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PHP HOW-TO
Al Dev (Alavoor Vasudevan) alavoor[AT]yahoo.com
v27.6, 05 Oct 2002
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/2000/XP, BeOS, Apple Macintosh (is the son
of FreeBSD Unix??), OS/2, all flavors of Unix like Solaris, HPUX, AIX,
SCO, Unixware, Sinix, BSD, SunOS, etc.. and mainframe operating sys
tems and on all operating systems where "C" compiler is available.
Table of Contents
- Introduction
- PHP runs on Microsoft Windows!!
- 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 ASP To PHP Converter - Migration From ASP2PHP
3.5 PHP Installation on UNIX'es and others
3.6 PHP Installation on Apple Macintosh
4. Quick Start steps
5. Major Features of PHP
5.1 Advantages of PHP over Java
5.1.1 Bad Points Of Java
5.1.2 PHP works with Java
5.1.3 PHP: Growing by the month
6. Brief History of PHP
7. A Simple Example
8. SOAPX4 and PhpXMLP
8.1 XML/XSLT Publishing Engine
9. PHP Libraries
9.1 Classes and PEAR
9.2 Other PHP Utilities
10. PHPGem package
11. PHP Application Servers
11.1 Build PHP based corporate Intranet and Internet
11.2 Popular PHP Applications
11.3 PHP Web Application Servers
11.4 PHP Template Engines
11.5 PHP based Web-Portal systems
12. Object Oriented Features - public, private, protected
13. HTML Editor
14. IDE tools for PHP
14.1 PHP IDE
14.2 PHP IDE for MS Windows only
14.3 PHP IDE for both MS Windows and Linux
14.4 PHP IDE for Linux only
14.5 PHP Utilities
15. Code Protection - Encoding Source Code
16. Convert Microsoft ASP scripts to PHP - ASP2PHP
17. ctags for PHP
18. PHP documenter (like Javadoc)
19. Debugging PHP
19.1 Debug with FILE and LINE
20. General purpose programming with PHP
20.1 Standalone MS Windows GUI applications using PHP
21. Web Application Standards - Fusebox
22. Performance benchmarking - PHP, ASP, JSP, Coldfusion
23. Limitations of PHP
24. PHP Tutorial
24.1 Primer on PHP Sessions
24.2 Session Management in PHP4
24.3 Session Propagation
24.4 User Management and Privileges
24.5 Step1: Creating the Users Table
25. PHP Training & PHP Help Desk
26. Related URLs
27. Other Formats of this Document
27.1 Acrobat PDF format
27.2 Convert Linuxdoc to Docbook format
27.3 Convert to MS WinHelp format
27.4 Reading various formats
28. Copyright
29. Appendix A PHP examples
29.1 PostgreSQL large object Example
29.2 User authentication Example
29.3 Network admin Example
30. Appendix B Midgard Installation
30.1 Testing Midgard PHP Server
30.2 Security OpenSSL
31. Appendix C - Debug tool phpcodesite
32. Appendix D - PERL versus PHP debate
- Introduction
(The latest version of this document is at
<http://www.milkywaygalaxy.freeservers.com>. You may want to check
there for changes).
Definition: PHP is a simple, object-oriented, interpreted, robust,
secure, very high-performance, architecture neutral, portable, dynamic
scripting language. PHP has "class" keyword similar to Java's "class"
keyword. And PHP is designed such that it is 5 times faster than
Java, since there is no virtual machine. PHP is very fast becoming a
standard, general purpose, object oriented scripting language. PHP is
not only meant for web applications but also can be used for
developing general applications.
PHP is the next big thing after HTML because today nobody writes
static HTML but uses PHP (generate on the fly, embedded dynamic HTML).
PHP 'kind-of' supercedes "static HTML". PHP is a very powerful
scripting language. PHP will overtake PERL/Python and will replace
PERL/Python. PHP is the next-generation PERL/Python scripting. PHP
can do whatever PERL or Python does and actually does much more, much
better and much, much cleaner.
PHP stands for 'Hypertext Pre-Processor' and is a server side HTML
scripting/programming language. PHP is C-like Web scripting language
runs on Apache, Netscape/iPlanet, and Microsoft IIS Web servers. 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
lets you write simple scripts right in your HTML files much like
JavaScript does, except, unlike JavaScript PHP is not browserdependant.
JavaScript is a client-side html-embedded language while
PHP is a server-side language. PHP is similar in concept to
Netscape's LiveWire Pro product and Microsoft's ASP and Sun
Microsystem's JSP.
PHP is not only used for creating web applications, but also for
creating general standalone applications.
