grab Bag
Chapter 7 File Access
1. Introduction
2. Opening a File
3. Opening Files with Unusual Filenames
4. Expanding Tildes in Filenames
5. Making Perl Report Filenames in Error Messages
6. Storing Filehandles into Variables
7. Writing a Subroutine That Takes Filehandles as Built-ins Do
8. Caching Open Output Filehandles
9. Printing to Many Filehandles Simultaneously
10. Opening and Closing File Descriptors by Number
11. Copying Filehandles
12. Creating Temporary Files
13. Storing a File Inside Your Program Text
14. Storing Multiple Files in the DATA Area
15. Writing a Unix-Style Filter Program
16. Modifying a File in Place with a Temporary File
17. Modifying a File in Place with the -i Switch
18. Modifying a File in Place Without a Temporary File
19. Locking a File
20. Flushing Output
21. Doing Non-Blocking I/O
22. Determining the Number of Unread Bytes
23. Reading from Many Filehandles Without Blocking
24. Reading an Entire Line Without Blocking
25. Program: netlock
26. Program: lockarea
Chapter 8 File Contents
1. Introduction
2. Reading Lines with Continuation Characters
3. Counting Lines (or Paragraphs or Records) in a File
4. Processing Every Word in a File
5. Reading a File Backward by Line or Paragraph
6. Trailing a Growing File
7. Picking a Random Line from a File
8. Randomizing All Lines
9. Reading a Particular Line in a File
10. Processing Variable-Length Text Fields
11. Removing the Last Line of a File
12. Processing Binary Files
13. Using Random-Access I/O
14. Updating a Random-Access File
15. Reading a String from a Binary File
16. Reading Fixed-Length Records
17. Reading Configuration Files
18. Testing a File for Trustworthiness
19. Treating a File as an Array
20. Setting the Default I/O Layers
21. Reading or Writing Unicode from a Filehandle
22. Converting Microsoft Text Files into Unicode
23. Comparing the Contents of Two Files
24. Pretending a String Is a File
25. Program: tailwtmp
26. Program: tctee
27. Program: laston
28. Program: Flat File Indexes
Chapter 9 Directories
1. Introduction
2. Getting and Setting Timestamps
3. Deleting a File
4. Copying or Moving a File
5. Recognizing Two Names for the Same File
6. Processing All Files in a Directory
7. Globbing, or Getting a List of Filenames Matching a Pattern
8. Processing All Files in a Directory Recursively
9. Removing a Directory and Its Contents
10. Renaming Files
11. Splitting a Filename into Its Component Parts
12. Working with Symbolic File Permissions Instead of Octal Values
13. Program: symirror
14. Program: lst
Chapter 10 Subroutines
1. Introduction
2. Accessing Subroutine Arguments
3. Making Variables Private to a Function
4. Creating Persistent Private Variables
5. Determining Current Function Name
6. Passing Arrays and Hashes by Reference
7. Detecting Return Context
8. Passing by Named Parameter
9. Skipping Selected Return Values
10. Returning More Than One Array or Hash
11. Returning Failure
12. Prototyping Functions
13. Handling Exceptions
14. Saving Global Values
15. Redefining a Function
16. Trapping Undefined Function Calls with AUTOLOAD
17. Nesting Subroutines
18. Writing a Switch Statement
19. Program: Sorting Your Mail
Chapter 11 References and Records
1. Introduction
2. Taking References to Arrays
3. Making Hashes of Arrays
4. Taking References to Hashes
5. Taking References to Functions
6. Taking References to Scalars
7. Creating Arrays of Scalar References
8. Using Closures Instead of Objects
9. Creating References to Methods
10. Constructing Records
11. Reading and Writing Hash Records to Text Files
12. Printing Data Structures
13. Copying Data Structures
14. Storing Data Structures to Disk
15. Transparently Persistent Data Structures
16. Coping with Circular Data Structures Using Weak References
17. Program: Outlines
18. Program: Binary Trees
Chapter 12 Packages, Libraries, and Modules
1. Introduction
2. Defining a Module's Interface
3. Trapping Errors in require or use
4. Delaying use Until Runtime
5. Making Variables Private to a Module
6. Making Functions Private to a Module
7. Determining the Caller's Package
8. Automating Module Cleanup
9. Keeping Your Own Module Directory
10. Preparing a Module for Distribution
11. Speeding Module Loading with SelfLoader
12. Speeding Up Module Loading with Autoloader
13. Overriding Built-in Functions
14. Overriding a Built-in Function in All Packages
15. Reporting Errors and Warnings Like Built-ins
16. Customizing Warnings
17. Referring to Packages Indirectly
18. Using h2ph to Translate C #include Files
19. Using h2xs to Make a Module with C Code
20. Writing Extensions in C with Inline::C
21. Documenting Your Module with Pod
22. Building and Installing a CPAN Module
23. Example: Module Template
24. Program: Finding Versions and Descriptions of Installed Modules
Chapter 13 Classes, Objects, and Ties
1. Introduction
2. Constructing an Object
3. Destroying an Object
4. Managing Instance Data
5. Managing Class Data
6. Using Classes as Structs
7. Cloning Constructors
8. Copy Constructors
9. Invoking Methods Indirectly
10. Determining Subclass Membership
11. Writing an Inheritable Class
12. Accessing Overridden Methods
13. Generating Attribute Methods Using AUTOLOAD
14. Coping with Circular Data Structures Using Objects
15. Overloading Operators
16. Creating Magic Variables with tie
Chapter 14 Database Access
1. Introduction
2. Making and Using a DBM File
3. Emptying a DBM File
