book

Programming PHP, 2nd Edition

by Rasmus Lerdorf, Kevin Tatroe, Peter MacIntyre

April 2006

Intermediate to advanced

540 pages

21h 16m

English

O'Reilly Media, Inc.

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A Note Regarding Supplemental Files
Foreword
Preface
Audience
Assumptions This Book Makes
Contents of This Book
Conventions Used in This Book
Using Code Examples
Comments and Questions
Safari® Enabled

Acknowledgments
Rasmus LerdorfKevin TatroePeter MacIntyreDedication
1. Introduction to PHP
1.1. What Does PHP Do?
1.2. A Brief History of PHP
1.2.1. The Evolution of PHP1.2.2. The Growth of PHP
1.3. Installing PHP
1.4. A Walk Through PHP
1.4.1. Configuration Page1.4.2. Forms1.4.3. Databases1.4.4. Graphics1.4.5. From the Shell
2. Language Basics
2.1. Lexical Structure
2.1.1. Case Sensitivity2.1.2. Statements and Semicolons2.1.3. Whitespace and Line Breaks2.1.4. Comments2.1.4.1. Shell-style comments2.1.4.2. C++ comments2.1.4.3. C comments2.1.5. Literals2.1.6. Identifiers2.1.6.1. Variable names2.1.6.2. Function names2.1.6.3. Class names2.1.6.4. Constants2.1.7. Keywords
2.2. Data Types
2.2.1. Integers2.2.2. Floating-Point Numbers2.2.3. Strings2.2.4. Booleans2.2.5. Arrays2.2.6. Objects2.2.7. Resources2.2.8. NULL
2.3. Variables
2.3.1. Variable Variables2.3.2. Variable References2.3.3. Variable Scope2.3.3.1. Local scope2.3.3.2. Global scope2.3.3.3. Static variables2.3.3.4. Function parameters2.3.4. Garbage Collection
2.4. Expressions and Operators
2.4.1. Number of Operands2.4.2. Operator Precedence2.4.3. Operator Associativity2.4.4. Implicit Casting2.4.5. Arithmetic Operators2.4.6. String Concatenation Operator2.4.7. Autoincrement and Autodecrement Operators2.4.8. Comparison Operators2.4.9. Bitwise Operators2.4.10. Logical Operators2.4.11. Casting Operators2.4.12. Assignment Operators2.4.12.1. Assignment2.4.12.2. Assignment with operation2.4.13. Miscellaneous Operators
2.5. Flow-Control Statements
2.5.1. if2.5.2. switch2.5.3. while2.5.4. for2.5.5. foreach2.5.6. declare2.5.7. exit and return
2.6. Including Code
2.7. Embedding PHP in Web Pages
2.7.1. XML Style2.7.2. SGML Style2.7.3. ASP Style2.7.4. Script Style2.7.5. Echoing Content Directly
3. Functions
3.1. Calling a Function
3.2. Defining a Function
3.3. Variable Scope
3.3.1. Global Variables3.3.2. Static Variables
3.4. Function Parameters
3.4.1. Passing Parameters by Value3.4.2. Passing Parameters by Reference3.4.3. Default Parameters3.4.4. Variable Parameters3.4.5. Missing Parameters
3.5. Return Values
3.6. Variable Functions
3.7. Anonymous Functions
4. Strings
4.1. Quoting String Constants
4.1.1. Variable Interpolation4.1.2. Single-Quoted Strings4.1.3. Double-Quoted Strings4.1.4. Here Documents
4.2. Printing Strings
4.2.1. echo4.2.2. print( )4.2.3. printf( )4.2.3.1. Format modifiers4.2.3.2. Type specifiers4.2.4. print_r( ) and var_dump( )
4.3. Accessing Individual Characters
4.4. Cleaning Strings
4.4.1. Removing Whitespace4.4.2. Changing Case
4.5. Encoding and Escaping
4.5.1. HTML4.5.1.1. Entity-quoting all special characters4.5.1.2. Entity-quoting only HTML syntax characters4.5.1.3. Removing HTML tags4.5.1.4. Extracting meta tags4.5.2. URLs4.5.2.1. RFC 1738 encoding and decoding4.5.2.2. Query-string encoding4.5.3. SQL4.5.4. C-String Encoding
4.6. Comparing Strings
4.6.1. Exact Comparisons4.6.2. Approximate Equality
4.7. Manipulating and Searching Strings
