PHP HOW-TO

PHP HOW-TO
Al Dev (Alavoor Vasudevan) [email protected]
v25.4, 13 July 2001

This document tells you howto develop PHP programs and also to migrate
all the Windows 95 GUI applications to powerful PHP + HTML + DHTML +
XML + Java applets + Javascript. The information in this document
applies to all the operating sytems where PHP is ported that is -
Linux, Windows 95/98/NT/ME, Windows 2000, BeOS, Apple Macintosh (is
BSD unix??), OS/2, all flavors of Unix like Solaris, HPUX, AIX, SCO,
Unixware, Sinix, BSD, SunOS, etc.. and mainframe operating systems
and on all operating systems where "C" compiler is available.
______________________________________________________________________

Table of Contents

1. Introduction

2. PHP runs on Microsoft Windows!!

3. PHP Download

3.1 PHP Installation on Microsoft Windows 95/98/NT/2000
3.2 Apache Webserver Quick-Install (10 seconds) on Microsoft Windows 95/98/NT/2000
3.3 SQL server for Microsoft
3.4 PHP Installation on unixes and others

4. Quick Start steps

5. PHP Libraries

5.1 Classes and PEAR
5.2 Other PHP Utilities

6. PHP Application Servers

6.1 Build PHP based corporate Intranet and Internet
6.2 Popular PHP Applications
6.3 PHP Web Application Servers
6.4 PHP Template Engines
6.5 PHP based Web-Portal systems

7. Object Oriented Features - public, private, protected

8. HTML Editor

9. IDE tools for PHP

9.1 PHP IDE
9.2 PHP IDE for MS Windows only
9.3 PHP IDE for both MS Windows and Linux
9.4 PHP IDE for Linux only
9.5 PHP Utilities
9.6 Convert Microsoft ASP scripts to PHP - ASP2PHP

10. ctags for PHP

11. Debugging PHP

11.1 Debug Tool - phpCodeSite
11.2 Debug Tool - phpDebug
11.3 Debug with FILE and LINE

12. General purpose programming with PHP

12.1 Standalone MS Windows GUI applications using PHP

13. Performance benchmarking - PHP, ASP, JSP, Coldfusion

14. Limitations of PHP

15. PHP Tutorial

15.1 Primer on PHP Sessions
15.2 Session Management in PHP4
15.3 User Management and Privileges
15.4 Step1: Creating the Users Table

16. Related URLs

17. Other Formats of this Document

17.1 Acrobat PDF format
17.2 Convert Linuxdoc to Docbook format
17.3 Convert to MS WinHelp format
17.4 Reading various formats

18. Copyright

19. Appendix A PHP examples

19.1 PostgreSQL large object Example
19.2 User authentication Example
19.3 Network admin Example

20. Appendix B Midgard Installation

20.1 Testing Midgard PHP Server
20.2 Security OpenSSL

21. Appendix C - Debug tool phpcodesite

______________________________________________________________________

1. Introduction

Definition: PHP is a simple, object-oriented, interpreted, robust,
secure, very high-performance, architecture neutral, portable, dynamic
scripting language. Everything inside "class" keyword in PHP will be
identical to Java language (in near future). And PHP is designed such
that it is 10 times faster than Java, since there is no virtual
machine. PHP is the international standard general purpose object
oriented scripting language.

PHP stands for 'Hypertext Pre-Processor' and is a server side HTML
scripting/programming language. PHP is a tool that lets you create
dynamic web pages. 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.

PHP was kept the "top secret and strictly confidential" computer
language by many companies in the world, but now had become the most
well-known and most widely used object oriented scripting language for
web, internet, e-commerce, general purpose and business-to-business
projects. Even today many competing companies keep PHP language as a
highly confidential matter not disclosing to outsiders (competitors).

PHP will storm the entire world and will take the IT industry by
surprise!! The power of PHP is that it is cross-platform and runs
everywhere!! It runs on Linux, Windows 95/98/NT, Windows 2000,
Solaris, HPUX and all flavors of unix. PHP is write once and deploy
anywhere and everywhere. It runs on many web-servers like Apache,
Microsoft IIS, etc..

PHP runs 5 to 20 times faster than Java!! In actual benchmarks, PHP
was 3.7 times faster than JSP (see ``''). PHP is extremely easy to use
and you can develop very complex web/e-commerce applications very
rapidly in a very short period of time. (In future PHP language will
imitate most features of Java language and Java programmers will love
PHP. And PHP will have java keywords like class, extends, interface,
implements, public, protected, private etc..).

It has object oriented features and takes the best features from Java,
C++, PERL and "C" languages. PHP language is a marriage of best
features from Java, C++, PERL and C.

PHP is the real gem of all the scripting/programming languges and will
soon become the "MECCA" for programmers world-wide!! PHP has a huge
user base and a large developer base as it runs on both
Window95/NT/2000 and all flavors of unixes.

A big surprise is waiting for us - Most probably PHP will be the
computer language/scripting language of the 21st century!!

PHP can be compiled and optimized to make it run even faster by using
the Zend Optimizer. Zend optimizer is integrated with PHP in PHP
version 4.0.

You would normally use a combination of PHP (70% code) +
HTML/DHTML/XML (25% code) + Javascript (5% code client side
validations) for your e-commerce projects.

2. PHP runs on Microsoft Windows!!

PHP initially started on unix platform, but it is very portable and
runs on MS Windows and MS IIS webserver. Today PHP has a large user
base on MS Windows 2000/NT/95/98, You will find a huge collection of
tools for PHP under MS Windows platform.

Many PHP programmers develop code on MS Windows and deploy on large
linux servers like IBM mainframe running linux, Compaq DEC Alpha and
Sun sparc.

A great advantage is that since PHP also runs on Unix/Linux,
developers on unix platform "cash on" the user base of PHP under MS
windows as the PHP code developed under MS Windows can be used on
unix/linux without any code change!!

PHP itself is written in 100% "C" langauge, and hence it runs on a
very wide variety of platforms like BeOS, Unix, MS Windows, Apple
Macintosh, IBM OS/2 and on many more operating systems.

PHP is very fast and is much faster than Java. For web development,
forget Java/JSP, it is PHP, PHP and PHP everywhere!! PHP is also
becoming a general purpose object oriented scripting language

3. PHP Download

� PHP main site <http://www.php.net>

� PHP resources <http://ils.unc.edu/web-db/php/links.html>

� PHP Code Exchange - <http://px.sklar.com>

3.1. PHP Installation on Microsoft Windows 95/98/NT/2000

PHP is IMMENSELY POPULAR on Microsoft Windows platform and is
surprisingly more popular than Microsoft's own ASP web scripting
language!! A major reason for popularity is that PHP is a object
oriented scripting language whereas ASP is not. PHP has a large
collection of re-usable classes (objects). PHP runs lot faster than
ASP on MS Windows and has more features and functionalities than
Microsoft ASP. PHP is much more robust, reliable and powerful than
ASP. And the user base of PHP is extremely large because PHP runs on
MS Windows, Linux, Mac OS and all unixes. Greatest advantage of PHP
is that you can develop on MS Windows and deploy on Linux or Unix and
vice versa!!

There are more PHP users under MS Windows98/NT/2000 than on any other
operating system!! Because there is so much demand for PHP on MS
Windows 98/NT/2000, a ready to install executable is made and you
simply double-click on the exe file to automatically install PHP in
just 2 minutes. Download the PHP executable install file from

� MS Windows exe installer for PHP
<http://php.weblogs.com/easywindows>

� Lots of info on PHP on MS Windows platform
<http://php.weblogs.com>

� Install and config of PHP on MS Windows
<http://www.php.net/manual/install-windows95-nt.php>

� PHP Triad installs a complete PHP server environment on Windows
platforms <http://www.phpgeek.com>

3.2. Apache Webserver Quick-Install (10 seconds) on Microsoft Windows
95/98/NT/2000

You need a web-server to run the PHP on MS Windows. You can use MS IIS
web server or you can use free Apache web-server for MS Windows
95/98/NT/2000. To save you lot of time here is the ready-to-install
setup.exe file for apache for Windows platform:

PHPTriad which is Apache+PHP+MySQL single package is at
<http://www.phpgeek.com/phptriad.php> and at mirrorsite
<http://sourceforge.net/projects/phptriad>. I very strongly recommend
PHPTriad as it is immensely popular among MS Windows users (millions
of downloads).

Apache binaries - <http://httpd.apache.org/dist/httpd/binaries/win32>

3.3. SQL server for Microsoft

SQL server can be on a seperate box which need not be running MS
Windows. You also need a SQL server for doing web development. I
recommend that you install Redhat Linux on a very old PC like (Pentium
or 486 box) and install the PostgreSQL
<http://www.geocities.com/alavoor/HOWTO/pgsql/PostgreSQL-HOWTO.html>
RPMs on it. You do not need any windows graphics for a database server
and at console mode startup the PostgreSQL
<http://www.geocities.com/alavoor/HOWTO/pgsql/PostgreSQL-HOWTO.html>
server. PostgreSQL
<http://www.geocities.com/alavoor/HOWTO/pgsql/PostgreSQL-HOWTO.html>
is 3 times faster than Oracle or MS SQL server.

You can also order ready-to-go cheap Linux boxes from -

� Egghead Egghead <http://www.egghead.com>, click on Auctions and
Linux boxes, you get best deals in live Auctions.

� Goto LinuxHardware <http://lhd.datapower.com> and click
ComputerSystems, LinuxOnline <http://www.linux.org/hardware>, Linux
hardware Crynwr <http://linux.crynwr.com>, Linux HarwareNet
<http://www.linuxhardware.net/vendors.html>

� US Land5 <http://www.land-5.com/CustomPage4.html>, US QLiTech
<http://www.qlitech.net/products/servers/athlon.html>, US
CompaqLinux <http://www.compaq.com/products/servers/linux>, US
VAlinux <http://www.valinux.com>, US StoreAnywhere
<http://www.storeanywhere.com>

� In Europe : UK GBdirect <http://www.gbdirect.co.uk/linux>, UK
MultiT <http://www.multithread.co.uk>, Hungary Leonardo
<http://www.leonardo.co.hu>, Belgium Mind <http://mind.be>, Germany
Spier <http://www.spier.be>

� DEC alpha linux DECalpha <http://www.alphalinux.org./hardware> and
CompaqAlphaLinux
<http://www.compaq.com/AlphaServer/linux/index.html>

You can also get PostgreSQL
<http://www.geocities.com/alavoor/HOWTO/pgsql/PostgreSQL-HOWTO.html>
for Windows NT/2000 from <http://www.askesis.nl>.

