Appendix C: PHP Installation and Basic Syntax

PHP began when Rasmus Lerdorf, in 1995, wrote a set of Perl scripts to track his online resume. The acronym PHP referred to using the scripts as his Personal Home Page tools. Subsequently, PHP/FI (Personal Home Page/Forms Interpreter) was released to the public. It has evolved into a popular and efficient language for web applications.

One of the reasons for PHP s popularity is that it can be easily integrated into web page HTML code. HTML tags directly identify the PHP code to be interpreted when viewed with a web server supporting PHP. Two of the most popular web servers that support PHP are Apache and Internet Information Services (IIS). The HTML tags that identify PHP code are standard, allowing the interface between the HTML web page source and the PHP application to be very efficient and convenient to maintain across various server platforms.

PHP is described as a web-embedded language , which means that the PHP code is embedded in, or inserted as a part of, the HTML source code. In addition to tying in closely with HTML, the PHP code is executed on a web server in the client/server architecture. The combination of HTML and PHP code in a web page is interpreted and executed when a page is requested by a browser viewing the page. In that way, it supports dynamic web page responses, which means that web pages can change depending on user input or other variable information. Any time you have looked at a web page with the current date and time, for instance, you have viewed a dynamic web page.

PHP and MySQL

PHP, like MySQL, is an open -source product with all the reliability and affordability that usually implies. PHP and MySQL also combine in a way that makes them ideal for a data-driven web site.

Note  

The PHP open source, as well as a great deal of useful information, is available from the PHP web site at http://www.php.net.

MySQL does not take up storage space or use large amounts of your CPU s resources; therefore, while it is ideal for small and medium database applications, it is also scalable for larger applications with little impact on its performance. In addition, MySQL s performance is outstanding, which makes it ideal for dynamic web applications.

The PHP server-side scripting language is easy to code, and all of its output goes directly to the browser, including errors. This makes it a great fit for dynamic web applications also.

The MySQL/PHP combination is collaborative. You ll find a wealth of documentation and support. Bugs are rapidly fixed. New features are openly considered .