PHP Cookbook

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PHP Cookbook

By David Sklar, Adam Trachtenberg

Publisher: O'Reilly Media

Released: November 2002

Pages: 640

PHP is a simple yet powerful open source scripting language that has become a big player in web development. Over a million web sites, from large corporate sites to small personal sites, are using PHP to serve dynamic web content. PHP's broad feature set, approachable syntax, and support for different operating systems and web servers make it an ideal language for rapid web development.

The PHP Cookbook is a collection of problems, solutions, and practical examples for PHP programmers. The book contains a unique and extensive collection of best practices for everyday PHP programming dilemmas. For every problem addressed in the book, there's a worked-out solution or "recipe" -- short, focused pieces of code that you can insert directly into your applications. But this book offers more than cut-and-paste code. You also get explanations of how and why the code works, so you can learn to adapt the problem-solving techniques to similar situations.

The recipes in the PHP Cookbook range from simple tasks, such as sending a database query and fetching URLs, to entire programs that demonstrate complex tasks, such as printing HTML tables and generating bar charts. This book contains over 250 recipes on the following topics:

Working with basic data types, including strings, numbers, dates and times, and arrays
PHP building blocks, such as variables, functions, classes, and objects
Web programming, including forms, database access, and XML
Useful features like regular expressions, encryption and security, graphics, internationalization and localization, and Internet services
Working with files and directories
Command-line PHP and PHP-GTK
PEAR, the PHP Extension and Application Repository

This book contains an impressive collection of useful code for PHP programmers, from novices to advanced practitioners. Instead of poking around mailing lists, online documentation, and other sources, you can rely on the PHP Cookbook to provide quick solutions to common problems, so you can spend your time on those out-of-the-ordinary problems specific to your application.

