Operation Manual

SERVER_SOFTWARE The name and version of the information server software
answering the request (and running the gateway). Format:
name/version.
SERVER_NAME The server's hostname, DNS alias, or IP address as it appears in
self-referencing URLs.
GATEWAY_INTERFACE The revision of the CGI specification to which this server
complies. Format: CGI/revision.
SERVER_PROTOCOL The name and revision of the information protocol this request
came in with. Format: protocol/revision.
SERVER_PORT The port number to which the request was sent.
REQUEST_METHOD The method with which the request was made. For HTTP, this is
Get, Head, Post, and so on.
PATH_INFO The 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 The server provides a translated version of PATH_INFO, which
takes the path and does any virtual-to-physical mapping to it.
SCRIPT_NAME A virtual path to the script being executed; used for self-
referencing URLs.
QUERY_STRING The query information that follows the question mark (?) in the
URL that referenced this script.
REMOTE_HOST The hostname making the request. If the server does not have
this information, it sets REMOTE_ADDR and does not set
REMOTE_HOST.
REMOTE_ADDR The IP address of the remote host making the request.
AUTH_TYPE If the server supports user authentication, and the script is
protected, this is 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, this is the user name they have authenticated as. (Also
available as AUTH_USER.)
REMOTE_IDENT If the HTTP server supports RFC 931 identification, this variable
is set to the remote user name 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 The length of the content as given by the client.
The following table lists the most common CGI variables created by the browser and passed to the server:
Variable Description
HTTP_REFERER The referring document. This is the document that linked to or
submitted form data.
HTTP_USER_AGENT The browser the client is currently using to send the request.
Format: software/version library/version.
HTTP_IF_MODIFIED_SINCE The last time the page was modified. This variable is sent at the
discretion of the browser, usually in response to the server having
sent the LAST_MODIFIED HTTP header. It can be used to take
advantage of browser-side caching.
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