PHP Manual

Mehdi Achour
Friedhelm Betz
Antony Dovgal
Nuno Lopes
Philip Olson
Georg Richter
Damien Seguy
Jakub Vrana
And several others

Edited by

Gabor Hojtsy

14-02-2005

Copyright

Copyright © 1997 - 2005 by the PHP Documentation Group. This material may be distributed only subject to the terms and conditions set forth in the Open Publication License, v1.0 or later. A copy of the Open Publication License is distributed with this manual, the latest version is presently available at http://www.opencontent.org/openpub/.

Distribution of substantively modified versions of this document is prohibited without the explicit permission of the copyright holder.

Distribution of the work or derivative of the work in any standard (paper) book form is prohibited unless prior permission is obtained from the copyright holder.

In case you are interested in redistribution or republishing of this document in whole or in part, either modified or unmodified, and you have questions, please contact the copyright holders at doc-license@lists.php.net. Note that this address is mapped to a publicly archived mailing list.

The 'Extending PHP 4.0' section of this manual is copyright © 2000 by Zend Technologies, Ltd. This material may be distributed only subject to the terms and conditions set forth in the Open Publication License, v1.0 or later (the latest version is presently available at http://www.opencontent.org/openpub/).


Table of Contents
Preface
Authors and Contributors
I. Getting Started
1. Introduction
2. A simple tutorial
II. Installation and Configuration
3. General Installation Considerations
4. Installation on Unix systems
5. Installation on Mac OS X
6. Installation on Windows systems
7. Installation of PECL extensions
8. Problems?
9. Runtime Configuration
III. Language Reference
10. Basic syntax
11. Types
12. Variables
13. Constants
14. Expressions
15. Operators
16. Control Structures
17. Functions
18. Classes and Objects (PHP 4)
19. Classes and Objects (PHP 5)
20. Exceptions
21. References Explained
IV. Security
22. Introduction
23. General considerations
24. Installed as CGI binary
25. Installed as an Apache module
26. Filesystem Security
27. Database Security
28. Error Reporting
29. Using Register Globals
30. User Submitted Data
31. Magic Quotes
32. Hiding PHP
33. Keeping Current
V. Features
34. HTTP authentication with PHP
35. Cookies
36. Sessions
37. Dealing with XForms
38. Handling file uploads
39. Using remote files
40. Connection handling
41. Persistent Database Connections
42. Safe Mode
43. Using PHP from the command line
VI. Function Reference
I. Apache-specific Functions
II. Advanced PHP debugger
III. Array Functions
IV. Aspell functions [deprecated]
V. BCMath Arbitrary Precision Mathematics Functions
VI. PHP bytecode Compiler
VII. Bzip2 Compression Functions
VIII. Calendar Functions
IX. CCVS API Functions [deprecated]
X. Classkit Functions
XI. Class/Object Functions
XII. COM and .Net (Windows)
XIII. ClibPDF Functions
XIV. Crack Functions
XV. Character Type Functions
XVI. CURL, Client URL Library Functions
XVII. Cybercash Payment Functions
XVIII. Cyrus IMAP administration Functions
XIX. Date and Time Functions
XX. Database (dbm-style) Abstraction Layer Functions
XXI. dBase Functions
XXII. DBM Functions [deprecated]
XXIII. DB++ Functions
XXIV. dbx Functions
XXV. Direct IO Functions
XXVI. Directory Functions
XXVII. DOM Functions
XXVIII. DOM XML Functions
XXIX. .NET Functions
XXX. Error Handling and Logging Functions
XXXI. Program Execution Functions
XXXII. Exif Functions
XXXIII. File Alteration Monitor Functions
XXXIV. FrontBase Functions
XXXV. Forms Data Format Functions
XXXVI. filePro Functions
XXXVII. Filesystem Functions
XXXVIII. FriBiDi Functions
XXXIX. FTP Functions
XL. Function Handling Functions
XLI. Gettext
XLII. GMP Functions
XLIII. HTTP Functions
XLIV. Hyperwave Functions
XLV. Hyperwave API Functions
XLVI. Firebird/InterBase Functions
XLVII. ICAP Functions [deprecated]
XLVIII. iconv Functions
XLIX. ID3 Functions
L. Informix Functions
LI. IIS Administration Functions
LII. Image Functions
LIII. IMAP, POP3 and NNTP Functions
LIV. PHP Options&Information
LV. Ingres II Functions
LVI. IRC Gateway Functions
LVII. PHP / Java Integration
LVIII. LDAP Functions
LIX. LZF Functions
LX. Mail Functions
LXI. mailparse Functions
LXII. Mathematical Functions
LXIII. MaxDB PHP Extension
LXIV. Multibyte String Functions
LXV. MCAL Functions
LXVI. Mcrypt Encryption Functions
LXVII. MCVE Payment Functions
LXVIII. Memcache Functions
LXIX. Mhash Functions
LXX. Mimetype Functions
LXXI. Ming functions for Flash
LXXII. Miscellaneous Functions
LXXIII. mnoGoSearch Functions
LXXIV. Mohawk Software Session Handler Functions
LXXV. mSQL Functions
LXXVI. Microsoft SQL Server Functions
LXXVII. muscat Functions
LXXVIII. MySQL Functions
LXXIX. Improved MySQL Extension
LXXX. Ncurses Terminal Screen Control Functions
LXXXI. Network Functions
LXXXII. YP/NIS Functions
LXXXIII. Lotus Notes Functions
LXXXIV. NSAPI-specific Functions
LXXXV. Object Aggregation/Composition Functions
LXXXVI. Oracle 8 functions
LXXXVII. OpenAL Audio Bindings
LXXXVIII. OpenSSL Functions
LXXXIX. Oracle Functions
XC. Output Control Functions
XCI. Object property and method call overloading
XCII. Ovrimos SQL Functions
XCIII. Parsekit Functions
XCIV. Process Control Functions
XCV. Regular Expression Functions (Perl-Compatible)
XCVI. PDF functions
XCVII. PDO Functions
XCVIII. Verisign Payflow Pro Functions
XCIX. PostgreSQL Functions
C. POSIX Functions
CI. Printer Functions
CII. Pspell Functions
CIII. qtdom Functions
CIV. Rar Functions
CV. GNU Readline
CVI. GNU Recode Functions
CVII. Regular Expression Functions (POSIX Extended)
CVIII. Semaphore, Shared Memory and IPC Functions
CIX. SESAM Database Functions
CX. Session Handling Functions
CXI. Shared Memory Functions
CXII. SimpleXML functions
CXIII. SNMP Functions
CXIV. SOAP Functions
CXV. Socket Functions
CXVI. Standard PHP Library (SPL) Functions
CXVII. SQLite Functions
CXVIII. Secure Shell2 Functions
CXIX. Stream Functions
CXX. String Functions
CXXI. Shockwave Flash Functions
CXXII. Sybase Functions
CXXIII. TCP Wrappers Functions
CXXIV. Tidy Functions
CXXV. Tokenizer Functions
CXXVI. ODBC Functions (Unified)
CXXVII. URL Functions
CXXVIII. Variable Handling Functions
CXXIX. vpopmail Functions
CXXX. W32api Functions
CXXXI. WDDX Functions
CXXXII. xattr Functions
CXXXIII. xdiff Functions
CXXXIV. XML Parser Functions
CXXXV. XML-RPC Functions
CXXXVI. XSL functions
CXXXVII. XSLT Functions
CXXXVIII. YAZ Functions
CXXXIX. Zip File Functions (Read Only Access)
CXL. Zlib Compression Functions
VII. Zend API
44. Overview
45. Extension Possibilities
46. Source Layout
47. PHP's Automatic Build System
48. Creating Extensions
49. Using Extensions
50. Troubleshooting
51. Source Discussion
52. Accepting Arguments
53. Creating Variables
54. Duplicating Variable Contents: The Copy Constructor
55. Returning Values
56. Printing Information
57. Startup and Shutdown Functions
58. Calling User Functions
59. Initialization File Support
60. Where to Go from Here
61. Reference: Some Configuration Macros
62. API Macros
VIII. PHP API: Interfaces for extension writers
63. Streams API for PHP Extension Authors
IX. FAQ: Frequently Asked Questions
64. General Information
65. Mailing lists
66. Obtaining PHP
67. Database issues
68. Installation
69. Build Problems
70. Using PHP
71. PHP and HTML
72. PHP and COM
73. PHP and other languages
74. Migrating from PHP 2 to PHP 3
75. Migrating from PHP 3 to PHP 4
76. Migrating from PHP 4 to PHP 5
77. Miscellaneous Questions
X. Appendixes
A. History of PHP and related projects
B. Migrating from PHP 4 to PHP 5
C. Migrating from PHP 3 to PHP 4
D. Migrating from PHP/FI 2 to PHP 3
E. Debugging PHP
F. Extending PHP 3
G. Configure options
H. php.ini directives
I. List of Function Aliases
J. List of Reserved Words
K. List of Resource Types
L. List of Supported Protocols/Wrappers
M. List of Available Filters
N. List of Supported Socket Transports
O. PHP type comparison tables
P. List of Parser Tokens
Q. About the manual
R. Open Publication License
S. Function Index

Preface

PHP, which stands for "PHP: Hypertext Preprocessor" is a widely-used Open Source general-purpose scripting language that is especially suited for Web development and can be embedded into HTML. Its syntax draws upon C, Java, and Perl, and is easy to learn. The main goal of the language is to allow web developers to write dynamically generated webpages quickly, but you can do much more with PHP.