Chapter 1 Strings
1. Introduction
2. Accessing Substrings
3. Replacing Substrings
4. Processing a String One Character at a Time
5. Reversing a String by Word or Character
6. Expanding and Compressing Tabs
7. Controlling Case
8. Interpolating Functions and Expressions Within Strings
9. Trimming Blanks from a String
10. Parsing Comma-Separated Data
11. Parsing Fixed-Width Delimited Data
12. Taking Strings Apart
13. Wrapping Text at a Certain Line Length
14. Storing Binary Data in Strings
Chapter 2 Numbers
1. Introduction
2. Checking Whether a String Contains a Valid Number
3. Comparing Floating-Point Numbers
4. Rounding Floating-Point Numbers
5. Operating on a Series of Integers
6. Generating Random Numbers Within a Range
7. Generating Biased Random Numbers
8. Taking Logarithms
9. Calculating Exponents
10. Formatting Numbers
11. Printing Correct Plurals
12. Calculating Trigonometric Functions
13. Doing Trigonometry in Degrees, not Radians
14. Handling Very Large or Very Small Numbers
15. Converting Between Bases
16. Calculating Using Numbers in Bases Other Than Decimal
Chapter 3 Dates and Times
1. Introduction
2. Finding the Current Date and Time
3. Converting Time and Date Parts to an Epoch Timestamp
4. Converting an Epoch Timestamp to Time and Date Parts
5. Printing a Date or Time in a Specified Format
6. Finding the Difference of Two Dates
7. Finding the Difference of Two Dates with Julian Days
8. Finding the Day in a Week, Month, Year, or the Week Number in a Year
9. Validating a Date
10. Parsing Dates and Times from Strings
11. Adding to or Subtracting from a Date
12. Calculating Time with Time Zones
13. Accounting for Daylight Saving Time
14. Generating a High-Precision Time
15. Generating Time Ranges
16. Using Non-Gregorian Calendars
17. Program: Calendar
Chapter 4 Arrays
1. Introduction
2. Specifying an Array Not Beginning at Element 0
3. Storing Multiple Elements per Key in an Array
4. Initializing an Array to a Range of Integers
5. Iterating Through an Array
6. Deleting Elements from an Array
7. Changing Array Size
8. Appending One Array to Another
9. Turning an Array into a String
10. Printing an Array with Commas
11. Checking if a Key Is in an Array
12. Checking if an Element Is in an Array
13. Finding the Position of an Element in an Array
14. Finding Elements That Pass a Certain Test
15. Finding the Largest or Smallest Valued Element in an Array
16. Reversing an Array
17. Sorting an Array
18. Sorting an Array by a Computable Field
19. Sorting Multiple Arrays
20. Sorting an Array Using a Method Instead of a Function
21. Randomizing an Array
22. Shuffling a Deck of Cards
23. Removing Duplicate Elements from an Array
24. Finding the Union, Intersection, or Difference of Two Arrays
25. Finding All Element Combinations of an Array
26. Finding All Permutations of an Array
27. Program: Printing an Array in a Horizontally Columned HTML Table
Chapter 5 Variables
1. Introduction
2. Avoiding == Versus = Confusion
3. Establishing a Default Value
4. Exchanging Values Without Using Temporary Variables
5. Creating a Dynamic Variable Name
6. Using Static Variables
7. Sharing Variables Between Processes
8. Encapsulating Complex Data Types as a String
9. Dumping Variable Contents as Strings
Chapter 6 Functions
1. Introduction
2. Accessing Function Parameters
3. Setting Default Values for Function Parameters
4. Passing Values by Reference
5. Using Named Parameters
6. Creating Functions That Take a Variable Number of Arguments
7. Returning Values by Reference
8. Returning More Than One Value
9. Skipping Selected Return Values
10. Returning Failure
11. Calling Variable Functions
12. Accessing a Global Variable Inside a Function
13. Creating Dynamic Functions
Chapter 7 Classes and Objects
1. Introduction
2. Instantiating Objects
3. Defining Object Constructors
4. Destroying an Object
5. Cloning Objects
6. Assigning Object References
7. Calling Methods on an Object Returned by Another Method
8. Accessing Overridden Methods
9. Using Property Overloading
10. Using Method Polymorphism
11. Finding the Methods and Properties of an Object
12. Adding Properties to a Base Object
13. Creating a Class Dynamically
14. Instantiating an Object Dynamically
Chapter 8 Web Basics
1. Introduction
2. Setting Cookies
3. Reading Cookie Values
4. Deleting Cookies
5. Redirecting to a Different Location
6. Using Session Tracking
7. Storing Sessions in a Database
8. Detecting Different Browsers
9. Building a GET Query String
10. Using HTTP Basic Authentication
11. Using Cookie Authentication
12. Flushing Output to the Browser
13. Buffering Output to the Browser
14. Compressing Web Output with gzip
15. Hiding Error Messages from Users
16. Tuning Error Handling
17. Using a Custom Error Handler
18. Logging Errors
19. Eliminating “headers already sent” Errors
20. Logging Debugging Information
21. Reading Environment Variables
22. Setting Environment Variables
23. Reading Configuration Variables
24. Setting Configuration Variables
25. Communicating Within Apache
26. Profiling Code
27. Program: Website Account (De)activator
28. Program: Abusive User Checker
Chapter 9 Forms
1. Introduction
2. Processing Form Input
3. Validating Form Input
4. Working with Multipage Forms
5. Redisplaying Forms with Preserved Information and Error Messages
6. Guarding Against Multiple Submission of the Same Form
7. Processing Uploaded Files
8. Securing PHP’s Form Processing
9. Escaping Control Characters from User Data
10. Handling Remote Variables with Periods in Their Names
11. Using Form Elements with Multiple Options
