The Common Gateway Interface (CGI) Version 1.1
RFC 3875

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Network Working Group                                        D. Robinson
Request for Comments: 3875                                       K. Coar
Category: Informational                   The Apache Software Foundation
                                                            October 2004

             The Common Gateway Interface (CGI) Version 1.1

Status of this Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard of any kind.  Distribution of this
   memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2004).

IESG Note

   This document is not a candidate for any level of Internet Standard.
   The IETF disclaims any knowledge of the fitness of this document for
   any purpose, and in particular notes that it has not had IETF review
   for such things as security, congestion control or inappropriate
   interaction with deployed protocols.  The RFC Editor has chosen to
   publish this document at its discretion.  Readers of this document
   should exercise caution in evaluating its value for implementation
   and deployment.

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 (WWW) since 1993.
   This specification defines the 'current practice' parameters of the
   'CGI/1.1' interface developed and documented at the U.S. National
   Centre for Supercomputing Applications.  This document also defines
   the use of the CGI/1.1 interface on UNIX(R) and other, similar
   systems.

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RFC 3875                    CGI Version 1.1                 October 2004

Table of Contents

   1.  Introduction. . . . . . . . . . . . . . . . . . . . . . . . .   4
       1.1. Purpose  . . . . . . . . . . . . . . . . . . . . . . . .   4
       1.2. Requirements . . . . . . . . . . . . . . . . . . . . . .   4
       1.3. Specifications . . . . . . . . . . . . . . . . . . . . .   4
       1.4. Terminology  . . . . . . . . . . . . . . . . . . . . . .   5

   2.  Notational Conventions and Generic Grammar. . . . . . . . . .   5
       2.1. Augmented BNF  . . . . . . . . . . . . . . . . . . . . .   5
       2.2. Basic Rules  . . . . . . . . . . . . . . . . . . . . . .   6
       2.3. URL Encoding . . . . . . . . . . . . . . . . . . . . . .   7

   3.  Invoking the Script . . . . . . . . . . . . . . . . . . . . .   8
       3.1. Server Responsibilities  . . . . . . . . . . . . . . . .   8
       3.2. Script Selection . . . . . . . . . . . . . . . . . . . .   9
       3.3. The Script-URI . . . . . . . . . . . . . . . . . . . . .   9
       3.4. Execution  . . . . . . . . . . . . . . . . . . . . . . .  10

   4.  The CGI Request . . . . . . . . . . . . . . . . . . . . . . .  10
       4.1. Request Meta-Variables . . . . . . . . . . . . . . . . .  10
            4.1.1.  AUTH_TYPE. . . . . . . . . . . . . . . . . . . .  11
            4.1.2.  CONTENT_LENGTH . . . . . . . . . . . . . . . . .  12
            4.1.3.  CONTENT_TYPE . . . . . . . . . . . . . . . . . .  12
            4.1.4.  GATEWAY_INTERFACE. . . . . . . . . . . . . . . .  13
            4.1.5.  PATH_INFO. . . . . . . . . . . . . . . . . . . .  13
            4.1.6.  PATH_TRANSLATED. . . . . . . . . . . . . . . . .  14
            4.1.7.  QUERY_STRING . . . . . . . . . . . . . . . . . .  15
            4.1.8.  REMOTE_ADDR. . . . . . . . . . . . . . . . . . .  15
            4.1.9.  REMOTE_HOST. . . . . . . . . . . . . . . . . . .  16
            4.1.10. REMOTE_IDENT . . . . . . . . . . . . . . . . . .  16
            4.1.11. REMOTE_USER. . . . . . . . . . . . . . . . . . .  16
            4.1.12. REQUEST_METHOD . . . . . . . . . . . . . . . . .  17
            4.1.13. SCRIPT_NAME. . . . . . . . . . . . . . . . . . .  17
            4.1.14. SERVER_NAME. . . . . . . . . . . . . . . . . . .  17
            4.1.15. SERVER_PORT. . . . . . . . . . . . . . . . . . .  18
            4.1.16. SERVER_PROTOCOL. . . . . . . . . . . . . . . . .  18
            4.1.17. SERVER_SOFTWARE. . . . . . . . . . . . . . . . .  19
            4.1.18. Protocol-Specific Meta-Variables . . . . . . . .  19
       4.2. Request Message-Body . . . . . . . . . . . . . . . . . .  20
       4.3. Request Methods  . . . . . . . . . . . . . . . . . . . .  20
            4.3.1.  GET. . . . . . . . . . . . . . . . . . . . . . .  20
            4.3.2.  POST . . . . . . . . . . . . . . . . . . . . . .  21
            4.3.3.  HEAD . . . . . . . . . . . . . . . . . . . . . .  21
            4.3.4.  Protocol-Specific Methods. . . . . . . . . . . .  21
       4.4. The Script Command Line. . . . . . . . . . . . . . . . .  21

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