PHP HOW-TO

PHP HOW-TO
Al Dev (Alavoor Vasudevan) [email protected]
v15.0, 21 Jan 2001

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

Table of Contents

1. Introduction

2. PHP Download

2.1 PHP Installation on Microsoft Windows 95/98/NT/2000
2.2 Apache Webserver Quick-Install (10 seconds) on Microsoft Windows 95/98/NT/2000
2.3 SQL server for Microsoft
2.4 PHP Installation on unixes and others

3. PHP Tutorial

3.1 Primer on PHP Sessions
3.2 Session Management in PHP4
3.3 User Management and Privileges
3.4 Step1: Creating the Users Table

4. PHP Web Application Servers

5. IDE tools for PHP

5.1 PHP IDE
5.2 PHP IDE for MS Windows only
5.3 PHP IDE for both MS Windows and Linux
5.4 PHP IDE for Linux only
5.5 PHP Utilities
5.6 Convert Microsoft ASP scripts to PHP - ASP2PHP

6. ctags for PHP ! Surprise!!!

7. Debugging PHP

7.1 Debug Tools
7.2 Debug with FILE and LINE

8. PHP Libraries

8.1 Other PHP Utilities
8.2 PHP Templates

9. Limitations of PHP

10. Related URLs

11. Other Formats of this Document

12. Copyright

13. Appendix A Database Wrapper Example

14. Appendix B SQL abstraction Example

15. Appendix C PostgreSQL large object Example

16. Appendix D User authentication Example

17. Appendix E Network admin Example

18. Appendix F PostgreSQL Database Wrapper Examples

19. Appendix G Microsoft SQL Server DB Wrapper Example

20. Appendix H Sybase SQL Server DB Wrapper Example

21. Appendix I phpDB.inc Example

22. Appendix J phpDBTest.php3 Example
23. Appendix H Midgard Installation

23.1 Testing Midgard PHP Server
23.2 Security OpenSSL

______________________________________________________________________

1. Introduction

PHP stands for 'Hypertext Pre-Processor' and is a server side HTML
scripting/programming language. PHP is a tool that lets you create
dynamic web pages. PHP-enabled web pages are treated just like regular
HTML pages and you can create and edit them the same way you normally
create regular HTML pages.

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

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

PHP runs 5 to 20 times faster than Java!! It is extremely easy to use
and you can develop very complex web/e-commerce applications very
rapidly in a very short period of time.

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

PHP is the real gem of all the scripting/programming languges and will
soon become the "MECCA" for programmers world-wide!! PHP has a huge
user base and a large developer base as it runs on both window95/NT
and all flavors of unixes.

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

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

2. PHP 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>

2.1. 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!! PHP runs lot faster than ASP on MS Windows and has more
features and functionalities than Microsoft ASP. PHP is much more
robust, reliable and powerful than ASP. And the user base of PHP is
extremely large because PHP runs on MS Windows, Linux, Mac OS and all
unixes. Greatest advantage of PHP is that you can develop on MS
Windows and deploy on Linux or Unix and vice versa!!

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

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

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

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

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

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

2.3. 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 RPMs on it. You do not need any
windows graphics for a database server and at console mode startup the
PostgreSQL server. PostgreSQL is 3 times faster than Oracle or MS SQL
server. You can also order ready-to-go cheap Linux boxes from
<http://www.egghead.com>, go here and click on Autions and Linux
boxes. You get best deals in live Auctions.

You can also get PostgreSQL for Windows NT/2000 from
<http://www.askesis.nl>.

See also the PostgreSQL howto at at
<http://www.linuxdoc.org/HOWTO/PostgreSQL-HOWTO.html>

2.4. PHP Installation on unixes and others

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

3. 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>

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

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

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

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

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

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

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

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

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

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

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

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

______________________________________________________________________
<?php echo $HTTP_USER_AGENT; ?>
______________________________________________________________________

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

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

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

______________________________________________________________________
<?php phpinfo()?>
______________________________________________________________________

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

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

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

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

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

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

You are using Internet Explorer

Dealing with Forms

One of the most powerful features of PHP is the way it handles HTML
forms. The basic concept that is important to understand is that any
form element in a form will automatically result in a variable with
the same name as the element being created on the target page. This
probably sounds confusing, so here is a simple example. Assume you
have a page with a form like this on it:

______________________________________________________________________
<form action="action.php3" method="POST">
Your name: <input type=text name=name>
You age: <input type=text name=age>
<input type=submit>
< /form>
______________________________________________________________________

There is nothing special about this form. It is a straight HTML form
with no special tags of any kind. When the user fills in this form and
hits the submit button, the action.php3 page is called. In this file
you would have something like this:

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

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

3.1. Primer on PHP Sessions

This section is written by Ying Zhang .

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

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

Let's illustrate this a little bit:

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

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

1. John looks at the product catalog.

2. Jane looks at the product catalog.

3. John adds an item to his basket.

4. Jane adds an item to her basket.

5. John goes to the checkout.

6. Jane goes to the checkout.

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

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

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

3.2. Session Management in PHP4

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

______________________________________________________________________
session_start();
session_register();
______________________________________________________________________

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

session_register("SESSION");

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

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

instead of

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

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

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

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

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

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

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

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

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

You will see something like this:

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

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

______________________________________________________________________
# more /tmp/sess_a3058a6bb1baf57f565c3844c8810f4b
______________________________________________________________________

You will see something like this:

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

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

3.3. User Management and Privileges

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

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

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

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

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

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

3.4. Step1: Creating the Users Table

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

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

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

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

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

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

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

4. PHP Web Application Servers

The following are available for PHP:

� Midgard PHP Web Application server is based on the PHP scripting
language and PHP runs extremely fast - faster than Java. 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

5. 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.

See also ``Midgard Web Application Server''

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!!

5.1. PHP IDE

PHP IDE tools are at :

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

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

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

5.2. PHP IDE for MS Windows only

PHP IDE/editor on MS Windows platform are :

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

� IDE for PHP PHP coder (MS Windows):
<http://phpcoder.stsoft.cjb.net>

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

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

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

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

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

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

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

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

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

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

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

5.3. PHP IDE for both MS Windows and Linux

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

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

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

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

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

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

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

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

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

5.4. PHP IDE for Linux only

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

� PHP editor (the BEST IDE for linux)
<http://www.coffeecup.com/select/editor.html> (rating 5 stars).

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

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

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

5.5. PHP Utilities

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

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

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

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

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

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

5.6. Convert Microsoft ASP scripts to PHP - ASP2PHP

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

6. ctags for PHP ! Surprise!!!

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

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

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

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

#define BUFF_LEN 1024
#define LOCATION 9

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

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

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

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

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

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

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

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

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

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

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

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

return dd;
}

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

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

7. Debugging PHP

7.1. Debug Tools

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

7.2. Debug with FILE and LINE

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

______________________________________________________________________
<?php

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

For a large group of files -

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

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

8. PHP Libraries

Visit the following web sites which have large collections of ready to
use PHP Libraries. These libraries will save you lots of time

� PHP Lib Netuse <http://phplib.netuse.de>

� 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>

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

8.1. 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>

8.2. PHP Templates

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

9. Limitations of PHP

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

1. PHP is NOT 100 % pure Object Oriented scripting language. PHP is
good if your PHP code size does not exceed 3,00,000 lines.
Maintainence of PHP code greater than 3,00,000 lines becomes more
difficult.

