[mod.std.unix] P1003.2 Shell Working Group

std-unix@ut-sally.UUCP (07/08/86)

Date: Mon, 7 Jul 86 10:01:08 PDT
From: amdahl!hlj@seismo.UUCP (Hal Jespersen)

[ This is the text of an article by a co-chair of the P1003.2 committee
that he wrote for the IEEE TCOS newsletter.  It is in a format which
should be printable on any ASCII terminal or line printer.

The next message will contain the pic source for a related figure.
-mod ]




                       P1003.2 Shell Working Group

                              Hal Jespersen

                            Amdahl Corporation


       A new Working Group has been formed under the sponsorship of
       the Technical Committee on Operating Systems-P1003.2.  It
       has been chartered by the IEEE Standards Board to produce a
       proposed Standard named ``Shell and Utility Application
       Interface for Computer Operating System Environment,'' but
       it is known internally as the ``Shell Group.'' This article
       will discuss the scope and objectives of the new group and
       solicit your participation in its work.

       The Shell Group has generally the same membership as the
       P1003.1 ``POSIXTM'' operating system group and meets as a
       subcommittee-of-the-whole during a portion of P1003.1's
       quarterly meetings.  The group is co-chaired by Hal
       Jespersen of Amdahl Corporation and Don Cragun of Sun
       Microsystems, Inc.

       The purpose of the group is to produce a Standard that will
       complement the basic POSIX operating system Standard by
       providing application programs with an interface to a Shell,
       its command language, and sets of common utility programs.
       It is not intended to specify interfaces that are human
       user-friendly, such as visual shells, desktop metaphors,
       command recall, mice, and so forth.  However, such programs
       will be expected to use the programmatic interfaces provided
       by the Standard.

       The official Scope of the proposed Standard, as approved by
       the Working Group in April, 1986:

                                     SCOPE

              1.  Specify a standard interface that may be accessed
                  in common by both applications programs and user
                  terminal-controlling programs to provide services
                  of a more complex nature than the primitives
                  provided by the 1003.1 Standard.

              2.  The interface will include one or more of the
                  following components:

                    a.  Application program primitives to specify
                        instructions to an implementation-defined
                        ``shell'' facility.

                    b.  A standard command language for a shell
                        that includes program execution, I/O
                        redirection and pipelining, argument







       P1003.2 Shell Working Group                                2



                        handling, variable substitution and
                        expansion, and a series of control
                        constructs similar to other high-level
                        structured programming languages.

                    c.  A recommended command syntax for command
                        naming and argument specification.

                    d.  Primitives to assist applications programs
                        and the shell language in parsing and
                        interpreting command arguments.

                    e.  Recommended environment variables for use
                        by shell scripts and application programs.

                    f.  A minimum directory hierarchy required for
                        the shell and applications.

                    g.  Suites of useful programs or shell
                        functions that may be used for data
                        filtering or manipulation, user environment
                        control, file maintenance, or software
                        development; these suites will be
                        separately implementable.

                    h.  Utilities and standards for the
                        installation of ``add-on'' applications.

              3.  The following is a non-exclusive list of areas
                  outside the scope of the Standard:

                    a.  administrative utilities (privileged,
                        system processes, daemons, etc.)

                    b.  installation or configuration utilities

                    c.  system or file system maintenance utilities

                    d.  networking utilities

                    e.  terminal control or user-interface programs
                        (window managers, etc.)

                    f.  graphics commands

                    g.  text formatting commands

                    h.  data base interfaces (e.g.  SQL, etc.)

             At the same meeting, the Working Group approved the
             following list of Objectives, which will guide the







       P1003.2 Shell Working Group                                3



             Group's work:

                                  OBJECTIVES

              1.  The Standard should be based on the existing
                  facilities and the architectural philosophies of
                  the UNIXr* operating system.

              2.  The Standard will be designed so that it will not
                  automatically exclude other operating systems
                  than those conforming to the 1003.1 Standard.
                  However, the Standard will not be unnecessarily
                  weakened in functionality or style to accommodate
                  other operating systems.

              3.  The Standard will be designed to maximize the
                  conformance and portability of existing UNIX
                  applications.

              4.  The Standard will be designed to maximize its
                  usefulness for international applications.

              5.  Interfaces to the standard shell(s) will be
                  structured so that other shells may be
                  substituted for specific applications.

              6.  The Standard will specify command input and
                  output formats with enough precision to allow
                  those commands to be correctly implemented from
                  the language of the Standard alone.

              7.  The Standard will specify program interfaces in
                  the C language, but will not rule out future
                  specifications in other languages.

             The next meeting will be held in Palo Alto,
             California, at the Hyatt Rickey's Hotel, 09:00-12:00
             Tuesday, September 17, 1986.  An agenda and directions
             to the hotel will be sent out in a future mailing to
             the 1003 mailing list.

             Your participation and support are encouraged.  All
             interested parties are invited to attend the next, and
             all future, meetings.  Proposals for inclusion in the
             Standard, or comments, are accepted from anyone.


       __________

         * UNIX is a registered trademark of AT&T.








       P1003.2 Shell Working Group                                4



             These documents, referred to as ``Requests For
             Comments,'' or RFC's, should be sent (preferably in
             machine-readable and printed form) to:

               Don Cragun
               Sun Microsystems, Inc.
               2550 Garcia Avenue
               Mountain View, CA  94043
               (415) 960-7487
               {amdahl|decvax|hplabs|ihnp4|seismo}!sun!dwc

             Information about the Working Group may be obtained
             from Don, or from:

               Hal Jespersen
               Amdahl Corporation
               Mailstop 316
               1250 East Arques Avenue
               Sunnyvale, CA  94088-3470
               (408) 746-8288
               {hplabs|ihnp4}!amdahl!hlj


Volume-Number: Volume 6, Number 24