4.7.1. Substrings4.7.2. Miscellaneous String Functions4.7.3. Decomposing a String4.7.3.1. Exploding and imploding4.7.3.2. Tokenizing4.7.3.3. sscanf( )4.7.4. String-Searching Functions4.7.4.1. Searches returning position4.7.4.2. Searches returning rest of string4.7.4.3. Searches using masks4.7.4.4. Decomposing URLs
4.8. Regular Expressions
4.8.1. The Basics4.8.2. Character Classes4.8.3. Alternatives4.8.4. Repeating Sequences4.8.5. Subpatterns
4.9. POSIX-Style Regular Expressions
4.9.1. Character Classes4.9.2. Anchors4.9.3. Functions4.9.3.1. Matching4.9.3.2. Replacing4.9.3.3. Splitting
4.10. Perl-Compatible Regular Expressions
4.10.1. Delimiters4.10.2. Match Behavior4.10.3. Character Classes4.10.4. Anchors4.10.5. Quantifiers and Greed4.10.6. Non-Capturing Groups4.10.7. Backreferences4.10.8. Trailing Options4.10.9. Inline Options4.10.10. Lookahead and Lookbehind4.10.11. Cut4.10.12. Conditional Expressions4.10.13. Functions4.10.13.1. Matching4.10.13.2. Replacing4.10.13.3. Splitting4.10.13.4. Filtering an array with a regular expression4.10.13.5. Quoting for regular expressions4.10.14. Differences from Perl Regular Expressions
5. Arrays
5.1. Indexed Versus Associative Arrays
5.2. Identifying Elements of an Array
5.3. Storing Data in Arrays
5.3.1. Adding Values to the End of an Array5.3.2. Assigning a Range of Values5.3.3. Getting the Size of an Array5.3.4. Padding an Array
5.4. Multidimensional Arrays
5.5. Extracting Multiple Values
5.5.1. Slicing an Array5.5.2. Splitting an Array into Chunks5.5.3. Keys and Values5.5.4. Checking Whether an Element Exists5.5.5. Removing and Inserting Elements in an Array
5.6. Converting Between Arrays and Variables
5.6.1. Creating Variables from an Array5.6.2. Creating an Array from Variables
5.7. Traversing Arrays
5.7.1. The foreach Construct5.7.2. The Iterator Functions5.7.3. Using a for Loop5.7.4. Calling a Function for Each Array Element5.7.5. Reducing an Array5.7.6. Searching for Values
5.8. Sorting
5.8.1. Sorting One Array at a Time5.8.2. Natural-Order Sorting5.8.3. Sorting Multiple Arrays at Once5.8.4. Reversing Arrays5.8.5. Randomizing Order
5.9. Acting on Entire Arrays
5.9.1. Calculating the Sum of an Array5.9.2. Merging Two Arrays5.9.3. Calculating the Difference Between Two Arrays5.9.4. Filtering Elements from an Array
5.10. Using Arrays
5.10.1. Sets5.10.2. Stacks
6. Objects
6.1. Terminology
6.2. Creating an Object
6.3. Accessing Properties and Methods
6.4. Declaring a Class
6.4.1. Declaring Methods6.4.2. Declaring Properties6.4.3. Declaring Constants6.4.4. Inheritance6.4.5. Interfaces6.4.6. Abstract Methods6.4.7. Constructors6.4.8. Destructors
6.5. Introspection
6.5.1. Examining Classes6.5.2. Examining an Object6.5.3. Sample Introspection Program
6.6. Serialization
7. Web Techniques
7.1. HTTP Basics
7.2. Variables
7.3. Server Information
7.4. Processing Forms
7.4.1. Methods7.4.2. Parameters7.4.3. Automatic Quoting of Parameters7.4.4. Self-Processing Pages7.4.5. Sticky Forms7.4.6. Multivalued Parameters7.4.7. Sticky Multivalued Parameters7.4.8. File Uploads7.4.9. Form Validation
7.5. Setting Response Headers
7.5.1. Different Content Types7.5.2. Redirections7.5.3. Expiration7.5.4. Authentication
7.6. Maintaining State
7.6.1. Cookies7.6.2. Sessions7.6.2.1. Session basics7.6.2.2. Alternatives to cookies7.6.2.3. Custom storage7.6.3. Combining Cookies and Sessions
7.7. SSL
8. Databases
8.1. Using PHP to Access a Database
8.2. Relational Databases and SQL
8.3. PEAR DB Basics
8.3.1. Data Source Names8.3.2. Connecting8.3.3. Error Checking8.3.4. Issuing a Query8.3.5. Fetching Results from a Query8.3.5.1. Returning the row8.3.5.2. Storing the row8.3.5.3. Inside a row array8.3.5.4. Finishing the result8.3.6. Disconnecting