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

3. But note a point that PHP was designed for very Rapid Web-
Application Development tool. If it takes about 2 months to code a
web application in C++, then using PHP you can develop the same web
application in about 4 days!! And with zend optimizer, the speed
of execution of PHP will be very close to that of equivalent C++
program!!

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

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

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

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

4. PHP has partial support for Object oriented features

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

6. PHP has Zend optimizer which speeds up the performance

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

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

WARNING: 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>

10. 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://metalab.unc.edu/LDP/HOWTO/PostgreSQL-HOWTO.html>

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

� Linux goodies main site <http://www.aldev.8m.com>

� Linux goodies mirror site <http://aldev.webjump.com>

11. Other Formats of this Document

This document is published in 12 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 and SGML.

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

� Plain text format is in:
<ftp://sunsite.unc.edu/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>

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

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

� sgml2html PHP-HOWTO.sgml (to generate html file)

� sgml2rtf PHP-HOWTO.sgml (to generate RTF file)

� sgml2latex PHP-HOWTO.sgml (to generate latex file)

LaTeX documents may be converted into PDF files simply by producing a
Postscript output using sgml2latex ( and dvips) and running the output
through the Acrobat distill ( <http://www.adobe.com>) command as
follows:
______________________________________________________________________
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.

This howto document is located at -

� <http://sunsite.unc.edu/LDP/HOWTO/PHP-HOWTO.html>

Also you can find this document at the following mirrors sites -

� <http://www.caldera.com/LDP/HOWTO/PHP-HOWTO.html>

� <http://www.WGS.com/LDP/HOWTO/PHP-HOWTO.html>

� <http://www.cc.gatech.edu/linux/LDP/HOWTO/PHP-HOWTO.html>

� <http://www.redhat.com/linux-info/ldp/HOWTO/PHP-HOWTO.html>

� Other mirror sites near you (network-address-wise) can be found at
<http://sunsite.unc.edu/LDP/hmirrors.html> select a site and go to
directory /LDP/HOWTO/PHP-HOWTO.html

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

xdvi -geometry 80x90 howto.dvi
man xdvi

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

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

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

To read postscript document give the command -

gv howto.ps
ghostscript howto.ps

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

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

12. 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.

13. Appendix A Database Wrapper Example

Submitted by: Barton Greg [email protected] To get this file, in the
web-browser, save this file as 'Text' type as pgsql.lib

______________________________________________________________________
This is a database wrapper for PostgreSQL, but
can be simply modified for any other database type.

<?php

if ($dbObjDefined != 1)
{
$dbObjDefined = 1;

// Wrapper class for database calls
class dbObj
{
// Connection handle to database
var $conn;

// Default connection parameters
var $host = "YourSite.com";
var $user = "johndoe";
var $password = "pwd";
var $port = "5432";
var $dbname = "MyDB";

// Open initial connection. $params is
// an associative array holding
// parameters to the pg_Connect function.
function init($params)
{
if(isset($parame[host]))
$host = $parame[host];
else
$host = $this->host;

if(isset($parame[user]))
$user = $parame[user];
else
$user = $this->user;

if(isset($parame[password]))
$password = $parame[password];
else
$password = $this->password;

if(isset($parame[port]))
$port = $parame[port];
else
$port = $this->port;

if(isset($parame[dbname]))
$dbname = $parame[dbname];
else
$dbname = $this->dbname;

$this->conn = pg_Connect ( " host=$host user=$user password=$password port=$port dbname=$dbname ");
}

// Send SQL to database connection.
// Return recordset object on success.
// Return 0 on failure.
function exec($SQL)
{
$this->resultset = pg_Exec($this->conn, $SQL);

if ($this->resultset)
{
$recset = new recordset;
$recset->init($this->resultset);
return $recset;
}
else
{
return 0;
}
}

function valid()
{
return $this->resultset;
}

// Close connection to database
function free()
{
pg_close($this->conn);
}
};

/*
** This is a simple recordset class which can be
** traversed using next(), prev(), and current() methods.
** It is initialized from a resultset returned from the
** function "pg_Exec" or can be generated by a call to the
** exec method from the dbObj class given above.
** Below "Tuples" means rows.
*/
class recordset
{
var $resultset;
var $index;
var $numFields;
var $numTuples;

function init($newResultset)
{
$this->resultset = $newResultset;
$this->index = 0;
$this->numFields = pg_NumFields($this->resultset);
$this->numTuples = pg_NumRows($this->resultset);
}

// Used in display() below
function valid()
{
return $this->resultset;
}

// Get a value by row number and either
// column name or column number
function getVal($row, $col)
{
return pg_Result($this->resultset, $row, $col);
}

// Return an array of field names
function getFields()
{
for ($i=0; $i < $this->numFields; $i++)
$retArray[] = pg_FieldName($this->resultset, $i);
return $retArray;
}

// Get number of columns in resultset
function getNumFields()
{
return $this->numFields;
}

// Get a tuple (associative array of
// column values) by row number
function getTupleDirect($row)
{
for ($i=0; $i < $this->numFields; $i++)
{
$retArray[pg_FieldName($this->resultset, $i)] =
pg_Result($this->resultset, $row, $i);
}
return $retArray;
}

// Get an array filled with all values in a column
// (using either column name or column number)
function getColumn($col)
{
for ($i=0; $i < $this->numTuples; $i++)
$retArray[] = pg_Result($this->resultset, $i, $col);
return $retArray;
}

// Return the number of records in the recordset
function getNumTuples()
{
return $this->numTuples;
}

// Get tuple pointed to by the current index
function getTuple()
{
if ($this->index >= 0 && $this->index < $this->numTuples)
return $this->getTupleDirect($this->index);
else
return 0;
}

function valueof($col)
{
if ($col < $this->numFields)
{
return pg_Result($this->resultset, $this->index, $col);
}
else
{
return "";
}
}

// Reached last row - end of rows ? Used in display() below
function eof()
{
return $this->index == $this->numTuples;
}

// Return 1 if index is within bounds of the recordset
function current()
{
if ($this->index >= 0 && $this->index < $this->numTuples)
return 1;
else
return 0;
}

// Increment index. Used in display() below
function next()
{
if ($this->index < $this->numTuples)
{
$this->index++;
return 1;
}
else
{
return 0;
}
}

// Decrement index
function prev()
{
if ($this->index >= 0)
{
$this->index--;
return 1;
}
else
{
return 0;
}
}

// Reset index to 0 - See also first()
function reset()
{
$this->index = 0;
}

// See also reset(). Used in display() below
function first()
{
$this->index = 0;
}

function last()
{
$this->index = $this->numTuples -1 ;
}

// Used in display() below
function showheader($col, $fmt = "")
{
printf("\t< th %s>%s< /th >\n", $fmt,
is_string($col) ? $col : pg_fieldname($this->resultset, $col));
}

// Used in display() below
function showvalue($col, $fmt = "", $def = " ")
{
$v = $this->valueof($col);
printf( "\t< td %s>%s< /td>\n", $fmt, $v == "" ? $def : $v);
}

function showurl($col, $fmt = "")
{
$v = $this->valueof($col);
if ( $v != "" )
{
printf("\t< td %s> < /td>\n", $fmt);
}
else
{
printf( "\t< td %s>< a href=%s>%s< /a>< /td>\n", $fmt, $v, $v);
}
}

function display()
{
if (!$this->valid() )
{
return;
}

printf( "<table cellspacing=1 cellpadding=1 border=1>\n");

printf( "<tr>\n");
for ($c = 0; $c < $this->cols; $c++ )
{
$this->showheader($c);
}
printf( "< /tr>\n");