PHP's strength are :
Why PHP ? PHP is the best because of the following reasons:
- PERL is the "ancestor" of PHP and PERL is used for a very long time
(more than 25 years old?). PHP has an advantage over PERL - PHP
supports client-side code and is easier to compile into a
executable. User base of PERL is very large. PHP tries to imitate
PERL and complement the PERL technology. PERL programmers like
PHP! PHP is actually a "modern PERL", but with a different name
called "PHP".
- Java is object-oriented but is very SLOW. Java programs run very
slow. Also Java is immensely complex and sophosticated technology
(has many layers like JVM, JIT compiler and others). And complexity
and sophostication leads to problems. If there is Linux on serverside
then why do you need Java in servers ? And Java is more like a
system programming language and it is faster to develop in
scripting languages (like PHP).
- Python is "good" but there are no C like brackets/braces which are
useful for code navigation in vi editor. It is like your hand is
broken if you cannot navigate rapidly the source code using
vi/emacs editor's seek braces/brackets commands. PHP is
technologically more advanced than Python.
- PHP is the best because it is object oriented and has the best
features of C/C++/Java/PERL/Python. It can replace PERL, Python,
Java, C, C++, awk, Unix shell scripting, MS Visual Basic and
others!! PHP runs direct and PHP is written in C.
- Each and every computer programmer knows why PHP is the best. Ask
your nearby computer programmer.
- Only PHP will prevail in the 21st and 22nd century and beyond!
- Why do think every PERL, Python and Java programmers are flocking
to PHP ?? There is a very strong reason.
- Every person in the world wants PHP. PHP blast is causing shockwaves
around the world!!
- The world is dominated by PHP. There is PHP everywhere and
anywhere... PHP, PHP, PHP everywhere..
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/2000/XP, 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 about 3.7 times faster than JSP (see ``''). PHP is extremely easy
to use and you can develop very complex web/e-commerce/generalstandalone
applications very rapidly in a very short period of time.
Developing applications in PHP is about TWO times faster than
developing in programming language like Java (because there is no need
for compilation in PHP). (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, Python 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/XP and all flavors of UNIX'es.
A big surprise is waiting for us - Most probably PHP will be the
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. First, you will write your application in PHP scripting
language during development, testing and debugging. Once the project
is ready for deployment you will use the Zend compiler to compile the
PHP to create executable which will run very fast.
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>
- Vex Net <http://www.vex.net/php>
Mirror sites are in many countries like www.COUNTRYCODE.php.net, where
COUNTRYCODE is like us, fe, sk etc.
- <http://www.fe.de.php.net>
- <http://www.sk.php.net>
- <http://php.iquest.net/>
- Questions e-mail to : rasmus@lerdorf.on.ca
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 UNIX'es. 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 about 3 times faster than Oracle or MS SQL server.
The PostgreSQL support code for PHP was written by Adam Sussman
asussman@vidya.com
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. ASP To PHP Converter - Migration From ASP2PHP
After installing PHP, you may want to migrate all the Microsoft ASP
programs to PHP. See the chapter ``ASP2PHP''.
3.5. PHP Installation on UNIX'es and others
See the installation guide and instructions at PHP main site
<http://www.php.net> or INSTALL file in the downloaded package itself.
3.6. PHP Installation on Apple Macintosh
Apple Macintosh is Unix like operating system. And actually it's
father is FreeBSD. It picked up many titbits from other Unices and is
quite powerful OS. See the Unix history at Unix Family Tree
<http://perso.wanadoo.fr/levenez/unix> and click on the item 12 to see
the Apple Mac position at Apple Mac tree
<http://perso.wanadoo.fr/levenez/unix/history.html#12>.
The installation and use of PHP on Apple Mac will be very similar to
that of on Unix OS.
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 see Form
classes, template classes at the site corporate Intranet/Internet
<http://www.milkywaygalaxy.freeservers.com>
- Third, design and create your own PHP classes by inheriting from
the generic PHP classes <http://phpclasses.upperdesign.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. Major Features of PHP
- Standard CGI, FastCGI and Apache module support - As a standard CGI
program, PHP can be installed on any UNIX machine running any UNIX
web server. With support for the new FastCGI standard, PHP can take
advantage of the speed improvements gained through this mechanism.
As an Apache module, PHP becomes an extremely powerful and
lightning fast alternative to CGI programmimg.
- Access Logging - With the access logging capabilities of PHP, users
can maintain their own hit counting and logging. It does not use
the system's central access log files in any way, and it provides
real-time access monitoring. The Log Viewer Script provides a quick
summary of the accesses to a set of pages owned by an individual
user. In addition to that, the package can be configured to
generate a footer on every page which shows access information. See
the bottom of this page for an example of this.
- Access Control - A built-in web-based configuration screen handles
access control configuration. It is possible to create rules for
all or some web pages owned by a certain person which place various
restrictions on who can view these pages and how they will be
viewed. Pages can be password protected, completely restricted,
logging disabled and more based on the client's domain, browser, email
address or even the referring document.
