Find out what a PHP file is and how this scripting language is used to build dynamic web pages and sites.
What Makes Up a PHP File?
What is a PHP file? To answer that question, we need to first look at what the term means. PHP itself stands for HyperText Preprocessor and is a server-side scripting language just like ASP (Active Server Pages) except that it can be used across platforms unlike ASP. Originally, the term stood for personal home page but was redefined for PHP initialization.
PHP is also open source, which means that it is free to download, use and edit to fit the needs of any project that it is being used for under the PHP License. The first inception of PHP came from Rasmus Lerdorf back in 1995 and has since grown at such a rate that there is now a group effort for PHP implementation called The PHP Group, who continues to expand the use of this open source scripting language.
Creating in PHP
A file that contains PHP can be created from either HTML (HyperText Markup Language) or XHTML (Extensible HyperText Markup Language) and each file can include text, tags and scripts depending on what the programmer wants to include in their own PHP files. Creating PHP files can greatly enhance web development but is best done by those who already understand HTML/XHTML.
In order to create dynamic web pages in all areas of web development, the PHP code file itself is embedded into the source HTML document of the web site. The source document is then read by a server which processes the PHP code through a command line. The command line, in general, is typed code that tells a computer what it needs to do with certain information. Once the command line is executed and read by an interpreter application, the web server can read the information of the PHP code file correctly and put it to work.
Common PHP code file extensions are .php, .php3, and .phtml, which will vary depending on web application and server-side development needs.
Using a PHP File
The main use of PHP files is for server-side scripting. In order to use PHP files in this way, web developers need to have a web browser, a web server and a server module. Connecting to a PHP installation will enable creation of the code for the PHP files that will open them for embedding the HTML/XHTML. In terms of web development there are loads of great reasons to use PHP, check out Using PHP for Easy Menu Updates for an example.
Having the the web browser is an important factor because the PHP files can display the code output from the server after embedding what the PHP file is supposed to do for the web page. The output from PHP files is not limited to just HTML/XHTML text. In using the embedding capabilities of PHP, items that can be outputted to a completed web page may be images, Flash movies and even .PDF files.
You can go beyond the question of what a PHP file is and further explore the subject through w3schools PHP Tutorial. You can also get started by installing and using PHP through PHP.net's Install Manual. The second link in the reference section will take you to PHP.net's information page and will not automatically begin installation.
The PHP Group, http://www.php.net
PHP Manual, http://www.php.net/manual/php3.php
Image Credit: © 2001-2011 The PHP Group