See also the PostgreSQL
<http://www.geocities.com/alavoor/HOWTO/pgsql/PostgreSQL-HOWTO.html>
howto at pgsql-howto
<http://www.geocities.com/alavoor/HOWTO/pgsql/PostgreSQL-HOWTO.html>

3.4. PHP Installation on unixes and others

See the installation guide and instructions at PHP main site
<http://www.php.net> or INSTALL file in the downloaded package itself.

4. Quick Start steps

To implement a project in object oriented PHP do -

� First you need connection to database sql servers - use one of
these:

� ADODB (Active Data Objects Data Base)
<http://php.weblogs.com/ADODB>

� Metabase (Database independent access and management)
<http://phpclasses.upperdesign.com/browse.html/package/20>

� Second you need generic PHP classes to create forms, tables and
other HTML objects. Get these from PHP classes at
<http://phpclasses.upperdesign.com>. See also the Top downloaded
classes from Top PHP classes
<http://phpclasses.upperdesign.com/browse.html/top> And visit
<http://www.phpclasses.com>. And see Form classes, template
classes at the site corporate Intranet/Internet
<http://www.aldev.8m.com/index.html#target5>

� Third, design and create your own PHP classes by inheriting from
the generic PHP classes <http://phpclasses.upperdesign.com> or
<http://www.phpclasses.com>.

� Fourth, use the template classes to seperate the presentation from
business logic, see <http://www.phpclasses.com>.

� Fifth, use IDE tools from ``''

� Most of your PHP code should be in classes for easy code
maintainence and re-usability.

See also Aldev's PHP classes
<http://phpclasses.upperdesign.com/browse.html/author/35463>

5. PHP Libraries

The PHP is a object-oriented scripting language. Hence PHP code is
"classes, classes, classes and classes". When you write PHP code you
must design your classes such that they are re-usable or they use
existing PHP classes. There are hundreds of PHP classes already
written and ready to use. There are classes for accessing databases,
classes for generating XML, HTML forms, classes for creating tables,
forms and other HTML objects. If you write some generic classes then
please upload to sites. By year 2005, there will be more than hundred
million re-usable PHP classes. Advantage of PHP classes are they
provide - data hiding, inheritance, encapsulation, reliability,
reusability and polymorphism. The most important PHP sites are PHP
classes and PEAR as given below.

5.1. Classes and PEAR

Visit the following web sites which have large collections of ready to
use PHP class libraries.

� PHP classes are at <http://phpclasses.upperdesign.com> and at
<http://www.phpclasses.com>.

� PEAR (PHP Extension and Application Repository) is a code
repository for PHP extensions and PHP library code similar to
Perl's CPAN and is at <http://pear.php.net> and mirror
<http://lxr.php.net/source/php4/pear> linux php-pear-rpms
<http://rpmfind.net/linux/rpm2html/search.php?query=pear> and pear-
tutorials <http://php.weblogs.com/php_pear_tutorials>.

� ADODB (Active Data Objects Data Base)
<http://php.weblogs.com/ADODB> : PHP's database access functions
are not standardised. Every database extension uses a different and
incompatibile API. This creates a need for a database class library
to hide the differences between the different databases
(encapsulate the differences) so we can easily switch databases.
ADODB currently support MySQL, PostgreSQL
<http://www.geocities.com/alavoor/HOWTO/pgsql/PostgreSQL-
HOWTO.html> , Interbase, Oracle, MS SQL 7, Foxpro, Access, ADO,
Sybase and generic ODBC. See also ADODB-manual
<http://php.weblogs.com/ADODB_manual>. The PhpLens
<http://phplens.com> is based on ADODB.

� Metabase (Database independent access and management)
<http://phpclasses.upperdesign.com/browse.html/package/20>

� PHP Hot scripts <http://www.hotscripts.com/PHP>

� Very popular PHP resources <http://php.resourceindex.com> and CGI-
Resources <http://cgi-resources.com>

� PHP projects are at <http://php.net/projects.php>

� PHP Lib Netuse <http://phplib.netuse.de> (This is deprecated,
merged with PEAR)

� PHP widgets <http://www.northern.ca/projects/phpwidgets>

� Generic Framework PHP4 <http://sourceforge.net/projects/gpfr>

� Source Forge PHP Lib <http://phplib.sourceforge.net>

� Source Forge PHP Snippets, go and click on PHP here
<http://sourceforge.net/snippet>
� E-gineer PHP lib <http://e-gineer.com/articles/php-hacker>

� FAQ PHP <http://php.faqts.com>

� PHP Lib <http://px.sklar.com>

� PHP Factory <http://alfalinux.sourceforge.net/phpfact.php3>

� PHP Builder site <http://phpbuilder.com/snippet>

� PHP developer <http://www.phpdeveloper.org>

� PHP newbie <http://www.newbienetwork.net>

� PHP walrus <http://www.evilwalrus.com>

5.2. Other PHP Utilities

Other PHP utilities are at :

� User Login sample:
<http://www.devshed.com/Server_Side/PHP/Commerce1>

� phpPDFtable is a class written in php to ease the creation of
tables in PDF files. It requires php (4.0 but should run with 3.x
too), and pdflib <http://sourceforge.net/projects/phppdftable>

� Data-Admin aims to provide a PHP based interface to Database
Administration. This will not be limited to just one or two
databases. Also, the underlying class library encapsulates the
native PHP database calls allowing the programmer to use one set of
fu <http://sourceforge.net/projects/dadmin>

� PSlib is a PHP library for generating PostScript files. It offers
an easy way of generating PostScript files: simple call PSlib
functions from within your PHP script and the PS files are created
on the fly <http://sourceforge.net/projects/pslib>

� A complete collection of php scripts that work tightly together to
create a highly customizable, dynamic and module oriented website
<http://sourceforge.net/projects/twebs>

� phpOpenTracker is a comprehensive solution for your site- and
visitor-tracking needs. The collected data is stored in a SQL
database, allowing complex, yet easy analysis. A powerful API for
analysis and report generation (HTML or PDF output) is included.
<http://www.phpopentracker.de>

� PHPShopCart is a shopping-cart web application demo written in PHP
and designed to connect to a MySQL database. It was written for the
book, "A Guide to Databases under Linux" (Syngress Media) but is
available under the GNU Public License.
<http://sourceforge.net/projects/phpshopcart>

6. PHP Application Servers

The PHP applications are categorized into more than 60 groups in
hotscripts.com site at HotScripts - PHP
<http://www.hotscripts.com/PHP/Scripts_and_Programs>. You MUST visit
this site before looking elsewhere.

6.1. Build PHP based corporate Intranet and Internet

Visit the site corporate Intranet/Internet
<http://www.aldev.8m.com/index.html#target5> for a very good
comparison and listing of applications.

6.2. Popular PHP Applications

The most popular PHP applications in the order are:

1. PHP-Nuke <http://www.hotscripts.com/Detailed/5947.html> and the
mainsite <http://phpnuke.org>

2. Smarty <http://www.hotscripts.com/Detailed/8817.html> and the
mainsite <http://www.phpinsider.com/php/code/Smarty>

3. eZ Publish <http://www.hotscripts.com/Detailed/7894.html> and the
mainsite <http://developer.ez.no/article/static/7>

4. Mambo Portal/Content Mgmt
<http://www.hotscripts.com/Detailed/10068.html> and the mainsite
<http://www.miro.com.au>

5. PHP Content Management System
<http://www.hotscripts.com/Detailed/8455.html> and the mainsite
<http://mcyra.homeip.net/homepage/phpcms/index.htm>

6. PHP Shop <http://www.hotscripts.com/Detailed/4131.html> and the
mainsite <http://www.phpshop.org>

7. phpWebSite <http://www.hotscripts.com/Detailed/9026.html> and the
mainsite <http://phpwebsite.appstate.edu>

8. myPHPCalendar <http://www.hotscripts.com/Detailed/4182.html> and
the mainsite <http://myPHPCalendar.sourceforge.net>

9. TreeMenu <http://www.hotscripts.com/Detailed/3704.html> and the
mainsite <http://apollo.spaceports.com/~refcentr/index.html>

10.
Backend <http://www.hotscripts.com/Detailed/5921.html> and the
mainsite <http://back-end.org>

11.
Typo3 Content Mgmt <http://www.hotscripts.com/Detailed/8392.html>
and the mainsite <http://www.typo3.com>

12.
E-Guest <http://www.hotscripts.com/Detailed/9956.html>

13.
PHProjekt <http://www.hotscripts.com/Detailed/7598.html> and the
mainsite <http://www.phprojekt.com/index.php>

14.
Phorum <http://www.hotscripts.com/Detailed/175.html> and the
mainsite <http://phorum.org>

PHP has several tools which are given below:

6.3. PHP Web Application Servers

The following are available for PHP:

� PHP Lens <http://phplens.com> is a rapid application development
component which allows PHP developers to dynamically and quickly
create web applications that retrieve information from databases.
With phpLens, data can be presented as html tables with facilities
to create, edit, paginate, search and delete records. PHPLens uses
ADODB. See also ADODB <http://php.weblogs.com/ADODB>.

� ADODB (Active Data Objects Data Base)
<http://php.weblogs.com/ADODB> : PHP's database access functions
are not standardised. Every database extension uses a different and
incompatibile API. This creates a need for a database class library
to hide the differences between the different databases
(encapsulate the differences) so we can easily switch databases.
ADODB currently support MySQL, PostgreSQL
<http://www.geocities.com/alavoor/HOWTO/pgsql/PostgreSQL-
HOWTO.html> , Interbase, Oracle, MS SQL 7, Foxpro, Access, ADO,
Sybase and generic ODBC. See also ADODB-manual
<http://php.weblogs.com/ADODB_manual>.