- PostgresSQL Support - Postgres is an advanced free RDBMS. PHP
supports embedding PostgreSQL "SQL queries" directly in .html
files.
- RFC-1867 File Upload Support - File Upload is a new feature in
Netscape 2.0. It lets users upload files to a web server. PHP
provides the actual Mime decoding to make this work and also
provides the additional framework to do something useful with the
uploaded file once it has been received.
- HTTP-based authentication control - PHP can be used to create
customized HTTP-based authentication mechanisms for the Apache web
server.
- Variables, Arrays, Associative Arrays - PHP supports typed
variables, arrays and even PERL-like associative arrays. These can
all be passed from one web page to another using either GET or POST
method forms.
- Conditionals, While Loops - PHP supports a full-featured C-like
scripting language. You can have if/then/elseif/else/endif
conditions as well as while loops and switch/case statements to
guide the logical flow of how the html page should be displayed.
- Extended Regular Expressions - Regular expressions are heavily used
for pattern matching, pattern substitutions and general string
manipulation. PHP supports all common regular expression
operations.
- Raw HTTP Header Control - The ability to have web pages send
customized raw HTTP headers based on some condition is essential
for high-level web site design. A frequent use is to send a
Location: URL header to redirect the calling client to some other
URL. It can also be used to turn off cacheing or manipulate the
last update header of pages.
- On-the-fly GIF image creation - PHP has support for Thomas
Boutell's GD image library which makes it possible to generate GIF
images on the fly.
- ISP "Safe Mode" support - PHP supports an unique "Safe Mode" which
makes it safe to have multiple users run PHP scripts on the same
server.
- Many more new features are being added in newer releases of PHP.
Visit the main web site at <http://www.php.net>
- It's Free! - One final essential feature. The package is completely
free. It is licensed under the GNU/GPL which allows you to use the
software for any purpose, commercial or otherwise.
5.1. Advantages of PHP over Java
PHP is an established server-side scripting language for creating
dynamic Web pages. As a language that has been designed expressly for
the Web, it brings many features that commercial entities are looking
for:
- Exceptionally short learning curve
- Quick development time
- Very high performance
This is essential for companies who are faced with scarce skilled
programming resources and ever-tighter time to market deadlines. In
addition, PHP supports all major platforms (UNIX, Windows and even
mainframes), and features native support for most popular databases.
All these factors make it a very good choice for Web development: such
shops working with PHP have reported being able to hire nonprogrammers
and have them producing usable code within days.
Programmers familiar with languages such as C, C++ or Java frequently
find that they can begin programming in PHP within a few hours.
The fact that PHP was designed specifically for Web development gives
it an edge as a development tool, as Intranet Design Magazine
explains:
"PHP was built with the needs of Web developers in mind... Unlike
other cumbersome, overhead-laden approaches, PHP is lightweight and
focused on the Web - where it can solve complex problem scenarios
quicker and more easily than comparable technologies."1
Java began its life as a programming language and was initially aimed
at running client-side applications inside of Web browsers. Over the
last few years, the problems associated with these "applets," as they
were known, has led Sun and many other Java developers to use the
language in other ways. One of the most prominent ways is in serverside
programming, allowing Web sites to connect to databases and
produce other server-side applications, or "servlets." Sun came out
with Java Server Pages (JSP) as a means of writing servlets. JSP, like
PHP, is highly portable across different platforms (even though PHP
supports any 32-bit or better platform, whereas JSP supports only
platforms that have a Java virtual machine available). However, a
beginner with no programming background will find it exceptionally
difficult to begin working with servlets,because of the complexity of
the language as well as the complicated JSP system design.
JSP's performance also leaves much to be desired: a recent survey in
ZDnet's eWeek online publication found that PHP is as much as 3.7
times faster than JSP. In the Web environment, this makes JSP a
significantly worse solution - because it can perform less
transactions per second, and features considerably slower response
times.
ZDnet's eWeek also noted that
"JSP is a relatively new technology and still has clear market
immaturities in terms of tools, support resources and available
talent."...Because JSP is based on Java, a strongly typed language, we
had to declare the types of variables we used and manually convert
between types when necessary. This makes JSP the hardest of the
scripting languages we tested for nonprogrammers to learn..."
5.1.1. Bad Points Of Java
- The server is under your control but you will never know what the
clients will be? MS Windows, Linux, Mac, Unix?? Java is designed
for client side computing with "Applets", "Swing" and "AWT".
- Java is a bad choice on the server-side! Since server OS is under
your control, you need something like PHP which runs directly
without any intermediate layers like Java virtual machine and JIT
compiler. You simply select Linux, Unix or MSWindows on server-side
and use PHP.