This manual consists primarily of a function reference, but also contains a language reference, explanations of some of PHP's major features, and other supplemental information.

You can download this manual in several formats at http://www.php.net/download-docs.php. More information about how this manual is developed can be found in the 'About the manual' appendix. If you are interested in the history of PHP, visit the relevant appendix.


Authors and Contributors

We highlight the currently most active people on the manual frontpage, but there are many more contributors who currently help in our work or provided a great amount of help to the project in the past. There are a lot of unnamed people who help out with their user notes on manual pages, which continually get included in the references, the work of whom we are also very thankful for. All the lists provided below are in alphabetical order.


Authors and Editors

The following contributors should be recognized for the impact they have made and/or continue to make by adding content to the manual: Jouni Ahto, Alexander Aulbach, Daniel Beckham, Stig Bakken, Jesus M. Castagnetto, Ron Chmara, John Coggeshall, Simone Cortesi, Markus Fischer, Wez Furlong, Sara Golemon, Rui Hirokawa, Brad House, Moriyoshi Koizumi, Rasmus Lerdorf, Andrew Lindeman, Stanislav Malyshev, Rafael Martinez, Yasuo Ohgaki, Derick Rethans, Sander Roobol, Egon Schmid, Thomas Schoefbeck, Sascha Schumann, Lars Torben Wilson, Jim Winstead, Jeroen van Wolffelaar and Andrei Zmievski.

The following contributors have done significant work editing the manual: Stig Bakken, Hartmut Holzgraefe and Egon Schmid.


User Note Maintainers

The currently most active maintainers are: Mehdi Achour, Friedhelm Betz, Vincent Gevers, Aidan Lister, Nuno Lopes and Tom Sommer.

These people have also put a lot of effort into managing user notes: Daniel Beckham, Victor Boivie, Jesus M. Castagnetto, Nicolas Chaillan, Ron Chmara, James Cox, Sara Golemon, Zak Greant, Szabolcs Heilig, Oliver Hinckel, Hartmut Holzgraefe, Rasmus Lerdorf, Andrew Lindeman, Maxim Maletsky, James Moore, Sebastian Picklum, Derick Rethans, Sander Roobol, Damien Seguy, Jason Sheets, Jani Taskinen, Yasuo Ohgaki, Philip Olson, Lars Torben Wilson, Jim Winstead, Jared Wyles and Jeroen van Wolffelaar.

I. Getting Started

Table of Contents
1. Introduction
2. A simple tutorial

Chapter 1. Introduction

What is PHP?

PHP (recursive acronym for "PHP: Hypertext Preprocessor") is a widely-used Open Source general-purpose scripting language that is especially suited for Web development and can be embedded into HTML.

Simple answer, but what does that mean? An example:

Example 1-1. An introductory example

<html>
    <head>
        <title>Example</title>
    </head>
    <body>

        <?php
        echo "Hi, I'm a PHP script!";
        ?>

    </body>
</html>

Notice how this is different from a script written in other languages like Perl or C -- instead of writing a program with lots of commands to output HTML, you write an HTML script with some embedded code to do something (in this case, output some text). The PHP code is enclosed in special start and end tags that allow you to jump into and out of "PHP mode".

What distinguishes PHP from something like client-side JavaScript is that the code is executed on the server. If you were to have a script similar to the above on your server, the client would receive the results of running that script, with no way of determining what the underlying code may be. You can even configure your web server to process all your HTML files with PHP, and then there's really no way that users can tell what you have up your sleeve.

The best things in using PHP are that it is extremely simple for a newcomer, but offers many advanced features for a professional programmer. Don't be afraid reading the long list of PHP's features. You can jump in, in a short time, and start writing simple scripts in a few hours.

Although PHP's development is focused on server-side scripting, you can do much more with it. Read on, and see more in the What can PHP do? section, or go right to the introductory tutorial if you are only interested in web programming.


What can PHP do?

Anything. PHP is mainly focused on server-side scripting, so you can do anything any other CGI program can do, such as collect form data, generate dynamic page content, or send and receive cookies. But PHP can do much more.

There are three main areas where PHP scripts are used.

  • Server-side scripting. This is the most traditional and main target field for PHP. You need three things to make this work. The PHP parser (CGI or server module), a webserver and a web browser. You need to run the webserver, with a connected PHP installation. You can access the PHP program output with a web browser, viewing the PHP page through the server. All these can run on your home machine if you are just experimenting with PHP programming. See the installation instructions section for more information.

  • Command line scripting. You can make a PHP script to run it without any server or browser. You only need the PHP parser to use it this way. This type of usage is ideal for scripts regularly executed using cron (on *nix or Linux) or Task Scheduler (on Windows). These scripts can also be used for simple text processing tasks. See the section about Command line usage of PHP for more information.

  • Writing desktop applications. PHP is probably not the very best language to create a desktop application with a graphical user interface, but if you know PHP very well, and would like to use some advanced PHP features in your client-side applications you can also use PHP-GTK to write such programs. You also have the ability to write cross-platform applications this way. PHP-GTK is an extension to PHP, not available in the main distribution. If you are interested in PHP-GTK, visit its own website.

PHP can be used on all major operating systems, including Linux, many Unix variants (including HP-UX, Solaris and OpenBSD), Microsoft Windows, Mac OS X, RISC OS, and probably others. PHP has also support for most of the web servers today. This includes Apache, Microsoft Internet Information Server, Personal Web Server, Netscape and iPlanet servers, Oreilly Website Pro server, Caudium, Xitami, OmniHTTPd, and many others. For the majority of the servers PHP has a module, for the others supporting the CGI standard, PHP can work as a CGI processor.

So with PHP, you have the freedom of choosing an operating system and a web server. Furthermore, you also have the choice of using procedural programming or object oriented programming, or a mixture of them. Although not every standard OOP feature is implemented in PHP 4, many code libraries and large applications (including the PEAR library) are written only using OOP code. PHP 5 fixes the OOP related weaknesses of PHP 4, and introduces a complete object model.

With PHP you are not limited to output HTML. PHP's abilities includes outputting images, PDF files and even Flash movies (using libswf and Ming) generated on the fly. You can also output easily any text, such as XHTML and any other XML file. PHP can autogenerate these files, and save them in the file system, instead of printing it out, forming a server-side cache for your dynamic content.

One of the strongest and most significant features in PHP is its support for a wide range of databases. Writing a database-enabled web page is incredibly simple. The following databases are currently supported:

Adabas DInterBasePostgreSQL
dBaseFrontBaseSQLite
EmpressmSQLSolid
FilePro (read-only)Direct MS-SQLSybase
HyperwaveMySQLVelocis
IBM DB2ODBCUnix dbm
InformixOracle (OCI7 and OCI8) 
IngresOvrimos 

We also have a DBX database abstraction extension allowing you to transparently use any database supported by that extension. Additionally PHP supports ODBC, the Open Database Connection standard, so you can connect to any other database supporting this world standard.

PHP also has support for talking to other services using protocols such as LDAP, IMAP, SNMP, NNTP, POP3, HTTP, COM (on Windows) and countless others. You can also open raw network sockets and interact using any other protocol. PHP has support for the WDDX complex data exchange between virtually all Web programming languages. Talking about interconnection, PHP has support for instantiation of Java objects and using them transparently as PHP objects. You can also use our CORBA extension to access remote objects.

PHP has extremely useful text processing features, from the POSIX Extended or Perl regular expressions to parsing XML documents. For parsing and accessing XML documents, PHP 4 supports the SAX and DOM standards, and you can also use the XSLT extension to transform XML documents. PHP 5 standardizes all the XML extensions on the solid base of libxml2 and extends the feature set adding SimpleXML and XMLReader support.

While using PHP in the e-commerce field, you'll find the Cybercash payment, CyberMUT, VeriSign Payflow Pro and MCVE functions useful for your online payment programs.

At last but not least, we have many other interesting extensions, the mnoGoSearch search engine functions, the IRC Gateway functions, many compression utilities (gzip, bz2), calendar conversion, translation...

As you can see this page is not enough to list all the features and benefits PHP can offer. Read on in the sections about installing PHP, and see the function reference part for explanation of the extensions mentioned here.


Chapter 2. A simple tutorial

Here we would like to show the very basics of PHP in a short, simple tutorial. This text only deals with dynamic webpage creation with PHP, though PHP is not only capable of creating webpages. See the section titled What can PHP do for more information.