$this->first();
while (!$this->eof())
{
printf( "<tr>\n");

for ($c = 0; $c < $this->cols; $c++)
{
$this->showvalue($c);
}

printf( "< /tr>\n");
$this->next();
}
printf("< /table\n");
}

// Free memory allocated to recordset.
function free()
{
pg_Freeresult($this->resultset);
}
};
}

?>
______________________________________________________________________

14. Appendix B SQL abstraction Example

Submitted by: Gianugo Rabellino [email protected] To get this file, in
the web-browser, save this file as 'Text' type as sqlabst.lib

______________________________________________________________________

PX: PHP Code Exchange
<?php

/*
* SAL - SQL Abstraction Library
* version 0.01
*/

/*
** Set the variable $dbtype to any of the following
** values: MySQL, mSQL, Postgres, ODBC before including this library
*/
// $dbtype = "MySQL";
// $dbtype = "mSQL";
// $dbtype = "PostgreSQL";
// $dbtype = "ODBC";

// SQL_connect($host, $user, $password, $db)
// returns the connection ID

function SQL_connect($host, $user, $password, $db)
{
global $dbtype;

switch ($dbtype)
{
case "MySQL":
$conn=mysql_pconnect($host, $user, $password);
mysql_select_db($db);
return $conn;
break;;

case "mSQL":
$conn=msql_pconnect($host);
msql_select_db($db);
return $conn;
break;;

case "PostgreSQL":
$conn=pg_pconnect($host, "5432", "",$db);
return $conn;
break;;

case "ODBC":
$conn=odbc_pconnect($db,$user,$password);
return $conn;
break;;

default:
$conn=mysql_pconnect($host, $user, $password);
mysql_select_db($db);
return $conn;
break;;
}
}

// SQL_query($host, $user, $password, $db)
// executes an SQL statement, returns a result identifier
function SQL_query($query, $id)
{
global $dbtype;
switch ($dbtype)
{
case "MySQL":
$res=mysql_query($query, $id);
return $res;
break;;

case "mSQL":
$res=msql_query($query, $id);
return $res;
break;;

case "PostgreSQL":
$res=pg_exec($id,$query);
return $res;
break;;

case "ODBC":
$rid=odbc_prepare($id,$query);
$res=odbc_execute($rid);
return $res;
break;;

default:
$res=mysql_query($query, $id);
return $res;
break;;
}
}

// SQL_num_rows($host, $user, $password, $db)
// given a result identifier, returns the number of affected rows
function SQL_num_rows($res)
{
global $dbtype;

switch ($dbtype)
{
case "MySQL":
$rows=mysql_num_rows($res);
return $rows;
break;;

case "mSQL":
$rows=msql_num_rows($res);
return $rows;
break;;

case "PostgreSQL":
$rows=pg_numrows($res);
return $rows;
break;;

case "ODBC":
$rows=odbc_num_rows($res);
return $rows;
break;;

default:
$rows=mysql_num_rows($res);
return $rows;
break;;
}
}

// SQL_fetchrow($res,$row)
// given a result identifier, returns an array with the resulting row
// Needs also a row number for compatibility with PostgreSQL
function SQL_fetch_row($res, $nr)
{
global $dbtype;

switch ($dbtype)
{
case "MySQL":
$row = array();
$row = mysql_fetch_row($res);
return $row;
break;;

case "mSQL":
$row = array();
$row = msql_fetch_row($res);
return $row;
break;;

case "PostgreSQL":
$row = array();
$row = pg_fetch_row($res,$nr);
return $row;
break;;

case "ODBC":
$row = array();
$cols = odbc_fetch_into($res, $nr, &$row);
return $row;
break;;

default:
$row = array();
$row = mysql_fetch_row($res);
return $row;
break;;
}
}

// SQL_fetch_array($res,$row)
// given a result identifier, returns an associative array
// with the resulting row using field names as keys.
// Needs also a row number for compatibility with PostgreSQL.
function SQL_fetch_array($res, $nr)
{
global $dbtype;

switch ($dbtype)
{
case "MySQL":
$row = array();
$row = mysql_fetch_array($res);
return $row;
break;;

case "mSQL":
$row = array();
$row = msql_fetch_array($res);
return $row;
break;;

case "PostgreSQL":
$row = array();
$row = pg_fetch_array($res,$nr);
return $row;
break;;

/*
* ODBC doesn't have a native _fetch_array(), so we have to
* use a trick. Beware: this might cause HUGE loads!
*/

case "ODBC":
$row = array();
$result = array();
$result = odbc_fetch_row($res, $nr);
$nf = count($result)+2; /* Field numbering starts at 1 */
for ($count=1; $count < $nf; $count++)
{
$field_name = odbc_field_name($res, $count);
$field_value = odbc_result($res, $field_name);
$row[$field_name] = $field_value;
}
return $row;
break;;
}
}
______________________________________________________________________

15. Appendix C PostgreSQL large object Example

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

______________________________________________________________________

PX: PHP Code Exchange - PostgreSQL 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);
?>
______________________________________________________________________

16. Appendix D 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>";
}
?>
______________________________________________________________________

17. Appendix E Network admin Example

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

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

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

Socket operations:

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

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

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

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

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

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

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

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

Whois: Querying a whois server uses the same concept:

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

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

1. You have a connection with low latency and

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

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

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

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

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

18. Appendix F PostgreSQL Database Wrapper Examples

Submitted by: Joe Thong [email protected] Site URL:
<http://phpdb.linuxbox.com>

Description: A PHP database wrapper for various database servers with
a powerful Recordset for result data manipulation. Database results
are flushed automatically by phpDB.

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

______________________________________________________________________
<?php
/*
Name: phpDB PostgreSQL module
Version: 1.02bR6
Description: A PHP database wrapper for various database
servers with a powerful recordset for result data
manipulation. Database results are flushed
automatically by phpDB.
*/

/* define this module, to prevent double class declaration. */
if (!defined("_PHPDB_ABSTRACT_LAYER")) {
define("_PHPDB_ABSTRACT_LAYER", 1 );
}
else
return;

//---------------------------------------
Class Name: phpDB
//---------------------------------------
class phpDB
{
/* public variables */
var $version = '1.02bR6'; // Version number of phpDB
// This variable keeps what database type is going to
// be used. Current supported database server are
// MySQL, MSQL, SQL Server, and Sybase
var $databaseType = '';
// Specifies which database is going to be used
var $databaseName = '';
// The hostname of the database server, port
// number is optional. e.g: "db.devNation.com"
var $hostname = '';
var $username = ''; // used to connect to the database server
var $password = ''; // Password for the username

// Private variables ------ starts with underscore
// An array of executed querys. For results cleanup purposes.
var $_queryIDList = array();
// The returned link identifier whenever a
// successful database connection is made
var $_connectionID = -1;
// A variable which was used to keep the returned
// last error message. The value will then returned
// by the errorMsg() function
var $_errorMsg = '';

// This variable keeps the last created result
// link identifier
var $_queryID = -1;
// A boolean variable to state whether its a persistent
// connection or normal connection
var $_isPersistentConnection = false;
// Holds the newly created result object,
// returned via the execute() method
var $_tempResultObj = '';