� Metabase (Database independent access and management)
<http://phpclasses.upperdesign.com/browse.html/package/20>

� Binary Cloud <http://www.binarycloud.com> is an opensource,
enterprise class web application platform It provides a complete
set of core services such as authentication, permissions, database
abstraction, and error handling - and a rich set of advanced tools
built on that foundation.

The system is deployed in a number of commercial installations and
has proven to be robust, scaleable, and secure. Binarycloud is
suitable for large-scale commerce and publishing projects, or
anything of similar complexity. It offers some unique security
features - such as selective encryption of database I/O - which
make it a particularly good choice for web applications that
require a high level of data security. And it's free.

� PEAR (PHP Extension and Application Repository) is a code
repository for PHP extensions and PHP library code similar to
Perl's CPAN and is at <http://lxr.php.net/source/php4/pear> and
pear-tutorials <http://php.weblogs.com/php_pear_tutorials>.

� Midgard is Content management system is based on Apache and uses
the PHP scripting language The main site of Midgard is at
<http://www.midgard-project.org> PHP can be compiled with Zend
compiler and optimizer <http://www.zend.com>. PHP runs very fast
and is about 5 to 10 times faster than Java.

See ``Midgard Installation''

� Ariadne <http://www.muze.nl/software/ariadne> is a web application
system. It consists of a complete framework for the easy
development and management of web applications, using PHP. The
system uses a modular approach, using abstract interfaces for all
transactions. This results in maximum freedom to change parts of
the systems workings or add new functionality without needing to
reprogram other parts

� Group IT Engine <http://groupit.org> is a turnkey group
collaboration and content management engine. It presently runs on
Unix machines using PHP and Apache. Using GroupIT you can
"Categorize your content", "Organize your contents into sections",
"Control access to your content" and many more additional features
<http://groupit.org/channel/features>.

6.4. PHP Template Engines

� Php Sitemanager - do code creation, a layout design, site
implementation and site management. Visit SiteManager
<http://www.roadsend.com/siteManager/home/treeMenu.php>

� Smarty Template Engine - is a template engine for PHP. One of the
unique aspects about Smarty that sets it apart from other
templating solutions is that it compiles the templates into native
PHP scripts upon the first invocation. After that, it merely
executes the compiled PHP scripts. Therefore, there is no costly
template file parsing for each request.

See Smarty QuickStart
<http://www.phpinsider.com/php/code/Smarty/QUICKSTART> and docs
about Smarty are at
<http://www.phpinsider.com/php/code/Smarty/docs>. Get it from
download-smarty <http://www.phpinsider.com/php/code/Smarty>.

� DreamTime Template <http://www.phptemplates.org>

� Fast Template <http://curtisonline.net/theme/phpfast-templates-
HOWTO.html> and main-site <http://www.thewebmasters.net>

� PHP template Layout classes commercial, VH Layout
<http://www.vhconsultants.com> and see this-article
<http://www.phpbuilder.com/columns/zhang19990610.php3>

6.5. PHP based Web-Portal systems

The following ready-made Web-Portal systems are available:

� PHP Nuke Web Portal system at PhpNuke
<http://sourceforge.net/projects/phpnuke>

� DarkPortal is a Web portal system similar to PHPNuke. It is based
on the user interface style of Slashdot and other news/portal
systems. It uses a modular core as a base for adding pluggable
modules to facilitate content creation and management. Its primary
goals are full separation of content from code, fully modular
portal plugins with standardized APIs, portability and database
abstraction, user level theme selection and plugin module
selection, and a modular user/group hierarchy with multiple levels
of moderation and admin capabilities. Visit DarkPortal
<http://freshmeat.net/redir/darkportal/13912/url_homepage>

� CMS system ezPublish <http://developer.ez.no>

� Mambo is a feature-rich, dynamic portal engine/content management
tool based on PHP/MySQL. It features a very powerful and extensive
admin manager, and uses a modular framework for extensibility.
Visit Mambo <http://www.mamboserver.com> and mirror
<http://www.miro.com.au>

7. Object Oriented Features - public, private, protected

PHP scripting language provides object oriented features through the
class keyword. Features like public, private and protected will be
supported in the future release (they are in TODO list). In the
meantime, you can use the following coding conventions to distinguish
between private, public and protected variables:

1. All private variables and functions always start with underscore
"_" followed by lowercase letters like var $_myvar;

2. All Protected variables and functions always start with "_T"
followed by lowercase letters like var $_Tmyvar;

3. All Public variables and functions do not start with underscore "_"
like var $myvar;

4. All variables and functions always start with lowercase letter (no
uppercase) like var $_myvar; and NOT like var $_Myvar;

______________________________________________________________________
class someabc {
var $_conn; // Private variable
var $_Tmyvar; // Protected variable
var $connMYCONNECTION; // Public variable
var $connToDb; // Public variable
var $myvar3; // Public variable
var $myvarTHISTEST; // Public variable

function _foofunction() {} // Private function
function _Tfoofunction() {} // Protected function
function foofunction() {} // Public function
}
______________________________________________________________________

The private, protected declarations provide the encapsulation and
data-hiding. But you must consider the following disadvantages of
encapsulation:

� Encapsulation usually requires more code, hence it sacrifices
performance especially for scripting languages like PHP

� Encapsulation requires lots of Set/Get methods for
private/protected properties.

� Since encapsulation unneccessarily increases the code size, it is
not recommended for scripting language like PHP.

� You can enforce a good degree of encapsulation by using the coding
convention suggested in this section.

8. HTML Editor

HTML editors for PHP on Windows 95/NT/2000 are:

� 1st Page 2000 - Rated 1st (the best HTML editor)
<http://www.evrsoft.com>

� Cool Page - Rated 2nd <http://www.coolpage.com>

� Coffeecup - Rated 3rd <http://www.coffeecup.com/editor>

� Arachnophilia - Rated 4th
<http://www.arachnoid.com/arachnophilia/index.html>

� Textpad <http://www.textpad.com> and textpad-php-add-ons
<http://www.textpad.com/add-ons/files/syntax/php4.zip>

The best HTML editor is 1st Page 2000, and it is a excellent HTML
editor.

9. IDE tools for PHP

Many HTML editors are supporting PHP. In near future every HTML
editors and XML editor will be supporting PHP "Rapid Application
Development" tool.

You will notice that some of the PHP editors run only on MS Windows.
Yes!! there are millions of PHP developers on MS Windows platform.
PHP is IMMENSELY POPULAR on Microsoft Windows platform and is
surprisingly more popular than Microsoft's own ASP web scripting
language!! PHP runs lot faster than ASP on MS Windows and has more
features and functionalities than Microsoft ASP. PHP is much more
robust, reliable and powerful than ASP. There are more PHP users
under MS Windows98/NT/2000 than on any other operating system!! PHP
initially started on Linux/unix environment but today there are more
PHP developers on MS Windows platform as compared to unix.

9.1. PHP IDE

PHP IDE tools are at :

� PHPAktThe PHP support in Macromedia Dreamweaver UltraDev that
allows Ultradev Developers to create PHP sites PHPAkt
<http://www.interakt.ro/products/PHAkt>

� PHP Lens <http://phplens.com> is a rapid application development
component which allows PHP developers to dynamically and quickly
create web applications that retrieve information from databases.
With phpLens, data can be presented as html tables with facilities
to create, edit, paginate, search and delete records. PHPLens uses
ADODB. See also ADODB <http://php.weblogs.com/ADODB>.

� PHP IDE and Editor "PHP Coder" <http://www.phpide.de> and mirror
<http://phpcoder.stsoft.cjb.net>

� Zend PHP IDE <http://zend.com/store/products/zend-ide.php>

� IDE for PHP scripting (Web Browser) :
<http://www.ekenberg.se/php/ide>
� Nexidion PHP IDE <http://www.nexidion.org>

� Enter in Search keyword 'PHP IDE' in Source Forge
<http://sourceforge.net>

� Color editor gvim for PHP (Win and linux) at
<http://metalab.unc.edu/LDP/HOWTO/Vim-HOWTO.html> and see also
``ptags of PHP''

9.2. PHP IDE for MS Windows only

PHP IDE/editor on MS Windows platform are :

� Rated 1st (the best PHP tool on MS Windows) : PHPTriad is a
complete PHP development and server environment for Windows. It
installs PHP, Apache, MySQL, and PHPMyAdmin, both installing and
setting up the environment. PHPTriad is at
<http://www.phpgeek.com/phptriad.php> and at mirrorsite
<http://sourceforge.net/projects/phptriad>

� Rated 2nd : PHP Coder <http://www.php-ide.com>

� Rated 3rd: PHPEd (Soyal), an excellent PHP editor (MS Windows)
<http://soysal.free.fr/PHPEd>

� IDE for PHP editor (MS Windows): <http://www.phpedit.com>

� Color editor gvim for PHP (Win and linux) at
<http://metalab.unc.edu/LDP/HOWTO/Vim-HOWTO.html> and see also
``ptags of PHP''

� IDE for PHP (MS Windows) <http://www.pc-service-
boerner.de/PHPScriptEditor.htm>

� "EditPlus Text editor" win32 <http://www.editplus.com> (high
rating 5 stars)

� eNotepad win32
<http://www.edisys.com/Products/eNotepad/enotepad.asp> (high rating
5 stars)

� PHP editor win32 <http://www.chami.com/html-kit> (high rating 5
stars)

� UltraEdit win32 <http://www.ultraedit.com> with PHP word file at
<http://www.ultraedit.com/downloads/additional.html>

� ScriptWorx editor win32
<http://www.softlite.net/products/scriptworx> (rating 4.5 stars)

� TextPad editor win32 <http://www.textpad.com> (rating 4.5 stars)

� PHP editor "ASPEdit" <http://www.tashcom.com/aspedit> (rating 3.5
stars) along with PHP code explorer <http://www.tashcom.com/codex>
(rating 4.5 stars)

� HTML/PHP editor Dreamweaver <http://www.dreamweaver.com>

� HTML/PHP editor Homesite <http://www.allaire.com/homesite>

� HTML/PHP editor Hotdog <http://www.hotdog.com>

9.3. PHP IDE for both MS Windows and Linux

PHP IDE/editor for bot MS Windows and Linux platforms are :

� PHP editor (for both windows and linux/unixes)
<http://www.coffeecup.com/select/editor.html> (rating 5 stars).

