Programming PHP

Table of Contents
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 Lerdorf
		Kevin Tatroe
		Peter MacIntyre
			Dedication
Introduction to PHP
	What Does PHP Do?
	A Brief History of PHP
		The Evolution of PHP
		The Growth of PHP
	Installing PHP
	A Walk Through PHP
		Configuration Page
		Forms
		Databases
		Graphics
		From the Shell
Language Basics
	Lexical Structure
		Case Sensitivity
		Statements and Semicolons
		Whitespace and Line Breaks
		Comments
			Shell-style comments
			C++ comments
			C comments
		Literals
		Identifiers
			Variable names
			Function names
			Class names
			Constants
		Keywords
	Data Types
		Integers
		Floating-Point Numbers
		Strings
		Booleans
		Arrays
		Objects
		Resources
		NULL
	Variables
		Variable Variables
		Variable References
		Variable Scope
			Local scope
			Global scope
			Static variables
			Function parameters
		Garbage Collection
	Expressions and Operators
		Number of Operands
		Operator Precedence
		Operator Associativity
		Implicit Casting
		Arithmetic Operators
		String Concatenation Operator
		Autoincrement and Autodecrement Operators
		Comparison Operators
		Bitwise Operators
		Logical Operators
		Casting Operators
		Assignment Operators
			Assignment
			Assignment with operation
		Miscellaneous Operators
	Flow-Control Statements
		if
		switch
		while
		for
		foreach
		declare
		exit and return
	Including Code
	Embedding PHP in Web Pages
		XML Style
		SGML Style
		ASP Style
		Script Style
		Echoing Content Directly
Functions
	Calling a Function
	Defining a Function
	Variable Scope
		Global Variables
		Static Variables
	Function Parameters
		Passing Parameters by Value
		Passing Parameters by Reference
		Default Parameters
		Variable Parameters
		Missing Parameters
	Return Values
	Variable Functions
	Anonymous Functions
Strings
	Quoting String Constants
		Variable Interpolation
		Single-Quoted Strings
		Double-Quoted Strings
		Here Documents
	Printing Strings
		echo
		print()
		printf()
			Format modifiers
			Type specifiers
		print_r() and var_dump()
	Accessing Individual Characters
	Cleaning Strings
		Removing Whitespace
		Changing Case
	Encoding and Escaping
		HTML
			Entity-quoting all special characters
			Entity-quoting only HTML syntax characters
			Removing HTML tags
			Extracting meta tags
		URLs
			RFC 1738 encoding and decoding
			Query-string encoding
		SQL
		C-String Encoding
	Comparing Strings
		Exact Comparisons
		Approximate Equality
	Manipulating and Searching Strings
		Substrings
		Miscellaneous String Functions
		Decomposing a String
			Exploding and imploding
			Tokenizing
			sscanf()
		String-Searching Functions
			Searches returning position
			Searches returning rest of string
			Searches using masks
			Decomposing URLs
	Regular Expressions
		The Basics
		Character Classes
		Alternatives
		Repeating Sequences
		Subpatterns
	POSIX-Style Regular Expressions
		Character Classes
		Anchors
		Functions
			Matching
			Replacing
			Splitting
	Perl-Compatible Regular Expressions
		Delimiters
		Match Behavior
		Character Classes
		Anchors
		Quantifiers and Greed
		Non-Capturing Groups
		Backreferences
		Trailing Options
		Inline Options
		Lookahead and Lookbehind
		Cut
		Conditional Expressions
		Functions
			Matching
			Replacing
			Splitting
			Filtering an array with a regular expression
			Quoting for regular expressions
		Differences from Perl Regular Expressions
Arrays
	Indexed Versus Associative Arrays
	Identifying Elements of an Array
	Storing Data in Arrays