// A constructor function for the phpDB object.
// When initializing, specify the dbType i.e: "mysql",
// "msql", "postgresql", "mssql", and "sybase"
function phpDB($dbType = "postgresql")
{
switch ($dbType) {
case "mysql":
case "msql":
case "postgresql":
case "mssql":
case "sybase":
case "informix":
$this->databaseType = $dbType;
break;
default:
return false;
}
}

// Returns: A positive link identifier on success, or
// false on error. Connect to the server with the provided
// arguments. The connection to the server will be closed
// when the script terminates, unless close() function is
// called beforehand
function connect($argHostname = "", $argUsername = "",
$argPassword = "", $argDatabaseName = "")
{
$connString = "";
$hostPieces = array();
/* Must specify the database argument */
if (!$argDatabaseName) {
return false;
}
if ($argHostname != "") {
$this->hostname = $argHostname;
}
if ($argUsername != "") {
$this->username = $argUsername;
}
if ($argPassword != "") {
$this->password = $argPassword;
}
if ($argDatabaseName != "") {
$this->databaseName = $argDatabaseName;
}
$hostPieces = split(":", $this->hostname);
if ($hostPieces[0]) {
$connString .= "host=$hostPieces[0]";
if (isset($hostPieces[1])) {
$connString .= " port=$hostPieces[1]";
}
}
if ($this->username) {
$connString .= " user=$this->username";
}
if ($this->password) {
$connString .= " password=$this->password";
}
$connString .= " dbname=$this->databaseName";

$this->_connectionID = @pg_Connect($connString);
return $this->_connectionID;
}

// Returns: A positive link identifier on success, or
// false on error. Connect to the server with the
// provided arguments. The connection to the server will
// not be closed when the script terminates. Instead it
// will be kept for later future use
function pconnect($argHostname = "", $argUsername = "",
$argPassword = "", $argDatabaseName = "")
{
$connString = "";
$hostPieces = array();
/* Must specify the database argument */
if (!$argDatabaseName) {
return false;
}
if ($argHostname != "") {
$this->hostname = $argHostname;
}
if ($argUsername != "") {
$this->username = $argUsername;
}
if ($argPassword != "") {
$this->password = $argPassword;
}
if ($argDatabaseName != "") {
$this->databaseName = $argDatabaseName;
}
$hostPieces = split(":", $this->hostname);
if ($hostPieces[0]) {
$connString .= "host=$hostPieces[0]";
if (isset($hostPieces[1])) {
$connString .= " port=$hostPieces[1]";
}
}
if ($this->username) {
$connString .= " user=$this->username";
}
if ($this->password) {
$connString .= " password=$this->password";
}
$connString .= " dbname=$this->databaseName";

$this->_connectionID = @pg_pConnect($connString);
if ($this->_connectionID) {
$this->_isPersistentConnection = true;
}
return $this->_connectionID;
}

// Returns: true on success, false on error Select
// the database name to be used PostgreSQL
// Note: function Not available
function selectDB($dbName) {
return false;
}

// Returns: the Recordset object disregard success
// or failure Send the sql statement to the database server
function execute($sql = "") {
// Instantiate an object without considering whether
// the query return any results or not
$this->_queryID = @pg_Exec($this->_connectionID, $sql);
$this->_tempResultObj = new Recordset($this->_queryID);
$this->_insertQuery($this->_queryID);
return $this->_tempResultObj;
}

// Returns: the last error message from previous
// database operation
function errorMsg() {
$this->_errorMsg = @pg_errormessage($this->_connectionID);
return $this->_errorMsg;
}

// Returns: true on success, false on failure
// Close the database connection
function close() {
if ($this->_queryIDList && sizeof($this->_queryIDList > 0)) {
while(list($_key, $_resultID) = each($this->_queryIDList)) {
@pg_freeresult($_resultID);
}
}
// If its not a persistent connection, then
// only the connection needs to be closed
if ($this->_isPersistentConnection != true) {
return @pg_close($this->_connectionID);
}
else {
return true;
}
}

// A PRIVATE function used by the constructor function
// of the query object. insert the successful returned
// query id to the query id list. Used for later results
// cleanup. A private function that's never meant to
// be used directly
function _insertQuery($query_id) {
$this->_queryIDList[] = $query_id;
}
}

//------------------------------
Class Name: Recordset
//------------------------------
class Recordset
{
/* public variables */
var $fields;
// indicates that the current record position is before
// the first record in a Recordset object
var $BOF = null;

// indicates that the current record position is after
// the last record in a Recordset object
var $EOF = null;

/* private variables */
var $_numOfRows = -1; // NEVER change the value! READ-ONLY!
var $_numOfFields = -1; // NEVER change the value! READ-ONLY!
// Holds anything that was returned from the database specific functions
var $_tempResult = '';
// This variable keeps the result link identifier
var $_queryID = -1;
// This variable keeps the current row in the Recordset
var $_currentRow = -1;

// Returns: query id on success and false if
// failed Constructor function
function Recordset($queryID)
{
$this->_queryID = $queryID;
if ($queryID) {
$this->_numOfRows = @pg_numrows($this->_queryID);
/* pg_numrows() returns -1 on error */
if ($this->_numOfRows == -1) {
$this->_numOfRows = 0;
}
$this->_numOfFields = @pg_numfields($this->_queryID);
/* pg_numfields() returns -1 on error */
if ($this->_numOfFields == -1) {
$this->_numOfFields = 0;
}
}
else {
$this->_numOfRows = 0;
$this->_numOfFields = 0;
}
/* If result set contains rows */
if ($this->_numOfRows > 0 && $this->_currentRow == -1) {
$this->_currentRow = 0;
$this->fields = @pg_fetch_array($this->_queryID, $this->_currentRow);
$this->EOF = false;
$this->BOF = false;
}
return $this->_queryID;
}

// Returns: true if successful, false if fail Set the Recordset
// pointer to a specified field offset. If the next call to
// fetchField() won't include a field offset, this field would
// be returned. PostgreSQL Note: function Not available
function fieldSeek($fieldOffset = -1) {
$this->_tempResult = false;
return $this->_tempResult;
}

// Returns: an object containing field information. Get column
// information in the Recordset object. fetchField() can be used
// in order to obtain information about fields in a certain query
// result. If the field offset isn't specified, the next field
// that wasn't yet retrieved by fetchField() is retrieved.
// PostgreSQL Note: function Not available
function fetchField($fieldOffset = -1) {
$this->_tempResult = false;
return $this->_tempResult;
}

// Returns: true if there still rows available, or false if there
// are no more rows. Moves to the next row in a specified Recordset
// object and makes that record the current row and the data
// corresponding to the row will be retrieved into the fields
// collection. Note: Unlike the moveRow() method, when _currentRow
// is getNumOfRows() - 1, EOF will immediately be true. If row number
// is not provided, the function will point to the
// first row automatically
function nextRow() {
if ($this->getNumOfRows() > 0) {
$this->fields = array();
$this->_currentRow++;
$this->fields = @pg_fetch_array($this->_queryID, $this->_currentRow);
/* This is not working. True all the time */
if ($this->fields) {
$this->_checkAndChangeEOF($this->_currentRow - 1);
return true;
}
}
$this->EOF = true;
return false;
}