PHP-enabled web pages are treated just like regular HTML pages and you can create and edit them the same way you normally create regular HTML pages.


What do I need?

In this tutorial we assume that your server has activated support for PHP and that all files ending in .php are handled by PHP. On most servers, this is the default extension for PHP files, but ask your server administrator to be sure. If your server supports PHP, then you do not need to do anything. Just create your .php files, put them in your web directory and the server will automatically parse them for you. There is no need to compile anything nor do you need to install any extra tools. Think of these PHP-enabled files as simple HTML files with a whole new family of magical tags that let you do all sorts of things. Most web hosts offer PHP support, but if your host does not, consider reading the PHP Links section for resources on finding PHP enabled web hosts.

Let us say you want to save precious bandwidth and develop locally. In this case, you will want to install a web server, such as Apache, and of course PHP. You will most likely want to install a database as well, such as MySQL.

You can either install these individually or choose a simpler way. Our manual has installation instructions for PHP (assuming you already have some webserver set up). In case you have problems with installing PHP yourself, we would suggest you ask your questions on our installation mailing list. If you choose to go on the simpler route, then locate a pre-configured package for your operating system, which automatically installs all of these with just a few mouse clicks. It is easy to setup a web server with PHP support on any operating system, including MacOSX, Linux and Windows. On Linux, you may find rpmfind and PBone helpful for locating RPMs. You may also want to visit apt-get to find packages for Debian.


Your first PHP-enabled page

Create a file named hello.php and put it in your web server's root directory (DOCUMENT_ROOT) with the following content:

Example 2-1. Our first PHP script: hello.php

<html>
 <head>
  <title>PHP Test</title>
 </head>
 <body>
 <?php echo '<p>Hello World</p>'; ?>
 </body>
</html>

Use your browser to access the file with your web server's URL, ending with the "/hello.php" file reference. When developing locally this URL will be something like http://localhost/hello.php or http://127.0.0.1/hello.php but this depends on the web server's configuration. If everything is configured correctly, this file will be parsed by PHP and the following output will be sent to your browser:

<html>
 <head>
  <title>PHP Test</title>
 </head>
 <body>
 <p>Hello World</p>
 </body>
</html>

This program is extremely simple and you really did not need to use PHP to create a page like this. All it does is display: Hello World using the PHP echo() statement. Note that the file does not need to be executable or special in any way. The server finds out that this file needs to be interpreted by PHP because you used the ".php" extension, which the server is configured to pass on to PHP. Think of this as a normal HTML file which happens to have a set of special tags available to you that do a lot of interesting things.

If you tried this example and it did not output anything, it prompted for download, or you see the whole file as text, chances are that the server you are on does not have PHP enabled, or is not configured properly. Ask your administrator to enable it for you using the Installation chapter of the manual. If you are developing locally, also read the installation chapter to make sure everything is configured properly. Make sure that you access the file via http with the server providing you the output. If you just call up the file from your file system, then it will not be parsed by PHP. If the problems persist anyway, do not hesitate to use one of the many PHP support options.

The point of the example is to show the special PHP tag format. In this example we used <?php to indicate the start of a PHP tag. Then we put the PHP statement and left PHP mode by adding the closing tag, ?>. You may jump in and out of PHP mode in an HTML file like this anywhere you want. For more details, read the manual section on the basic PHP syntax.

A Note on Text Editors: There are many text editors and Integrated Development Environments (IDEs) that you can use to create, edit and manage PHP files. A partial list of these tools is maintained at PHP Editors List. If you wish to recommend an editor, please visit the above page and ask the page maintainer to add the editor to the list. Having an editor with syntax highlighting can be helpful.

A Note on Word Processors: Word processors such as StarOffice Writer, Microsoft Word and Abiword are not optimal for editing PHP files. If you wish to use one for this test script, you must ensure that you save the file as plain text or PHP will not be able to read and execute the script.

A Note on Windows Notepad: If you are writing your PHP scripts using Windows Notepad, you will need to ensure that your files are saved with the .php extension. (Notepad adds a .txt extension to files automatically unless you take one of the following steps to prevent it.) When you save the file and are prompted to provide a name for the file, place the filename in quotes (i.e. "hello.php"). Alternatively, you can click on the 'Text Documents' drop-down menu in the 'Save' dialog box and change the setting to "All Files". You can then enter your filename without quotes.

Now that you have successfully created a working PHP script, it is time to create the most famous PHP script! Make a call to the phpinfo() function and you will see a lot of useful information about your system and setup such as available predefined variables, loaded PHP modules, and configuration settings. Take some time and review this important information.

Example 2-2. Get system information from PHP

<?php phpinfo(); ?>


Something Useful

Let us do something more useful now. We are going to check what sort of browser the visitor is using. For that, we check the user agent string the browser sends as part of the HTTP request. This information is stored in a variable. Variables always start with a dollar-sign in PHP. The variable we are interested in right now is $_SERVER['HTTP_USER_AGENT'].

Note: $_SERVER is a special reserved PHP variable that contains all web server information. It is known as an autoglobal (or superglobal). See the related manual page on superglobals for more information. These special variables were introduced in PHP 4.1.0. Before this time, we used the older $HTTP_*_VARS arrays instead, such as $HTTP_SERVER_VARS. Although deprecated, these older variables still exist. (See also the note on old code.)

To display this variable, you can simply do:

Example 2-3. Printing a variable (Array element)

<?php echo $_SERVER['HTTP_USER_AGENT']; ?>

A sample output of this script may be:

Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)

There are many types of variables available in PHP. In the above example we printed an Array element. Arrays can be very useful.

$_SERVER is just one variable that PHP automatically makes available to you. A list can be seen in the Reserved Variables section of the manual or you can get a complete list of them by looking at the output of the phpinfo() function used in the example in the previous section.

You can put multiple PHP statements inside a PHP tag and create little blocks of code that do more than just a single echo. For example, if you want to check for Internet Explorer you can do this:

Example 2-4. Example using control structures and functions

<?php
if (strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE') !== FALSE) {
    echo 'You are using Internet Explorer.<br />';
}
?>

A sample output of this script may be:

You are using Internet Explorer.<br />

Here we introduce a couple of new concepts. We have an if statement. If you are familiar with the basic syntax used by the C language, this should look logical to you. Otherwise, you should probably pick up an introductory PHP book and read the first couple of chapters, or read the Language Reference part of the manual. You can find a list of PHP books at http://www.php.net/books.php.

The second concept we introduced was the strpos() function call. strpos() is a function built into PHP which searches a string for another string. In this case we are looking for 'MSIE' (so-called needle) inside $_SERVER['HTTP_USER_AGENT'] (so-called haystack). If the needle is found inside the haystack, the function returns the position of the needle relative to the start of the haystack. Otherwise, it returns FALSE. If it does not return FALSE, the if expression evaluates to TRUE and the code within its {braces} is executed. Otherwise, the code is not run. Feel free to create similar examples, with if, else, and other functions such as strtoupper() and strlen(). Each related manual page contains examples too. If you are unsure how to use functions, you will want to read both the manual page on how to read a function definition and the section about PHP functions.

We can take this a step further and show how you can jump in and out of PHP mode even in the middle of a PHP block:

Example 2-5. Mixing both HTML and PHP modes

<?php
if (strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE') !== FALSE) {
?>
<h3>strpos() must have returned non-false</h3>
<p>You are using Internet Explorer</p>
<?php
} else {
?>
<h3>strpos() must have returned false</h3>
<p>You are not using Internet Explorer</p>
<?php
}
?>

A sample output of this script may be:

<h3>strpos() must have returned non-false</h3>
<p>You are using Internet Explorer</p>

Instead of using a PHP echo statement to output something, we jumped out of PHP mode and just sent straight HTML. The important and powerful point to note here is that the logical flow of the script remains intact. Only one of the HTML blocks will end up getting sent to the viewer depending on the result of strpos(). In other words, it depends on whether the string MSIE was found or not.


Dealing with Forms

One of the most powerful features of PHP is the way it handles HTML forms. The basic concept that is important to understand is that any form element will automatically be available to your PHP scripts. Please read the manual section on Variables from outside of PHP for more information and examples on using forms with PHP. Here is an example HTML form:

Example 2-6. A simple HTML form

<form action="action.php" method="post">
 <p>Your name: <input type="text" name="name" /></p>
 <p>Your age: <input type="text" name="age" /></p>
 <p><input type="submit" /></p>
</form>

There is nothing special about this form. It is a straight HTML form with no special tags of any kind. When the user fills in this form and hits the submit button, the action.php page is called. In this file you would write something like this:

Example 2-7. Printing data from our form

Hi <?php echo $_POST['name']; ?>.
You are <?php echo $_POST['age']; ?> years old.

A sample output of this script may be:

Hi Joe. You are 22 years old.