		Adding Values to the End of an Array
		Assigning a Range of Values
		Getting the Size of an Array
		Padding an Array
	Multidimensional Arrays
	Extracting Multiple Values
		Slicing an Array
		Splitting an Array into Chunks
		Keys and Values
		Checking Whether an Element Exists
		Removing and Inserting Elements in an Array
	Converting Between Arrays and Variables
		Creating Variables from an Array
		Creating an Array from Variables
	Traversing Arrays
		The foreach Construct
		The Iterator Functions
		Using a for Loop
		Calling a Function for Each Array Element
		Reducing an Array
		Searching for Values
	Sorting
		Sorting One Array at a Time
		Natural-Order Sorting
		Sorting Multiple Arrays at Once
		Reversing Arrays
		Randomizing Order
	Acting on Entire Arrays
		Calculating the Sum of an Array
		Merging Two Arrays
		Calculating the Difference Between Two Arrays
		Filtering Elements from an Array
	Using Arrays
		Sets
		Stacks
Objects
	Terminology
	Creating an Object
	Accessing Properties and Methods
	Declaring a Class
		Declaring Methods
		Declaring Properties
		Declaring Constants
		Inheritance
		Interfaces
		Abstract Methods
		Constructors
		Destructors
	Introspection
		Examining Classes
		Examining an Object
		Sample Introspection Program
	Serialization
Web Techniques
	HTTP Basics
	Variables
	Server Information
	Processing Forms
		Methods
		Parameters
		Automatic Quoting of Parameters
		Self-Processing Pages
		Sticky Forms
		Multivalued Parameters
		Sticky Multivalued Parameters
		File Uploads
		Form Validation
	Setting Response Headers
		Different Content Types
		Redirections
		Expiration
		Authentication
	Maintaining State
		Cookies
		Sessions
			Session basics
			Alternatives to cookies
			Custom storage
		Combining Cookies and Sessions
	SSL
Databases
	Using PHP to Access a Database
	Relational Databases and SQL
	PEAR DB Basics
		Data Source Names
		Connecting
		Error Checking
		Issuing a Query
		Fetching Results from a Query
			Returning the row
			Storing the row
			Inside a row array
			Finishing the result
		Disconnecting
	Advanced Database Techniques
		Placeholders
		Prepare/Execute
		Shortcuts
		Details About a Query Response
		Sequences
		Metadata
		Transactions
	Sample Application
		Database Tables
		Database Connection
		Administrator’s Page
		Adding a Business
		Displaying the Database
		PHP Data Objects
			Making a connection
			Interaction with the database
			PDO and prepared statements
Graphics
	Embedding an Image in a Page
	The GD Extension
	Basic Graphics Concepts
	Creating and Drawing Images
		The Structure of a Graphics Program
		Changing the Output Format
		Testing for Supported Image Formats
		Reading an Existing File
		Basic Drawing Functions
	Images with Text
		Fonts
		TrueType Fonts
	Dynamically Generated Buttons
		Caching the Dynamically Generated Buttons
		A Faster Cache
	Scaling Images
	Color Handling
		Using the Alpha Channel
		Identifying Colors
		True Color Color Indexes
		Text Representation of an Image
PDF
	PDF Extensions
	Documents and Pages
		A Simple Example
		Initializing the Document
		Outputting Basic Text - Cells
	Text
		Coordinates
		Text Attributes
		Page Headers, Footers, and Class Extension
		Images and Links
		Tables and Data
XML
	Lightning Guide to XML
	Generating XML
	Parsing XML
		Element Handlers
		Character Data Handler
		Processing Instructions
		Entity Handlers
			External entities
			Unparsed entities
		Default Handler
		Options
			Character encoding
			Case folding
