PHP is a general-purpose scripting language especially suited to web development. PHP code is usually processed on a web server by a PHP interpreter implemented as a module, a daemon or as a Common Gateway Interface (CGI) executable. On a web server, the result of the interpreted and executed PHP code – which may be any type of data, such as generated HTML or binary image data – would form the whole or part of an HTTP response.

Whenever a browser sends a request for a page, it also sends a number of other headers to the script, containing information such as the browser type. It also includes information such as the visitors IP address.

The following PHP code will display the visitor’s IP:

// Use getenv()
echo getenv(‘REMOTE_ADDR’);

// Or use a Superglobal ($_SERVER or $_ENV)