It should be obvious what this does. There is nothing more to it. The $_POST['name'] and $_POST['age'] variables are automatically set for you by PHP. Earlier we used the $_SERVER autoglobal; above we just introduced the $_POST autoglobal which contains all POST data. Notice how the method of our form is POST. If we used the method GET then our form information would live in the $_GET autoglobal instead. You may also use the $_REQUEST autoglobal, if you do not care about the source of your request data. It contains the merged information of GET, POST and COOKIE data. Also see the import_request_variables() function.

You can also deal with XForms input in PHP, although you will find yourself comfortable with the well supported HTML forms for quite some time. While working with XForms is not for beginners, you might be interested in them. We also have a short introduction to handling data received from XForms in our features section.


Using old code with new versions of PHP

Now that PHP has grown to be a popular scripting language, there are a lot of public repositories and libraries containing code you can reuse. The PHP developers have largely tried to preserve backwards compatibility, so a script written for an older version will run (ideally) without changes in a newer version of PHP. In practice, some changes will usually be needed.

Two of the most important recent changes that affect old code are:

  • The deprecation of the old $HTTP_*_VARS arrays (which need to be indicated as global when used inside a function or method). The following autoglobal arrays were introduced in PHP 4.1.0. They are: $_GET, $_POST, $_COOKIE, $_SERVER, $_FILES, $_ENV, $_REQUEST, and $_SESSION. The older $HTTP_*_VARS arrays, such as $HTTP_POST_VARS, still exist as they have since PHP 3. As of PHP 5.0.0, the long PHP predefined variable arrays may be disabled with the register_long_arrays directive.

  • External variables are no longer registered in the global scope by default. In other words, as of PHP 4.2.0 the PHP directive register_globals is off by default in php.ini. The preferred method of accessing these values is via the autoglobal arrays mentioned above. Older scripts, books, and tutorials may rely on this directive being on. If it were on, for example, one could use $id from the URL http://www.example.com/foo.php?id=42. Whether on or off, $_GET['id'] is available.

For more details on these changes, see the section on predefined variables and links therein.


What's next?

With your new knowledge you should be able to understand most of the manual and also the various example scripts available in the example archives. You can also find other examples on the php.net websites in the links section: http://www.php.net/links.php.

To view various slide presentations that show more of what PHP can do, see the PHP Conference Material Sites: http://conf.php.net/ and http://talks.php.net/


Chapter 3. General Installation Considerations

Before starting the installation, first you need to know what do you want to use PHP for. There are three main fields you can use PHP, as described in the What can PHP do? section:

  • Server-side scripting

  • Command line scripting

  • Client-side GUI applications

For the first and most common form, you need three things: PHP itself, a web server and a web browser. You probably already have a web browser, and depending on your operating system setup, you may also have a web server (e.g. Apache on Linux and MacOS X; IIS on Windows). You may also rent webspace at a company. This way, you don't need to set up anything on your own, only write your PHP scripts, upload it to the server you rent, and see the results in your browser.

While setting up the server and PHP on your own, you have two choices for the method of connecting PHP to the server. For many servers PHP has a direct module interface (also called SAPI). These servers include Apache, Microsoft Internet Information Server, Netscape and iPlanet servers. Many other servers have support for ISAPI, the Microsoft module interface (OmniHTTPd for example). If PHP has no module support for your web server, you can always use it as a CGI or FastCGI processor. This means you set up your server to use the CGI executable of PHP to process all PHP file requests on the server.

If you are also interested to use PHP for command line scripting (e.g. write scripts autogenerating some images for you offline, or processing text files depending on some arguments you pass to them), you always need the command line executable. For more information, read the section about writing command line PHP applications. In this case, you need no server and no browser.

With PHP you can also write desktop GUI applications using the PHP-GTK extension. This is a completely different approach than writing web pages, as you do not output any HTML, but manage windows and objects within them. For more information about PHP-GTK, please visit the site dedicated to this extension. PHP-GTK is not included in the official PHP distribution.

From now on, this section deals with setting up PHP for web servers on Unix and Windows with server module interfaces and CGI executables. You will also find information on the command line executable in the following sections.

PHP source code and binary distributions for Windows can be found at http://www.php.net/downloads.php. We recommend you to choose a mirror nearest to you for downloading the distributions.


Chapter 4. Installation on Unix systems

This section will guide you through the general configuration and installation of PHP on Unix systems. Be sure to investigate any sections specific to your platform or web server before you begin the process.

As our manual outlines in the General Installation Considerations section, we are mainly dealing with web centric setups of PHP in this section, although we will cover setting up PHP for command line usage as well.

There are several ways to install PHP for the Unix platform, either with a compile and configure process, or through various pre-packaged methods. This documentation is mainly focused around the process of compiling and configuring PHP. Many Unix like systems have some sort of package installation system. This can assist in setting up a standard configuration, but if you need to have a different set of features (such as a secure server, or a different database driver), you may need to build PHP and/or your webserver. If you are unfamiliar with building and compiling your own software, it is worth checking to see whether somebody has already built a packaged version of PHP with the features you need.

Prerequisite knowledge and software for compiling:

  • Basic Unix skills (being able to operate "make" and a C compiler)

  • An ANSI C compiler

  • flex: Version 2.5.4

  • bison: Version 1.28 (preferred), 1.35, or 1.75

  • A web server

  • Any module specific components (such as gd, pdf libs, etc.)

The initial PHP setup and configuration process is controlled by the use of the commandline options of the configure script. You could get a list of all available options along with short explanations running ./configure --help. Our manual documents the different options separately. You will find the core options in the appendix, while the different extension specific options are descibed on the reference pages.

When PHP is configured, you are ready to build the module and/or executables. The command make should take care of this. If it fails and you can't figure out why, see the Problems section.


Apache 1.3.x on Unix systems

This section contains notes and hints specific to Apache installs of PHP on Unix platforms. We also have instructions and notes for Apache 2 on a separate page.

You can select arguments to add to the configure on line 10 below from the list of core configure options and from extension specific options described at the respective places in the manual. The version numbers have been omitted here, to ensure the instructions are not incorrect. You will need to replace the 'xxx' here with the correct values from your files.

Example 4-1. Installation Instructions (Apache Shared Module Version) for PHP

1.  gunzip apache_xxx.tar.gz
2.  tar -xvf apache_xxx.tar
3.  gunzip php-xxx.tar.gz
4.  tar -xvf php-xxx.tar
5.  cd apache_xxx
6.  ./configure --prefix=/www --enable-module=so
7.  make
8.  make install
9.  cd ../php-xxx

10. Now, configure your PHP.  This is where you customize your PHP
    with various options, like which extensions will be enabled.  Do a
    ./configure --help for a list of available options.  In our example
    we'll do a simple configure with Apache 1 and MySQL support.  Your
    path to apxs may differ from our example.

      ./configure --with-mysql --with-apxs=/www/bin/apxs

11. make
12. make install

    If you decide to change your configure options after installation,
    you only need to repeat the last three steps. You only need to
    restart apache for the new module to take effect. A recompile of
    Apache is not needed.

    Note that unless told otherwise, 'make install' will also install PEAR,
    various PHP tools such as phpize, install the PHP CLI, and more.

13. Setup your php.ini file:

      cp php.ini-dist /usr/local/lib/php.ini

    You may edit your .ini file to set PHP options.  If you prefer your
    php.ini in another location, use --with-config-file-path=/some/path in
    step 10.

    If you instead choose php.ini-recommended, be certain to read the list
    of changes within, as they affect how PHP behaves.

14. Edit your httpd.conf to load the PHP module.  The path on the right hand
    side of the LoadModule statement must point to the path of the PHP
    module on your system.  The make install from above may have already
    added this for you, but be sure to check.

    For PHP 4:

      LoadModule php4_module libexec/libphp4.so

    For PHP 5:

      LoadModule php5_module libexec/libphp5.so

15. And in the AddModule section of httpd.conf, somewhere under the
    ClearModuleList, add this:

    For PHP 4:

      AddModule mod_php4.c

    For PHP 5:

      AddModule mod_php5.c

16. Tell Apache to parse certain extensions as PHP.  For example,
    let's have Apache parse the .php extension as PHP.  You could
    have any extension(s) parse as PHP by simply adding more, with
    each separated by a space.  We'll add .phtml to demonstrate.

      AddType application/x-httpd-php .php .phtml

    It's also common to setup the .phps extension to show highlighted PHP
    source, this can be done with:

      AddType application/x-httpd-php-source .phps

17. Use your normal procedure for starting the Apache server. (You must
    stop and restart the server, not just cause the server to reload by
    using a HUP or USR1 signal.)

Alternatively, to install PHP as a static object:

Example 4-2. Installation Instructions (Static Module Installation for Apache) for PHP

1.  gunzip -c apache_1.3.x.tar.gz | tar xf -
2.  cd apache_1.3.x
3.  ./configure
4.  cd ..