		Using the Parser
		Errors
		Methods as Handlers
		Sample Parsing Application
	Parsing XML with DOM
	Parsing XML with SimpleXML
	Transforming XML with XSLT
	Web Services
		Servers
		Clients
Security
	Filter Input
		SQL Injection
	Escape Output
		Filenames
			Check for relative paths
	Cross-Site Scripting
	Session Fixation
	File Uploads
		Distrust Browser-Supplied Filenames
		Beware of Filling Your Filesystem
		Surviving register_globals
	File Access
		Restrict Filesystem Access to a Specific Directory
		Get It Right the First Time
		Don’t Use Files
		Session Files
		Concealing PHP Libraries
	PHP Code
	Shell Commands
	More Information
	Security Recap
Application Techniques
	Code Libraries
	Templating Systems
	Handling Output
		Output Buffering
		Compressing Output
	Error Handling
		Error Reporting
		Error Suppression
		Triggering Errors
		Defining Error Handlers
			Logging in error handlers
			Output buffering in error handlers
	Performance Tuning
		Benchmarking
		Profiling
		Optimizing Execution Time
		Optimizing Memory Requirements
		Reverse Proxies and Replication
			Reverse-proxy cache
			Load balancing and redirection
			MySQL replication
			Putting it all together
Extending PHP
	Architectural Overview
	What You’ll Need
		The PHP Source
		Software Tools
	Building Your First Extensions
		Command-Line PHP
		Planning Your Extension
		Creating a Skeleton Extension
		Fleshing Out the Skeleton
		Compiling Your Extension
			Standalone extensions
			Compiling the extension into PHP
		Testing Your Extension
	The config.m4 File
		No External Dependencies
		External Dependencies
	Memory Management
	The pval/zval Data Type
		MAKE_STD_ZVAL()
		SEPARATE_ZVAL()
		zval_copy_ctor()
		Accessor Macros
	Parameter Handling
		A Simple Example
		A More Complex Example
		An Example with Variable Argument List
	Returning Values
		Simple Types
		Arrays
		Objects
	References
	Global Variables
		SAPI Globals (SG)
		Executor Globals (EG)
		Internal Extension Globals
	Creating Variables
	Extension INI Entries
	Resources
	Where to Go from Here
PHP on Windows
	Installing and Configuring PHP on Windows
		Going Straight to the Source
		Configuring PHP with a Web Server
			Configuration common to all Microsoft installations
			Manually configuring Apache
			Other installers and prepackaged distributions
		Adding Extensions to the Base Distribution
		Adding the MySQL Extension
	Writing Portable Code for Windows and Unix
		Determining the Platform
		Handling Paths Across Platforms
		The Environment
		Sending Mail
		End-of-Line Handling
		End-of-File Handling
		External Commands
		Common Platform-Specific Extensions
	Interfacing with COM
		Background
		PHP Functions
		Determining the API
		Completing a Word Document
	Interacting with ODBC Data Sources
		Configuring a DSN
		Working with Access
Function Reference
	PHP Functions by Category
		Arrays
		Classes and Objects
		Date and Time
		Errors and Logging
		Files, Directories, and Filesystem
		Functions
		HTTP
		Images
		Mail
		Math
		Network
		Output Control
		PHP Options/Info
		Program Execution
		Strings
		Type Functions
		URLs
		Variable Functions
	Alphabetical Listing of PHP Functions
		abs
		acos
		acosh
		addcslashes
		addslashes
		Array
		array_change_key_case
		array_chunk
		array_combine
		array_count_values
		array_diff
		array_diff_assoc
		array_diff_uassoc
		array_fill
		array_filter
		array_flip
		array_intersect
		array_intersect_assoc
		array_intersect_uassoc
		array_key_exists
		array_keys
		array_map