� HTML/PHP editors Amaya <http://www.w3.org/Amaya>

� Folding text editor (Win and linux) <http://fte.sourceforge.net>

� PHP Editor (Win and linux) <http://www.scintilla.org>

� Color editor gvim for PHP (Win and linux) at
<http://metalab.unc.edu/LDP/HOWTO/Vim-HOWTO.html> and see also
``ptags of PHP''

� Jed (win and linux) <http://space.mit.edu/~davis/jed.html>

� Editors for PHP : <http://www.itworks.demon.co.uk/phpeditors.htm>

� Editors for PHP :
<http://www.oodie.com/tools/index.php?view=editor>

9.4. PHP IDE for Linux only

The best IDE for PHP on linux is Coffeecup Editor as given below:

� Color editor gvim for PHP (Win and linux) at
<http://metalab.unc.edu/LDP/HOWTO/Vim-HOWTO.html> and see also
``ptags of PHP''

� PHP editor <http://www.coffeecup.com/select/editor.html> (rating 5
stars).

� HTML/PHP editors Quanta <http://quanta.sourceforge.net>

� HTML/PHP editors Blue Fish <http://bluefish.linuxave.net>

� HTML editors AswEdit <http://www.advasoft.com>

9.5. PHP Utilities

� Zend Optimizers <http://www.zend.com>

� Zend Compilers <http://www.zend.com>

� Lots of info on PHP on MS Windows platform
<http://php.weblogs.com>

� PHP GroupWare Apps <http://www.phpgroupware.org>

� PHP Web Shop <http://www.phpshop.org>

� PHP Nuke Web Portal system PhpNuke
<http://sourceforge.net/projects/phpnuke>

9.6. Convert Microsoft ASP scripts to PHP - ASP2PHP

To convert ASP scripts to PHP use this utility
<http://asp2php.naken.cc>

10. ctags for PHP

Tags are extremely valuable and are used for navigation of source code
inside the editors like vi, emacs, CRiSP, NEdit etc... If you had
programmed a lot in C, C++ or Java you might have used the ctags
program to create tags. To see the online manual page, type 'man
ctags' at linux/unix bash prompt.

The ptags program for PHP is given below, which you can use to create
the tags for PHP source code. Your productivity will improve 3 to 4
times if you use ptags.

See also Vim color text editor for PHP, C, C++ at
<http://metalab.unc.edu/LDP/HOWTO/Vim-HOWTO.html>

______________________________________________________________________
// Save this file as ptags.cpp and compile by
// g++ -o ptags ptags.cpp
//*****************************************************************
// Copyright policy is GNU/GPL but additional request is
// that you include author's name and email on all copies
// Author : Al Dev Email: [email protected]
// Usage : ptags *.php3 *.inc
// This will generate a file called tags
//*****************************************************************
#include <iostream.h>
#include <fstream>
#include <stdio.h> // for sprintf
#include <stdlib.h> // for system
#include <string.h> // for memset
#include <ctype.h> // for isspace

#define BUFF_LEN 1024
#define LOCATION 9

char *ltrim(char *dd);
char *rtrim(char *ee);

main(int argc, char **argv)
{
if (argc < 2)
{
cerr << "\nUsage: " << argv[0] << " file .... " << endl;
exit(0);
}

char fname[100] = "tag_file.out";
FILE *fpout;
ofstream fout(fname);
if (fout.fail())
{
cerr << "\nError opening file : " << fname << endl;
exit(-1);
}
//fpout = fopen(fname, "w");

for (int ii = 1; ii < argc; ii++)
{
/*
char buff[2024];

sprintf(buff, "\\rm -f %s; ls %s > %s 2>/dev/null", outfile, argv[1], outfile);
cout << "\nbuff = " << buff << endl;

system(buff);
fclose(fp);
*/
FILE *fpin = NULL;
fpin = fopen(argv[ii], "r");
if (fpin == NULL)
{
cerr << "\nError opening file : " << argv[ii] << endl;
exit(-1);
}
char buff[BUFF_LEN + 100];
memset(buff, 0, BUFF_LEN +10);
for ( ; fgets(buff, BUFF_LEN, fpin) != NULL; )
{
char aa[BUFF_LEN + 100];
char aapointer[BUFF_LEN + 100];
memset(aa, 0, BUFF_LEN +10);
strcpy(aa, buff);
strcpy(aapointer, ltrim(aa));
strcpy(aa, aapointer);

// Remove the trailing new line..
{
int tmpii = strlen(aa);
if (aa[tmpii-1] == '\n')
aa[tmpii-1] = 0;
}
//cout << "aa is : " << aa << endl;
//cout << "aapointer is : " << aapointer << endl;
if (strncmp(aa, "function ", LOCATION) != 0)
continue;
//cout << buff << endl;

// Example tags file output is like -
// al2 al.c /^al2()$/;" f
{
char bb[BUFF_LEN + 100];
memset(bb, 0, BUFF_LEN +10);
strcpy(bb, & aa[LOCATION]);
char *cc = bb;
while (cc != NULL && *cc != '(')
*cc++;
*cc = 0;
cc = rtrim(bb);
//cout << "bb is : " << bb << endl;
//cout << cc << "\t" << argv[ii] << "\t" << "/^" << aa << "$/;\"\tf" << endl;
fout << cc << "\t" << argv[ii] << "\t" << "/^" << aa << "$/;\"\tf" << endl;
//fprintf(fpout, "%s\t%s\t/^%s$/;\"f\n", cc, argv[ii], aa );
}

memset(buff, 0, BUFF_LEN +10);
}
fclose(fpin);
}
fout.flush();
fout.close();
//fclose(fpout);

// Sort and generate the tag file
{
char tmpaa[1024];
sprintf(tmpaa, "sort %s > tags; \\rm -f %s", fname, fname);
system(tmpaa);
}
}

char *ltrim(char *dd)
{
if (dd == NULL)
return NULL;

while (isspace(*dd))
dd++;

return dd;
}

char *rtrim(char *ee)
{
if (ee == NULL)
return NULL;

int tmpii = strlen(ee) - 1;
for (; tmpii >= 0 ; tmpii--)
{
if (isspace(ee[tmpii]) )
{
//cout << "\nis a space!!" << endl;
ee[tmpii] = 0;
}
}
return ee;
}
______________________________________________________________________

11. Debugging PHP

11.1. Debug Tool - phpCodeSite

PHP Debugger called 'phpCodeSite' is available at
<http://phpcodesite.phpedit.com> and see also ``Appendix C''

11.2. Debug Tool - phpDebug

PHP Debugger is available at <http://www.phpdebug.com>

11.3. Debug with FILE and LINE

To debug PHP programs create a file "debug2.inc" having the following
functions :

______________________________________________________________________
<?php

/* define this variable, to prevent double declaration. */
if (!defined("_DEBUG2_DEFINED_"))
{
define("_DEBUG2_DEFINED_", 1 );
}
else
return; // if this file is already included then return

# file name : debug2.inc
# Functions for debuging the PHP source code
#*****************************************************************
# Copyright policy is GNU/GPL but additional request is
# that you include author's name and email on all copies
# Author : Al Dev Email: [email protected]
#*****************************************************************

# Usage of this functions -
# In your source code put something like -
# debug2_(__FILE__, __LINE__, "f_somevariable", $f_somevariable);
# And this will generate output in debug.out file.

//function debug2_($fname, $lname, $debug_var, $debug_value=0) {}

// Give read, exec for all on directory /debug2_logs
// chmod a+rwx /debug2_logs
// But here you need to open the file in append mode.
$fp_debug2 = fopen("/debug2_logs/debug.out", "a");
if ($fp_debug2 == false)
{
print "<b>File open failed - global.var.inc<b>";
exit;
}

function debug2_($fname, $lname, $debug_var, $debug_value=0)
{
global $fp_debug2;

//print "<br> debug_value is : $debug_value <br>";
if (!$debug_value)
{
fwrite($fp_debug2, "\n ". $fname ." ". $lname .": $debug_var");
}
else
{
fwrite($fp_debug2, "\n ". $fname . " ". $lname .": $debug_var = $debug_value");
}
//print "<br> f_cookie is : $f_cookie <br>";
}

// In your first page, which is generally index.php3
// truncate the debug2_logs file in beginning of code
function init_debug_file()
{
global $fp_debug2;

$fp_debug2 = fopen("/debug2_logs/debug.out", "w");
if ($fp_debug2 == false)
{
print "<b>File open failed - global.var.inc<b>";
exit;
}
system("chmod a+rwx /debug2_logs/debug.out");
}
?>
______________________________________________________________________

In your PHP source code initial page which is generally index.php3,
put a line like

______________________________________________________________________
<?php
include ("debug2.inc");

init_debug_file();
// all other commands follows here ...
// ...........
?>
______________________________________________________________________

To output debug values, in your PHP source code files, put debug2_()
calls as illustrated below:

______________________________________________________________________
<?php
include ("debug2.inc");
debug2_(__FILE__, __LINE__, "f_somevariable", $f_somevariable);

function aa()
{
$aa = 8;
debug2_(__FILE__, __LINE__, "aa", $aa);
}
?>
______________________________________________________________________

When you run the PHP program the output will be traced in the file
called debug.out giving the filename, linenumber, variable name and
it's value.

Use the debug2_() generously in your code. The usage of debug2_()
calls in your program will NOT have any impact on the final production
code and also has no impact on the performance because they will be
filtered out as described below. You can use copy and paste to save
time of typing debug2() calls or use the 'yank to buffer' feature of
Vi editor and paste.