5.  gunzip -c php-4.x.y.tar.gz | tar xf -
6.  cd php-4.x.y
7.  ./configure --with-mysql --with-apache=../apache_1.3.x
8.  make
9.  make install

10. cd ../apache_1.3.x

11. ./configure --prefix=/www --activate-module=src/modules/php4/libphp4.a
    (The above line is correct! Yes, we know libphp4.a does not exist at this
    stage. It isn't supposed to. It will be created.)

12. make
    (you should now have an httpd binary which you can copy to your Apache bin dir if
    is is your first install then you need to "make install" as well)

13. cd ../php-4.x.y
14. cp php.ini-dist /usr/local/lib/php.ini

15. You can edit /usr/local/lib/php.ini file to set PHP options.
    Edit your httpd.conf or srm.conf file and add:
    AddType application/x-httpd-php .php

Depending on your Apache install and Unix variant, there are many possible ways to stop and restart the server. Below are some typical lines used in restarting the server, for different apache/unix installations. You should replace /path/to/ with the path to these applications on your systems.

Example 4-3. Example commands for restarting Apache

1. Several Linux and SysV variants:
/etc/rc.d/init.d/httpd restart

2. Using apachectl scripts:
/path/to/apachectl stop
/path/to/apachectl start

3. httpdctl and httpsdctl (Using OpenSSL), similar to apachectl:
/path/to/httpsdctl stop
/path/to/httpsdctl start

4. Using mod_ssl, or another SSL server, you may want to manually
stop and start:
/path/to/apachectl stop
/path/to/apachectl startssl

The locations of the apachectl and http(s)dctl binaries often vary. If your system has locate or whereis or which commands, these can assist you in finding your server control programs.

Different examples of compiling PHP for apache are as follows:

./configure --with-apxs --with-pgsql

This will create a libphp4.so shared library that is loaded into Apache using a LoadModule line in Apache's httpd.conf file. The PostgreSQL support is embedded into this libphp4.so library.

./configure --with-apxs --with-pgsql=shared

This will create a libphp4.so shared library for Apache, but it will also create a pgsql.so shared library that is loaded into PHP either by using the extension directive in php.ini file or by loading it explicitly in a script using the dl() function.

./configure --with-apache=/path/to/apache_source --with-pgsql

This will create a libmodphp4.a library, a mod_php4.c and some accompanying files and copy this into the src/modules/php4 directory in the Apache source tree. Then you compile Apache using --activate-module=src/modules/php4/libphp4.a and the Apache build system will create libphp4.a and link it statically into the httpd binary. The PostgreSQL support is included directly into this httpd binary, so the final result here is a single httpd binary that includes all of Apache and all of PHP.

./configure --with-apache=/path/to/apache_source --with-pgsql=shared

Same as before, except instead of including PostgreSQL support directly into the final httpd you will get a pgsql.so shared library that you can load into PHP from either the php.ini file or directly using dl().

When choosing to build PHP in different ways, you should consider the advantages and drawbacks of each method. Building as a shared object will mean that you can compile apache separately, and don't have to recompile everything as you add to, or change, PHP. Building PHP into apache (static method) means that PHP will load and run faster. For more information, see the Apache webpage on DSO support.

Note: Apache's default httpd.conf currently ships with a section that looks like this:

User nobody
Group "#-1"

Unless you change that to "Group nogroup" or something like that ("Group daemon" is also very common) PHP will not be able to open files.

Note: Make sure you specify the installed version of apxs when using --with-apxs=/path/to/apxs. You must NOT use the apxs version that is in the apache sources but the one that is actually installed on your system.


Apache 2.0 on Unix systems

This section contains notes and hints specific to Apache 2.0 installs of PHP on Unix systems.

Warning

We do not recommend using a threaded MPM in production with Apache2. Use the prefork MPM instead, or use Apache1. For information on why, read the following FAQ entry

You are highly encouraged to take a look at the Apache Documentation to get a basic understanding of the Apache 2.0 Server.

PHP and Apache 2.0.x compatibility notes: The following versions of PHP are known to work with the most recent version of Apache 2.0.x:

These versions of PHP are compatible to Apache 2.0.40 and later.

Apache 2.0 SAPI-support started with PHP 4.2.0. PHP 4.2.3 works with Apache 2.0.39, don't use any other version of Apache with PHP 4.2.3. However, the recommended setup is to use PHP 4.3.0 or later with the most recent version of Apache2.

All mentioned versions of PHP will work still with Apache 1.3.x.

Download the most recent version of Apache 2.0 and a fitting PHP version from the above mentioned places. This quick guide covers only the basics to get started with Apache 2.0 and PHP. For more information read the Apache Documentation. The version numbers have been omitted here, to ensure the instructions are not incorrect. You will need to replace the 'NN' here with the correct values from your files.

Example 4-4. Installation Instructions (Apache 2 Shared Module Version)

1.  gzip -d httpd-2_0_NN.tar.gz
2.  tar xvf httpd-2_0_NN.tar
3.  gunzip php-NN.tar.gz
4.  tar -xvf php-NN.tar
5.  cd httpd-2_0_NN
6.  ./configure --enable-so
7.  make
8.  make install

    Now you have Apache 2.0.NN available under /usr/local/apache2,
    configured with loadable module support and the standard MPM prefork.
    To test the installation use your normal procedure for starting
    the Apache server, e.g.:
    /usr/local/apache2/bin/apachectl start
    and stop the server to go on with the configuration for PHP:
    /usr/local/apache2/bin/apachectl stop.

9.  cd ../php-NN

10. Now, configure your PHP.  This is where you customize your PHP
    with various options, like which extensions will be enabled.  Do a
    ./configure --help for a list of available options.  In our example
    we'll do a simple configure with Apache 2 and MySQL support.  Your
    path to apxs may differ, in fact, the binary may even be named apxs2 on
    your system.

      ./configure --with-apxs2=/usr/local/apache2/bin/apxs --with-mysql

11. make
12. make install

    If you decide to change your configure options after installation,
    you only need to repeat the last three steps. You only need to
    restart apache for the new module to take effect. A recompile of
    Apache is not needed.

    Note that unless told otherwise, 'make install' will also install PEAR,
    various PHP tools such as phpize, install the PHP CLI, and more.

13. Setup your php.ini

    cp php.ini-dist /usr/local/lib/php.ini

    You may edit your .ini file to set PHP options.  If you prefer having
    php.ini in another location, use --with-config-file-path=/some/path in
    step 10.

    If you instead choose php.ini-recommended, be certain to read the list
    of changes within, as they affect how PHP behaves.

14. Edit your httpd.conf to load the PHP module.  The path on the right hand
    side of the LoadModule statement must point to the path of the PHP
    module on your system.  The make install from above may have already
    added this for you, but be sure to check.

    For PHP 4:

      LoadModule php4_module libexec/libphp4.so

    For PHP 5:

      LoadModule php5_module libexec/libphp5.so

15. Tell Apache to parse certain extensions as PHP.  For example,
    let's have Apache parse the .php extension as PHP.  You could
    have any extension(s) parse as PHP by simply adding more, with
    each separated by a space.  We'll add .phtml to demonstrate.

      AddType application/x-httpd-php .php .phtml

    It's also common to setup the .phps extension to show highlighted PHP
    source, this can be done with:

      AddType application/x-httpd-php-source .phps

16. Use your normal procedure for starting the Apache server, e.g.:

      /usr/local/apache2/bin/apachectl start

Following the steps above you will have a running Apache 2.0 with support for PHP as SAPI module. Of course there are many more configuration options available for both, Apache and PHP. For more information use ./configure --help in the corresponding source tree. In case you wish to build a multithreaded version of Apache 2.0 you must overwrite the standard MPM-Module prefork either with worker or perchild. To do so append to your configure line in step 6 above either the option --with-mpm=worker or --with-mpm=perchild. Take care about the consequences and understand what you are doing. For more information read the Apache documentation about the MPM-Modules.

Note: If you want to use content negotiation, read related FAQ.

Note: To build a multithreaded version of Apache your system must support threads. This also implies to build PHP with experimental Zend Thread Safety (ZTS). Therefore not all extensions might be available. The recommended setup is to build Apache with the standard prefork MPM-Module.


Caudium

PHP 4 can be built as a Pike module for the Caudium webserver. Note that this is not supported with PHP 3. Follow the simple instructions below to install PHP 4 for Caudium.

Example 4-5. Caudium Installation Instructions

1.  Make sure you have Caudium installed prior to attempting to
    install PHP 4. For PHP 4 to work correctly, you will need Pike
    7.0.268 or newer. For the sake of this example we assume that
    Caudium is installed in /opt/caudium/server/.
2.  Change directory to php-x.y.z (where x.y.z is the version number).
3.  ./configure --with-caudium=/opt/caudium/server
4.  make
5.  make install
6.  Restart Caudium if it's currently running.
7.  Log into the graphical configuration interface and go to the
    virtual server where you want to add PHP 4 support.
8.  Click Add Module and locate and then add the PHP 4 Script Support module.
9.  If the documentation says that the 'PHP 4 interpreter isn't
    available', make sure that you restarted the server. If you did
    check /opt/caudium/logs/debug/default.1 for any errors related to
    <filename>PHP4.so</filename>. Also make sure that
    <filename>caudium/server/lib/[pike-version]/PHP4.so</filename>
    is present.
10. Configure the PHP Script Support module if needed.

