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- From: <jsh@usenix.org>
-
-
- An Update on UNIX* and C Standards Activities
-
- January 1990
-
- USENIX Standards Watchdog Committee
-
- Jeffrey S. Haemer, Report Editor
-
- IEEE 1003.0: POSIX Guide Update
-
- Charles Severance <crs@convex.cl.msu.edu> reports on the January 8-12,
- 1990 meeting in New Orleans, LA:
-
- Dot zero is producing a guide to the POSIX Open System Environment
- (OSE). The guide will bring existing and evolving standards together
- to provide specifications for all aspects of an OSE -- everything
- from application programming interfaces to user interfaces and system
- management. It will give users an overview of the 1003, and other,
- related standards, describe their interrelationships, and help them
- select the subset of available standards necessary for any particular
- application.
-
- Draft Six Review
-
- This meeting, the group reviewed draft six. Points of special
- interest were:
-
- + the formal definition of ``open system''
-
- + internationalization
-
- + an editorial review of the entire document to insure a consistent
- style
-
- + a review of some high-level architecture diagrams, proposed to
- make Chapter 3 (``Overall Architecture'') easier to understand,
-
- The only one of these discussed by the entire group was the definition
- of ``Open System.'' To simplify the definition we created a definition
- for ``Open Standard'' which was used in the Open System definition.
- Here is the definition we finally agreed on:
-
- Open System: A system that implements sufficient Open
- Specifications for interfaces, services, and supporting formats
- which enable properly engineered applications software: a) to be
-
- __________
-
- * UNIX is a registered trademark of AT&T in the U.S. and other
- countries.
-
- January 1990 Standards Update IEEE 1003.0: POSIX Guide
-
-
- - 2 -
-
- ported across a wide range of systems with minimal changes, b) to
- interoperate with other applications on local and remote systems,
- and c) to interact with users in a style which facilitates user
- portability.
-
- Open Specification: A public specification which is maintained by
- an open, public, consensus process to accommodate new
- technologies over time and consistent with international
- standards.
-
- The group won't define ``user portability'' until next meeting, but
- the idea is that users should see a consistent interface from
- application to application, both within and across systems. Public
- user-interface standards should simplify both user training and vendor
- documentation.
-
- The other issues were handled in small working groups.
-
- 1. Internationalization
-
- The internationalization group identified parts of the document
- affected by internationalization and other ``cross-component''
- issues, such as system management and security. They promise to
- present new, draft text for the internationalization sections by
- the next meeting.
-
- 2. Editorial review
-
- The editorial review group tackled the no-fun jobs of reviewing
- the entire draft for style and identifying areas that had too
- much, or too little detail. Along the way, they proposed a
- style guide and template for sections of Chapter 4.
-
- 3. Architectural overview
-
- The architecture group continued work on Chapter 3 to complete
- the text of the chapter. Also the group worked to simplify the
- chapter to make it easier to understand. The CCTA (UK)
- presented a high-level classification scheme called ``MUSIC''
- (Management, User Interface, System Interface, Information
- Interchange, and Communication) as a potential contribution to
- chapter 3. The chapter will have extensive modifications and
- additions for the next meeting.
-
- Application profiles
-
- Next meeting we'll discuss exactly what must be in a POSIX Application
- Environment Profile (AEP). Profiles will affect and generate
- procurement issues, so this will be a key discussion.
-
- January 1990 Standards Update IEEE 1003.0: POSIX Guide
-
-
- - 3 -
-
- Profiles specify a set of standards for specific computing areas, such
- as supercomputing. Not all standards will be required for all areas;
- a profile lists the subset of the standards necessary for a particular
- area.
-
- The biggest point of contention in this discussion will probably be
- whether 1003.1 [Editor: the system interfaces set out in the Ugly
- Green Book] will be required for all profiles. Should vendors be
- allowed to advertise compliance to, say, 1003.11 (transaction
- processing), if they've implemented that standard on an underlying
- system that doesn't support lower-level POSIX calls like fopen()?
- (There isn't a standard for 1003.11 yet, but you get the idea.)
-
- One argument advanced for requiring 1003.1 is that it will force
- vendors to adopt it more quickly. I don't think that 1003.1 needs any
- help in that area. Another is that requiring compliance will insure
- that vendors who want to advertise POSIX-compliant systems are
- following the general POSIX direction and not just implementing the
- simplest standard so they can claim that their system implements
- ``some POSIX.''
-
- An argument made against the requirement is that it may damage
- implementations. For example, real-time systems may lack even a file
- system, and may want a very limited subset of the POSIX interface to
- keep the implementation as small as possible. If all of 1003.1 is
- required, vendors may have to add costly and unnecessary features just
- to claim POSIX compatibility.
-
- When the dust settles, I think 1003.1 will be strongly suggested but
- not required, because 1003.1 is a pretty arbitrary subset of any list
- of ``required system interfaces.''
-
- [Editor: We disagree. 1003.1 is a set of applications programming
- interfaces carefully chosen to be necessary and sufficient to make an
- operating system UNIX-like for the C programmer. Providing standards
- for a UNIX-like operating system should be the goal of the POSIX
- standards, and attempts by vendors uncomfortable with UNIX to dilute
- the effort should be cut off at the pass.]
-
- [Author: POSIX must evolve a set of independent standards that have
- UNIX as their heritage. POSIX standards are all evolving as UNIX-like
- standards. Why discourage a vendor from implementing some subset of
- UNIX-like standards just because the vendor is not ready to provide a
- complete 1003.1 implementation? ]
-
- January 1990 Standards Update IEEE 1003.0: POSIX Guide
-
-
- - 4 -
-
- Want to go to a POSIX meeting?
-
- This was my first POSIX meeting. In case you haven't been and are
- thinking of going, here are a couple of things you'll want to know.
-
- New people and their new ideas, are welcomed. As a practical matter,
- it helps to stick with a group for the entire week. It's tough to
- understand much if you come into an advanced discussion, cold, It
- would help if each group summarized its purpose and listed the big
- issues at the beginning of each meeting, to get everyone in the proper
- frame of mind, but that doesn't always happen. Still, you'll be
- granted a sort of first-time armor to protect you when you ask naive
- questions or need clarification. For extra insurance, use the phrase
- ``I will take an action item...'' often.
-
- January 1990 Standards Update IEEE 1003.0: POSIX Guide
-
-
- Volume-Number: Volume 19, Number 56
-
-