When you are done development and testing and when you are ready to
deploy on the production server, filter out the debug2_ calls from
your source code. At unix prompt -

______________________________________________________________________
bash$ mkdir production
bash$ grep -v debug2_ filea.php3 > production/filea.php3
______________________________________________________________________

For a large group of files -

______________________________________________________________________
bash$ mkdir production
bash$ ls *.php3 | while read ans
do
grep -v debug2_ $ans > production/$ans
done
______________________________________________________________________

And now copy the files from production to the deployment area.

12. General purpose programming with PHP

PHP is very powerful and is designed such that it can replace awk,
sed, unix shell, perl, "C", C++ and Java.

The object oriented features of PHP is developing very rapidly and in
near future will surpass the object oriented features of Java
language. All the object oriented features are implemented in PHP via
class keyword just like in Java.

If you want to use PHP as a stand-alone program, just like a shell
script, "C" or perl program, then use this technique:

______________________________________________________________________
bash$ php filename.php
bash$ php -h
bash$ php -?
bash$ /usr/bin/php -?
bash$ php -i
______________________________________________________________________

The command php filename.php will execute the file filename.php. You
are invoking the php program which you wrote in filename.php from the
bash commmandline instead of from the web-browser.

On Microsoft Windows platform you will bringup a MSDOS prompt from
Start->Run->cmd and put C:\Program Files\php\bin in your path
environment and

______________________________________________________________________
C:\> php filename.php
C:\> php -h
C:\> php -?
or
C:\> c:\Program Files\php\bin\php filename.php
______________________________________________________________________

12.1. Standalone MS Windows GUI applications using PHP

Since PHP is general purpose scripting language and is like a "glue"
language, you can use it develop standalone MS Windows GUI
applications. PHP can be very easily combined with MS Windows C++ GUI
classes to create GUI applications. And developing applications with
PHP is extremely fast as it is a scripting language and it's runtime
performance is also excellent as compared with other scripting
languages like Perl, Visual Basic and Python.

PHP can also be used for developing standalone GUI applications for
Linux/Unixes.

13. Performance benchmarking - PHP, ASP, JSP, Coldfusion

It is very important to bear in mind that performance and running
speed of the web scripting engine must be given TOP PRIORITY. That is,
how many pages per second the scripting engine can pump out to the
browser clients. The greater the number of pages pumped out to clients
in a given period of time, then the better and more powerful the
scripting engine is.

The Zdnet
<http://www.zdnet.com/enterprise/stories/linux/0,12249,2646052,00.html>
did a evaluation and benchmarking of 4 web scripting languages. During
benchmarking, the same spec and identical cpu, memory boxes were used.
Under identical conditions, it was found that PHP was the fastest -
about 3.7 times faster than JSP and about 1.2 times faster than ASP.
Read the report at eWeek
<http://www.zdnet.com/enterprise/stories/linux/0,12249,2646052,00.html>
and mirror-site <http://aldev0.virtualave.net/php-asp-jsp-cf.html> The
benchmark results are -

� PHP pumped out about 47 pages/second

� Microsoft ASP pumped out about 43 pages/second

� Allaire ColdFusion pumped out about 29 pages/second

� Sun Java JSP pumped out about 13 pages/second

See also PHP, ASP benchmarks at <http://aldev0.virtualave.net/php-
perl-benchmarks.html>

Whenever you design a web site, give attention to these important
points:

� Speed of web scripting engine - how many pages per second it can
pump out.

� KISS policy (Keep It Simple Stupid!!) - your web page should be
very simple without any fancy graphics (because web users do not
want to wait for long and they want the information very fast). And
information they read is just plain text!!

14. Limitations of PHP

Everything has limitations or disadvantages and PHP is no exception.
The following are the limitations of PHP (so be WARNED !!)

1. PHP is NOT 100 % pure Object Oriented scripting language. But in
near future PHP may support 100% object oriented scripting (PHP
may imitate most of the syntax of Java language). PHP already
imitates some features of Java language. (In future PHP language
will imitate most features of Java language and Java programmers
will love PHP. And PHP will have java keywords like class, extends,
interface, implements, public, protected, private etc..).

2. PHP will NOT give the performance of "C" or "C++" language. Because
it is scripting language and is interpreted it will be a bit slower
than the optimized "C++" programs. For top performance, you should
use "C++" and fast-CGI with database/webserver connection pooling
and use C++ compiler optimizer "-O3" options. Zend optimizer in
PHP 4 will speed up the performance of PHP and bring it very close
to optimized "C" code .

3. But note a point that PHP was designed for very Rapid Web-
Application Development tool. If it takes about 3 months to code a
web application in C++, then using PHP you can develop the same web
application in just 4 days!! And with zend optimizer, the speed of
execution of PHP will be very close to that of equivalent C++
program!! Hence, there is really no advantage in using C/C++ for
web development. PHP itself is written in 100% "C" language.

On the other hand, PHP has lot of advantages and it's advantages
outweigh it's limitations -

1. You can very rapidly develop web applications in PHP as compile and
link is eliminated in PHP scripting language.

2. PHP applications are very stable and do not depend on the browser
technologies unlike Javascript applications which depend on
browsers. PHP will give you the freedom to select any server
platform. The browser does not know that the HTML page is generated
by PHP !!

3. PHP has excellent database conectivity to all SQL database servers.

4. PHP has partial support for Object oriented features

5. PHP has C++, Perl, Javascript like syntax features and has programs
like

6. PHP has Zend optimizer which speeds up the performance

7. PHP runs on all unixes, linux, Windows 95/NT/2000 and is more
powerful than ASP, JSP and others.

8. PHP has a very large user base and developer base.

See also Python: If you want 100% pure Object Oriented scripting
language than you MUST consider Python. The 'Python' is a object
oriented scripting language from ground up. You would be using the
Python Web Application server called 'Zope' which is available at -
<http://www.zope.org> and python is at <http://www.python.org>

15. PHP Tutorial

Visit the following PHP tutorial sites -

� PHP Resource index - important PHP site - has complete scripts,
Functions, classes, documentation, examples and tutorials
<http://php.resourceindex.com>

� PHP portal <http://zend.com>

� PHP Hot scripts site <http://www.hotscripts.com/PHP>

� Very popular PHP resources <http://php.resourceindex.com> and CGI-
Resources <http://cgi-resources.com>

� Simple tutorial <http://www.php.net/tut.php>

� Web Monkey
<http://hotwired.lycos.com/webmonkey/99/21/index2a.html>

� Dev Shed <http://www.devshed.com/Server_Side/PHP/Introduction>

� PHP TidBits <http://www.htmlwizard.net/resources/tutorials>

� PHP Builder <http://www.phpbuilder.com/getit>

In this tutorial we assume that your server has support for PHP
activated and that all files ending in .php3 are handled by PHP.

Your first PHP-enabled page: Create a file named hello.php3 and in it
put the following lines:

______________________________________________________________________
<html><head><title>PHP Test< /title>< /head>
<body>
<?php echo "Hello World<P>"; ?>
< /body>< /html>
______________________________________________________________________

Note that this is not like a CGI script. Think of it as a normal HTML
file which happens to have a set of special tags available to you.

If you tried this example and it didn't output anything, chances are
that the server you are on does not have PHP enabled. Ask your
administrator to enable it for you.

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
all you want.

We are going to check what sort of browser the person viewing the page
is using. In order to do that we check the user agent string that the
browser sends as part of its request. This information is stored in a
variable. Variables always start with a dollar-sign in PHP. The
variable we are interested in is $HTTP_USER_AGENT. To display this
variable we can simply do:

______________________________________________________________________
<?php echo $HTTP_USER_AGENT; ?>
______________________________________________________________________

For the browser that you are using right now to view this page, this
displays:

Mozilla/4.0 (compatible; MSIE 4.01; Windows 98)

There are many other variables that are automatically set by your web
server. You can get a complete list of them by creating a file that
looks like this:

______________________________________________________________________
<?php phpinfo()?>
______________________________________________________________________

Then load up this file in your browser and you will see a page full of
information about PHP along with a list of all the variables available
to you.

You can put multiple PHP statements inside a PHP tag and create little
blocks of code that do more than just a single echo.

______________________________________________________________________
<?php
if(strstr($HTTP_USER_AGENT,"MSIE")) {
echo "You are using Internet Explorer<br>";
}
?>
______________________________________________________________________

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:

______________________________________________________________________
<?php
if(strstr($HTTP_USER_AGENT,"MSIE"))
{
?>
< center>< b>You are using Internet Explorer< /b>< /center>
<?
}
else
{
?>
< center>< b>You are not using Internet Explorer< /b>< /center>
<?
}
?>
______________________________________________________________________

Instead of using a PHP echo statement to output something, we jumped
out of PHP mode and just sent straight HTML. The important and power�
ful point to note here is that the logical flow of the script remain
intact. Only one of the HTML blocks will end up getting sent to the
viewer. Running this script right now results in:

You are using Internet Explorer

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 in a form will automatically result in a variable with
the same name as the element being created on the target page. This
probably sounds confusing, so here is a simple example. Assume you
have a page with a form like this on it:

______________________________________________________________________
<form action="action.php3" method="POST">
Your name: <input type=text name=name>
You age: <input type=text name=age>
<input type=submit>
< /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.php3 page is called. In this file
you would have something like this:

______________________________________________________________________
Hi <?php echo $name?>. You are <?php echo $age?> years old.
______________________________________________________________________

Surprise!! The $name and $age variables are automatically set for you
by PHP !!

15.1. Primer on PHP Sessions

This section is written by Ying Zhang .

Before we begin, let's quickly go over the concept of a session and
the reason we need it. It's hard (for me) to define what a session is
exactly, so let's use an example that should be very familiar to you
-- logging in to your computer and using it every day. After you log
in, your computer knows who you are. Every action that you perform is
done so with your name.

