The PHP Hypertext Preprocessor (PHP) is a programming language that allows web developers to create dynamic content that interacts with databases. PHP is basically used for developing web based software applications. This tutorial helps you to build your base with PHP.
PHP started out as a small open source project that evolved as more and more people found out how useful it was. Rasmus Lerdorf unleashed the first version of PHP way back in 1994.
- PHP is a recursive acronym for “PHP: Hypertext Preprocessor”.
- PHP is a server side scripting language that is embedded in HTML. It is used to manage dynamic content, databases, session tracking, even build entire e-commerce sites.
- It is integrated with a number of popular databases, including MySQL, PostgreSQL, Oracle, Sybase, Informix, and Microsoft SQL Server
- PHP is pleasingly zippy in its execution, especially when compiled as an Apache module on the Unix side. The MySQL server, once started, executes even very complex queries with huge result sets in record-setting time.
- PHP is forgiving: PHP language tries to be as forgiving as possible.
- PHP Syntax is C-Like.
7. PHP supports a large number of major protocols such as POP3, IMAP, and LDAP. PHP4 added support for Java and distributed object architectures (COM and CORBA), making n-tier development a possibility for the first time.
Common use of PHP
- PHP performs system functions, i.e. from files on a system it can create, open, read, write, and close them.
- PHP can handle forms, i.e. gather data from files, save data to a file, thru email you can send data, return data to the user.
- You add, delete, modify elements within your database thru PHP.
- Access cookies variables and set cookies.
- Using PHP, you can restrict users to access some pages of your website.
- It can encrypt data.
Characteristics of PHP
Five important Characteristicsharacteristics make PHP’s practical nature possible
“Hello World” Script in PHP
To get a feel for PHP, first start with simple PHP scripts. Since “Hello, World!” is an essential example, first we will create a friendly little “Hello, World!” script.
As mentioned earlier, PHP is embedded in HTML. That means that in amongst your normal HTML (or XHTML if you’re cutting-edge) you’ll have PHP statements like this
It will produce the following result-
If you examine the HTML output of the above example, you’ll notice that the PHP code is not present in the file sent from the server to your Web browser. All of the PHP present in the Web page is processed and stripped from the page; the only thing returned to the client from the Web server is pure HTML output.
All PHP code must be included inside one of the three special markup tags ate are recognised by the PHP Parser.
<?php PHP code goes here ?>
<? PHP code goes here ?>
<Script language=”php”>PHP code goes here </script>
A most common tag is the <?php…?> and we will also use the same tag in our tutorial.
From the next chapter we will start with PHP Environment Setup on your machine and then we will dig out almost all concepts related to PHP to make you comfortable with the PHP language.
PHP Environment setup
We have set up the PHP Programming environment on-line, so that you can compile and execute all the available examples on line. It gives you confidence in what you are reading and enables you to verify the programs with different options. Feel free to modify any example and execute it on-line.
In order to develop and run PHP Web pages three vital components need to be installed on your computer system.
- Web Server − PHP will work with virtually all Web Server software, including Microsoft’s Internet Information Server (IIS) but then most often used is freely available Apache Server. Download Apache for free here − http://httpd.apache.org/download.cgi
- Database − PHP will work with virtually all database software, including Oracle and Sybase but most commonly used is freely available MySQL database. Download MySQL for free here −http://www.mysql.com/downloads/
- PHP Parser − In order to process PHP script instructions a parser must be installed to generate HTML output that can be sent to the Web Browser. This tutorial will guide you how to install PHP parser on your computer.
PHP Parser Installation
Before you proceed it is important to make sure that you have proper environment setup on your machine to develop your web programs using PHP.
Type the following address into your browser’s address box.
If this displays a page showing your PHP installation related information then it means you have PHP and Webserver installed properly. Otherwise you have to follow given procedure to install PHP on your computer.
This section will guide you to install and configure PHP over the following four platforms −
- PHP Installation on Linux or Unix with Apache
- PHP Installation on Mac OS X with Apache
- PHP Installation on Windows NT/2000/XP with IIS
- PHP Installation on Windows NT/2000/XP with Apache
If you are using Apache as a Web Server then this section will guide you to edit Apache Configuration Files.
Just Check it here − PHP Configuration in Apache Server
PHP.INI File Configuration
The PHP configuration file, php.ini, is the final and most immediate way to affect PHP’s functionality.
Just Check it here − PHP.INI File Configuration
Windows IIS Configuration
To configure IIS on your Windows machine you can refer your IIS Reference Manual shipped along with IIS.
Read also:PHP Syntax Overview