php tutorial - Introduction to PHP - php programming - learn php - php code - php script

• what is php - PHP stands for Hypertext Preprocessor.

• The PHP programming language is a server-side scripting language.

• The PHP language runs on the server-side. This means that the execution (read starting) of the scripts are done on the server where the web-site is hosted.
• Generally, PHP is embedded with HTML and Scripting Language.
• HTML embedded means, that you can use PHP statements (read a piece of PHP code) within an HTML code.
• PHP files are returned to the browser as plain HTML.

PHP runs on different platforms (Windows, Linux, Unix, etc.)

PHP is compatible with almost all servers used today (Apache, IIS, etc.)

PHP is FREE to download from the official PHP resource: www.php.net

PHP is easy to learn and runs efficiently on the server side

The PHP code is enclosed in special start and end processing instructions <?php and ?> that allow you to jump into and out of "PHP mode."

History of PHP

Created by Rasmus Lerdorf in 1995 for tracking access to his resume

Originally a set of Perl scripts known as the “Personal Home Page”

tools

Rewritten in C with database functionality

Added a forms interpreter and released as PHP/FI: includes Perl-like variables, and HTML embedded syntax

Rewritten again in and released as version 2.0 in November of 1997

Estimated user base in 1997 is several thousand users and 50,000 web sites served

Rewritten again in late 1997 by Andi Gutmans and Zeev Suraski

More functionality added, database support, protocols and APIs

User base in 1998 estimated 10,000 users and 100,000 web sites installed

Version 3.0 was released in June 1998 as PHP

Estimated user base in tens of thousands and hundreds of thousands of web sites served

Rewritten again in 1997 by Andi Gutmans and Zeev Suraski

More functionality added (OOP features), database support, protocols and APIs

PHP 3.0 is released in June 1998 with some OO capability

The core is rewritten in 1998 for improved performance of complex applications

The core is rewritten in 1998 by Zeev and Andi and dubbed the “Zend Engine”

The engine is introduced in mid 1999 and is released with version 4.0 in May of 2000

The estimated user base is hundreds of thousands of developers and several million of web sites served

Version 5.0 will include version 2.0 of the Zend Engine

New object model is more powerful and intuitive

Objects will no longer be passed by value; they now will be passed by reference

Increases performance and makes OOP more attractive

Why PHP :

Characteristics of PHP :

• PHP is free and an open source software product.
• PHP supports many databases (MySQL, Sybase, Oracle and many others.)
• PHP runs on different platforms (Unix, Linux, Windows.)
• PHP is mostly support in all the web-servers used today (Apache, IIS (Internet Information Services), etc.)
• A PHP file can contain plain text, HTML tags and scripts.
• The PHP files can have one of the following extensions: .php, php3 or phtml.

PHP - Installation

On windows, you can download and install WAMP. With one installation and you get an Apache webserver, database server and php. http://www.wampserver.com

On mac, you can download and install MAMP. http://www.mamp.info/en/index.html

PHP Hello World

The above code renders as HTML that looks like below html code :

PHP - Complete Functions Lists

How PHP Pages are Accessed and Interpreted

Client: Web browser Web server

1. Form submitted with a submit button
2. Action sends a request to the php file in server
3. Receive the request, find the file, and read it
4. Execute the PHP commands
5. Send the results back
6. results returned as HTML file
7. Web browser renders the HTML file, displaying the results

Embedding PHP Statements Within HTML Documents

One way to use PHP is to embed PHP scripts within HTML tags in an HTML document.

Save the file first with extension html

Validate the html file

Change the extension to php

Access the script by URL on server

---