$_SERVER

$_SERVER is a superglobal variable which holds the data about the headers, script locations, network addresses, paths, etc.

Example:

 

<?php
echo $_SERVER['PHP_SELF'] . '<br>';
echo $_SERVER['DOCUMENT_ROOT'] . '<br>';
echo $_SERVER['SERVER_ADDR'] . '<br>';
echo $_SERVER['SERVER_NAME'] . '<br>';
echo $_SERVER['REQUEST_METHOD'] . '<br>';
echo $_SERVER['REQUEST_TIME'] . '<br>';
echo $_SERVER['HTTP_USER_AGENT'] . '<br>';
echo $_SERVER['REMOTE_ADDR'];
?>

 

The following table lists some of the important elements of $_SERVER

 

Element/Code	Description
$_SERVER['PHP_SELF']	Returns the filename of the currently executing script
$_SERVER['GATEWAY_INTERFACE']	Returns the version of the Common Gateway Interface the server is using
$_SERVER['SERVER_ADDR']	Returns the IP address of the host server
$_SERVER['SERVER_NAME']	Returns the name of the host server
$_SERVER['SERVER_SOFTWARE']	Returns the server identification string
$_SERVER['SERVER_PROTOCOL']	Returns the name and revision of the information protocol
$_SERVER['REQUEST_METHOD']	Returns the request method used to access the page
$_SERVER['REQUEST_TIME']	Returns the timestamp of the start of the request
$_SERVER['QUERY_STRING']	Returns the query string if the page is accessed via a query string
$_SERVER['HTTP_ACCEPT']	Returns the Accept header from the current request
$_SERVER['HTTP_ACCEPT_CHARSET']	Returns the Accept_Charset header from the current reques
$_SERVER['HTTP_HOST']	Returns the Host header from the current request
$_SERVER['HTTP_REFERER']	Returns the complete URL of the current page
$_SERVER['HTTPS']	Is the script queried through a secure HTTP protocol
$_SERVER['REMOTE_ADDR']	Returns the IP address from where the user is viewing the current page
$_SERVER['REMOTE_HOST']	Returns the Hostname from where the user is viewing the current page
$_SERVER['REMOTE_PORT']	Returns the port being used on the user's machine to communicate with the web server
$_SERVER['SCRIPT_FILENAME']	Returns the absolute pathname of the currently executing script
$_SERVER['SERVER_ADMIN']	Returns the value given to the SERVER_ADMIN directive in the web server configuration file
$_SERVER['SERVER_PORT']	Returns the port on the server machine being used by the web server for communication
$_SERVER['SERVER_SIGNATURE']	Returns the server version and virtual host name which are added to server-generated pages
$_SERVER['PATH_TRANSLATED']	Returns the file system-based path to the current script
$_SERVER['SCRIPT_NAME']	Returns the path of the current script
$_SERVER['SCRIPT_URI']	Returns the URI of the current page