Programming PHP

Server Information

The $_SERVER array contains a lot of useful information from the web server. Much of this information comes from the environment variables required in the CGI specification (http://hoohoo.ncsa.uiuc.edu/cgi/env.html).

Here is a complete list of the entries in $_SERVER that come from CGI:

SERVER_SOFTWARE

A string that identifies the server (e.g., “Apache/1.3.22 (Unix) mod_perl/1.26 PHP/4.1.0”).

SERVER_NAME

The hostname, DNS alias, or IP address for self-referencing URLs (e.g., “www.example.com”).

GATEWAY_INTERFACE

The version of the CGI standard being followed (e.g., “CGI/1.1”).

SERVER_PROTOCOL

The name and revision of the request protocol (e.g., “HTTP/1.1”).

SERVER_PORT

The server port number to which the request was sent (e.g., “80”).

REQUEST_METHOD

The method the client used to fetch the document (e.g., “GET”).

PATH_INFO

Extra path elements given by the client (e.g., “/list/users”).

PATH_TRANSLATED

The value of PATH_INFO, translated by the server into a filename (e.g., “/home/httpd/htdocs/list/users”).

SCRIPT_NAME

The URL path to the current page, which is useful for self-referencing scripts (e.g., “/~me/menu.php”).

QUERY_STRING

Everything after the ? in the URL (e.g., “name=Fred+age=35”).

REMOTE_HOST

The hostname of the machine that requested this page (e.g., “dialup-192-168-0-1.example.com”). If there’s no DNS for the machine, this is blank and REMOTE_ADDR is the only information given.

REMOTE_ADDR

A string containing the IP address of the machine ...