		array_merge
		array_merge_recursive
		array_multisort
		array_pad
		array_pop
		array_push
		array_rand
		array_reduce
		array_reverse
		array_search
		array_shift
		array_slice
		array_splice
		array_sum
		array_udiff
		array_udiff_assoc
		array_udiff_uassoc
		array_uintersect
		array_uintersect_assoc
		array_uintersect_uassoc
		array_unique
		array_unshift
		array_values
		array_walk
		array_walk_recursive
		arsort
		asin
		asinh
		asort
		assert
		assert_options
		atan
		atan2
		atanh
		base64_decode
		base64_encode
		base_convert
		basename
		bin2hex
		bindec
		call_user_func
		call_user_func_array
		call_user_method
		call_user_method_array
		ceil
		chdir
		checkdate
		checkdnsrr
		chgrp
		chmod
		chop
		chown
		chr
		chroot
		chunk_split
		class_exists
		class_implements
		class_parents
		clearstatcache
		closedir
		closelog
		compact
		connection_aborted
		connection_status
		constant
		convert_cyr_string
		convert_uudecode
		convert_uuencode
		copy
		cos
		cosh
		count
		count_chars
		crc32
		create_function
		crypt
		ctype_alnum
		ctype_alpha
		ctype_cntrl
		ctype_digit
		ctype_graph
		ctype_lower
		ctype_print
		ctype_punct
		ctype_space
		ctype_upper
		ctype_xdigit
		current
		date
		date_sunrise
		date_sunset
		debug_backtrace
		debug_print_backtrace
		decbin
		dechex
		decoct
		define
		defined
		define_syslog_variables
		deg2rad
		dir
		dirname
		diskfreespace
		disk_free_space
		disk_total_space
		dl
		dns_check_record
		dns_get_mx
		doubleval
		each
		echo
		empty
		end
		ereg
		ereg_replace
		eregi
		eregi_replace
		error_log
		error_reporting
		escapeshellarg
		escapeshellcmd
		exec
		exp
		explode
		extension_loaded
		extract
		fclose
		feof
		fflush
		fgetc
		fgetcsv
		fgets
		fgetss
		file
		file_exists
		fileatime
		filectime
		file_get_contents
		filegroup
		fileinode
		filemtime
		fileowner
		fileperms
		file_put_contents
		filesize
		filetype
		floatval
		flock
		floor
		flush
		fmod
		fnmatch
		fopen
		fpassthru
		fprintf
		fputs
		fread
		fscanf
		fseek
		fsockopen
		fstat
		ftell
		ftruncate
		func_get_arg
		func_get_args
		func_num_args
		function_exists
		fwrite
		get_browser
		get_cfg_var
		get_class
		get_class_methods
		get_class_vars
		get_current_user
		get_declared_classes
		get_declared_interfaces
		get_defined_constants
		get_defined_functions
		get_defined_vars
		get_extension_funcs
		get_headers
		get_html_translation_table
		getimagesize
		get_included_files
		get_include_path
		get_loaded_extensions
		get_magic_quotes_gpc
		get_magic_quotes_runtime
		get_meta_tags
		getmygid
		getmyuid
		get_object_vars
		get_parent_class
		get_required_files
		get_resource_type
		getcwd
		getdate
		getenv
		gethostbyaddr
		gethostbyname
		gethostbynamel
		getlastmod
		getmxrr
		getmyinode
		getmypid
		getprotobyname
		getprotobynumber
		getrandmax
		getrusage
		getservbyname
		getservbyport
		gettimeofday
		gettype
		glob
		gmdate
		gmmktime
		gmstrftime
		header
		headers_list
		headers_sent
		hebrev
		hebrevc
		hexdec
		highlight_file
		highlight_string
		htmlentities
		html_entity_decode
		htmlspecialchars
		http_build_query
		hypot
		idate
		ignore_user_abort
		image_type_to_mime_type
		implode
		import_request_variables
		in_array
		ini_alter
		ini_get
		ini_get_all
		ini_restore
		ini_set
		interface_exists
		intval
		ip2long
		iptcparse
		is_a
		is_array
		is_bool
		is_callable
		is_dir
		is_double
		is_executable
		is_file
		is_finite
		is_float
		is_infinite
		is_int
		is_integer
		is_link
		is_long
