Contents

ACKNOWLEDGMENTS xviiINTRODUCTION xix

PART 1

Writing Basic PHP Programs

1 CreatingPHPPrograms ........................................Creating a PHP Script ..........................................

Writing PHP Scripts .....................................WritingthePHPCodeSkeleton ............................CreatingOutputforaWebBrowser .........................DocumentingaPHPScript ................................

ExecutingaPHPScript """""""""""""""""""'"

UpIoadingaPHPScript """"""""""""""""'"

Executing a Script .......................................Project 1-1: A First PHP Script ...,...............................

TroubleshootingaScript ..................................MasteryCheck ...............................................

2 PHPBuildingBlocks ...........................................Numbers and Strings ...........................................

Numbers ,........Strings ................................................

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LiteralsandVariables ..........................................Project 2-1: Viewing the Values of PHP Variables. . . . . . . . . . . . . . . . . . . .Scalars and Arrays .............................................Operators and Functions .......................................

Operators ..............................................Functions ..............................................

Project 2-2: A Calculation in PHP .................................MasteryCheck ...............................................

3 CreatingHTMLForms .........................................FormDesignBasics ............................................

DesigningaForm .......................................CreatinganHTMLForm ..................................

Project 3-1: Viewing Form Fields .................................Creating Form Controls ........................................

Creating Customized Text Boxes ...........................Creating Text Areas ......................................Creating Password Boxes ..................................Creating Check Boxes ....................................Creating Radio Buttons ...................................Creating Selects .........................................Creating Hidden Fields ...................................

Project3-2:AnHTMLBusyBox ..................................MoreonSubmittingaForm .....................................

Using an Image to Submit Data .............................CreatingaResetButton ...................................CreatingaMulti-FormPage ...............................Using a Link to Provide Data to a Script. . . . . . . . . . . . . . . . . . . . . .

Project3-3:AMulti-FormHTMLPage .............................MasteryCheck ...............................................

4 AccessingData ...............................................GettingandUsingDatafromaForm ..............................

SendingOutputtotheBrowser .............................Constructing Strings that Embed Values of Variables. . . . . . . . . . . .

Project 4-1: The E-mail Address Books .............................ProjectGoals ...........................................

Getting and Using Data from an Environment Variable. . . . . . . . . . . . . . . .Project 4-2: Viewing Environment Variables. . . . . . . . . . . . . . . . . . . . . . . .

ProjectGoals ...........................................MasteryCheck ...............................................

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5 WorkingwithScalarValues .....................................Working with Constants and Dynamic Variables. . . . . . . . . . . . . . . . . . . . .

Working with Constants ..................................Working with Dynamic Variables ...........................

Working with Types """"""""""""""""""""'"AutomaticTypeConversion ...............................ManualTypeConversion .................................

Project 5-1: A Simple Calculator ..................................Project 5-2: A Date Calculator ...................................Project5-3:ANewsStoryGenerator ..............................MasteryCheck ...............................................

PART2

Writing More Advanced PUP Programs

6 Writing Conditional Statements ,

UsingTrue/FalseValues ........................................Writing Simple if Statements ...................................Project6-1:TestingNumericValues ..............................Writing More Sophisticated if Statements. . . . . . . . . . . . . . . . . . . . . . . . .Writing switch, break, and default Statements. . . . . . . . . . . . . . . . .Writing for Statements ,.....Writing while and do while Statements. . . . . . . . . . . . . . . . . . . . . . . . .Project 6-2: Validating User Input ,....MasteryCheck ...............................................

7 Using Functions 127UsingaFunction , 128Using Included Files 129DefiningaFunction 131

Calling a User-Defined Function 132Terminating Function Execution. . . . . . . . . . . . . . . . . . . . . . . . . .. 133RecursiveFunctions 133DefiningDefaultArguments 134

PHPVariablesandReferences 136.Using Global Variables 136Using Local and Static Variables 137Using References (PHP4) 139

Project7-1:The ContactForm Revisited. . . . . . . . . . . . . . . . . . . . . . . . . .. 141MasteryCheck 148

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111 PHP 4: A Beginner's Guide

8 Using Arrays 149Creating Arrays 150

Creating an Array Using Assignment. . . . . . . . . . . . . . . . . . . . . . .. 150Usingthearray() Function 152

Iterating Through an Array 154Iterating Through a Sequential Array. . . . . . . . . . . . . . . . . . . . . . .. 155SearchingaSequentialArray 155The break Statement 156The continue Statement 157

Iterating Through a Non-Sequential Array. . . . . . . . . . . . . . . . . . .. 158Working with List Functions 160

Thekey() Function 161Theeach() Function 161Thelist() Function 162

SortingArrays 164Project 8-1: The Contact Form Revisited. . . . . . . . . . . . . . . . . . . . . . . . . .. 166MasteryCheck 170

9 Using Strings .................................................Creating and Displaying Strings ..................................