12. Creating Dropdown Menus Based on the Current Date
Chapter 10 Database Access
1. Introduction
2. Using Text-File Databases
3. Using DBM Databases
4. Connecting to a SQL Database
5. Querying a SQL Database
6. Retrieving Rows Without a Loop
7. Modifying Data in a SQL Database
8. Repeating Queries Efficiently
9. Finding the Number of Rows Returned by a Query
10. Escaping Quotes
11. Logging Debugging Information and Errors
12. Assigning Unique ID Values Automatically
13. Building Queries Programmatically
14. Making Paginated Links for a Series of Records
15. Caching Queries and Results
16. Program: Storing a Threaded Message Board
Chapter 11 Web Automation
1. Introduction
2. Fetching a URL with the GET Method
3. Fetching a URL with the POST Method
4. Fetching a URL with Cookies
5. Fetching a URL with Headers
6. Fetching an HTTPS URL
7. Debugging the Raw HTTP Exchange
8. Marking Up a Web Page
9. Extracting Links from an HTML File
10. Converting ASCII to HTML
11. Converting HTML to ASCII
12. Removing HTML and PHP Tags
13. Using Smarty Templates
14. Parsing a Web Server Log File
15. Program: Finding Stale Links
16. Program: Finding Fresh Links
Chapter 12 XML
1. Introduction
2. Generating XML Manually
3. Generating XML with the DOM
4. Parsing XML with the DOM
5. Parsing XML with SAX
6. Transforming XML with XSLT
7. Sending XML-RPC Requests
8. Receiving XML-RPC Requests
9. Sending SOAP Requests
10. Receiving SOAP Requests
11. Exchanging Data with WDDX
12. Reading RSS Feeds
Chapter 13 Regular Expressions
1. Introduction
2. Switching From ereg to preg
3. Matching Words
4. Finding the nth Occurrence of a Match
5. Choosing Greedy or Nongreedy Matches
6. Matching a Valid Email Address
7. Finding All Lines in a File That Match a Pattern
8. Capturing Text Inside HTML Tags
9. Escaping Special Characters in a Regular Expression
10. Reading Records with a Pattern Separator
Chapter 14 Encryption and Security
1. Introduction
2. Keeping Passwords Out of Your Site Files
3. Obscuring Data with Encoding
4. Verifying Data with Hashes
5. Storing Passwords
6. Checking Password Strength
7. Dealing with Lost Passwords
8. Encrypting and Decrypting Data
9. Storing Encrypted Data in a File or Database
10. Sharing Encrypted Data with Another Web Site
11. Detecting SSL
12. Encrypting Email with GPG
Chapter 15 Graphics
1. Introduction
2. Drawing Lines, Rectangles, and Polygons
3. Drawing Arcs, Ellipses, and Circles
4. Drawing with Patterned Lines
5. Drawing Text
6. Drawing Centered Text
7. Building Dynamic Images
8. Getting and Setting a Transparent Color
9. Serving Images Securely
10. Program: Generating Bar Charts from Poll Results
Chapter 16 Internationalization and Localization
1. Introduction
2. Listing Available Locales
3. Using a Particular Locale
4. Setting the Default Locale
5. Localizing Text Messages
6. Localizing Dates and Times
7. Localizing Currency Values
8. Localizing Images
9. Localizing Included Files
10. Managing Localization Resources
11. Using gettext
12. Reading or Writing Unicode Characters
Chapter 17 Internet Services
1. Introduction
2. Sending Mail
3. Sending MIME Mail
4. Reading Mail with IMAP or POP3
5. Posting Messages to Usenet Newsgroups
6. Reading Usenet News Messages
7. Getting and Putting Files with FTP
8. Looking Up Addresses with LDAP
9. Using LDAP for User Authentication
10. Performing DNS Lookups
11. Checking if a Host Is Alive
12. Getting Information About a Domain Name
Chapter 18 Files
1. Introduction
2. Creating or Opening a Local File
3. Creating a Temporary File
4. Opening a Remote File
5. Reading from Standard Input
6. Reading a File into a String
7. Counting Lines, Paragraphs, or Records in a File
8. Processing Every Word in a File
9. Reading a Particular Line in a File
10. Processing a File Backward by Line or Paragraph
11. Picking a Random Line from a File
12. Randomizing All Lines in a File
13. Processing Variable Length Text Fields
14. Reading Configuration Files
15. Reading from or Writing to a Specific Location in a File
16. Removing the Last Line of a File
17. Modifying a File in Place Without a Temporary File
18. Flushing Output to a File
19. Writing to Standard Output
20. Writing to Many Filehandles Simultaneously
21. Escaping Shell Metacharacters
22. Passing Input to a Program
23. Reading Standard Output from a Program
24. Reading Standard Error from a Program
25. Locking a File
26. Reading and Writing Compressed Files
27. Program: Unzip
Chapter 19 Directories
1. Introduction
2. Getting and Setting File Timestamps
3. Getting File Information
4. Changing File Permissions or Ownership
5. Splitting a Filename into Its Component Parts
6. Deleting a File
7. Copying or Moving a File
8. Processing All Files in a Directory Recursively
9. Getting a List of Filenames Matching a Pattern
10. Processing All Files in a Directory
11. Making New Directories
12. Removing a Directory and Its Contents
13. Program: Web Server Directory Listing
14. Program: Site Search
Chapter 20 Client-Side PHP
1. Introduction
2. Parsing Program Arguments
3. Parsing Program Arguments with getopt
4. Reading from the Keyboard
5. Reading Passwords
6. Displaying a GUI Widget in a Window
7. Displaying Multiple GUI Widgets in a Window
8. Responding to User Actions
9. Displaying Menus
10. Program: Command Shell
11. Program: Displaying Weather Conditions
Chapter 21 PEAR
1. Introduction
2. Using the PEAR Package Manager
3. Finding PEAR Packages
4. Finding Information About a Package
5. Installing PEAR Packages
6. Installing PECL Packages
7. Upgrading PEAR Packages
8. Uninstalling PEAR Packages
9. Documenting Classes with PHPDoc