// Returns: true on success, false on failure moveRow() moves
// the internal row pointer of the Recordset object to point
// to the specified row number and the data corresponding to
// the row will be retrieved into the fields collection. If
// row number is not provided, the function will point to
// the first row automatically
function moveRow($rowNumber = 0) {
if ($rowNumber == 0) {
return $this->firstRow();
}
else if ($rowNumber == ($this->getNumOfRows() - 1)) {
return $this->lastRow();
}
if ($this->getNumOfRows() > 0 && $rowNumber < $this->getNumOfRows()) {
$this->fields = null;
$this->_currentRow = $rowNumber;
$this->fields = @pg_fetch_array($this->_queryID, $this->_currentRow);
/* This is not working. True all the time */
if ($this->fields) {
// No need to call _checkAndChangeEOF() because
// the possibility of moving to the last row
// has been handled by the above code
$this->EOF = false;
return true;
}
}
$this->EOF = true;
return false;
}

// Returns: true on success, false on failure firstRow()
// moves the internal row pointer of the Recordset object
// to the first row and the data corresponding to the row
// will be retrieved into the fields collection
function firstRow() {
if ($this->getNumOfRows() > 0) {
$this->fields = array();
$this->_currentRow = 0;
$this->fields = @pg_fetch_array($this->_queryID, $this->_currentRow);
$this->EOF = true;
/* This is not working. True all the time */
if ($this->fields) {
return true;
}
}
$this->EOF = true;
return false;
}

// Returns: true on success, false on failure lastRow()
// moves the internal row pointer of the Recordset object
// to the last row and the data corresponding to the row
// will be retrieved into the fields collection
function lastRow() {
if ($this->getNumOfRows() > 0) {
$this->fields = array();
$num_of_rows = $this->getNumOfRows();
/* $num_of_rows decremented at above */
$this->_currentRow = --$num_of_rows;
$this->fields = @pg_fetch_array($this->_queryID, $this->_currentRow);
/* This is not working. True all the time */
if ($this->fields) {
/* Special case for making EOF false. */
$this->EOF = false;
return true;
}
}
$this->EOF = true;
return false;
}

// close() only needs to be called if you are worried about
// using too much memory while your script is running. All
// associated result memory for the specified result identifier
// will automatically be freed
function close() {
$this->_tempResult = @pg_freeresult($this->_queryID);
return $this->_tempResult;
}

// Returns: the number of rows in a result set.
// Get number of rows in result
function getNumOfRows() {
return $this->_numOfRows;
}

// Returns: the number of fields in a result set.
// Get number of fields in result
function getNumOfFields() {
return $this->_numOfFields;
}

/* Check and change the status of EOF. */
function _checkAndChangeEOF($currentRow) {
if ($currentRow >= ($this->_numOfRows - 1)) {
$this->EOF = true;
}
else {
$this->EOF = false;
}
}
}
?>
______________________________________________________________________

19. Appendix G Microsoft SQL Server DB Wrapper Example

Submitted by: Joe Thong [email protected] Site URL:
<http://phpdb.linuxbox.com>

Description: A PHP database wrapper for various database servers with
a powerful Recordset for result data manipulation. Database results
are flushed automatically by phpDB.

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

______________________________________________________________________
<?php
/*
Name: phpDB Microsoft SQL Server module
Version: 1.02bR6
Description: A PHP database wrapper for various
database servers with a powerful
Recordset for result data manipulation. Database
results are flushed automatically by phpDB.
*/
// Define this module, to prevent double class declaration
if (!defined("_PHPDB_ABSTRACT_LAYER"))
{
define("_PHPDB_ABSTRACT_LAYER", 1 );
}
else
return;

//------------------------------
Class Name: phpDB
//------------------------------
class phpDB
{
// public variables
var $version = '1.02bR6'; // Version number of phpDB

// This variable keeps what database type is going
// to be used. Current supported database server
// are MySQL, MSQL, SQL Server, PostgreSQL and Sybase
var $databaseType = '';
var $databaseName = ''; // Specifies which database is going to be used

// The hostname of the database server, port
// number is optional. e.g: "db.devNation.com"
var $hostname = '';

var $username = ''; // to connect to the database server
var $password = ''; // Password for the username

// Private variables ----- starts with underscore

// An array of executed querys. For results cleanup purposes
var $_queryIDList = array();

// The returned link identifier whenever a
// successful database connection is made
var $_connectionID = -1;

// A variable which was used to keep the returned last
// error message. The value will then returned
// by the errorMsg() function
var $_errorMsg = '';
// This variable keeps the last created result link identifier
var $_queryID = -1;

// A boolean variable to state whether its a
// persistent connection or normal connection
var $_isPersistentConnection = false;

// Holds the newly created result object, returned
// via the execute() method
var $_tempResultObj = '';

// A constructor function for the phpDB object.
// When initializing, specify the dbType i.e: "mysql",
// "msql", "postgresql", "mssql", and "sybase"
function phpDB($dbType = "mssql")
{
switch ($dbType)
{
case "mysql":
case "msql":
case "postgresql":
case "mssql":
case "sybase":
case "informix":
$this->databaseType = $dbType;
break;
default:
return false;
}
}

// Returns: A positive link identifier on success,
// or false on error. Connect to the server with
// the provided arguments. The connection to the server
// will be closed when the script terminates, unless
// close() function is called beforehand.
function connect($argHostname = "", $argUsername = "",
$argPassword = "", $argDatabaseName = "")
{
$boolDBSelected;
if ($argHostname != "") {
$this->hostname = $argHostname;
}
if ($argUsername != "") {
$this->username = $argUsername;
}
if ($argPassword != "") {
$this->password = $argPassword;
}
if ($argDatabaseName != "") {
$this->databaseName = $argDatabaseName;
}

$this->_connectionID = @mssql_connect($this->hostname, $this->username, $this->password);

if ($this->databaseName && $this->_connectionID) {
$boolDBSelected = @mssql_select_db($this->databaseName);
if(!$boolDBSelected) { /* If DB selection fails */
@mssql_close($this->_connectionID); /* Close the current connection */
return false;
}
}
return $this->_connectionID;
}

// Returns: A positive link identifier on success, or
// false on error Connect to the server with the provided
// arguments. The connection to the server will not be closed
// when the script terminates. Instead it will be kept for
// later future use
function pconnect($argHostname = "", $argUsername = "",
$argPassword = "", $argDatabaseName = "")
{
$boolDBSelected;
if ($argHostname != "") {
$this->hostname = $argHostname;
}
if ($argUsername != "") {
$this->username = $argUsername;
}
if ($argPassword != "") {
$this->password = $argPassword;
}
if ($argDatabaseName != "") {
$this->databaseName = $argDatabaseName;
}

$this->_connectionID = @mssql_pconnect($this->hostname, $this->username, $this->password);
if ($this->_connectionID) {
$this->_isPersistentConnection = true;
}

if ($this->databaseName && $this->_connectionID) {
$boolDBSelected = @mssql_select_db($this->databaseName);
if(!$boolDBSelected) { /* if DB selection fails */
return false; /* Persistent connection can't be closed */
}
}
return $this->_connectionID;
}

// Returns: true on success, false on error Select the
// database name to be used
function selectDB($dbName)
{
$this->databaseName = $dbName;
if ($this->_connectionID) {
return @mssql_select_db($dbName);
}
else {
/* No database selected */
return false;
}
}