- Java is very complicated due to many layers like JVM, JIT, whereas
PHP is quite simple, fast and runs directly on the server operating
system. This means Java technologies can never be faster than PHP!
- Java technology is very bad choice on the server-side. When you
have Linux on server which is completely under your control why do
you need Java?? By the way, the browser clients never know that you
are using Linux + Apache + PHP !! (The clients may think that the
HTML pages are coming from MS Windows + MS IIS !! )
- Use Java technology on the client-side. Use Java inside web
browsers like Applets and other client applications like Swing, AWT
and others.
5.1.2. PHP works with Java
It is important to note JSP is just one language with which Java
objects can be accessed. PHP also can also integrate with Java, which
means that it can be used as the scripting language for activating
Java logic, just as much as JSP can. Unlike JSP, however, PHP also
integrates with other component models, such as Microsoft's COM, and
adding support for new object models is extremely easy. This means
PHP's extensibility is infinite. JSP, on the other hand, is completely
dependent on Java.
IBM programmer Sam Ruby uses PHP in combination with Java. Using the
native Java support in PHP, Java objects can be created and used
transparently, as if they were regular PHP objects.
AuctionWatch , which enables businesses of all sizes to benefit from
dynamic pricing environments, has over 2.6 million unique visitors per
month; 300K+ registered users; 1.2 million+ auctions launched every
month. They tried to use Java, but opted for PHP because it's easier
to use and much faster to develop with. For further information,
please contact Ben Margolin, Director of Seller Services for
AuctionWatch (ben@auctionwatch.com).
Programming consultant Reuven Lerner has made some comparisons among
the languages. His view of PHP is summarized as follows:
"The language is easy to learn. Graphic artists and Web designers
might claim that they are not programmers, but the fact is that
they're doing increasingly large projects in JavaScript, VBScript, and
other simple programming languages. PHP is much more regular and welldefined
than PERL, and is much easier for new programmers to grasp
than Java. Indeed, PHP seems like a server-side version of what
JavaScript could have been, but isn't. Someone with little or no
programming experience can learn PHP and work with it after a very
short period of time. This is probably true for VBScript, but
certainly not for PERL or Java....PHP is a truly remarkable and
powerful system. I can see why it has become a popular system for
producing Web sites.... I think that it will be a very strong
competitor against Java and JSPs, and will rise significantly in my
recommendations for clients and internal use."
5.1.3. PHP: Growing by the month
JSP enjoys the backing of Sun; hence its constant media attention. It
is interesting to note that despite the lack of any publicity
campaign, PHP's popularity is growing at a monthly rate of 8-11%, a
percentage far greater than the Internet's 4% monthly growth -- as the
demand for server-based applications has risen. More than 6.5 million
sites use PHP (Netcraft May 2001 survey). PHP is used on 39% of Apache
servers; PERL trails fourth, with 11% of the market. Apache maintains
59% of the Web server market; Microsoft IIS is second, with 28% of
market share (E-Soft Inc./SecuritySpace's May 2001 report).
Prominent corporations using PHP include Unilever, Philips, NTT,
Cisco, Japan Airlines, Air Canada, Lufthansa, GE Marketplace,
Wallstreet:Online Germany; AuctionWatch, VillageVoice, Dialpad and
BMC.
- Intranet Design Magazine: PHP From an IT Manager's Perspective, Jun
4, 2000.
<http://linuxtoday.com/news_story.php3?ltsn=2000-06-04-002-04-NWHL
-SW>
- eWEEK: Four scripting languages speed development, October 30,
2000.
<http://www.zdnet.com/eweek/stories/general/0,11011,2646052,00.html>
- Brief History of PHP
PHP began life as a simple little cgi wrapper written in PERL. The
name of this first package was Personal Home Page Tools, which later
became Personal Home Page Construction Kit.
Old name is Professional Home Pages (PHP) and new name is PHP
Hypertext Pre-Processor.
A tool was written to easily embed SQL queries into web pages. It was
basically another CGI wrapper that parsed SQL queries and made it easy
to create forms and tables based on these queries. This tool was named
FI (Form Interpreter).
PHP/FI version 2.0 is a complete rewrite of these two packages
combined into a single program. It evolved to a simple programming
language embedded inside HTML files. PHP eliminates the need for
numerous small PERL cgi programs by allowing you to place simple
scripts directly in your HTML files. This speeds up the overall
performance of your web pages since the overhead of forking PERL
several times has been eliminated. It also makes it easier to manage
large web sites by placing all components of a web page in a single
html file. By including support for various databases, it also makes
it trivial to develop database enabled web pages. Many people find the
embedded nature much easier to deal with than trying to create
separate HTML and CGI files.
Now PHP/FI is renamed as PHP.