4. Converting Between DBM Files
5. Merging DBM Files
6. Sorting Large DBM Files
7. Storing Complex Data in a DBM File
8. Persistent Data
9. Saving Query Results to Excel or CSV
10. Executing an SQL Command Using DBI
11. Escaping Quotes
12. Dealing with Database Errors
13. Repeating Queries Efficiently
14. Building Queries Programmatically
15. Finding the Number of Rows Returned by a Query
16. Using Transactions
17. Viewing Data One Page at a Time
18. Querying a CSV File with SQL
19. Using SQL Without a Database Server
20. Program: ggh—Grep Netscape Global History
Chapter 15 Interactivity
1. Introduction
2. Parsing Program Arguments
3. Testing Whether a Program Is Running Interactively
4. Clearing the Screen
5. Determining Terminal or Window Size
6. Changing Text Color
7. Reading Single Characters from the Keyboard
8. Ringing the Terminal Bell
9. Using POSIX termios
10. Checking for Waiting Input
11. Reading Passwords
12. Editing Input
13. Managing the Screen
14. Controlling Another Program with Expect
15. Creating Menus with Tk
16. Creating Dialog Boxes with Tk
17. Responding to Tk Resize Events
18. Removing the DOS Shell Window with Windows Perl/Tk
19. Graphing Data
20. Thumbnailing Images
21. Adding Text to an Image
22. Program: Small termcap Program
23. Program: tkshufflepod
24. Program: graphbox
Chapter 16 Process Management and Communication
1. Introduction
2. Gathering Output from a Program
3. Running Another Program
4. Replacing the Current Program with a Different One
5. Reading or Writing to Another Program
6. Filtering Your Own Output
7. Preprocessing Input
8. Reading STDERR from a Program
9. Controlling Input and Output of Another Program
10. Controlling the Input, Output, and Error of Another Program
11. Communicating Between Related Processes
12. Making a Process Look Like a File with Named Pipes
13. Sharing Variables in Different Processes
14. Listing Available Signals
15. Sending a Signal
16. Installing a Signal Handler
17. Temporarily Overriding a Signal Handler
18. Writing a Signal Handler
19. Catching Ctrl-C
20. Avoiding Zombie Processes
21. Blocking Signals
22. Timing Out an Operation
23. Turning Signals into Fatal Errors
24. Program: sigrand
Chapter 17 Sockets
1. Introduction
2. Writing a TCP Client
3. Writing a TCP Server
4. Communicating over TCP
5. Setting Up a UDP Client
6. Setting Up a UDP Server
7. Using Unix Domain Sockets
8. Identifying the Other End of a Socket
9. Finding Your Own Name and Address
10. Closing a Socket After Forking
11. Writing Bidirectional Clients
12. Forking Servers
13. Pre-Forking Servers
14. Non-Forking Servers
15. Multitasking Server with Threads
16. Writing a Multitasking Server with POE
17. Writing a Multihomed Server
18. Making a Daemon Server
19. Restarting a Server on Demand
20. Managing Multiple Streams of Input
21. Program: backsniff
22. Program: fwdport
Chapter 18 Internet Services
1. Introduction
2. Simple DNS Lookups
3. Being an FTP Client
4. Sending Mail
5. Reading and Posting Usenet News Messages
6. Reading Mail with POP3
7. Simulating Telnet from a Program
8. Pinging a Machine
9. Accessing an LDAP Server
10. Sending Attachments in Mail
11. Extracting Attachments from Mail
12. Writing an XML-RPC Server
13. Writing an XML-RPC Client
14. Writing a SOAP Server
15. Writing a SOAP Client
16. Program: rfrm
17. Program: expn and vrfy
Chapter 19 CGI Programming
1. Introduction
2. Writing a CGI Script
3. Redirecting Error Messages
4. Fixing a 500 Server Error
5. Writing a Safe CGI Program
6. Executing Commands Without Shell Escapes
7. Formatting Lists and Tables with HTML Shortcuts
8. Redirecting to a Different Location
9. Debugging the Raw HTTP Exchange
10. Managing Cookies
11. Creating Sticky Widgets
12. Writing a Multiscreen CGI Script
13. Saving a Form to a File or Mail Pipe
14. Program: chemiserie
Chapter 20 Web Automation
1. Introduction
2. Fetching a URL from a Perl Script
3. Automating Form Submission
4. Extracting URLs
5. Converting ASCII to HTML
6. Converting HTML to ASCII
7. Extracting or Removing HTML Tags
8. Finding Stale Links
9. Finding Fresh Links
10. Using Templates to Generate HTML
11. Mirroring Web Pages
12. Creating a Robot
13. Parsing a Web Server Log File
14. Processing Server Logs
15. Using Cookies
16. Fetching Password-Protected Pages
17. Fetching https:// Web Pages
18. Resuming an HTTP GET
19. Parsing HTML
20. Extracting Table Data
21. Program: htmlsub
22. Program: hrefsub
Chapter 21 mod_perl
1. Introduction
2. Authenticating
3. Setting Cookies
4. Accessing Cookie Values
5. Redirecting the Browser
6. Interrogating Headers
7. Accessing Form Parameters
8. Receiving Uploaded Files
9. Speeding Up Database Access
10. Customizing Apache's Logging
11. Transparently Storing Information in URLs
12. Communicating Between mod_perl and PHP
13. Migrating from CGI to mod_perl
14. Sharing Information Between Handlers
15. Reloading Changed Modules
16. Benchmarking a mod_perl Application
17. Templating with HTML::Mason
18. Templating with Template Toolkit
Chapter 22 XML
1. Introduction
2. Parsing XML into Data Structures
3. Parsing XML into a DOM Tree
4. Parsing XML into SAX Events
5. Making Simple Changes to Elements or Text
6. Validating XML
7. Finding Elements and Text Within an XML Document
8. Processing XML Stylesheet Transformations
9. Processing Files Larger Than Available Memory
10. Reading and Writing RSS Files
11. Writing XML

