CGI Environment Variables CGI Environment VariablesIn order to pass data about the information request from the server to the script, the server uses command line arguments as well as environment variables. These environment variables are set when the server executes the gateway program.
Windows/DOS Note: Any physical paths must be in in the Windows/DOS syntax, with "\" separators instead of the Unix "/". Full paths must include drive letters and/or UNC network node name components as needed to resolve any ambiguity. Under no circumstances must scripts rely on any pre-existing or implied "working directory".
The following environment variables are not request-specific and are set for all requests:
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 would appear in self-referencing URLs.
GATEWAY_INTERFACE The revision of the CGI specification to which this server complies. Format: CGI/revision
OUTPUT_FILE - Windows OnlyThe Windows httpd server creates this variable with the DOS path/filename of the temp file that is to receive the script output that is to be sent back to the client.
SERVER_PROTOCOL The name and revision of the information protcol 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", etc.
HTTP_ACCEPT The MIME types which the client will accept, as given by HTTP headers. Other protocols may need to get this information from elsewhere. Each item in this list should be separated by commas as per the HTTP spec.
Format: type/subtype, type/subtype
Windows/DOS Note: The list of acceptable MIME types
is placed into a file, one type per line. The value of
HTTP_ACCEPT is set to the DOS path/filename
of this file.
PATH_INFO The extra path information, as given by the client. In other words, 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. This information should be decoded by the server if it comes from a URL before it is passed to the CGI script.
PATH_TRANSLATED The server provides a translated version of PATH_INFO, which takes the path and does any virtual-to-physical mapping to it.
Windows/DOS Note: The result of virtual-to-physical mapping will be in DOS path syntax.
SCRIPT_NAME A virtual path to the script being executed, used for self-referencing URLs.
QUERY_STRING The information which follows the ? in the URL which referenced this script. This is the query information. It should not be decoded in any fashion. This variable should always be set when there is query information, regardless of command line decoding.
REMOTE_HOST The hostname making the request. If the server does not have this information, it should set REMOTE_ADDR and leave this unset.
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 If the server supports user authentication, and the script is protected, this is the username they have authenticated as.
REMOTE_IDENT If the HTTP server supports RFC 931 identification, then this variable will be set to the remote user name retrieved from the server. Usage of this variable should be limited to logging only.
CONTENT_TYPE For queries which have attached information, such as HTTP POST and PUT, this is the content type of the data.
CONTENT_LENGTH The length of the said content as given by the client.
CONTENT_FILE - Windows OnlyThe Windows httpd server creates this variable with the DOS path/filename to the temp file that contains the content sent by the client. The length of this file will be exactly CONTENT_LENGTH bytes.
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