7. A Simple Example
Suppose you have a form:
<FORM ACTION="/cgi-bin/php.cgi/~userid/display.html" METHOD=POST>
<INPUT TYPE="text" name="name">
<INPUT TYPE="text" name="age">
<INPUT TYPE="submit">
<FORM>
Your display.html file could then contain something like:
< ?echo "Hi $ name, you are $ age years old!<p>" >
It's that simple! PHP automatically creates a variable for each form
input field in your form. You can then use these variables in the
ACTION URL file.
The next step once you have figured out how to use variables is to
start playing with some logical flow tags in your pages. For example,
if you wanted to display different messages based on something the
user inputs, you would use if/else logic. In our above example, we can
display different things based on the age the user entered by changing
our display.html to:
<?
if($age>50);
echo "Hi $name, you are ancient!<p>";
elseif($age>30);
echo "Hi $name, you are very old!<p>";
else;
echo "Hi $name.";
endif;
>
PHP provides a very powerful scripting language which will do much
more than what the above simple example demonstrates. See the section
on the PHP Script Language for more information.
You can also use PHP to configure who is allowed to access your pages.
This is done using a built-in configuration screen. With this you
could for example specify that only people from certain domains would
be allowed to see your pages, or you could create a rule which would
password protect certain pages. See the Access Control section for
more details.
PHP is also capable of receiving file uploads from any RFC-1867
compliant web browser. This feature lets people upload both text and
binary files. With PHP's access control and logical functions, you
have full control over who is allowed to upload and what is to be done
with the file once it has been uploaded. See the File Upload section
for more details.
PHP has support for the PostgreSQL database package. It supports
embedded SQL queries in your .HTML files.
PHP also has support for the mysql database package. It supports
embedded SQL queries in your .HTML files.
8. SOAPX4 and PhpXMLP
SOAP is an XML-based protocol for messaging and RPC-style
communication between two processes. The World Wide Web Consortium's
XML Protocol (XP) Working Group is working on a SOAP standard, which
will be called XP.
The SOAPX4 (Simple Object Access Protocol) implementation for PHP is
at <http://dietrich.ganx4.com/soapx4>.
Alternate SOAP implementation is at
<http://sourceforge.net/projects/phpxmlp>.
8.1. XML/XSLT Publishing Engine
Krysalis is the XML/XSLT publishing engine, inspired from Cocoon but
adapted to the PHP technology.
InterAKT has developed Krysalis to achieve what the next generation of
web services have to offer - the complete separation of the
information, application logic and presentation layer.
Krysalis is an open-source PHP development platform, based on the
XML/XSLT core. It reused most of PHAkt code to create the Krysalis
taglib library.
Major features are:
- Dynamic XML support.
- Dynamic PDF generation.
- Sitemap description with regular expressions.
- PXP page caching.
- Multiple transformation pipelines.
- Multiple connection types to various databases (ADODB).
Please visit the Krysalis site for more information
<http://www.interakt.ro/products/Krysalis>.
9. 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.
9.1. 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>.
- 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 peartutorials
<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/PostgreSQLHOWTO.
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 CGIResources
<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>
9.2. 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>
10. PHPGem package
PHPGem is a PHP-script which accelerates the creation of PHP-scripts
for working with tables. It works with different SQL-servers such as
PostgreSQL, MySQL, mSQL, ODBC, and Adabas. You input a description of
and parameters for your tables' fields (field name, on/off searching
in the field, etc.), and PHPGem outputs another PHP-script which will
work with the tables (view/add/edit/delete/duplicate entries and
search). PHPGem works with multi-level nested tables. PHPGem allows
you to specify a level of access for each table and for each field for
each user. PHPGem also support images.
PHPGem is at <http://sptl.org/phpgem>
11. 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.
11.1. Build PHP based corporate Intranet and Internet
Visit the site corporate Intranet/Internet
<http://www.milkywaygalaxy.freeservers.com> for a very good comparison
and listing of applications.
11.2. Popular PHP Applications
The most popular PHP applications in the order are:
- PHP-Nuke <http://www.hotscripts.com/Detailed/5947.html> and the
mainsite <http://phpnuke.org>
- Smarty <http://www.hotscripts.com/Detailed/8817.html> and the
mainsite <http://www.phpinsider.com/php/code/Smarty>
- eZ Publish <http://www.hotscripts.com/Detailed/7894.html> and the
mainsite <http://developer.ez.no/article/static/7>
- Mambo Portal/Content Mgmt
<http://www.hotscripts.com/Detailed/10068.html> and the mainsite
<http://www.miro.com.au>
- PHP Content Management System
<http://www.hotscripts.com/Detailed/8455.html> and the mainsite
<http://mcyra.homeip.net/homepage/phpcms/index.htm>
- PHP Shop <http://www.hotscripts.com/Detailed/4131.html> and the
mainsite <http://www.phpshop.org>
- phpWebSite <http://www.hotscripts.com/Detailed/9026.html> and the
mainsite <http://phpwebsite.appstate.edu>
- myPHPCalendar <http://www.hotscripts.com/Detailed/4182.html> and
the mainsite <http://myPHPCalendar.sourceforge.net>
- 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:
11.3. PHP Web Application Servers
The following are available for PHP:
- LogiCreate WebApp Server (for PHP)
The LogiCreate system was designed primarily with open source
technologies of Linux, Apache and PHP, LogiCreate provides a unique
value in price/performance and costs are kept reasonable. Visit
<http://www.logicreate.com> and click on Download button and read
the white papers there.