// Returns: the Recordset object disregard success or
// failure Send the sql statement to the database server
function execute($sql = "")
{
$this->_queryID = @mssql_query($sql, $this->_connectionID);
// Instantiate an object without considering whether
// the query return any results or not
$this->_tempResultObj = new Recordset($this->_queryID);
$this->_insertQuery($this->_queryID);
return $this->_tempResultObj;
}

// Returns: the last error message from previous database
// operation Note: This function is NOT available for
// Microsoft SQL Server
function errorMsg()
{
$this->_errorMsg = "errorMsg() is not available for Microsoft SQL Server";
return $this->_errorMsg;
}

/* Returns: true on success, false on failure
Close the database connection. */
function close() {
if ($this->_queryIDList && sizeof($this->_queryIDList > 0)) {
while(list($_key, $_resultID) = each($this->_queryIDList)) {
@mssql_free_result($_resultID);
}
}
// If its not a persistent connection, then
// only the connection needs to be closed
if ($this->_isPersistentConnection != true) {
return @mssql_close($this->_connectionID);
}
else {
return true;
}
}

// A PRIVATE function used by the constructor function of
// the query object. insert the successful returned
// query id to the query id list. Used for later results
// cleanup. A private function that's never meant to be
// used directly
function _insertQuery($query_id) {
$this->_queryIDList[] = $query_id;
}
}

//---------------------------------------
Class Name: Recordset
//---------------------------------------
class Recordset
{
/* public variables */
var $fields;
// indicates that the current record position is
// before the first record in a Recordset object
var $BOF = null;
// indicates that the current record position is
// after the last record in a Recordset object
var $EOF = null;

// Private variables
var $_numOfRows = -1; // NEVER change the value! READ-ONLY!
var $_numOfFields = -1; // NEVER change the value! READ-ONLY!

// Holds anything that was returned from the
// database specific functions
var $_tempResult = '';
// This variable keeps the result link identifier
var $_queryID = -1;
// This variable keeps the current row in the Recordset
var $_currentRow = -1;

// Returns: query id on success and false if
// failed Constructor function
function Recordset($queryID)
{
$this->_queryID = $queryID;
if ($queryID) {
$this->_numOfRows = @mssql_num_rows($this->_queryID);
$this->_numOfFields = @mssql_num_fields($this->_queryID);
}
else {
$this->_numOfRows = 0;
$this->_numOfFields = 0;
}
// If result set contains rows
if ($this->_numOfRows > 0 && $this->_currentRow == -1) {
$this->_currentRow = 0;
$this->fields = @mssql_fetch_array($this->_queryID);
$this->EOF = false;
$this->BOF = false;
}
return $this->_queryID;
}
// Returns: true if successful, false if fail Set
// the Recordset pointer to a specified field offset.
// If the next call to fetchField() won't include a
// field offset, this field would be returned
function fieldSeek($fieldOffset = -1) {
$this->_tempResult = @mssql_field_seek($this->_queryID, $fieldOffset);
return $this->_tempResult;
}

// Returns: an object containing field information.
// Get column information in the Recordset object.
// fetchField() can be used in order to obtain information
// about fields in a certain query result. If the field
// offset isn't specified, the next field that wasn't yet
// retrieved by fetchField() is retrieved
function fetchField($fieldOffset = -1) {
if ($fieldOffset != -1) {
$this->_tempResult = @mssql_fetch_field($this->_queryID, $fieldOffset);
}
// The $fieldOffset argument is not provided thus its -1
else if ($fieldOffset == -1) {
$this->_tempResult = @mssql_fetch_field($this->_queryID);
}
return $this->_tempResult;
}

// Returns: true if there still rows available, or false
// if there are no more rows. Moves to the next row in a
// specified Recordset object and makes that record the current
// row and the data corresponding to the row will be retrieved
// into the fields collection. Note: Unlike the moveRow() method,
// when _currentRow is getNumOfRows() - 1, EOF will immediately be
// true. If row number is not provided, the function will point
// to the first row automatically
function nextRow()
{
if ($this->getNumOfRows() > 0) {
$this->fields = array();
$this->_currentRow++;
$this->fields = @mssql_fetch_array($this->_queryID);
// This is not working. True all the time
if ($this->fields) {
$this->_checkAndChangeEOF($this->_currentRow - 1);
return true;
}
}
$this->EOF = true;
return false;
}

// Returns: true on success, false on failure moveRow()
// moves the internal row pointer of the Recordset object
// to point to the specified row number and the data
// corresponding to the row will be retrieved into the fields
// collection. If row number is not provided, the function will
// point to the first row automatically
function moveRow($rowNumber = 0)
{
if ($rowNumber == 0) {
return $this->firstRow();
}
else if ($rowNumber == ($this->getNumOfRows() - 1)) {
return $this->lastRow();
}
if ($this->getNumOfRows() > 0 && $rowNumber < $this->getNumOfRows()) {
$this->fields = null;
$this->_currentRow = $rowNumber;
if(@mssql_data_seek($this->_queryID, $this->_currentRow)) {
$this->fields = @mssql_fetch_array($this->_queryID);
/* This is not working. True all the time */
if ($this->fields) {
// No need to call _checkAndChangeEOF() because
// the possibility of moving to the last row has
// been handled by the above code
$this->EOF = false;
return true;
}
}
}
$this->EOF = true;
return false;
}

// Returns: true on success, false on failure firstRow() moves
// the internal row pointer of the Recordset object to the first
// row and the data corresponding to the row will be retrieved
// into the fields collection
function firstRow()
{
if ($this->getNumOfRows() > 0) {
$this->fields = array();
$this->_currentRow = 0;
if (@mssql_data_seek($this->_queryID, $this->_currentRow)) {
$this->fields = @mssql_fetch_array($this->_queryID);
$this->EOF = false;
/* This is not working. True all the time */
if ($this->fields) {
return true;
}
}
}
$this->EOF = true;
return false;
}

// Returns: true on success, false on failure lastRow() moves
// the internal row pointer of the Recordset object to the last
// row and the data corresponding to the row will be retrieved
// into the fields collection
function lastRow()
{
if ($this->getNumOfRows() > 0) {
$this->fields = array();
$num_of_rows = $this->getNumOfRows();
$this->_tempResult = @mssql_data_seek($this->_queryID, --$num_of_rows);
if ($this->_tempResult) {
/* $num_of_rows decremented at above */
$this->_currentRow = $num_of_rows;
$this->fields = @mssql_fetch_array($this->_queryID);
/* This is not working. True all the time */
if ($this->fields) {
/* Special case for making EOF false. */
$this->EOF = false;
return true;
}
}
}
$this->EOF = true;
return false;
}

// close() only needs to be called if you are worried about using
// too much memory while your script is running. All associated
// result memory for the specified result identifier will
// automatically be freed
function close() {
$this->_tempResult = @mssql_free_result($this->_queryID);
return $this->_tempResult;
}

// Returns: the number of rows in a result set. Get
// number of rows in result
function getNumOfRows() {
return $this->_numOfRows;
}

/* Returns: the number of fields in a result set.
Get number of fields in result. */
function getNumOfFields() {
return $this->_numOfFields;
}

/* Check and change the status of EOF. */
function _checkAndChangeEOF($currentRow) {
if ($currentRow >= ($this->_numOfRows - 1)) {
$this->EOF = true;
}
else {
$this->EOF = false;
}
}
}
?>
______________________________________________________________________

20. Appendix H Sybase SQL Server DB Wrapper Example

Submitted by: Joe Thong [email protected] Site URL:
<http://phpdb.linuxbox.com>

Description: A PHP database wrapper for various database servers with
a powerful Recordset for result data manipulation. Database results
are flushed automatically by phpDB.