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Product Details

Title:

Perl Cookbook, Second Edition

By:

Tom Christiansen, Nathan Torkington

Publisher:

O'Reilly Media

Formats:

Print
Ebook
Safari Books Online

Print Release:

August 2003

Ebook Release:

February 2009

Pages:

976

Print ISBN:

978-0-596-00313-5

| ISBN 10:

0-596-00313-7

Ebook ISBN:

978-0-596-15888-0

| ISBN 10:

0-596-15888-2

Customer Reviews

About the Authors

Tom Christiansen

Tom Christiansen is a freelance consultant specializing in Perl training and writing. After working for several years for TSR Hobbies (of Dungeons and Dragons fame), he set off for college where he spent a year in Spain and five in America, dabbling in music, linguistics, programming, and some half-dozen different spoken languages. Tom finally escaped UW-Madison with B.A.s in Spanish and computer science and an M.S. in computer science. He then spent five years at Convex as a jack-of-all-trades working on everything from system administration to utility and kernel development, with customer support and training thrown in for good measure. Tom also served two terms on the USENIX Association Board of directors. With over fifteen years' experience in UNIX system administration and programming, Tom presents seminars internationally. Living in the foothills above Boulder, Colorado, surrounded by mule deer, skunks, and the occasional mountain lion and black bear, Tom takes summers off for hiking, hacking, birding, music making, and gaming.

View Tom Christiansen's full profile page.
Nathan Torkington

Nathan Torkington is a banjo player, father, and husband. His crimes in the computing community include: coauthor of the Perl Cookbook, editor for O'Reilly and Associates, content coordinator for the Open Source Convention and Perl Conference, and project manager for perl6.

View Nathan Torkington's full profile page.

Colophon

Our look is the result of reader comments, our own experimentation, and feedback from distribution channels. Distinctive covers complement our distinctive approach to technical topics, breathing personality and life into potentially dry subjects. The animal featured on the cover of Perl Cookbook, Second Edition is a bighorn sheep. Bighorn sheep (Ovis canadensis) are wild sheep noted, not surprisingly, for their large, curved horns. Male bighorns grow to approximately 5 feet long and 40 inches tall to the shoulder and weigh up to 350 pounds. Their horns measure up to 18 inches in circumference and 4 feet long and can weigh up to 30 pounds. Despite their bulk, bighorns are adept at negotiating mountainous terrains. With their sharp, cloven hooves they can walkon ledges as thin as two inches. They have excellent eyesight that enables them to locate footholds and to accurately judge distances between ledges. They can jump as far as 20 feet from ledge to ledge.