- 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/PostgreSQLHOWTO.
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>.
- Ampoliros <http://www.ampoliros.com> Ampoliros is an advanced and
easy to use distributed PHP Web applications platform, featuring a
powerful Xml-Rpc and Soap interface. It is suitable as an
Internet/Intranet development and deployment system. It has a very
strong modular architecture and allows very fast deployment of web
solutions. Ampoliros is backed by Solarix, which offers
customization, complete Ampoliros based solutions, support,
developer programs and other services.
11.4. 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>.
11.5. 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>
- Content Management system (CMS) PostNuke at <http://postnuke.com>
12. 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:
- All private variables and functions always start with underscore
"_" followed by lowercase letters like var $_myvar;
- All Protected variables and functions always start with "_T"
followed by lowercase letters like var $_Tmyvar;
- All Public variables and functions do not start with underscore "_"
like var $myvar;
- 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.
13. HTML Editor
HTML editors for PHP on Windows 95/NT/2000 are:
The best HTML editor is 1st Page 2000, and it is a excellent HTML
editor.
14. 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.
14.1. PHP IDE
PHP IDE tools are at :
- PHAktThe PHP support in Macromedia Dreamweaver UltraDev that allows
Ultradev Developers to create PHP sites PHAkt
<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" is now renamed to Maguma and is
available at <http://www.maguma.com/english/index.php>
- HAPEdit at <http://hapedit.free.fr>
- Cross-platform IDE : Activestate Komodo
<http://www.activestate.com/Products/Komodo>
- 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''
14.2. 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-serviceboerner.
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)
- Code-genie editor similar to UltaEdit or TextPad but smaller in
size <http://www.code-genie.com>
- 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>
14.3. 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/UNIX)
<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>
14.4. PHP IDE for Linux only
The best IDE for PHP on linux is Coffeecup Editor as given below:
14.5. PHP Utilities
Zend is a server-side caching software speeds up Web site performance,
maximizes hardware resources, and improves the online experience of
customers, providing a good return on investment. Zend accelerator
caches PHP scripts, helping to reduce processing time and Web server
load while enabling administrators to monitor site performance in
real time. Cost is $980 and supports Linux, Solaris and FreeBSD.
Zends provides:
- Enables IT to serve more Web site visitors with existing hardware
- Speeds up Web site response time
- Provides real-time performance monitoring
- Zend Optimizers <http://www.zend.com>
- Zend Compilers <http://www.zend.com>
- IonCube PHP Accelerator (PHPA) <http://www.php-accelerator.co.uk>
The ionCube PHP Accelerator is an easily installed PHP Zend engine
extension that provides a PHP cache, and is capable of delivering a
substantial acceleration of PHP scripts without requiring any
script changes, loss of dynamic content, or other application
compromises.
- APC "Alternative PHP Cache" is an open-source alternative to Zend's
commercial accelerator which is at
<http://apc.communityconnect.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>
15. Code Protection - Encoding Source Code
If you want to distribute your PHP source code to your clients, you
may want to encode it to protect your code so that it cannot be viewed
by the users. Use encoding to hide password, encode scripts etc.
Many enterprises require securing the source code as a pre-condition
for release process.
Use one of the following Encoding tools:
To convert ASP scripts to PHP use this utility
<http://asp2php.naken.cc>
See also <http://www.asp2php.com>
17. 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 latest version of ctags
supports PHP language and is available from
<http://ctags.sourceforge.net>.
NOTE: Do NOT use the ptags given below but instead use the latest
ctags which supports PHP language. The program below is just a
exercise and sample and was created when older versions of ctags did
not support PHP. The listing below is kept for historical reasons (a
musuem).
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: alavoor[AT]yahoo.com
// 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;
}
18. PHP documenter (like Javadoc)
- The phpDocumentor is a script for creating documentation from
comments in php code. It is at <http://phpdocu.sourceforge.net>.
- The Doxygen documentation <http://www.stack.nl/~dimitri/doxygen>
system can be used along with this Doxygen PHP PERL
<http://www.stack.nl/~dimitri/doxygen/download.html#latestman>
script. Download Doxygen and the PERL script from download page.