Additional Escape Sequences """""""""""""""

Working with ASCII Codes ................................Single-quoted Strings .....................................Creating Formatted Output ................................

ManipulatingStrings ...........................................GettingtheLengthofaString ..............................Trimming a String .......................................Converting Strings to All Upper- or Lowercase. . . . . . . . . . . . . . . .

Comparing and Searching Strings .................................Comparing Strings .......................................Finding and Extracting Substrings. . . . . . . . . . . . . . . . . . . . . . . . . .Replacing a Substring ....................................MatchingCharacters .....................................

Project 9-1: A Regular Expression Matcher. . . . . . . . . . . . . . . . . . . . . . . . .Project Goals ...........................................

MasteryCheck ...............................................

PART 3

Working with Stored Data

10 Using Cookies 199Accessing and Creating Cookies 200

AccessingaCookie 200

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CreatingaCookie 201DeletingaCookie 203

Advanced Cookie Techniques 203Storing Multiple Values in a Cookie. . . . . . . . . . . . . . . . . . . . . . . .. 203Specifying Access to a Cookie and Other Options. . . . . . . . . . . . .. 205

ProjectlO-l:ALoginPage 207MasteryCheck 210

11 Working with Files and Directories 211The Unix File System 212

Working with Unix Files 212Working with Unix Directories 221

WorkingwithFiles 225Ownership and Privilege Issues 226ObtainingaFile'sAttributes 227Changing File Privileges 229Changing File Ownership 230OpeningaFile 230Verifying Completion of a File Operation. . . . . . . . . . . . . . . . . . . .. 232ClosingaFile 233ReadingfromaFile 234NavigatingaFile 237WritingtoaFile 239

Project11-1:APageHitCounter 240Getting Exclusive Access to a File 242

Project 11-2: An Improved Page Hit Counter. . . . . . . . . . . . . . . . . . . . . . .. 244CopyingaFile 246RenamingaFile 247DeletingaFile 247

WorkingwithDirectories 250Getting and Changing the Working Directory. . . . . . . . . . . . . . . .. 250ManipulatingPaths 250Viewing and Changing Directory Privileges. . . . . . . . . . . . . . . . . .. 251ReadingDirectoryContents 252CreatingaDirectory 253Deleting a Directory 253

Projectl1-3:AnAddressBookBrowser 254MasteryCheck 259

12 Sending and Receiving E-mail ,.. 261SendingE-mail 262Project 12-1: A Form Submission Script. . . . . . . . . . . . . . . . . . . . . . . . . . .. 263

ProjectGoals 264

x PHP 4: A Beginner's Guide

ReceivingE-mail 267OpeningaMailbox 267Switching Folders , 269ClosingaMailbox 271Getting Information about a Mailbox. . . . . . . . . . . . . . . . . . . . . . .. 271Getting a list of Messages 274WorkingwithMessagelDs 275Getting Information about a Message. . . . . . . . . . . . . . . . . . . . . . .. 275GettingaMessageBody 276GettingMessageHeaders 277MarkingaMessageforDeletion 279

Project 12-2: An E-mail Browser 281Project Goals 281

ManipulatingFolders 286listing Existing Folders 287CreatingaFolder 287Renaming a Folder 288DeletingaFolder 288Copying Messages to a Folder 289Moving Messages to a Folder 290

MasteryCheck 291

13 ReiationalDatabaseandSQLPrimer 293Relational Database Concepts 294

Structure of a Relational Database. . . . . . . . . . . . . . . . . . . . . . . . . .. 294Rationale for Relational Databases. . . . . . . . . . . . . . . . . . . . . . . . .. 296

Facilitating Sharing of Data 296Providing Data Independence 297Ad Hoc Querying 297Organizing Data 298Securing Data 298Minimizing Necessary Programmer Expertise. . . . . . . . . . . . . . . .. 298Achieving Computational Efficiency. . . . . . . . . . . . . . . . . . . . . . . .. 298Deciding When to Use a Relational DBMS. . . . . . . . . . . . . . . . . . .. 299

