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