Colophon

Title:

PHP Cookbook

By:

David Sklar, Adam Trachtenberg

Publisher:

O'Reilly Media

Formats:

Print
Safari Books Online

Print:

November 2002

Pages:

640

Print ISBN:

978-1-56592-681-3

| ISBN 10:

1-56592-681-1

David Sklar

is an independent software development and strategic technology consultant. He was a co-founder and the Chief Technology Officer of Student.Com and TVGrid.Com. At both companies, David oversaw the architecture and development of varied systems to deliver personalized dynamic content to users around the world. After discovering PHP as a solution to his web programming needs in 1996, he created the PX (http://px.sklar.com/), which enables PHP users to exchange programs. Since then, he has continued to rely on PHP for personal and professional projects. When away from the computer, David eats mini-donuts, plays records, and likes to cook. He lives in New York City and has a degree in Computer Science from Yale University.

View David Sklar's full profile page.
Adam Trachtenberg

Adam Trachtenberg has an MBA from Columbia Business School. At business school, he focused on general management and operations, with an emphasis on the field of technology. Adam also has a BA from Columbia University. As an undergraduate, he majored in mathematics and his other studies included computer science and Chinese. Before returning to school, he co-founded and served as Vice President for Development at two companies, Student.Com and TVGrid.Com. At both firms, he led the front- and middle-end web site design and development, worked on corporate planning and strategy, and served as liaison between the product and marketing teams. During study breaks, Adam enjoys playing squash, reading fiction, and eating in New York City's many wonderful restaurants. He wishes he was a better at playing pool, knew the constellations, and was handy around the house.

View Adam Trachtenberg'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 on the cover of PHP Cookbook is a Galapagos land iguana (Conolophus subcristatus). Once abundant in the Galapagos Islands, this iguana proved tasty to the settlers of the early 1800s, and domestic animals later introduced on the islands played further havoc with the reptile's home and food supply. Today there are no iguanas left on Santiago Island and very few left on the other islands.

Distantly related to the green iguana of the South American continent, Galapagos land iguanas can be over three feet long, with males weighing up to 30 pounds. Their tough, scaly skin is yellow with scattered patches of white, black, brown, and rust. These lizards resemble mythical creatures of the past-- dragons with long tails, clawed feet, and spiny crests. In reality, however, they are harmless.

Land iguanas live in the drier areas of the islands and in the morning are found basking in the sun. During midday, however, they seek the shade of cactus, rocks, and trees. To conserve body heat at night, they sleep in burrows dug in the ground.

These reptiles are omnivores, but they generally depend on low-growing plants and shrubs, as well as the fallen fruits and pads of cactus trees. These plants provide most of the moisture they need; however, they will drink fresh water whenever it's available.