- PHPXref is a small PERL script to make working with the source code
of a large PHP site somewhat easier. Cross references functions,
variables and database tables defined and used across your various
PHP files Generates documentation for each function defined in the
PHP files by utilizing formatted comments placed next to each
function The output is a tree of HTML files that can be downloaded
and browsed on a local machine without having to setup a web
server, etc. It is at <http://phpxref.sourceforge.net>.
19. Debugging PHP
You can use one of the following debuggers.
List of PHP debuggers :
- <http://download.php.net/manual/en/debugger.php>.
- <http://dd.cron.ru/dbg>
- Zend-IDE has PHP debugger
<http://www.zend.com/store/products/zend-ide.php>
- Soysal editor has PHP debugger <http://www.soysal.com/PHPEd>
- APD (Advanced PHP Debugger) <http://apd.communityconnect.com>
- PHP symbolic debugger
<http://members.ozemail.com.au/~djf01/body.html> and at
<http://freshmeat.net/projects/body-phpdebugger>
- Cross-platform IDE : Activestate Komodo
<http://www.activestate.com/Products/Komodo>
- The PHP Symbolic Debugger called Body
<http://members.ozemail.com.au/~djf01/body.html>
- PHP Debugger called 'phpCodeSite' is available at
<http://phpcodesite.phpedit.com> and see also ``Appendix C''
- Code crusader <http://www.newplanetsoftware.com/jcc>
- PHP Debugger is available at <http://www.phpdebug.com>
19.1. 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: alavoor[AT]yahoo.com
#*****************************************************************
# 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.
20. General purpose programming with PHP
PHP is very powerful and is designed such that it can replace awk,
sed, UNIX shell, PERL, Python, "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 build the CGI version of PHP, you can use it from the command
line simply typing: php filename where filename is the file you want
to parse. You can also create standalone PHP scripts by making the
first line of your script look something like:
#!/usr/local/bin/php -q
The "-q" suppresses the printing of the HTTP headers. You can leave
off this option if you like.
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 -q 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 -q filename.php
C:\> php -h
C:\> php -?
or
C:\> c:\Program Files\php\bin\php filename.php
20.1. 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/UNIX'es.
21. Web Application Standards - Fusebox
Fusebox is a FREE web application standard attempting to reduce the
70% software failure rate by creating a standard methodology for
writing web applications. This development methodology works with ANY
web application small and large.
- Fusebox Org <http://www.fusebox.org>
- PHP-Fusebox development <http://php-fusebox.sourceforge.net>
- <http://bombusbee.com>
- Techsedition <http://www.techspedition.com>
- <http://www.fusebox.com>
- <http://www.devshed.com/Server_Side/PHP/Fusebox>
22. 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://24.221.230.253/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://24.221.230.253/php-perlbenchmarks.
html>
Whenever you design a web site, give attention to these important
points:
Everything has limitations or disadvantages and PHP is no exception.
The following are the limitations of PHP (so be WARNED !!)
- 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..).
- 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 .
- But note a point that PHP was designed for very Rapid WebApplication
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 -
- You can very rapidly develop web applications in PHP as compile and
link is eliminated in PHP scripting language.
- 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 !!
- PHP has excellent database conectivity to all SQL database servers.
- PHP has partial support for Object oriented features
- PHP has C++, PERL, Javascript like syntax features and has programs
like
- PHP has Zend optimizer which speeds up the performance
- PHP runs on all UNIX'es, linux, Windows 95/NT/2000 and is more
powerful than ASP, JSP and others.
- 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>
24. 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 CGIResources
<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>
- PHP tutorials at <http://www.cgi-network.net>
- LinuxGuruZ PHP tutorials at <http://www.linuxguruz.org>
- PHP Wizard <http://www.phpWizard.net>
In this tutorial we assume that your server has support for PHP
activated and that all files ending in .php are handled by PHP. If
you are using Apache then you should edit httpd.conf and make
appropriate changes to enable PHP.
Your first PHP-enabled page: Create a file named hello.php and in it
put the following lines:
<html>
<head>
<title>
PHP Test</title>
</head>
<body>
<h1>
This is an example of php script.
<br>
Below, you will see one line saying 'Hello World' and 'foo is foobar':
</h1>
<?php
echo "Hello World";
$foo = "foobar";
echo "<br>foo is $foo";
?>
</body>
</html>
Copy this file hello.php to the directory known to Apache, like
/var/www/html which is also known as DocumentRoot in httpd.conf file.
Now, to run this example, bring up a web browser and type the URL
http://localhost/hello.php or you can type http://127.0.0.1/hello.php.
But make sure you bring up Apache web server on your system. When you
run the example you will get an output like:
This is an example of php script.