DatabaseImplementation 300DatabaseDesign 300E-RModeling 300DatabaseNormalization 304RefinementofE-RModels 307

MySQLDatabaseCreation 309AccessingDatabaseData:SQLQueries 314ChangingDatabaseData 318

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Sorting, Aggregating, and Grouping 322Expressions and Functions 325Joins 329Project13-1:WorkingwithSQL 331MasteryCheck 335

PART4

Using Advanced PHP Facilities14 Accessing Relational Databases 339

UsingMySQLDatabases 340ConnectingtotheMySQLServer 340Selecting the Database 342Checking for Errors 342Suppressing Unwanted Errors and Warnings. . . . . . . . . . . . . . . . .. 343Closing the MySQL Server Connection. . . . . . . . . . . . . . . . . . . . . .. 344

Performing UPDATE, INSERT, and DELETEQueries. . . . . . . . . . . . . . . .. 345Themysql_query() Function , 346

Checking Queries That Do Not Return Table Rows. . . . . . . . . . . . . . . . . .. 346Using Auto_Increment TableColumns. . . . . . . . . . . . . . . . . . . . . . . ., 347Processing the Results of SELECTQueries. . . . . . . . . . . . . . . . . . . . . . . . .. 349WorkingwithResultsets 354

Obtaining the Number of Resultset Columns. . . . . . . . . . . . . . . . .. 354Obtaining the Name of a Resultset Column. . . . . . . . . . . . . . . . . .. 354Obtaining the Length of a Resultset Column. . . . . . . . . . . . . . . . .. 355Obtaining the MySQLFlags Associated with a Resultset Column.. 355Obtaining the MySQLType of a Resultset Column. . . . . . . . . . . .. 356Determining the MySQLTable Associatedwith a Resultset Column.. 357Obtaining the Complete Resultset Structure. . . . . . . . . . . . . . . . . .. 357Accessing Resultset Columns Non-sequentially. . . . . . . . . . . . . . .. 359

ExploringtheDBMS 360Determining the Databases Hosted by a Server. . . . . . . . . . . . . . . .. 361Determining the Tables Contained Within a Database. . . . . . . . . .. 362Determining the Columns Contained Within a Table. . . . . . . . . .. 363

Quotes and Magic Quotes 365MagicQuotes 366EscapingandUnescaping , 367EscapingHTMLText 367EscapingURLs , 369

Other PHP Data Management Facilities. . . . . . . . . . . . . . . . . . . . . . . . . . .. 370Postgresql 370ODBC 371

..xu PHP 4: A Beginner's Guide

LDAP 372XML 372

Project 14-1: An Address Book Browser. . . . . . . . . . . . . . . . . . . . . . . . . . .. 374MasteryCheck 380

15 Using Classes and Objects 381Introduction to Object-oriented 382

Classes 383Inheritance 384

Defining and Instantiating a Class 386Instantiating an Object 387DefiningaConstructor 388

Using Inheritance 390Overriding Methods 391Invoking an Overridden Method 393

Object Arrays 395ProjectI5-1:WorkingwithObjects 397MasteryCheck 401

16 Using Application Templates 403Introduction to Templates 404Using a Template 405

Creating the Template File """""""""""""""" 406Instantiating a FastTemplate Object. . . . . . . . . . . . . . . . . . . . . . . .. 406Associating a Template Variable with the Template File. . . . . . . .. 407Assigning Values to the Template Variables. . . . . . . . . . . . . . . . . .. 407Parsing the Template Variable Associated with the Template File.. 408Printing the Template Variable Containing the Result. . . . . . . . . .. 408ConstructingaCompleteWebSite 408

Project 16-1: Working with Templates 410MasteryCheck 415

17 DebuggingPHPScripts 417Debugging and Common Programming Errors. . . . . . . . . . . . . . . . . . . . .. 418

Understanding Bugs 419Syntax Errors 420Run-time Error Messages 421Incorrect or Missing Output 423

ErrorMessageManagementinPHP 424AvoidingErrorMessages 424Suppressing Error Messages 425Logging Error Messages 426

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The Art and Practice of Debugging 429ReproducingtheSymptom 430Pinpointing the Bug 430UnderstandingtheBug 432Fixing the Bug 432Testing the Program 433