You can of course compile your Caudium module with support for the various extensions available in PHP 4. See the reference pages for extension specific configure options.

Note: When compiling PHP 4 with MySQL support you must make sure that the normal MySQL client code is used. Otherwise there might be conflicts if your Pike already has MySQL support. You do this by specifying a MySQL install directory the --with-mysql option.


fhttpd related notes

To build PHP as an fhttpd module, answer "yes" to "Build as an fhttpd module?" (the --with-fhttpd=DIR option to configure) and specify the fhttpd source base directory. The default directory is /usr/local/src/fhttpd. If you are running fhttpd, building PHP as a module will give better performance, more control and remote execution capability.

Note: Support for fhttpd is no longer available as of PHP 4.3.0.


Sun, iPlanet and Netscape servers on Sun Solaris

This section contains notes and hints specific to Sun Java System Web Server, Sun ONE Web Server, iPlanet and Netscape server installs of PHP on Sun Solaris.

From PHP 4.3.3 on you can use PHP scripts with the NSAPI module to generate custom directory listings and error pages. Additional functions for Apache compatibility are also available. For support in current webservers read the note about subrequests.

You can find more information about setting up PHP for the Netscape Enterprise Server (NES) here: http://benoit.noss.free.fr/php/install-php4.html

To build PHP with Sun JSWS/Sun ONE WS/iPlanet/Netscape webservers, enter the proper install directory for the --with-nsapi=[DIR] option. The default directory is usually /opt/netscape/suitespot/. Please also read /php-xxx-version/sapi/nsapi/nsapi-readme.txt.

  1. Install the following packages from http://www.sunfreeware.com/ or another download site:

    autoconf-2.13
    automake-1.4
    bison-1_25-sol26-sparc-local
    flex-2_5_4a-sol26-sparc-local
    gcc-2_95_2-sol26-sparc-local
    gzip-1.2.4-sol26-sparc-local
    m4-1_4-sol26-sparc-local
    make-3_76_1-sol26-sparc-local
    mysql-3.23.24-beta (if you want mysql support)
    perl-5_005_03-sol26-sparc-local
    tar-1.13 (GNU tar)

  2. Make sure your path includes the proper directories PATH=.:/usr/local/bin:/usr/sbin:/usr/bin:/usr/ccs/bin and make it available to your system export PATH.

  3. gunzip php-x.x.x.tar.gz (if you have a .gz dist, otherwise go to 4).

  4. tar xvf php-x.x.x.tar

  5. Change to your extracted PHP directory: cd ../php-x.x.x

  6. For the following step, make sure /opt/netscape/suitespot/ is where your netscape server is installed. Otherwise, change to the correct path and run:
    ./configure --with-mysql=/usr/local/mysql \
    --with-nsapi=/opt/netscape/suitespot/ \
    --enable-libgcc

  7. Run make followed by make install.

After performing the base install and reading the appropriate readme file, you may need to perform some additional configuration steps.

Configuration Instructions for Sun/iPlanet/Netscape. Firstly you may need to add some paths to the LD_LIBRARY_PATH environment for the server to find all the shared libs. This can best done in the start script for your webserver. The start script is often located in: /path/to/server/https-servername/start. You may also need to edit the configuration files that are located in: /path/to/server/https-servername/config/.

  1. Add the following line to mime.types (you can do that by the administration server):
    type=magnus-internal/x-httpd-php exts=php

  2. Edit magnus.conf (for servers >= 6) or obj.conf (for servers < 6) and add the following, shlib will vary depending on your system, it will be something like /opt/netscape/suitespot/bin/libphp4.so. You should place the following lines after mime types init.
    Init fn="load-modules" funcs="php4_init,php4_execute,php4_auth_trans" shlib="/opt/netscape/suitespot/bin/libphp4.so"
    Init fn="php4_init" LateInit="yes" errorString="Failed to initialize PHP!" [php_ini="/path/to/php.ini"]
    (PHP >= 4.3.3) The php_ini parameter is optional but with it you can place your php.ini in your webserver config directory.

  3. Configure the default object in obj.conf (for virtual server classes [version 6.0+] in their vserver.obj.conf):
    <Object name="default">
    .
    .
    .
    .#NOTE this next line should happen after all 'ObjectType' and before all 'AddLog' lines
    Service fn="php4_execute" type="magnus-internal/x-httpd-php" [inikey=value inikey=value ...]
    .
    .
    </Object>
    (PHP >= 4.3.3) As additional parameters you can add some special php.ini-values, for example you can set a docroot="/path/to/docroot" specific to the context php4_execute is called. For boolean ini-keys please use 0/1 as value, not "On","Off",... (this will not work correctly), e.g. zlib.output_compression=1 instead of zlib.output_compression="On"

  4. This is only needed if you want to configure a directory that only consists of PHP scripts (same like a cgi-bin directory):
    <Object name="x-httpd-php">
    ObjectType fn="force-type" type="magnus-internal/x-httpd-php"
    Service fn=php4_execute [inikey=value inikey=value ...]
    </Object>
    After that you can configure a directory in the Administration server and assign it the style x-httpd-php. All files in it will get executed as PHP. This is nice to hide PHP usage by renaming files to .html.

  5. Setup of authentication: PHP authentication cannot be used with any other authentication. ALL AUTHENTICATION IS PASSED TO YOUR PHP SCRIPT. To configure PHP Authentication for the entire server, add the following line to your default object:
    <Object name="default">
    AuthTrans fn=php4_auth_trans
    .
    .
    .
    </Object>

  6. To use PHP Authentication on a single directory, add the following:
    <Object ppath="d:\path\to\authenticated\dir\*">
    AuthTrans fn=php4_auth_trans
    </Object>

Note: The stacksize that PHP uses depends on the configuration of the webserver. If you get crashes with very large PHP scripts, it is recommended to raise it with the Admin Server (in the section "MAGNUS EDITOR").


CGI environment and recommended modifications in php.ini

Important when writing PHP scripts is the fact that Sun JSWS/Sun ONE WS/iPlanet/Netscape is a multithreaded web server. Because of that all requests are running in the same process space (the space of the webserver itself) and this space has only one environment. If you want to get CGI variables like PATH_INFO, HTTP_HOST etc. it is not the correct way to try this in the old PHP 3.x way with getenv() or a similar way (register globals to environment, $_ENV). You would only get the environment of the running webserver without any valid CGI variables!

Note: Why are there (invalid) CGI variables in the environment?

Answer: This is because you started the webserver process from the admin server which runs the startup script of the webserver, you wanted to start, as a CGI script (a CGI script inside of the admin server!). This is why the environment of the started webserver has some CGI environment variables in it. You can test this by starting the webserver not from the administration server. Use the command line as root user and start it manually - you will see there are no CGI-like environment variables.

Simply change your scripts to get CGI variables in the correct way for PHP 4.x by using the superglobal $_SERVER. If you have older scripts which use $HTTP_HOST, etc., you should turn on register_globals in php.ini and change the variable order too (important: remove "E" from it, because you do not need the environment here):
variables_order = "GPCS"
register_globals = On


Special use for error pages or self-made directory listings (PHP >= 4.3.3)

You can use PHP to generate the error pages for "404 Not Found" or similar. Add the following line to the object in obj.conf for every error page you want to overwrite:
Error fn="php4_execute" code=XXX script="/path/to/script.php" [inikey=value inikey=value...]
where XXX is the HTTP error code. Please delete any other Error directives which could interfere with yours. If you want to place a page for all errors that could exist, leave the code parameter out. Your script can get the HTTP status code with $_SERVER['ERROR_TYPE'].

Another possibility is to generate self-made directory listings. Just create a PHP script which displays a directory listing and replace the corresponding default Service line for type="magnus-internal/directory" in obj.conf with the following:
Service fn="php4_execute" type="magnus-internal/directory" script="/path/to/script.php" [inikey=value inikey=value...]
For both error and directory listing pages the original URI and translated URI are in the variables $_SERVER['PATH_INFO'] and $_SERVER['PATH_TRANSLATED'].


Note about nsapi_virtual() and subrequests (PHP >= 4.3.3)

The NSAPI module now supports the nsapi_virtual() function (alias: virtual()) to make subrequests on the webserver and insert the result in the webpage. This function uses some undocumented features from the NSAPI library. On Unix the module automatically looks for the needed functions and uses them if available. If not, nsapi_virtual() is disabled.

Note: But be warned: Support for nsapi_virtual() is EXPERIMENTAL!!!


CGI and commandline setups

The default is to build PHP as a CGI program. This creates a commandline interpreter, which can be used for CGI processing, or for non-web-related PHP scripting. If you are running a web server PHP has module support for, you should generally go for that solution for performance reasons. However, the CGI version enables users to run different PHP-enabled pages under different user-ids.