So what's so special about that -- we take it for granted every time
we have to login to any system. What's the big deal with doing this on
the web? Well, the web (or specifically, the HTTP protocol) is
connectionless. That means each request made to a web server is
independent of all the other requests. Whereas your computer keeps
information about you in memory and knows when you log in and out, a
web server doesn't. A web server simply waits for requests and sends
responses.

Let's illustrate this a little bit:

______________________________________________________________________
John Doe __________ Jane Doe
1 | | 2
3 ------------>|web server|<---------- 4
5 |__________| 6
______________________________________________________________________

Let's say we only have two people, John Doe and Jane Doe, accessing
MyMarket, and their actions are like this:

1. John looks at the product catalog.

2. Jane looks at the product catalog.

3. John adds an item to his basket.

4. Jane adds an item to her basket.

5. John goes to the checkout.

6. Jane goes to the checkout.

Since HTTP is connectionless, each request is completely isolated from
the other requests. So how does the server know who's doing what? How
does the server know that actions 1, 3, 5 are from John, and actions
2, 4, 6 are from Jane? Well, to make a long story short, the web
server doesn't have to know. It can continue on happily responding to
requests, session management has to be done with the backend scripting
language.

What we need is a way to group together requests by the same person
into the same session. This is where PHP4's session management
capabilities come in. It can group together requests made from the
same source (eg. client's browser) into the same session, we have to
provide the smarts to associate users with sessions.

In other words, PHP4's session management can tell us requests 1, 3,
and 5 belong to the same session (call it session A). Our application
has to know that session A is owned by John Doe.

15.2. Session Management in PHP4

PHP4 adds some session management functions that make our life easier
when dealing with sessions. The ones we are interested in are:

______________________________________________________________________
session_start();
session_register();
______________________________________________________________________

session_start() is used to start up PHP4's session management
capabilities; you need to call it before you use any of the other
session functions. session_register() is used to tell PHP which
variables to track in the session. A typical call to these functions
would look like this:

session_register("SESSION");

This tells PHP to start up the session manager, and tells PHP that the
variable called SESSION is a session variable. You can register as
many session variables as you like, but I prefer to only register one
session variable called SESSION, and anything I need persistent I put
into this variable. For example, I like to say:

______________________________________________________________________
session_register("SESSION");
$SESSION["var1"] = 5;
$SESSION["var2"] = 6;
______________________________________________________________________

instead of

______________________________________________________________________
session_register("var1");
session_register("var2");
$var1 = 5;
$var2 = 6;
______________________________________________________________________

because after you register lots of session variables, you tend to for�
get what they were, well, at least I do :).

Anyhow, by now you probably want to see some code in action, so create
a script called session_test.php somewhere accessible, and put into
it:

______________________________________________________________________
<?
session_start();
session_register("SESSION");

if (! isset($SESSION)) {
$SESSION["count"] = 0;
echo "<li>Counter initialized, please reload this page to see it increment";
} else {
echo "<li>Waking up session $PHPSESSID";
$SESSION["count"]++;
}
echo "<li>The counter is now $SESSION[count] ";
?>
______________________________________________________________________

Fire that up in your browser, the first time you hit the page, it
should say " Counter initialized, please reload this page to see it
increment". Each time you reload it, the counter value should
increment by one. You will also see the session ID. If it does, then
hurray, your PHP4 session manager works :)

So how does this work? Well, when you call session_start(), PHP4
determines a unique session ID for the client. This session ID is an
MD5 hash of something (not sure what), and it is stored as a cookie on
the client's PC.

Now each time that client makes a request, PHP4 will read this session
ID and load up the data for the session. When you call
session_register(), you are telling PHP4 which variables you want kept
in the session. Each page that loads up, the previous values for the
registered variables will be reloaded, and each time the page ends
PHP4 will save the values of the registered variables.

By default, PHP keeps track of the sessions in temporary files in the
/tmp directory, take a listings and see for yourself:

You will see something like this:

______________________________________________________________________
-rw------- 1 apache web 10 May 7 15:27 sess_6dd9ea8e61cd49cd3ad6de8c8b8885e8
-rw------- 1 apache web 10 May 7 19:49 sess_7d7f97afb6759948f554b00272494e52
-rw------- 1 apache web 6 May 9 01:00 sess_8ab78830e151add9d79b628958ce4eb9
-rw------- 1 apache web 31 May 9 11:41 sess_a3058a6bb1baf57f565c3844c8810f4b
-rw------- 1 apache web 30 May 9 11:42 sess_c379faad83ad3dc8ab6d22c14dbab3b4
-rw------- 1 apache web 6 May 8 01:00 sess_cd68a5054241aff1a8157c289683e869
-rw------- 1 apache web 34 May 7 15:17 sess_cd97e41912b28c44cc0481b7d978cb61
-rw------- 1 apache web 42 May 9 11:23 sess_d1285edd0c951c70b1aec17a5f602fc0
-rw------- 1 apache web 30 May 9 11:42 sess_da93f6e19b6be01257d7a6453766a23d
-rw------- 1 apache web 42 May 7 21:26 sess_e837123c1af78c538e89b47030fde337
______________________________________________________________________

Each one of those files is a session, let's take a look at one of them
(note, you probably have to su to root to peek inside a session file).
Tip: don't just cut and paste the following commands, you need to
specify the name of a real file:

______________________________________________________________________
# more /tmp/sess_a3058a6bb1baf57f565c3844c8810f4b
______________________________________________________________________

You will see something like this:

______________________________________________________________________
SESSION|a:1:{s:5:"count";i:234;}
______________________________________________________________________

Does that look familiar? It should if you've ever used the serialize()
and unserialize() functions in PHP. If not, don't worry about it.
Anyhow, I just wanted to illustrate how sessions were stored. You can
rewrite the PHP session handlers to store sessions into a database or
whatever else, but that's beyond the scope of this tutorial (but it's
not hard at all).

15.3. User Management and Privileges

Okay, we've spend enough time on PHP4's session management, all you
really need to get out of that was the two functions session_start()
and session_register(). Let's get back to the issue of keeping track
of users.

PHP can help us keep track of sessions, and group requests from the
same session together. Now, we have to do our part and associate user
accounts with these sessions. We will use a variable called
SESSION["user"] to keep track of user information. When a user logs
in, we will put their information into this variable. As long as this
variable is defined, we will assume that a user has logged in. When a
user logs off, we will clear out this variable.

Specifically, we will keep the following information about the user:

______________________________________________________________________
SESSION["user"]["username"] This is the user's login ID (their nick name if you will), and it is how we tell users apart from each other.
SESSION["user"]["firstname"] The user's firstname.
SESSION["user"]["lastname"] The user's lastname.
SESSION["user"]["email"] The user's email address.
SESSION["user"]["priv"] The user's privilege level.
______________________________________________________________________

Let's talk a bit about the privilege levels. We are going to have two
levels of security: (1) normal customers and (2) administrative users.
Normal customers can use the system, browse through the catalog, and
do other customer functions. Administrators can do everything a normal
user can do, but also has the ability to perform system administrative
functions. In real life, there are probably many more privilege levels
that you want defined but we are going to keep things simple here.

This is all fine and dandy, but where do we get this user information
from? We need to have a way to store all the users on the system, and
the perfect place for that would be in the database. We're going to
create a users table to hold all our users.

15.4. Step1: Creating the Users Table

Start up database server and login to database. Let's create the user
table:

______________________________________________________________________
psql> CREATE TABLE users (
-> username char(16) not null,
-> password char(32) not null,
-> priv char(5) not null,
-> firstname varchar(64) not null,
-> lastname varchar(64) not null,
-> email varchar(128) not null,
-> phone varchar(32) not null,
-> address varchar(255) not null,
-> PRIMARY KEY (username),
-> UNIQUE email (email)
-> );
______________________________________________________________________

Notice the constraints we've put on the users table, the username is
the primary key (which makes sense, you should be able to identify a
user record based on the username). The email address has a unique
constraint as well because we don't want duplicate email addresses.

Now let's add a record to create the root user with the password
password:

______________________________________________________________________
psql> INSERT INTO users VALUES (
-> 'root',
-> '5f4dcc3b5aa765d61d8327deb882cf99',
-> 'admin',
-> 'System',
-> 'Administrator',
-> '[email protected]',
-> '555-5555',
-> '123 5 Avenue'
-> );
______________________________________________________________________

Notice the password looks a bit wierd,
5f4dcc3b5aa765d61d8327deb882cf99. This is the MD5 hash of the the word
"password", I won't go into details here, but the important thing to
note is that it's a one-way algorithm and it always produces a 32
character string.

That's it, we have a users table to track our users, and one
administrative account so we can try logging in and out of the system
using the example tar file (download the example tar file from
<http://www.devshed.com/Server_Side/PHP/Commerce1> ).

16. Related URLs

Visit following locators which are related to C, C++ -

� Vim color text editor for C++, C
<http://metalab.unc.edu/LDP/HOWTO/Vim-HOWTO.html>

� SQL database server for PHP PostgreSQL
<http://www.geocities.com/alavoor/HOWTO/pgsql/PostgreSQL-
HOWTO.html> at pgsql-howto
<http://www.geocities.com/alavoor/HOWTO/pgsql/PostgreSQL-
HOWTO.html>

� Source code control system CVS HOWTO for C++ programs
<http://metalab.unc.edu/LDP/HOWTO/CVS-HOWTO.html>

� Linux goodies main site <http://www.aldev.8m.com> Mirror sites are
at - <http://aldev0.webjump.com>, angelfire
<http://www.angelfire.com/country/aldev0>, geocities
<http://www.geocities.com/alavoor/index.html>, virtualave
<http://aldev0.virtualave.net>, 50megs <http://aldev0.50megs.com>,
theglobe <http://members.theglobe.com/aldev1/index.html>, NBCi
<http://members.nbci.com/alavoor>, Terrashare
<http://aldev.terrashare.com>, Fortunecity
<http://members.fortunecity.com/aldev>, Freewebsites
<http://aldev.freewebsites.com>, Tripod
<http://members.tripod.lycos.com/aldev>, Spree
<http://members.spree.com/technology/aldev>, Escalix
<http://www.escalix.com/freepage/aldev>, Httpcity
<http://www.httpcity.com/aldev/index.html>, Freeservers
<http://aldev.freeservers.com>.