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

______________________________________________________________________
<?php
/*
Name: phpDB Sybase module
Version: 1.02bR6
Description: A PHP database wrapper for various database
servers with a powerful Recordset for result data
manipulation. Database results are flushed
automatically by phpDB.
*/

// Define this module, to prevent double class declaration
if (!defined("_PHPDB_ABSTRACT_LAYER")) {
define("_PHPDB_ABSTRACT_LAYER", 1 );
}
else
return;

//-------------------------------
Class Name: phpDB
//-------------------------------
class phpDB
{
/* public variables */
var $version = '1.02bR6'; // Version number of phpDB
// This variable keeps what database type is going
// to be used. Current supported database server
// are MySQL, MSQL, SQL Server, and Sybase
var $databaseType = '';
// Specifies which database is going to be used
var $databaseName = '';
// The hostname of the database server, port number
// is optional. e.g: "db.devNation.com"
var $hostname = '';
var $username = ''; // to connect to the database server
var $password = ''; // Password for the username

// Private variables --- starts with underscore
// An array of executed querys. For results
// cleanup purposes
var $_queryIDList = array();
// The returned link identifier whenever a successful
// database connection is made
var $_connectionID = -1;
// A variable which was used to keep the returned last
// error message. The value will then returned by
// the errorMsg() function
var $_errorMsg = '';
// This variable keeps the last created result
// link identifier
var $_queryID = -1;
// A boolean variable to state whether its a
// persistent connection or normal connection
var $_isPersistentConnection = false;
// Holds the newly created result object, returned
// via the execute() method
var $_tempResultObj = '';

// A constructor function for the phpDB object. When
// initializing, specify the dbType i.e: "mysql",
// "msql", "postgresql", "mssql", and "sybase"
function phpDB($dbType = "sybase")
{
switch ($dbType) {
case "mysql":
case "msql":
case "postgresql":
case "mssql":
case "sybase":
case "informix":
$this->databaseType = $dbType;
break;
default:
return false;
}
}

// Returns: A positive link identifier on success, or
// false on error. Connect to the server with the
// provided arguments. The connection to the server will be
// closed when the script terminates, unless close()
// function is called beforehand
function connect($argHostname = "", $argUsername = "",
$argPassword = "", $argDatabaseName = "")
{
$boolDBSelected;
if ($argHostname != "") {
$this->hostname = $argHostname;
}
if ($argUsername != "") {
$this->username = $argUsername;
}
if ($argPassword != "") {
$this->password = $argPassword;
}
if ($argDatabaseName != "") {
$this->databaseName = $argDatabaseName;
}

$this->_connectionID = @sybase_connect($this->hostname, $this->username, $this->password);

if ($this->databaseName && $this->_connectionID) {
$boolDBSelected = @sybase_select_db($this->databaseName);
/* If DB selection fails */
if(!$boolDBSelected) {
/* Close the current connection */
@sybase_close($this->_connectionID);
return false;
}
}
return $this->_connectionID;
}

// Returns: A positive link identifier on success, or false
// on error. Connect to the server with the provided
// arguments. The connection to the server will not be closed
// when the script terminates. Instead it will be kept for later future use
function pconnect($argHostname = "", $argUsername = "",
$argPassword = "", $argDatabaseName = "")
{
$boolDBSelected;
if ($argHostname != "") {
$this->hostname = $argHostname;
}
if ($argUsername != "") {
$this->username = $argUsername;
}
if ($argPassword != "") {
$this->password = $argPassword;
}
if ($argDatabaseName != "") {
$this->databaseName = $argDatabaseName;
}

$this->_connectionID = @sybase_pconnect($this->hostname, $this->username, $this->password);
if ($this->_connectionID) {
$this->_isPersistentConnection = true;
}

if ($this->databaseName && $this->_connectionID) {
$boolDBSelected = @sybase_select_db($this->databaseName);
/* if DB selection fails */
if(!$boolDBSelected) {
/* Persistent connection can't be closed */
return false;
}
}
return $this->_connectionID;
}

/* Returns: true on success, false on error
Select the database name to be used */
function selectDB($dbName) {
$this->databaseName = $dbName;
if ($this->_connectionID) {
return @sybase_select_db($dbName);
}
else {
/* No database selected */
return false;
}
}

/* Returns: the Recordset object disregard success or failure
Send the sql statement to the database server. */
function execute($sql = "") {
$this->_queryID = @sybase_query($sql, $this->_connectionID);
// Instantiate an object without considering whether
// the query return any results or not
$this->_tempResultObj = new Recordset($this->_queryID);
$this->_insertQuery($this->_queryID);
return $this->_tempResultObj;
}

/* Returns: the last error message from previous database operation
Note: This function is NOT available for Sybase. */

function errorMsg() {
$this->_errorMsg = "errorMsg() is not available for Sybase";
return $this->_errorMsg;
}

/* Returns: true on success, false on failure
Close the database connection. */

function close() {
if ($this->_queryIDList && sizeof($this->_queryIDList > 0)) {
while(list($_key, $_resultID) = each($this->_queryIDList)) {
@sybase_free_result($_resultID);
}
}
// If its not a persistent connection, then
// only the connection needs to be closed
if ($this->_isPersistentConnection != true) {
return @sybase_close($this->_connectionID);
}
else {
return true;
}
}

// A PRIVATE function used by the constructor function
// of the query object. insert the successful returned
// query id to the query id list. Used for later results
// cleanup. A private function that's never meant
// to be used directly
function _insertQuery($query_id) {
$this->_queryIDList[] = $query_id;
}
}

//----------------------------------
Class Name: Recordset
//----------------------------------
class Recordset
{
/* public variables */
var $fields;
// indicates that the current record position is
// before the first record in a Recordset object
var $BOF = null;
// indicates that the current record position
// is after the last record in a Recordset object
var $EOF = null;

// Private variables - starts with underscore
var $_numOfRows = -1; // NEVER change the value! READ-ONLY!
var $_numOfFields = -1; // NEVER change the value! READ-ONLY!
// Holds anything that was returned from
// the database specific functions
var $_tempResult = '';
// This variable keeps the result link identifier
var $_queryID = -1;
// This variable keeps the current row in the Recordset
var $_currentRow = -1;

// Returns: query id on success and false if
// failed Constructor function
function Recordset($queryID) {
$this->_queryID = $queryID;
if ($queryID) {
$this->_numOfRows = @sybase_num_rows($this->_queryID);
$this->_numOfFields = @sybase_num_fields($this->_queryID);
}
else {
$this->_numOfRows = 0;
$this->_numOfFields = 0;
}
/* If result set contains rows */
if ($this->_numOfRows > 0 && $this->_currentRow == -1) {
$this->_currentRow = 0;
$this->fields = @sybase_fetch_array($this->_queryID);
$this->EOF = false;
$this->BOF = false;
}
return $this->_queryID;
}

// Returns: true if successful, false if fail Set
// the Recordset pointer to a specified field offset.
// If the next call to fetchField() won't include a
// field offset, this field would be returned
function fieldSeek($fieldOffset = -1) {
$this->_tempResult = @sybase_field_seek($this->_queryID, $fieldOffset);
return $this->_tempResult;
}