Warning

By using the CGI setup, your server is open to several possible attacks. Please read our CGI security section to learn how to defend yourself from those attacks.

As of PHP 4.3.0, some important additions have happened to PHP. A new SAPI named CLI also exists and it has the same name as the CGI binary. What is installed at {PREFIX}/bin/php depends on your configure line and this is described in detail in the manual section named Using PHP from the command line. For further details please read that section of the manual.


Testing

If you have built PHP as a CGI program, you may test your build by typing make test. It is always a good idea to test your build. This way you may catch a problem with PHP on your platform early instead of having to struggle with it later.


Benchmarking

If you have built PHP 3 as a CGI program, you may benchmark your build by typing make bench. Note that if safe mode is on by default, the benchmark may not be able to finish if it takes longer then the 30 seconds allowed. This is because the set_time_limit() can not be used in safe mode. Use the max_execution_time configuration setting to control this time for your own scripts. make bench ignores the configuration file.

Note: make bench is only available for PHP 3.


Using Variables

Some server supplied environment variables are not defined in the current CGI/1.1 specification. Only the following variables are defined there: AUTH_TYPE, CONTENT_LENGTH, CONTENT_TYPE, GATEWAY_INTERFACE, PATH_INFO, PATH_TRANSLATED, QUERY_STRING, REMOTE_ADDR, REMOTE_HOST, REMOTE_IDENT, REMOTE_USER, REQUEST_METHOD, SCRIPT_NAME, SERVER_NAME, SERVER_PORT, SERVER_PROTOCOL, and SERVER_SOFTWARE. Everything else should be treated as 'vendor extensions'.


HP-UX specific installation notes

This section contains notes and hints specific to installing PHP on HP-UX systems. (Contributed by paul_mckay at clearwater-it dot co dot uk).

Note: These tips were written for PHP 4.0.4 and Apache 1.3.9.

  1. You need gzip, download a binary distribution from http://hpux.connect.org.uk/ftp/hpux/Gnu/gzip-1.2.4a/gzip-1.2.4a-sd-10.20.depot.Z uncompress the file and install using swinstall.

  2. You need gcc, download a binary distribution from http://gatekeep.cs.utah.edu/ftp/hpux/Gnu/gcc-2.95.2/gcc-2.95.2-sd-10.20.depot.gz. uncompress this file and install gcc using swinstall.

  3. You need the GNU binutils, you can download a binary distribution from http://hpux.connect.org.uk/ftp/hpux/Gnu/binutils-2.9.1/binutils-2.9.1-sd-10.20.depot.gz. uncompress this file and install binutils using swinstall.

  4. You now need bison, you can download a binary distribution from http://hpux.connect.org.uk/ftp/hpux/Gnu/bison-1.28/bison-1.28-sd-10.20.depot.gz, install as above.

  5. You now need flex, you need to download the source from one of the http://www.gnu.org mirrors. It is in the non-gnu directory of the ftp site. Download the file, gunzip, then tar -xvf it. Go into the newly created flex directory and run ./configure, followed by make, and then make install.

    If you have errors here, it's probably because gcc etc. are not in your PATH so add them to your PATH.

  6. Download the PHP and apache sources.

  7. gunzip and tar -xvf them. We need to hack a couple of files so that they can compile OK.

  8. Firstly the configure file needs to be hacked because it seems to lose track of the fact that you are a hpux machine, there will be a better way of doing this but a cheap and cheerful hack is to put lt_target=hpux10.20 on line 47286 of the configure script.

  9. Next, the Apache GuessOS file needs to be hacked. Under apache_1.3.9/src/helpers change line 89 from echo "hp${HPUXMACH}-hpux${HPUXVER}"; exit 0 to: echo "hp${HPUXMACH}-hp-hpux${HPUXVER}"; exit 0

  10. You cannot install PHP as a shared object under HP-UX so you must compile it as a static, just follow the instructions at the Apache page.

  11. PHP and Apache should have compiled OK, but Apache won't start. you need to create a new user for Apache, e.g. www, or apache. You then change lines 252 and 253 of the conf/httpd.conf in Apache so that instead of

    User nobody
    Group nogroup

    you have something like

    User www
    Group sys

    This is because you can't run Apache as nobody under hp-ux. Apache and PHP should then work.


OpenBSD installation notes

This section contains notes and hints specific to installing PHP on OpenBSD 3.6.


Using Binary Packages

Using binary packages to install PHP on OpenBSD is the recommended and simplest method. The core package has been separated from the various modules, and each can be installed and removed independently from the others. The files you need can be found on your OpenBSD CD or on the FTP site.

The main package you need to install is php4-core-4.3.8.tgz, which contains the basic engine (plus gettext and iconv). Next, take a look at the module packages, such as php4-mysql-4.3.8.tgz or php4-imap-4.3.8.tgz. You need to use the phpxs command to activate and deactivate these modules in your php.ini.

Example 4-6. OpenBSD Package Install Example

# pkg_add php4-core-4.3.8.tgz
# /usr/local/sbin/phpxs -s
# cp /usr/local/share/doc/php4/php.ini-recommended /var/www/conf/php.ini
  (add in mysql)
# pkg_add php4-mysql-4.3.8.tgz
# /usr/local/sbin/phpxs -a mysql
  (add in imap)
# pkg_add php4-imap-4.3.8.tgz
# /usr/local/sbin/phpxs -a imap
  (remove mysql as a test)
# pkg_delete php4-mysql-4.3.8
# /usr/local/sbin/phpxs -r mysql
  (install the PEAR libraries)
# pkg_add php4-pear-4.3.8.tgz

Read the packages(7) manual page for more information about binary packages on OpenBSD.


Using Ports

You can also compile up PHP from source using the ports tree. However, this is only recommended for users familiar with OpenBSD. The PHP 4 port is split into two sub-directories: core and extensions. The extensions directory generates sub-packages for all of the supported PHP modules. If you find you do not want to create some of these modules, use the no_* FLAVOR. For example, to skip building the imap module, set the FLAVOR to no_imap.


Common Problems

  • The default install of Apache runs inside a chroot(2) jail, which will restrict PHP scripts to accessing files under /var/www. You will therefore need to create a /var/www/tmp directory for PHP session files to be stored, or use an alternative session backend. In addition, database sockets need to be placed inside the jail or listen on the localhost interface. If you use network functions, some files from /etc such as /etc/resolv.conf and /etc/services will need to be moved into /var/www/etc. The OpenBSD PEAR package automatically installs into the correct chroot directories, so no special modification is needed there. More information on the OpenBSD Apache is available in the OpenBSD FAQ.

  • The OpenBSD 3.6 package for the gd extension requires XFree86 to be installed. If you do not wish to use some of the font features that require X11, install the php4-gd-4.3.8-no_x11.tgz package instead.


Older Releases

Older releases of OpenBSD used the FLAVORS system to compile up a statically linked PHP. Since it is hard to generate binary packages using this method, it is now deprecated. You can still use the old stable ports trees if you wish, but they are unsupported by the OpenBSD team. If you have any comments about this, the current maintainer for the port is Anil Madhavapeddy (avsm at openbsd dot org).


Solaris specific installation tips

This section contains notes and hints specific to installing PHP on Solaris systems.


Required software

Solaris installs often lack C compilers and their related tools. Read this FAQ for information on why using GNU versions for some of these tools is necessary. The required software is as follows:

  • gcc (recommended, other C compilers may work)

  • make

  • flex

  • bison

  • m4

  • autoconf

  • automake

  • perl

  • gzip

  • tar

  • GNU sed

In addition, you will need to install (and possibly compile) any additional software specific to your configuration, such as Oracle or MySQL.


Using Packages

You can simplify the Solaris install process by using pkgadd to install most of your needed components.


Gentoo installation notes

This section contains notes and hints specific to installing PHP on Gentoo Linux.


Using Portage (emerge)

While you can just download the PHP source and compile it yourself, using Gentoo's packaging system is the simplest and cleanest method of installing PHP. If you are not familiar with building software on Linux, this is the way to go.

If you have built your Gentoo system so far, you are probably used to Portage already. Installing Apache and PHP is no different than the other system tools.

The first decision you need to make is whether you want to install Apache 1.3.x or Apache 2.x. While both can be used with PHP, the steps given below will use Apache 1.3.x. Another thing to consider is whether your local Portage tree is up to date. If you have not updated it recently, you need to run emerge sync before anything else. This way, you will be using the most recent stable version of Apache and PHP.

Now that everything is in place, you can use the following example to install Apache and PHP:

Example 4-7. Gentoo Install Example with Apache 1.3

# emerge \<apache-2
# USE="-*" emerge php mod_php
# ebuild /var/db/pkg/dev-php/mod_php-<your PHP version>/mod_php-<your PHP version>.ebuild config
# nano /etc/conf.d/apache
  Add "-D PHP4" to APACHE_OPTS

# rc-update add apache default
# /etc/init.d/apache start

You can read more about emerge in the excellent Portage Manual provided on the Gentoo website.