17. Other Formats of this Document

This document is published in 14 different formats namely - DVI,
Postscript, Latex, Adobe Acrobat PDF, LyX, GNU-info, HTML, RTF(Rich
Text Format), Plain-text, Unix man pages, single HTML file, SGML
(Linuxdoc format), SGML (Docbook format), MS WinHelp format.

This howto document is located at -

� <http://www.linuxdoc.org> and click on HOWTOs and search for howto
document name using CTRL+f or ALT+f within the web-browser.

You can also find this document at the following mirrors sites -

� <http://www.caldera.com/LDP/HOWTO>

� <http://www.linux.ucla.edu/LDP>

� <http://www.cc.gatech.edu/linux/LDP>

� <http://www.redhat.com/mirrors/LDP>

� Other mirror sites near you (network-address-wise) can be found at
<http://www.linuxdoc.org/mirrors.html> select a site and go to
directory /LDP/HOWTO/xxxxx-HOWTO.html

� You can get this HOWTO document as a single file tar ball in HTML,
DVI, Postscript or SGML formats from -
<ftp://www.linuxdoc.org/pub/Linux/docs/HOWTO/other-formats/> and
<http://www.linuxdoc.org/docs.html#howto>

� Plain text format is in:
<ftp://www.linuxdoc.org/pub/Linux/docs/HOWTO> and
<http://www.linuxdoc.org/docs.html#howto>

� Single HTML file format is in:
<http://www.linuxdoc.org/docs.html#howto>

Single HTML file can be created with command (see man sgml2html) -
sgml2html -split 0 xxxxhowto.sgml

� Translations to other languages like French, German, Spanish,
Chinese, Japanese are in
<ftp://www.linuxdoc.org/pub/Linux/docs/HOWTO> and
<http://www.linuxdoc.org/docs.html#howto> Any help from you to
translate to other languages is welcome.

The document is written using a tool called "SGML-Tools" which can
be got from - <http://www.sgmltools.org> Compiling the source you
will get the following commands like

� sgml2html xxxxhowto.sgml (to generate html file)

� sgml2html -split 0 xxxxhowto.sgml (to generate a single page html
file)

� sgml2rtf xxxxhowto.sgml (to generate RTF file)

� sgml2latex xxxxhowto.sgml (to generate latex file)

17.1. Acrobat PDF format

PDF file can be generated from postscript file using either acrobat
distill or Ghostscript. And postscript file is generated from DVI
which in turn is generated from LaTex file. You can download distill
software from <http://www.adobe.com>. Given below is a sample
session:

______________________________________________________________________
bash$ man sgml2latex
bash$ sgml2latex filename.sgml
bash$ man dvips
bash$ dvips -o filename.ps filename.dvi
bash$ distill filename.ps
bash$ man ghostscript
bash$ man ps2pdf
bash$ ps2pdf input.ps output.pdf
bash$ acroread output.pdf &
______________________________________________________________________

Or you can use Ghostscript command ps2pdf. ps2pdf is a work-alike for
nearly all the functionality of Adobe's Acrobat Distiller product: it
converts PostScript files to Portable Document Format (PDF) files.
ps2pdf is implemented as a very small command script (batch file) that
invokes Ghostscript, selecting a special "output device" called
pdfwrite. In order to use ps2pdf, the pdfwrite device must be included
in the makefile when Ghostscript was compiled; see the documentation
on building Ghostscript for details.

17.2. Convert Linuxdoc to Docbook format

This document is written in linuxdoc SGML format. The Docbook SGML
format supercedes the linuxdoc format and has lot more features than
linuxdoc. The linuxdoc is very simple and is easy to use. To convert
linuxdoc SGML file to Docbook SGML use the program ld2db.sh and some
perl scripts. The ld2db output is not 100% clean and you need to use
the clean_ld2db.pl perl script. You may need to manually correct few
lines in the document.

� Download ld2db program from
<http://www.dcs.gla.ac.uk/~rrt/docbook.html> or from Al Dev site
<http://www.aldev.8m.com/cppsrc.html>

� Download the cleanup_ld2db.pl perl script from from Al Dev site
<http://www.aldev.8m.com/cppsrc.html>

The ld2db.sh is not 100% clean, you will get lots of errors when
you run

___________________________________________________________________
bash$ ld2db.sh file-linuxdoc.sgml db.sgml
bash$ cleanup.pl db.sgml > db_clean.sgml
bash$ gvim db_clean.sgml
bash$ docbook2html db.sgml
___________________________________________________________________

And you may have to manually edit some of the minor errors after run�
ning the perl script. For e.g. you may need to put closing tag <
/Para> for each < Listitem>

17.3. Convert to MS WinHelp format

You can convert the SGML howto document to Microsoft Windows Help
file, first convert the sgml to html using:

______________________________________________________________________
bash$ sgml2html xxxxhowto.sgml (to generate html file)
bash$ sgml2html -split 0 xxxxhowto.sgml (to generate a single page html file)
______________________________________________________________________

Then use the tool HtmlToHlp <http://javadocs.planetmirror.com/html�
tohlpe.html>. You can also use sgml2rtf and then use the RTF files
for generating winhelp files.

17.4. Reading various formats

In order to view the document in dvi format, use the xdvi program. The
xdvi program is located in tetex-xdvi*.rpm package in Redhat Linux
which can be located through ControlPanel | Applications | Publishing
| TeX menu buttons. To read dvi document give the command -

xdvi -geometry 80x90 howto.dvi
man xdvi

And resize the window with mouse. To navigate use Arrow keys, Page
Up, Page Down keys, also you can use 'f', 'd', 'u', 'c', 'l', 'r',
'p', 'n' letter keys to move up, down, center, next page, previous
page etc. To turn off expert menu press 'x'.

You can read postscript file using the program 'gv' (ghostview) or The
ghostscript program is in ghostscript*.rpm package and gv program is
in gv*.rpm package in Redhat Linux which can be located through
ControlPanel | Applications | Graphics menu buttons. The gv program is
much more user friendly than ghostscript. Also ghostscript and gv are
available on other platforms like OS/2, Windows 95 and NT, you view
this document even on those platforms.

� Get ghostscript for Windows 95, OS/2, and for all OSes from
<http://www.cs.wisc.edu/~ghost>

To read postscript document give the command -

gv howto.ps
ghostscript howto.ps

You can read HTML format document using Netscape Navigator, Microsoft
Internet explorer, Redhat Baron Web browser or any of the 10 other web
browsers.

You can read the latex, LyX output using LyX a X-Windows front end to
latex.

18. Copyright

Copyright policy is GNU/GPL as per LDP (Linux Documentation project).
LDP is a GNU/GPL project. Additional requests are - Please retain the
author's name, email address and this copyright notice on all the
copies. If you make any changes or additions to this document then you
please intimate all the authors of this document.

19. Appendix A PHP examples

19.1. PostgreSQL large object Example

Submitted by: PHP code exchange [email protected] To get this file, in the
web-browser, save this file as 'Text' type as pgsql_largeobj.lib

______________________________________________________________________

PX: PHP Code Exchange -
<url name="PostgreSQL" url="http://www.geocities.com/alavoor/HOWTO/pgsql/PostgreSQL-HOWTO.html">
large object access

<?
$database = pg_Connect ( "", "", "", "", "jacarta");
pg_exec ($database, "BEGIN");
$oid = pg_locreate ($database);
echo ( "$oid\n");
$handle = pg_loopen ($database, $oid, "w");
echo ( "$handle\n");
pg_lowrite ($handle, "foo");
pg_loclose ($handle);
pg_exec ($database, "COMMIT");
pg_close ($database);
?>
______________________________________________________________________

19.2. User authentication Example

To get this file, in the web-browser, save this file as 'Text' type as
user_pw.lib

From the PHP 3 Manual: Works only if PHP is an Apache module. Instead
of simply printing out the $PHP_AUTH_USER and $PHP_AUTH_PW, you would
probably want to check the username and password for validity. Perhaps
by sending a query to a database, or by looking up the user in a dbm
file.

______________________________________________________________________
<?php
if (!$PHP_AUTH_USER)
{
Header("WWW-authenticate: basic realm=\"My Realm\"");
Header("HTTP/1.0 401 Unauthorized");
echo "Text to send if user hits Cancel button\n";
exit;
}
else
{
echo "Hello $PHP_AUTH_USER.<P>";
echo "You entered $PHP_AUTH_PW as your password.<P>";
}
?>
______________________________________________________________________

19.3. Network admin Example

To get this file, in the web-browser, save this file as 'Text' type as
network.lib

PHP: network adminstrator's best friend from
<http://www.phpWizard.net>

As a web-developer, you're probably used to such lovely tools as ping,
whois, nslookup etc. But what when you need one of those utilities at
a client's office and have no access to telnet? Good guess. Time to
look up the functions in the "Network" section of the PHP manual.

Socket operations:

The most important function there is fsockopen(). Using this function,
you can connect to any open port on a server and establish a socket
connection with it. The function's syntax is as following:

______________________________________________________________________
int fsockopen(string hostname, int port, int [errno], string [errstr]);
______________________________________________________________________

The first two arguments are obvious, the next two are optional and
used for error handling. The "errno" and "errstr" should be passed by
reference. "Passing by reference" means that the original variable
will get modified. Normally, the content of a variable passed to a
function wouldn't be modified.

So, you could use this function to open a connection to a webserver
and print out the headers:

______________________________________________________________________
function get_headers($host, $path = "/")
{
$fp = fsockopen ("$host", 80, &$errnr, &$errstr) or die("$errno: $errstr");
fputs($fp,"GET $path HTTP/1.0\n\n");
while (!$end)
{
$line = fgets($fp, 2048);
if (trim($line) == "")
$end = true;
else
echo $line;
}
fclose($fp);
}
______________________________________________________________________

In this example you see that you can apply any file operations (fread,
fwrite etc) to the the pointer you got using the fsockopen() call.
Note that the example realizes a HTTP/1.0 client - it won't work with
name-based virtual hosts.