// Returns: an object containing field information.
// Get column information in the Recordset object.
// fetchField() can be used in order to obtain information
// about fields in a certain query result. If the field
// offset isn't specified, the next field that wasn't yet
// retrieved by fetchField() is retrieved
function fetchField($fieldOffset = -1) {
if ($fieldOffset != -1) {
$this->_tempResult = @sybase_fetch_field($this->_queryID, $fieldOffset);
}
/* The $fieldOffset argument is not provided thus its -1 */
else if ($fieldOffset == -1) {
$this->_tempResult = @sybase_fetch_field($this->_queryID);
}
return $this->_tempResult;
}

// Returns: true if there still rows available, or
// false if there are no more rows. Moves to the next
// row in a specified Recordset object and makes that record
// the current row and the data corresponding to the row will
// be retrieved into the fields collection. Note: Unlike
// the moveRow() method, when _currentRow is getNumOfRows() - 1,
// EOF will immediately be true. If row number is not
// provided, the function will point to the
// first row automatically
function nextRow() {
if ($this->getNumOfRows() > 0) {
$this->fields = array();
$this->_currentRow++;
$this->fields = @sybase_fetch_array($this->_queryID);
/* This is not working. True all the time */
if ($this->fields) {
$this->_checkAndChangeEOF($this->_currentRow - 1);
return true;
}
}
$this->EOF = true;
return false;
}

// Returns: true on success, false on failure moveRow()
// moves the internal row pointer of the Recordset object
// to point to the specified row number and the data
// corresponding to the row will be retrieved into the
// fields collection. If row number is not provided, the
// function will point to the first row automatically
function moveRow($rowNumber = 0) {
if ($rowNumber == 0) {
return $this->firstRow();
}
else if ($rowNumber == ($this->getNumOfRows() - 1)) {
return $this->lastRow();
}
if ($this->getNumOfRows() > 0 && $rowNumber < $this->getNumOfRows()) {
$this->fields = null;
$this->_currentRow = $rowNumber;
if(@sybase_data_seek($this->_queryID, $this->_currentRow)) {
$this->fields = @sybase_fetch_array($this->_queryID);
/* This is not working. True all the time */
if ($this->fields) {
// No need to call _checkAndChangeEOF()
// because the possibility of moving to the
// last row has been handled by the above code
$this->EOF = false;
return true;
}
}
}
$this->EOF = true;
return false;
}

// Returns: true on success, false on failure firstRow()
// moves the internal row pointer of the Recordset object
// to the first row and the data corresponding to the row
// will be retrieved into the fields collection
function firstRow() {
if ($this->getNumOfRows() > 0) {
$this->fields = array();
$this->_currentRow = 0;
if (@sybase_data_seek($this->_queryID, $this->_currentRow)) {
$this->fields = @sybase_fetch_array($this->_queryID);
$this->EOF = false;
/* This is not working. True all the time */
if ($this->fields) {
return true;
}
}
}
$this->EOF = true;
return false;
}

// Returns: true on success, false on failure lastRow()
// moves the internal row pointer of the Recordset object
// to the last row and the data corresponding to the row
// will be retrieved into the fields collection
function lastRow() {
if ($this->getNumOfRows() > 0) {
$this->fields = array();
$num_of_rows = $this->getNumOfRows();
$this->_tempResult = @sybase_data_seek($this->_queryID, --$num_of_rows);
if ($this->_tempResult) {
/* $num_of_rows decremented at above */
$this->_currentRow = $num_of_rows;
$this->fields = @sybase_fetch_array($this->_queryID);
/* This is not working. True all the time */
if ($this->fields) {
/* Special case for making EOF false. */
$this->EOF = false;
return true;
}
}
}
$this->EOF = true;
return false;
}

// close() only needs to be called if you are worried
// about using too much memory while your script is
// running. All associated result memory for the
// specified result identifier will automatically be freed
function close() {
$this->_tempResult = @sybase_free_result($this->_queryID);
return $this->_tempResult;
}

/* Returns: the number of rows in a result set.
Get number of rows in result. */

function getNumOfRows() {
return $this->_numOfRows;
}

/* Returns: the number of fields in a result set.
Get number of fields in result. */

function getNumOfFields() {
return $this->_numOfFields;
}

/* Check and change the status of EOF. */
function _checkAndChangeEOF($currentRow) {
if ($currentRow >= ($this->_numOfRows - 1)) {
$this->EOF = true;
}
else {
$this->EOF = false;
}
}
}
?>
______________________________________________________________________

21. Appendix I phpDB.inc Example

Submitted by: Joe Thong [email protected] Site URL:
<http://phpdb.linuxbox.com>

Description: A PHP database wrapper for various database servers with
a powerful Recordset for result data manipulation. Database results
are flushed automatically by phpDB.

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

______________________________________________________________________
<?php
/*
Name: phpDB General module
Version: 1.02bR6
Description: A PHP database wrapper for various
database servers. Database results are flushed
automatically by phpDB. Supported database
servers are MySQL, MSQL, PostgreSQL, Microsoft
SQL Server and Sybase.
*/

if (!defined("_PHPDB_GENERAL_LAYER")) {
define("_PHPDB_GENERAL_LAYER", 1 );
}
else
return;

// Fill in the database server that you're
// going to use. Consult the phpDB Reference
// Manual for more information
$databaseType = '';
// The phpDB module root path. No trailing slash
$phpDBRootPath = '.';

function useDB($dbType = "")
{
GLOBAL $phpDBRootPath;
switch (strtolower($dbType))
{
case "mysql":
case "msql":
case "postgresql":
case "mssql":
case "sybase":
case "informix":
include("$phpDBRootPath". "/phpDB-" . "$dbType.lib");
break;
case "":
die("Please edit phpDB.inc in order to use phpDB");
return false;
default:
die("Invalid database selection");
return false;
}
return true;
}

useDB($databaseType);
?>
______________________________________________________________________

22. Appendix J phpDBTest.php3 Example

Submitted by: Joe Thong [email protected] Site URL:
<http://phpdb.linuxbox.com>

Description: A PHP database wrapper for various database servers with
a powerful Recordset for result data manipulation. Database results
are flushed automatically by phpDB.

To get this file, in the web-browser, save this file as 'Text' type as
phpDBTest.php3

______________________________________________________________________
<html>
< head>
< title>Untitled< /title>
< /head>

< body>
<?php
// Assumed this file is placed in the same directory with phpDB.inc
include("phpDB.inc");
$db = new phpDB();
$db->pconnect("hostName", "userName", "passWord", "databaseName") or die ("Can't connect to database server or select database");
$rs = $db->execute("SELECT * FROM Items");
$numOfRows = $rs->getNumOfRows();
echo "Number of Rows: $numOfRows";

$rs->firstRow(); // optional, but recommended
while (!$rs->EOF) {
// Fields collection accessible as associative arrays too
echo "<br>" . $rs->fields[0];
$rs->nextRow(); // NOTE: nextRow() is placed at below
}

$rs->close();
$db->close(); // optional
?>
< /body>
< /html>
______________________________________________________________________

23. Appendix H Midgard Installation

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

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

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

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

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

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

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

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

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

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

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

23.1. Testing Midgard PHP Server

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

______________________________________________________________________
<?phpinfo()?>
______________________________________________________________________

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

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

23.2. Security OpenSSL

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

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