Understanding fifi.php: A Quick Guide to PHP Files

What is fifi.php?

fifi.php is a PHP script file. In PHP projects, files with the .php extension contain code that is executed on the server to generate content that is sent to a web browser. The name fifi.php is just a placeholder used in tutorials to illustrate how PHP files work.

How PHP files are executed

When a request asks for a PHP file, the web server passes the file to the PHP interpreter. The interpreter runs the PHP code and outputs HTML (or other content). The browser only sees the resulting output, not the PHP source. PHP can be embedded in HTML or be standalone.

Naming conventions for PHP files

PHP files use the .php extension. Use descriptive names (no spaces; use hyphens or underscores). On some servers the file system is case-sensitive, so be consistent (e.g., Fifi.php vs fifi.php).

A minimal fifi.php example

<?php
// Simple hello from fifi.php
echo '<p>Hello from fifi.php!</p>';
?>

Running fifi.php locally

If you have PHP installed, you can run a built-in server. From the directory containing fifi.php, run:

• For PHP 5.4+:

php -S localhost:8000

Then open http://localhost:8000/fifi.php in a browser. If you are working on a larger project, you can point the server to the project root.

Security and best practices

• Never display raw user input directly. Use htmlspecialchars to escape output.
• Validate and sanitize inputs before using them in queries or file operations.
• Disable display_errors in a production environment and log errors instead.
• Keep your PHP version up to date and follow the site's security best practices.

Common pitfalls

• Using short PHP tags <? ?> if the server does not enable them.
• Omitting the opening <?php tag or mismatching PHP blocks.
• Mixing PHP and HTML without clear boundaries, which makes maintenance harder.