Finger: Naturally, you can also open connections to other ports.
Writing a small finger client with PHP is trivial therefore. Let's
change the example from above to query a finger daemon:

______________________________________________________________________
function finger ($host, $user)
{
$fp = fsockopen($host, 79, &$errno, &$errstr) or die("$errno: $errstr");
fputs($fp, "$user\n");
while (!feof($fp))
echo fgets($fp, 128);
fclose($fp);
}
______________________________________________________________________

Whois: Querying a whois server uses the same concept:

______________________________________________________________________
// domain is like "phpwizard.net"
function whois($domain, $server="whois.internic.net")
{
$fp = fsockopen ($server, 43, &$errnr, &$errstr) or die("$errno: $errstr");
fputs($fp, "$domain\n");
while (!feof($fp))
echo fgets($fp, 2048);
fclose($fp);
}
______________________________________________________________________

Blocking and non-blocking operations: But there's a problem with all
those functions. They work fine if

1. You have a connection with low latency and

2. If the server you're connecting to is up and running.

If not, your script will be busy until it times out. The reason for
this is that default socket connections are blocking and don't time
out. You can avoid these "hanging scripts" by switching to non-
blocking socket operations. The function set_socket_blocking() does
just that: it set all operations on a socket (first parameter:
socket pointer) to either blocking (second parameter: true) or
false (second parameter: false). Using non-blocking operations, the
finger function would like like this:

______________________________________________________________________
$fp = fsockopen($host, 79, &$errno, &$errstr) or die("$errno: [ ] $errstr");
set_socket_blocking($fp, 0);
fputs($fp, "$user\n");

$stop = time() + $timeout;
while (!feof($fp) && time() < $stop )
echo fgets($fp, 128);
fclose($fp);
______________________________________________________________________

Modifying these 3 functions to use non-blocking socket calls is left
as an exercise for you.

20. Appendix B Midgard Installation

RPMs for Midgard from <http://www.midgard-
project.org/download/binaries> currently do not include PostgreSQL
<http://www.geocities.com/alavoor/HOWTO/pgsql/PostgreSQL-HOWTO.html> ,
and hence you need to install from the source tar ball file .

Download the Midgard source tarball and read the INSTALL.REDHAT file -

______________________________________________________________________
bash# cd midgard-lib-1.4beta6
bash# ./configure --prefix=/usr/local --with-mysql=/usr/local --includedir=/usr/include/mysql --with-midgard=/usr/local --with-pgsql=/var/lib/pgsql --includedir=/usr/include/pgsql
bash# make
bash# make install
bash# ldconfig -v | grep -i midga
Copy the header files, just in case make install did not do that..
bash# cp *.h /usr/local/include

bash# cd ../mod_midgard-1.4beta5c
bash# ./configure --prefix=/usr/local --with-mysql=/usr/local --includedir=/usr/include/mysql --with-midgard=/usr --with-pgsql=/var/lib/pgsql --includedir=/usr/include/pgsql
bash# make
bash# make install
#modify apache line to correct /usr/.....
bash# vi /etc/httpd/conf/httpd.conf (or it is /etc/apache/httpd.conf)
bash# /etc/init.d/apache restart
#apache should restart!!!

bash# cd ../midgard-php-1.4beta6
bash# ./configure '--with-apxs' '--with-mysql' '--with-pgsql' '--with-midgard' --prefix=/usr/local --with-midgard=/usr/local

bash# gvim Makefile
And add -I/usr/include/pgsql to INCLUDE variable.

Also add $(INCLUDE) to $(APXS) command as below -
libphp3.so: mod_php3.c libmodphp3-so.a pcrelib/libpcre.a midgard/libphpmidgard.a
-@test -f ./mod_php3.c || test -L ./mod_php3.c || $(LN_S) $(srcdir)/mod_php3.c ./mod_php3.c
-@test -f ./mod_php3.c || test -h ./mod_php3.c || $(LN_S) $(srcdir)/mod_php3.c ./mod_php3.c
$(APXS) -c -o libphp3.so -I$(srcdir) $(INCLUDE) -I. -I/usr/local/include -I/usr/lib/glib/include -Wl,'-rpath /usr/local/lib' ./mod_php3.c libmodphp3-so.a $(APXS_LDFLAGS)

bash# make
bash# make install
#modify apache line to correct /usr/.....
# and add lines like these -
LoadModule php4_module modules/libphp4.so
AddModule mod_php4.c
LoadModule php4_module lib/apache/libphp4.so

<IfModule mod_php4.c>
AddType application/x-httpd-php4 .php4
AddType application/x-httpd-php4 .php
AddType application/x-httpd-php4-source .phps
AddType application/x-httpd-php .php
</IfModule>

bash# vi /etc/httpd/conf/httpd.conf (or it is /etc/apache/httpd.conf)

bash# /etc/init.d/apache restart
#apache should restart!!!
______________________________________________________________________

20.1. Testing Midgard PHP Server

To test the installation do this - Create a file in your document root
directory. I usually call it info.php and in it put this single line:

______________________________________________________________________
<?phpinfo()?>
______________________________________________________________________

Then load it up in your browser: http://localhost/info.php

You should see a nice summary page showing all sorts of information
about your setup. You probably shouldn't leave this file around on a
production server, but for debugging and general info during
development, it is very handy.

20.2. Security OpenSSL

You may also need to get the RSA package for to enable SSL encryption
from <ftp://ftp.deva.net/pub/sources/crypto/rsaref20.1996.tar.Z> See
also OpenSSL RPM package on Linux cdrom ( <http://www.openssl.org>

If you do not want the SSL to be enabled (or if you face any problem),
then download the source RPM of Apache-Midgard and edit the *.spec
file and comment out SSL and rebuild the RPM.

21. Appendix C - Debug tool phpcodesite

______________________________________________________________________
<
?php
/* phpCodeSite (Idea from CodeSite - Raize Software)
* @version 0.1b - 20001125
* @author S�bastien Hordeaux - <
[email protected]>
* @licence GNU Public Licence
* Main site : http://phpcodesite.phpedit.com
*/

/*
** How does it work ?
Place a CS_EnterMethod() at the beginning of each method/function
Place a CS_ExitMethod() at the beginning of each method/function
Use CS_SendError() to log an error message
Use CS_SendNote() to log a simple note message
Use CS_SendMessage() to log a message
To log variables: CS_SendVar & CS_SendArray()
To see input data (global PHP variables) use CS_SendInputData()
*/

if(defined("FLAG_PHPCODESITE_PHP")) return FALSE;
define("FLAG_PHPCODESITE_PHP", 1);

// Start without increment
$CS_Step = 0;

CS_SetEnabled(TRUE);
// CS_SetEnabled(FALSE);

// Switch between Enable/Disable mode
function CS_SetEnabled($state){
global $CS_Enabled;
$CS_Enabled = $state;
CS_Write($CS_Enabled?"<
pre>":"<
/pre>");
}

// Add a level to the reported items
function CS_IncStep(){
global $CS_Step;
$CS_Step++;
}

// Remove a level to the reported items
function CS_DecStep(){
global $CS_Step;
$CS_Step--;
if($CS_Step <
0)
$CS_Step = 0;
}

// Log an item
function CS_Log($msg){
global $CS_Step;
for($i = 0; $i <
$CS_Step; $i++)
CS_WriteIndent();
CS_Write($msg);
}

// Write data to the target output
function CS_Write($str){
global $CS_Enabled;
if($CS_Enabled)
echo "$str";
}

// Write an indent block
function CS_WriteIndent(){
CS_Write("| ");
}

// Beginning a new method
function CS_EnterMethod($methodName){
CS_Log("--> $methodName\n");
CS_IncStep();
}

// Exit a method
function CS_ExitMethod($methodName){
CS_DecStep();
CS_Log("<
-- $methodName\n");
}

// Log a note
function CS_SendNote($note){
CS_Log("[O] $note\n");
}

// Send a simple message
function CS_SendMessage($msg){
CS_Log("[M] $msg\n");
}

// Log an error
function CS_SendError($msg){
CS_Log("<
b>[E] $msg<
/b>\n");
}

// Log a variable
function CS_SendVar($varName, $value){
if(is_array($value)){
CS_SendArray($value, $varName);
}else{
CS_Log("[L] $varName = \"$value\"\n");
}
}

// Write all global variables to the report
function CS_SendInputData(){
global $HTTP_GET_VARS, $HTTP_POST_VARS, $HTTP_COOKIE_VARS,
$HTTP_SERVER_VARS, $HTTP_ENV_VARS, $HTTP_SESSION_VARS;
CS_Write("----------------------------------------------------------\n");
CS_SendArray($HTTP_GET_VARS, "HTTP_GET_VARS");
CS_SendArray($HTTP_POST_VARS, "HTTP_POST_VARS");
CS_SendArray($HTTP_COOKIE_VARS, "HTTP_COOKIE_VARS");
CS_SendArray($HTTP_SERVER_VARS, "HTTP_SERVER_VARS");
CS_SendArray($HTTP_ENV_VARS, "HTTP_ENV_VARS");
CS_SendArray($HTTP_SESSION_VARS, "HTTP_SESSION_VARS");
CS_Write("----------------------------------------------------------\n");
}

// Log an array
function CS_SendArray($array, $arrayStr = ""){
if(!empty($arrayStr))
CS_Log("\$$arrayStr");
if(count($array) == 0){
CS_Log(" = Array()\n");
}else{
CS_Write(" = Array(\n");
while(list($key2, $value2) = each($array)){
CS_WriteIndent();
if(empty($arrayStr))
CS_WriteIndent();
CS_Log("$key2");
if(!is_array($value2))
CS_Write(" => ".htmlentities($value2)."\n");
else
CS_SendArray($value2);
}
CS_WriteIndent();
if(empty($arrayStr))
CS_WriteIndent();
CS_Log(")\n");
}
}
?>
______________________________________________________________________