8.4. Advanced Database Techniques
8.4.1. Placeholders8.4.2. Prepare/Execute8.4.3. Shortcuts8.4.4. Details About a Query Response8.4.5. Sequences8.4.6. Metadata8.4.7. Transactions
8.5. Sample Application
8.5.1. Database Tables8.5.2. Database Connection8.5.3. Administrator’s Page8.5.4. Adding a Business8.5.5. Displaying the Database8.5.6. PHP Data Objects8.5.6.1. Making a connection8.5.6.2. Interaction with the database8.5.6.3. PDO and prepared statements
9. Graphics
9.1. Embedding an Image in a Page
9.2. The GD Extension
9.3. Basic Graphics Concepts
9.4. Creating and Drawing Images
9.4.1. The Structure of a Graphics Program9.4.2. Changing the Output Format9.4.3. Testing for Supported Image Formats9.4.4. Reading an Existing File9.4.5. Basic Drawing Functions
9.5. Images with Text
9.5.1. Fonts9.5.2. TrueType Fonts
9.6. Dynamically Generated Buttons
9.6.1. Caching the Dynamically Generated Buttons9.6.2. A Faster Cache
9.7. Scaling Images
9.8. Color Handling
9.8.1. Using the Alpha Channel9.8.2. Identifying Colors9.8.3. True Color Color Indexes9.8.4. Text Representation of an Image
10. PDF
10.1. PDF Extensions
10.2. Documents and Pages
10.2.1. A Simple Example10.2.2. Initializing the Document10.2.3. Outputting Basic Text - Cells
10.3. Text
10.3.1. Coordinates10.3.2. Text Attributes10.3.3. Page Headers, Footers, and Class Extension10.3.4. Images and Links10.3.5. Tables and Data
11. XML
11.1. Lightning Guide to XML
11.2. Generating XML
11.3. Parsing XML
11.3.1. Element Handlers11.3.2. Character Data Handler11.3.3. Processing Instructions11.3.4. Entity Handlers11.3.4.1. External entities11.3.4.2. Unparsed entities11.3.5. Default Handler11.3.6. Options11.3.6.1. Character encoding11.3.6.2. Case folding11.3.7. Using the Parser11.3.8. Errors11.3.9. Methods as Handlers11.3.10. Sample Parsing Application
11.4. Parsing XML with DOM
11.5. Parsing XML with SimpleXML
11.6. Transforming XML with XSLT
11.7. Web Services
11.7.1. Servers11.7.2. Clients
12. Security
12.1. Filter Input
12.1.1. SQL Injection
12.2. Escape Output
12.2.1. Filenames12.2.1.1. Check for relative paths
12.3. Cross-Site Scripting
12.4. Session Fixation
12.5. File Uploads
12.5.1. Distrust Browser-Supplied Filenames12.5.2. Beware of Filling Your Filesystem12.5.3. Surviving register_globals
12.6. File Access
12.6.1. Restrict Filesystem Access to a Specific Directory12.6.2. Get It Right the First Time12.6.3. Don’t Use Files12.6.4. Session Files12.6.5. Concealing PHP Libraries
12.7. PHP Code
12.8. Shell Commands
12.9. More Information
12.10. Security Recap
13. Application Techniques
13.1. Code Libraries
13.2. Templating Systems
13.3. Handling Output
13.3.1. Output Buffering13.3.2. Compressing Output
13.4. Error Handling
13.4.1. Error Reporting13.4.2. Error Suppression13.4.3. Triggering Errors13.4.4. Defining Error Handlers13.4.4.1. Logging in error handlers13.4.4.2. Output buffering in error handlers
13.5. Performance Tuning
13.5.1. Benchmarking13.5.2. Profiling13.5.3. Optimizing Execution Time13.5.4. Optimizing Memory Requirements13.5.5. Reverse Proxies and Replication13.5.5.1. Reverse-proxy cache13.5.5.2. Load balancing and redirection13.5.5.3. MySQL replication13.5.5.4. Putting it all together
14. Extending PHP
14.1. Architectural Overview
14.2. What You’ll Need
14.2.1. The PHP Source14.2.2. Software Tools
14.3. Building Your First Extensions
