User Guide

18 Chapter 1: Reserved Words and Variables
CGI server variables
The following table describes common CGI environment variables that the server creates (some
of these are not available with some servers):
CGI server variable Description
SERVER_SOFTWARE Name and version of the information server software answering
the request (and running the gateway). Format: name/version.
SERVER_NAME Server's hostname, DNS alias, or IP address as it appears in self-
referencing URLs.
GATEWAY_INTERFACE CGI specification revision with which this server complies. Format:
CGI/revision.
SERVER_PROTOCOL Name and revision of the information protocol this request came in
with. Format: protocol/revision.
SERVER_PORT Port number to which the request was sent.
REQUEST_METHOD Method with which the request was made. For HTTP, this is Get,
Head, Post, and so on.
PATH_INFO Extra path information, as given by the client. Scripts can be
accessed by their virtual pathname, followed by extra information
at the end of this path. The extra information is sent as
PATH_INFO.
PATH_TRANSLATED Translated version of PATH_INFO after any virtual-to-physical
mapping.
SCRIPT_NAME Virtual path to the script that is executing; used for self-referencing
URLs.
QUERY_STRING Query information that follows the ? in the URL that referenced
this script.
REMOTE_HOST Hostname making the request. If the server does not have this
information, it sets REMOTE_ADDR and does not set
REMOTE_HOST.
REMOTE_ADDR IP address of the remote host making the request.
AUTH_TYPE If the server supports user authentication, and the script is
protected, the protocol-specific authentication method used to
validate the user.
REMOTE_USER
AUTH_USER
If the server supports user authentication, and the script is
protected, the username the user has authenticated as. (Also
available as AUTH_USER.)
REMOTE_IDENT If the HTTP server supports RFC 931 identification, this variable is
set to the remote username retrieved from the server. Use this
variable for logging only.
CONTENT_TYPE For queries that have attached information, such as HTTP POST
and PUT, this is the content type of the data.
CONTENT_LENGTH Length of the content as given by the client.