		is_nan
		is_null
		is_numeric
		is_object
		is_readable
		is_real
		is_resource
		is_scalar
		is_string
		is_subclass_of
		is_uploaded_file
		is_writable
		is_writeable
		isset
		join
		key
		krsort
		ksort
		lcg_value
		levenshtein
		link
		linkinfo
		list
		localeconv
		localtime
		log
		log10
		log1p
		long2ip
		lstat
		ltrim
		mail
		max
		md5
		md5_file
		metaphone
		method_exists
		microtime
		min
		mkdir
		mktime
		money_format
		move_uploaded_file
		mt_getrandmax
		mt_rand
		mt_srand
		natcasesort
		natsort
		next
		nl_langinfo
		nl2br
		number_format
		ob_clean
		ob_end_clean
		ob_end_flush
		ob_flush
		ob_get_clean
		ob_get_contents
		ob_get_flush
		ob_get_length
		ob_get_level
		ob_gzhandler
		ob_implicit_flush
		ob_list_handlers
		ob_start
		octdec
		opendir
		openlog
		ord
		output_add_rewrite_var
		output_reset_rewrite_vars
		pack
		parse_ini_file
		parse_str
		parse_url
		passthru
		pathinfo
		pclose
		pfsockopen
		php_ini_scanned_files
		php_logo_guid
		php_sapi_name
		php_uname
		phpcredits
		phpinfo
		phpversion
		pi
		popen
		pos
		pow
		prev
		print
		print_r
		printf
		putenv
		quoted_printable_decode
		quotemeta
		rad2deg
		rand
		range
		rawurldecode
		rawurlencode
		readdir
		readfile
		readlink
		realpath
		register_shutdown_function
		register_tick_function
		rename
		reset
		restore_error_handler
		restore_exception_handler
		restore_include_path
		rewind
		rewinddir
		rmdir
		round
		rsort
		rtrim
		serialize
		set_error_handler
		set_exception_handler
		set_file_buffer
		set_include_path
		set_magic_quotes_runtime
		set_time_limit
		setcookie
		setlocale
		setrawcookie
		settype
		sha1
		sha1_file
		shell_exec
		show_source
		shuffle
		similar_text
		sin
		sinh
		sizeof
		sleep
		socket_get_status
		socket_set_blocking
		socket_set_timeout
		sort
		soundex
		split
		spliti
		sprintf
		sql_regcase
		sqrt
		srand
		sscanf
		stat
		str_ireplace
		str_pad
		str_repeat
		str_replace
		str_rot13
		str_shuffle
		str_split
		str_word_count
		strcasecmp
		strchr
		strcmp
		strcoll
		strcspn
		strftime
		stripcslashes
		stripslashes
		strip_tags
		stripos
		stristr
		strlen
		strnatcasecmp
		strnatcmp
		strncasecmp
		strncmp
		strpbrk
		strpos
		strrchr
		strrev
		strripos
		strrpos
		strspn
		strstr
		strtok
		strtolower
		strtotime
		strtoupper
		strtr
		strval
		substr
		substr_compare
		substr_count
		substr_replace
		symlink
		syslog
		system
		tan
		tanh
		tempnam
		time
		time_nanosleep
		tmpfile
		touch
		trigger_error
		trim
		uasort
		ucfirst
		ucwords
		uksort
		umask
		uniqid
		unlink
		unpack
		unregister_tick_function
		unserialize
		unset
		urldecode
		urlencode
		user_error
		usleep
		usort
		var_dump
		var_export
		version_compare
		vprintf
		vsprintf
		wordwrap
		zend_logo_guid
		zend_version
Extension Overview
	Optional Extensions Listing
		BCMath Arbitrary Precision Mathematics
		Calendar
		cPDF
		COM
		ctype
		CURL
		dBase
		DBM-Style Database Abstraction
		dbx
		DOM XML
		EXIF
		FrontBase
		FDF
		File Alteration Monitor
		filePro
		FTP
		Gd/gd2
		gettext
		GMP
		Hyperwave
		iconv
		IMAP, POP3, and NNTP
		Informix
		Ingres II
		InterBase
		IRC Gateway
		Java
		LDAP
		mcrypt
		MCVE
		mhash
		Microsoft SQL Server
		Ming
		mnoGoSearch
		msession
		mSQL
		MySQL
		ODBC
		openssl
		Oracle
		OvrimosSQL
		Verisign Payflow Pro
		PostgreSQL
		pspell
		Readline
		Recode
		shmop
		SNMP
		sockets
		Sybase
		System V Semaphore and Shared Memory
		tidy
		WDDX
		XML Parser
		YAZ
		YP/NIS
		zlib Compression
Index