If you need to use Apache 2, you can simply use emerge apache in the last example.


Better control on configuration

In the last section, PHP was emerged without any activated modules. As of this writing, the only module activated by default with Portage is XML which is needed by PEAR. This may not be what you want and you will soon discover that you need more activated modules, like MySQL, gettext, GD, etc.

When you compile PHP from source yourself, you need to activate modules via the configure command. With Gentoo, you can simply provide USE flags which will be passed to the configure script automatically. To see which USE flags to use with emerge, you can try:

Example 4-8. Getting the list of valid USE flags

# USE="-*" emerge -pv php

[ebuild  N    ] dev-php/php-4.3.6-r1  -X -berkdb -crypt -curl -debug -doc
-fdftk -firebird -flash -freetds -gd -gd-external -gdbm -gmp -hardenedphp
-imap -informix -ipv6 -java -jpeg -kerberos -ldap -mcal -memlimit -mssql
-mysql -ncurses -nls -oci8 -odbc -pam -pdflib -png -postgres -qt -readline
-snmp -spell -ssl -tiff -truetype -xml2 -yaz  3,876 kB

As you can see from the last output, PHP considers a lot of USE flags. Look at them closely and choose what you need. If you choose a flag and you do not have the proper libraries, Portage will compile them for you. It is a good idea to use emerge -pv again to see what Portage will compile in accordance to your USE flags. As an example, if you do not have X installed and you choose to include X in the USE flags, Portage will compile X prior to PHP, which can take a couple of hours.

If you choose to compile PHP with MySQL, cURL and GD support, the command will look something like this:

Example 4-9. Install PHP with USE flags

# USE="-* curl mysql gd" emerge php mod_php

As in the last example, do not forget to emerge php as well as mod_php. php is responsible for the command line version of PHP as mod_php is for the Apache module version of PHP.


Common Problems

  • If you see the PHP source instead of the result the script should produce, you have probably forgot to edit /etc/conf.d/apache. Apache needs to be started with the -D PHP4 flag. To see if the flag is present, you should be able to see it when using ps ax | grep apache while Apache is running.

  • Due to slotting problems, you might end up with more than one version of PHP installed on your system. If this is the case, you need to unmerge the old versions manually by using emerge unmerge mod_php-<old version>.

  • If you cannot emerge PHP because of Java, try putting -* in front of your USE flags like in the above examples.

  • If you are having problems configuring Apache and PHP, you can always search the Gentoo Forums. Try searching with the keywords "Apache PHP".


Chapter 5. Installation on Mac OS X

This section contains notes and hints specific to installing PHP on Mac OS X. There are two slightly different versions of Mac OS X, Client and Server, our manual deals with installing PHP on both systems. Note that PHP is not available for MacOS 9 and earlier versions.


Using Packages

There are a few pre-packaged and pre-compiled versions of PHP for Mac OS X. This can help in setting up a standard configuration, but if you need to have a different set of features (such as a secure server, or a different database driver), you may need to build PHP and/or your web server yourself. If you are unfamiliar with building and compiling your own software, it's worth checking whether somebody has already built a packaged version of PHP with the features you need.


Compiling for OS X Server

Mac OS X Server install.

  1. Get the latest distributions of Apache and PHP.

  2. Untar them, and run the configure program on Apache like so.
    ./configure --exec-prefix=/usr \
    --localstatedir=/var \
    --mandir=/usr/share/man \
    --libexecdir=/System/Library/Apache/Modules \
    --iconsdir=/System/Library/Apache/Icons \
    --includedir=/System/Library/Frameworks/Apache.framework/Versions/1.3/Headers \
    --enable-shared=max \
    --enable-module=most \
    --target=apache

  3. If you want the compiler to do some optimization, you may also want to add this line:
    setenv OPTIM=-O2

  4. Next, go to the PHP 4 source directory and configure it.
    ./configure --prefix=/usr \
        --sysconfdir=/etc \
        --localstatedir=/var \
        --mandir=/usr/share/man \
        --with-xml \
        --with-apache=/src/apache_1.3.12
    If you have any other additions (MySQL, GD, etc.), be sure to add them here. For the --with-apache string, put in the path to your apache source directory, for example /src/apache_1.3.12.

  5. Type make and make install. This will add a directory to your Apache source directory under src/modules/php4.

  6. Now, reconfigure Apache to build in PHP 4.
    ./configure --exec-prefix=/usr \
    --localstatedir=/var \
    --mandir=/usr/share/man \
    --libexecdir=/System/Library/Apache/Modules \
    --iconsdir=/System/Library/Apache/Icons \
    --includedir=/System/Library/Frameworks/Apache.framework/Versions/1.3/Headers \
    --enable-shared=max \
    --enable-module=most \
    --target=apache \
    --activate-module=src/modules/php4/libphp4.a
    You may get a message telling you that libmodphp4.a is out of date. If so, go to the src/modules/php4 directory inside your Apache source directory and run this command: ranlib libmodphp4.a. Then go back to the root of the Apache source directory and run the above configure command again. That'll bring the link table up to date. Run make and make install again.

  7. Copy and rename the php.ini-dist file to your bin directory from your PHP 4 source directory: cp php.ini-dist /usr/local/bin/php.ini or (if your don't have a local directory) cp php.ini-dist /usr/bin/php.ini.


Compiling for MacOS X Client

The following instructions will help you install a PHP module for the Apache web server included in MacOS X. This version includes support for the MySQL and PostgreSQL databases. These instructions are graciously provided by Marc Liyanage.

Warning

Be careful when you do this, you could screw up your Apache web server!

Do this to install:

  1. Open a terminal window.

  2. Type wget http://www.diax.ch/users/liyanage/software/macosx/libphp4.so.gz, wait for the download to finish.

  3. Type gunzip libphp4.so.gz.

  4. Type sudo apxs -i -a -n php4 libphp4.so

  5. Now type sudo open -a TextEdit /etc/httpd/httpd.conf. TextEdit will open with the web server configuration file. Locate these two lines towards the end of the file: (Use the Find command)
    #AddType application/x-httpd-php .php
    #AddType application/x-httpd-php-source .phps
    Remove the two hash marks (#), then save the file and quit TextEdit.

  6. Finally, type sudo apachectl graceful to restart the web server.

PHP should now be up and running. You can test it by dropping a file into your Sites folder which is called test.php. Into that file, write this line: <?php phpinfo() ?>.

Now open up 127.0.0.1/~your_username/test.php in your web browser. You should see a status table with information about the PHP module.


Chapter 6. Installation on Windows systems

This section applies to Windows 98/Me and Windows NT/2000/XP/2003. PHP will not work on 16 bit platforms such as Windows 3.1 and sometimes we refer to the supported Windows platforms as Win32. Windows 95 is no longer supported as of PHP 4.3.0.

There are two main ways to install PHP for Windows: either manually or by using the installer.

If you have Microsoft Visual Studio, you can also build PHP from the original source code.

Once you have PHP installed on your Windows system, you may also want to load various extensions for added functionality.

Warning

There are several all-in-one installers over the Internet, but none of those are endorsed by PHP.net, as we believe that the manual installation is the best choice to have your system secure and optimised.


Windows Installer

The Windows PHP installer is available from the downloads page at http://www.php.net/downloads.php. This installs the CGI version of PHP and for IIS, PWS, and Xitami, it configures the web server as well. The installer does not include any extra external PHP extensions (php_*.dll) as you'll only find those in the Windows Zip Package and PECL downloads.

Note: While the Windows installer is an easy way to make PHP work, it is restricted in many aspects as, for example, the automatic setup of extensions is not supported. Use of the installer isn't the preferred method for installing PHP.

First, install your selected HTTP (web) server on your system, and make sure that it works.

Run the executable installer and follow the instructions provided by the installation wizard. Two types of installation are supported - standard, which provides sensible defaults for all the settings it can, and advanced, which asks questions as it goes along.

The installation wizard gathers enough information to set up the php.ini file, and configure certain web servers to use PHP. One of the web servers the PHP installer does not configure for is Apache, so you'll need to configure it manually.

Once the installation has completed, the installer will inform you if you need to restart your system, restart the server, or just start using PHP.

Warning

Be aware, that this setup of PHP is not secure. If you would like to have a secure PHP setup, you'd better go on the manual way, and set every option carefully. This automatically working setup gives you an instantly working PHP installation, but it is not meant to be used on online servers.


Manual Installation Steps

This install guide will help you manually install and configure PHP with a web server on Microsoft Windows. To get started you'll need to download the zip binary distribution from the downloads page at http://www.php.net/downloads.php.

Although there are many all-in-one installation kits, and we also distribute a PHP installer for Microsoft Windows, we recommend you take the time to setup PHP yourself as this will provide you with a better understanding of the system, and enables you to install PHP extensions easily when needed.

Upgrading from a previous PHP version: Previous editions of the manual suggest moving various