in Section 6 of the HTTP specification [3]. Note that this allows an
   HTTP/0.9 response to an HTTP/1.0 request.

   The server should attempt to ensure that the script output is sent
   directly to the client, with minimal buffering.

9.2. Parsed Header Output

   The script returns a CGI response message.

      CGI-Response = *( CGI-Header | HTTP-Header ) NL [ Entity-Body ]
      CGI-Header   = Content-type
                   | Location
                   | Status
                   | extension-header

   The response comprises headers and a body, separated by a blank line.
   The headers are either CGI headers to be interpreted by the server,
   or HTTP headers to be included in the response returned to the client
   if the request method is HTTP. At least one CGI-Header must be
   supplied, but no CGI header can be repeated with the same field-name.




 
INTERNET-DRAFT       Common Gateway Interface - 1.1     15 February 1996


   If a body is supplied, then a Content-type header is required,
   otherwise the script must send a Location or Status header. If a
   Location header is returned, then no HTTP-Headers may be supplied.

   The CGI headers have the generic syntax:

      generic-header = field-name ":" [ field-value ] NL
      field-name     = 1*<any CHAR, excluding CTLs, SP and ":">
      field-value    = *( field-content | LWSP )
      field-content  = *( token | tspecial | quoted-string )

   The field-name is not case sensitive; a NULL field value is
   equivalent to the header not being sent.

   Content-Type

      The Internet Media Type [9] of the entity body, which is to be
      sent unmodified to the client.

         Content-Type = "Content-Type" ":" media-type NL

   Location

      This is used to specify to the server that the script is returning
      a reference to a document rather than an actual document.

         Location         = "Location" ":"
                            ( fragment-URI | rel-URL-abs-path ) NL
         fragment-URI     = URI [ # fragmentid ]
         URI              = scheme ":" *qchar
         fragmentid       = *qchar
         rel-URL-abs-path = "/" [ hpath ] [ "?" query-string ]
         hpath            = fpsegment *( "/" psegment )
         fpsegment        = 1*hchar
         psegment         = *hchar
         hchar            = alpha | digit | safe | extra
                          | ":" | "@" | "& | "="

      The location value is either an absolute URI with optional
      fragment, as defined in RFC 1630 [1], or an absolute path and
      optional query-string. If an absolute URI is returned by the
      script, then the server will generate a redirect HTTP response
      message, and if no entity body is supplied by the script, then the
      server will produce one. If the Location value is a path, then the
      server will generate the response that it would have produced in
      response to a request containing the URL

         protocol "://" SERVER_NAME ":" SERVER_PORT rel-URL-abs-path




 
INTERNET-DRAFT       Common Gateway Interface - 1.1     15 February 1996


      The location header may only be sent if the REQUEST_METHOD is HEAD
      or GET.

   Status

      The Status header is used to indicate to the server what status
      code it will use in the response message. It should not be sent if
      the script returns a Location header.

         Status        = "Status" ":" 3digit SP reason-phrase NL
         reason-phrase = *<CHAR, excluding CTLs, NL>

      The valid status codes are listed in section 6.1.1 of the HTTP/1.0
      specification [3]. If the script does not return a Status header,
      then "200 OK" should be assumed.