14.3.1. Command-Line PHP14.3.2. Planning Your Extension14.3.3. Creating a Skeleton Extension14.3.4. Fleshing Out the Skeleton14.3.5. Compiling Your Extension14.3.5.1. Standalone extensions14.3.5.2. Compiling the extension into PHP14.3.6. Testing Your Extension
14.4. The config.m4 File
14.4.1. No External Dependencies14.4.2. External Dependencies
14.5. Memory Management
14.6. The pval /zval Data Type
14.6.1. MAKE_STD_ZVAL( )14.6.2. SEPARATE_ZVAL( )14.6.3. zval_copy_ctor( )14.6.4. Accessor Macros
14.7. Parameter Handling
14.7.1. A Simple Example14.7.2. A More Complex Example14.7.3. An Example with Variable Argument List
14.8. Returning Values
14.8.1. Simple Types14.8.2. Arrays14.8.3. Objects
14.9. References
14.10. Global Variables
14.10.1. SAPI Globals (SG)14.10.2. Executor Globals (EG )14.10.3. Internal Extension Globals
14.11. Creating Variables
14.12. Extension INI Entries
14.13. Resources
14.14. Where to Go from Here
15. PHP on Windows
15.1. Installing and Configuring PHP on Windows
15.1.1. Going Straight to the Source15.1.2. Configuring PHP with a Web Server15.1.2.1. Configuration common to all Microsoft installations15.1.2.2. Manually configuring Apache15.1.2.3. Other installers and prepackaged distributions15.1.3. Adding Extensions to the Base Distribution15.1.4. Adding the MySQL Extension
15.2. Writing Portable Code for Windows and Unix
15.2.1. Determining the Platform15.2.2. Handling Paths Across Platforms15.2.3. The Environment15.2.4. Sending Mail15.2.5. End-of-Line Handling15.2.6. End-of-File Handling15.2.7. External Commands15.2.8. Common Platform-Specific Extensions
15.3. Interfacing with COM
15.3.1. Background15.3.2. PHP Functions15.3.3. Determining the API15.3.4. Completing a Word Document
15.4. Interacting with ODBC Data Sources
15.4.1. Configuring a DSN15.4.2. Working with Access
A. Function Reference
A.1. PHP Functions by Category
A.1.1. ArraysA.1.2. Classes and ObjectsA.1.3. Date and TimeA.1.4. Errors and LoggingA.1.5. Files, Directories, and FilesystemA.1.6. FunctionsA.1.7. HTTPA.1.8. ImagesA.1.9. MailA.1.10. MathA.1.11. NetworkA.1.12. Output ControlA.1.13. PHP Options/InfoA.1.14. Program ExecutionA.1.15. StringsA.1.16. Type FunctionsA.1.17. URLsA.1.18. Variable Functions
A.2. Alphabetical Listing of PHP Functions
B. Extension Overview
B.1. Optional Extensions Listing
About the Authors
Colophon
Copyright

Content preview from Programming PHP, 2nd Edition

Chapter 4. Strings

Most data you encounter as you program will be sequences of characters, or strings. Strings hold people’s names, passwords, addresses, credit card numbers, photographs, purchase histories, and more. For that reason, PHP has an extensive selection of functions for working with strings.

This chapter shows the many ways to write strings in your programs, including the sometimes-tricky subject of interpolation (placing a variable’s value into a string), then covers functions for changing, quoting, and searching strings. By the end of this chapter, you’ll be a string-handling expert.

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ISBN: 0596006810Errata Page

Cloud Computing

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Programming Languages

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Soft Skills

Programming PHP, 2nd Edition

by Rasmus Lerdorf, Kevin Tatroe, Peter MacIntyre

Chapter 4. Strings

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

More than 5,000 organizations count on O’Reilly

Julian F.

Addison B.

Amir M.

Mark W.

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