Below, you will see one line saying 'Hello World' and 'foo is foobar':
Hello World
foo is foobar
If you get some errors or if you see the file with tags then your
Apache Web server may not be working properly or PHP is not enabled.
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 !!
24.1. 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:
- John looks at the product catalog.
- Jane looks at the product catalog.
- John adds an item to his basket.
- Jane adds an item to her basket.
- John goes to the checkout.
- 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.
24.2. 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 is either stored in a
cookie on the client's PC or is propagated in the URL.
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. If you leave this set to a world-readable directory,
such as /tmp (the default), other users on the server may be able to
hijack sessions by getting the list of files in that directory.
session.save_path defines the argument which is passed to the save
handler. If you choose the default files handler, this is the path
where the files are created. Defaults to /tmp.
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).
24.3. Session Propagation
There are two methods to propagate a session id:
The session module supports both methods. Cookies are optimal, but
since they are not reliable (clients are not bound to accept them),
we cannot rely on them. The second method embeds the session id
directly into URLs.
PHP is capable of doing this transparently when compiled with
--enable-trans-sid. If you enable this option, relative URIs will be
changed to contain the session id automatically. Alternatively, you
can use the constant SID which is defined, if the client did not send
the appropriate cookie. SID is either of the form
session_name=session_id or is an empty string.
The following example demonstrates how to register a variable, and how
to link correctly to another page using SID.
Example : Counting the number of hits of a single user
<html>
<h1>Example : Counting the number of hits of a single user</h1>
<br>
<php
session_register ("count");
$count++;
?>
Hello visitor, you have seen this page <?php echo $count; ?> times.<p>;
<php
# the <?=SID?> is necessary to preserve the session id
# in the case that the user has disabled cookies
?>
To continue, <A HREF="nextpage.php?<?=SID?>">click here</A>
<html>
The <?=SID?> is not necessary, if --enable-trans-sid was used to com
pile PHP.
Note: Non-relative URLs are assumed to point to external sites and
hence don't append the SID, as it would be a security risk to leak the
SID to a different server.
24.4. 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.
24.5. 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',
-> 'root@mymarket.com',
-> '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> ).
25. PHP Training & PHP Help Desk
To obtain hands on training and to attend PHP courses:
- PHP Training - 5 day hands on courses
<http://www.tapinternet.com/php>
- PHP Help Desk - 'as needed' live support (phone/email/chat), code
audits for performance and security, and more. Visit
<http://www.phphelpdesk.com>
26. 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/PostgreSQLHOWTO.
html> at pgsql-howto
<http://www.geocities.com/alavoor/HOWTO/pgsql/PostgreSQLHOWTO.
html>
- Source code control system CVS HOWTO for C++ programs
<http://metalab.unc.edu/LDP/HOWTO/CVS-HOWTO.html>
- Linux goodies main site is at <http://24.221.230.253> and
secondary site at <http://www.milkywaygalaxy.freeservers.com>
Mirror sites are at - angelfire
<http://www.angelfire.com/country/aldev0>, geocities
<http://www.geocities.com/alavoor/index.html>, virtualave
<http://aldev0.virtualave.net>, Fortunecity
<http://members.fortunecity.com/aldev>, Freewebsites
<http://aldev.freewebsites.com>, Tripod
<http://members.tripod.lycos.com/aldev>, 101xs
<http://www.101xs.com/101xs/aldev>, 50megs
<http://aldev0.50megs.com>,
27. 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 -
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
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)
27.1. 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.
27.2. 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.
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>
27.3. 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.
27.4. 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.
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.
28. 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.
29. Appendix A PHP examples
29.1. PostgreSQL large object Example
Submitted by: PHP code exchange px@sklar.com 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);
?>
29.2. 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 $PHP_AUTH_PW as your password.<P>";
}
?>
29.3. Network admin Example
To get this file, in the web-browser, save this file as 'Text' type as
network.lib
PHP: network adminstrator's best friend from
<http://www.phpWizard.net>
As a web-developer, you're probably used to such lovely tools as ping,
whois, nslookup etc. But what when you need one of those utilities at
a client's office and have no access to telnet? Good guess. Time to
look up the functions in the "Network" section of the PHP manual.
Socket operations:
The most important function there is fsockopen(). Using this function,
you can connect to any open port on a server and establish a socket
connection with it. The function's syntax is as following:
int fsockopen(string hostname, int port, int [errno], string [errstr]);
The first two arguments are obvious, the next two are optional and
used for error handling. The "errno" and "errstr" should be passed by
reference. "Passing by reference" means that the original variable
will get modified. Normally, the content of a variable passed to a
function wouldn't be modified.
So, you could use this function to open a connection to a webserver
and print out the headers:
function get_headers($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 | 