Competition for ewes is intense and often leads to fierce battles that can continue for a full day. During the battle two rams race at each other at speeds of up to 20 miles an hour, clashing their horns together. The skull of the bighorn sheep is doublelayered to provide protection from these blows. Horn size is a significant factor in determining rank, and rams will only fight other rams with an equivalently sized horn. Mature males usually stay apart from the females and young. In these "bachelor flocks" the lower-ranking males often play the part of ewes and behave in a submissive manner toward the dominant males. The dominant male, in turn, behaves like a courting ram and mounts the lower-ranking male. This behavior is believed to enable the rams to live together without rankdisputes that might otherwise drive the lower-ranking males out of the flock.

Bighorns can be found in the Rocky Mountains from Canada to Colorado and in the desert from California to west Texas and Mexico. They are threatened with extinction as a result of disease, habitat reduction, and hunting. Genevieve d'Entremont was the production editor and copyeditor for Perl Cookbook, Second Edition. Phil Dangler, Emily Quill, Matt Hutchinson, and Colleen Gorman provided quality control. Mary Agner and Jamie Peppard provided production assistance. Nancy Crumpton wrote the index.

Edie Freedman designed the cover of this book, using a 19th-century engraving from the Dover Pictorial Archive. Emma Colby produced the cover layout with Quark-XPress 4.1 using Adobe's ITC Garamond font.

David Futato designed the interior layout. This bookwas converted by Julie Hawks and Andrew Savikas from Pod to FrameMaker 5.5.6 with a format conversion tool created by ErikRay, Jason McIntosh, Neil Walls, and Mike Sierra that uses Perl and XML technologies. The text font is Linotype Birka; the heading font is Adobe Myriad Condensed; and the code font is LucasFont's TheSans Mono Condensed. The illustrations that appear in the bookwere produced by Robert Romano and Jessamyn Read using Macromedia FreeHand 9 and Adobe Photoshop 6. The warning icon was drawn by Christopher Bing. This colophon was written by Clairemarie Fisher O'Leary.

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O'Reilly Books & Videos

Perl Cookbook, Second Edition

Chapter 1 Strings

Introduction

Accessing Substrings

Establishing a Default Value

Exchanging Values Without Using Temporary Variables

Converting Between Characters and Values

Using Named Unicode Characters

Processing a String One Character at a Time

Reversing a String by Word or Character

Treating Unicode Combined Characters as Single Characters

Canonicalizing Strings with Unicode Combined Characters

Treating a Unicode String as Octets

Expanding and Compressing Tabs

Expanding Variables in User Input

Controlling Case

Properly Capitalizing a Title or Headline

Interpolating Functions and Expressions Within Strings

Indenting Here Documents

Reformatting Paragraphs

Escaping Characters

Trimming Blanks from the Ends of a String

Parsing Comma-Separated Data

Constant Variables

Soundex Matching

Program: fixstyle

Program: psgrep

Chapter 2 Numbers

Introduction

Checking Whether a String Is a Valid Number

Rounding Floating-Point Numbers

Comparing Floating-Point Numbers

Operating on a Series of Integers

Working with Roman Numerals

Generating Random Numbers

Generating Repeatable Random Number Sequences

Making Numbers Even More Random

Generating Biased Random Numbers

Doing Trigonometry in Degrees, Not Radians

Calculating More Trigonometric Functions

Taking Logarithms

Multiplying Matrices

Using Complex Numbers

Converting Binary, Octal, and Hexadecimal Numbers

Putting Commas in Numbers

Printing Correct Plurals

Program: Calculating Prime Factors

Chapter 3 Dates and Times

Introduction

Finding Today's Date

Converting DMYHMS to Epoch Seconds

Converting Epoch Seconds to DMYHMS

Adding to or Subtracting from a Date

Difference of Two Dates

Day in a Week/Month/Year or Week Number

Parsing Dates and Times from Strings

Printing a Date

High-Resolution Timers

Short Sleeps

Program: hopdelta

Chapter 4 Arrays

Introduction

Specifying a List in Your Program

Printing a List with Commas

Changing Array Size

Implementing a Sparse Array

Iterating Over an Array

Iterating Over an Array by Reference

Extracting Unique Elements from a List

Finding Elements in One Array but Not Another

Computing Union, Intersection, or Difference of Unique Lists

Appending One Array to Another

Reversing an Array

Processing Multiple Elements of an Array

Finding the First List Element That Passes a Test

Finding All Elements in an Array Matching Certain Criteria

Sorting an Array Numerically

Sorting a List by Computable Field

Implementing a Circular List