INTERNET-DRAFT                                           D.R.T. Robinson
<draft-robinson-www-interface-01.txt>            University of Cambridge
Expires 15 August 1996                                  15 February 1996

              The WWW Common Gateway Interface Version 1.1

Status of this memo

   This document is an Internet-Draft. Internet-Drafts are working
   documents of the Internet Engineering Task Force (IETF), its areas
   and its working groups. Note that other groups may also distribute
   working documents as Internet-Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced or obsoleted by other documents at any
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   To learn the current status of any Internet-Draft, please check the
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   Distribution of this document is unlimited. Please send comments to
   the author; general discussion about CGI should take place on the
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Abstract

   The Common Gateway Interface (CGI) is a simple interface for running
   external programs, software or gateways under an information server
   in a platform-independent manner. Currently, the supported
   information servers are HTTP servers.

   The interface has been in use by the World-Wide Web since 1993. This
   specification defines the interface known as `CGI/1.1', and its use
   on the Unix(R) and AmigaDOS(tm) systems.

1. Introduction

1.1. Purpose

   Together the HTTP [3] server and the CGI script are responsible for
   servicing a client request by sending back responses. The client
   request comprises a Universal Resource Identifier (URI) [1], a
   request method and various ancillary information about the request
   provided by the transport mechanism.




 
INTERNET-DRAFT       Common Gateway Interface - 1.1     15 February 1996


   The CGI defines the abstract parameters, known as environment
   variables, which describe the client's request. Together with a
   concrete programmer interface this specifies a platform-independent
   interface between the script and the HTTP server.

1.2. Requirements

   This specification uses the same words as RFC 1123 [5] to define the
   significance of each particular requirement. These are:

   must

      This word or the adjective `required' means that the item is an
      absolute requirement of the specification.

   should

      This word or the adjective `recommended' means that there may
      exist valid reasons in particular circumstances to ignore this
      item, but the full implications should be understood and the case
      carefully weighed before choosing a different course.

   may

      This word or the adjective `optional' means that this item is
      truly optional. One vendor may choose to include the item because
      a particular marketplace requires it or because it enhances the
      product, for example; another vendor may omit the same item.

   An implementation is not compliant if it fails to satisfy one or more
   of the `must' requirements for the protocols it implements. An
   implementation that satisfies all of the `must' and all of the
   `should' requirements for its features is said to be `unconditionally
   compliant'; one that satisfies all of the `must' requirements but not
   all of the `should' requirements for its features is said to be
   `conditionally compliant'.

1.3. Specifications

   Not all of the functions and features of the CGI are defined in the
   main part of this specification. The following phrases are used to
   describe the features which are not specified: