Core PHP: $_SERVER Variables: Script Name (7.0)

Predefined Variables

A superglobal is a predefined variable that is always accessible, regardless of scope. You can access the PHP superglobals through any function, class, or file.

PHP's superglobal variables are $_SERVER, $GLOBALS, $_REQUEST, $_POST, $_GET, $_FILES, $_ENV, $_COOKIE, $_SESSION.

$_SERVER

$_SERVER is an array that includes information such as headers, paths, and script locations. The entries in this array are created by the web server.
$_SERVER['SCRIPT_NAME'] returns the path of the current script:

<?php
echo $_SERVER['SCRIPT_NAME'];
//Outputs "/somefile.php"
?>

Our example was written in a file called somefile.php, which is located in the root of the web server.