Depending on their size, land iguanas reach maturity between 8 and 15 years of age. They congregate and mate during specific periods, which vary from island to island. The females then migrate to suitable areas to nest. After digging a burrow, the female lays 2 to 20 eggs in the nest. She then defends the covered nest site to prevent other females from nesting in the same spot. Young iguanas hatch 85 to 110 days later and take about a week to dig their way out of the nest. Normally, if hatchlings survive the first year when food is often scarce and native predators such as hawks, egrets, herons, and snakes are a danger, they can live for more than 60 years. In reality, predation by feral cats is far worse because the young must survive and grow for at least three to four years before becoming large enough that cats can't kill them. Mary Anne Weeks Mayo was the production editor and copyeditor for PHP Cookbook. Sarah Jane Shangraw proofread the book. Darren Kelly and Jane Ellin provided quality control. Julie Flanagan, Brian Sawyer, Genevieve d'Entremont, and Judy Hoer provided production assistance. Ellen Troutman-Zaig wrote the index.

Emma Colby designed the cover of this book, based on a series design by Edie Freedman. The cover image is a 19th-century engraving from the Dover Pictorial Archive. Emma produced the cover layout with QuarkXPress 4.1 using Adobe's ITC Garamond font.

David Futato designed the interior layout. This book was converted to FrameMaker 5.5.6 with a format conversion tool created by Erik Ray, 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 Lucas-Font's TheSans Mono Condensed. The illustrations that appear in the book were produced by Robert Romano and Jessamyn Read using Macromedia FreeHand 9 and Adobe Photoshop 6. This colophon was compiled by Mary Anne Weeks Mayo.

Description

Table of Contents

Product Details

About the Author

Colophon

Recommended for You

Chapter 1 Strings

Introduction

Accessing Substrings

Replacing Substrings

Processing a String One Character at a Time

Reversing a String by Word or Character

Expanding and Compressing Tabs

Controlling Case

Interpolating Functions and Expressions Within Strings

Trimming Blanks from a String

Parsing Comma-Separated Data

Parsing Fixed-Width Delimited Data

Taking Strings Apart

Wrapping Text at a Certain Line Length

Storing Binary Data in Strings

Chapter 2 Numbers

Introduction

Checking Whether a String Contains a Valid Number

Comparing Floating-Point Numbers

Rounding Floating-Point Numbers

Operating on a Series of Integers

Generating Random Numbers Within a Range

Generating Biased Random Numbers

Taking Logarithms

Calculating Exponents

Formatting Numbers

Printing Correct Plurals

Calculating Trigonometric Functions

Doing Trigonometry in Degrees, not Radians

Handling Very Large or Very Small Numbers

Converting Between Bases

Calculating Using Numbers in Bases Other Than Decimal

Chapter 3 Dates and Times

Introduction

Finding the Current Date and Time

Converting Time and Date Parts to an Epoch Timestamp

Converting an Epoch Timestamp to Time and Date Parts

Printing a Date or Time in a Specified Format

Finding the Difference of Two Dates

Finding the Difference of Two Dates with Julian Days

Finding the Day in a Week, Month, Year, or the Week Number in a Year

Validating a Date

Parsing Dates and Times from Strings

Adding to or Subtracting from a Date

Calculating Time with Time Zones

Accounting for Daylight Saving Time

Generating a High-Precision Time

Generating Time Ranges

Using Non-Gregorian Calendars

Program: Calendar

Chapter 4 Arrays

Introduction

Specifying an Array Not Beginning at Element 0

Storing Multiple Elements per Key in an Array

Initializing an Array to a Range of Integers

Iterating Through an Array

Deleting Elements from an Array

Changing Array Size

Appending One Array to Another

Turning an Array into a String

Printing an Array with Commas

Checking if a Key Is in an Array

Checking if an Element Is in an Array

Finding the Position of an Element in an Array

Finding Elements That Pass a Certain Test

Finding the Largest or Smallest Valued Element in an Array

Reversing an Array

Sorting an Array

Sorting an Array by a Computable Field

Sorting Multiple Arrays

Sorting an Array Using a Method Instead of a Function

Randomizing an Array

Shuffling a Deck of Cards

Removing Duplicate Elements from an Array

Finding the Union, Intersection, or Difference of Two Arrays

Finding All Element Combinations of an Array

Finding All Permutations of an Array

Program: Printing an Array in a Horizontally Columned HTML Table

Chapter 5 Variables

Introduction