Project 17-1: PHPErrorMessages 434MasteryCheck 437

PARTV

Appendixes

A AnswerstoMasteryChecks 441Modulel:CreatingPHPPrograms 442Module2:PHPBuildingBlocks 442Module 3: Creating HTML Forms 443Module4:AccessingData 444Module 5: Working with Scalar Values. . . . . . . . . . . . . . . . . . . . . .. 445Module 6: Writing Conditional Statements. . . . . . . . . . . . . . . . . . .. 446Module7:UsingFunctions 447Module8:UsingArrays 448Module9:UsingStrings 449Modulel0:UsingCookies 449Module 11: Working with Files and Directories. . . . . . . . . . . . . . .. 450Module 12: Sending and Receiving E-mail. . . . . . . . . . . . . . . . . . .. 451Module 13: Relational Database and SQL Primer. . . . . . . . . . . . . . .. 452Module 14: Accessing Relational Databases. . . . . . . . . . . . . . . . . .. 452Module 15: Using Classes and Objects. . . . . . . . . . . . . . . . . . . . . .. 453Module 16: Using Application Templates. . . . . . . . . . . . . . . . . . . .. 454Modulel7:DebuggingPHPScripts 455

B InstallingPHP 457RedHatLinux7.1 458

InstallingApache 458InstallingPHP 458InstallingMySQL 459InstallingIMAP 459ConfiguringMySQL 460Starting the Apache Service 460Testing the Installation 461

Other Linux and Unix Releases 462WindowsNT/2000and95/98 463

Apache 464lIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 464

.XIV PHP 4: A Beginner's Guide

PWS 464PHP 464

C PHPResources 465WebSites 466Mailing lists 467Newsgroups 467

D Unix Essentials 469

BasicUnixConcepts 470Files 470Directories 471Paths 471User Accounts 473User Groups 474Ownership and Permissions 474

BasicUnixTechniques 475LogginglnandOut 476IssuingaUnixCommand 477ChangingYourPassword 477SeeingWho'sLoggedin 478Checking Whether a Host Is Alive 478ReadingandSendingE-Mail 479Changing the Current Working Directory. . . . . . . . . . . . . . . . . . .. 479ViewingDirectoryContents 480

Viewing File Contents and Command Output. . . . . . . . . . . . . . . .. 481EditingaFile 482CreatingaDirectory 482DeletingaFile 482Deleting a Directory 483CopyingaFileorDirectory 483Renaming a File or Directory 484Shell Metacharacters and Name Globbing . . . . . . . . . . . . . . . . . . . .. 484Consulting Online Unix Documentation. . . . . . . . . . . . . . . . . . . .. 485Reporting Disk Space Usage 485SettingFileOwnership 486Setting File Permissions 486Finding a File 487Finding a File Containing Specified Text. . . . . . . . . . . . . . . . . . . .. 488DeterminingtheTypeofaFile 489ComparingTextFiles 489WorkingwithCompressedFiles 489WorkingwithTarballs 490Transferring Files to and from Remote Hosts. . . . . . . . . . . . . . . . .. 491

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E Escapes 493

F ASCII 495

G PHP Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 501

H Security """""""""""""""""""""""""'" 505ThreatsandRisks 506Countermeasures 508

Authenticating and Authorizing Users. . . . . . . . . . . . . . . . . . . . . .. 508DistrustingUserlnput 508Employing Cryptographic Measures. . . . . . . . . . . . . . . . . . . . . . . .. 509Properly Configuring Servers 509Securing Databases 509Resources 510

I PHPFunctions 511

Array Functions 513AspellFunctions 515Calendar Functions 516

Class/ObjectFunctions 516Character type Functions 517DateandTimeFunctions 518

Directory Functions 518Error Handling and Logging Functions. . . . . . . . . . . . . . . . . . . . . . . . . . .. 519FilesystemFunctions 519FTPFunctions 522HTTPFunctions 523

IMAP,POP3andNNTPFunctions 524Mail Functions , 527MathematicalFunctions 527Miscellaneous Functions 529

MySQLFunctions 530Output Control Functions 533PHPoptions&information 533Program Execution Functions 535PO~XFunctlons , 535

POSIX Extended Regular Expression Functions. . . . . . . . . . . . . . . . . . . .. 537Session Handling Functions 537String Functions 538URLFunctions 542Variable Functions 542

Index , 545