PHP Predefined Variables

Script filename:
/home/gangara4/public_html/infost440/a3/predefined.php

User agent:
Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)

Server software:
Apache

What Each Variable Means

$_SERVER['SCRIPT_FILENAME'] shows the full path and filename of the current script.

$_SERVER['HTTP_USER_AGENT'] provides information about the visitor's browser and operating system.

$_SERVER['SERVER_SOFTWARE'] identifies the software used by the web server.

Explanation

Predefined variables are created automatically by PHP and provide information that a script may need. The $_SERVER superglobal contains details about the current file, the visitor's browser, and the web server. Because it is superglobal, it can be accessed from anywhere in a PHP script without creating it first.