The REXX Sourcebook

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By Dirk Terrell

About the REXX SourceBook

The REXX Sourcebook is a collection of REXX information gotten from various places on the Internet and turned into a document. Except as noted, I have not contributed any of the factual information contained herein.

Dirk Terrell

Frequently Asked Questions About REXX

By Eric Giguère

Introduction

This document is intended to serve as a useful reference for REXX-related information. It aims for breadth as opposed to depth, and references to other material are given where appropriate. Suggestions and updates should be sent to the author in an attempt to keep this document relevant and up- to-date.

Readers will notice the prevalence of OS/2-related materials in this document. Most of the REXX-related activity at this time is occurring on the OS/2 platform. This document is not intended to be OS/2-specific. The author is quite happy to include information on other platforms if you pass it on to him.

More information on REXX can also be had from the REXX Language Association.

What is REXX

REXX is a programming language designed by Michael Cowlishaw of IBM UK Laboratories. In his own words: "REXX is a procedural language that allows programs and algorithms to be written in a clear and structured way." REXX doesn't look that different from any other procedural language. Here's a simple REXX program:

/* Count some numbers */

say "Counting..."
do i = 1 to 10
say "Number" i
end

What makes REXX different from most other languages is that it is also designed to be used as a macro language by arbitrary application programs. The idea is that application developers don't have to design their own macro languages and interpreters. Instead they use REXX as the macro language and support the REXX programming interface. If a REXX macro comes across an expression or function call that it cannot resolve, it can ask the application to handle it instead. The application only has to support the features that are specific to it, freeing the developer from handling the mundane (and time-consuming) task of writing a language interpreter. And if all applications use REXX as their macro language, the user only has to learn one language instead of a dozen.

REXX and the Internet

Networks connect computers in various ways for the exchange of data. The terminology is a bit confusing to the new user. Here are the definitions this document uses:

Usenet: Not really a network, just the set of machines that exchange network news. Network news is really an extended form of electronic mail that groups messages from individuals into newsgroups that users can read using special newsreaders.

Internet: The worldwide network based on TCP/IP protocols. Besides being able to receive mail and newsgroups, these machines can use programs like ftp and telnet to communicate with other machines in real time. Most Internet machines are Unix-based.

BITNET: The worldwide network that connects many IBM mainframes. BITNET users can also transfer files using methods that are incompatible with those of the Internet.

NewsGroups

The Usenet group comp.lang.rexx exists for discussion of REXX in all its variations. Anything posted to this newsgroup also gets sent to the REXXLIST mailing list (see below) and vice-versa.

Other newsgroups of interest are machine-specific. Recommended groups are comp.os.os2.programmer and comp.sys.amiga.programmer.

FTP Sites of Interest

FTP is a file transmission protocol used on the Internet to transfer files between machines. The transfers are done in real time and usually require that the user have an account on both machines. However, many machines on the Internet support what is known as anonymous FTP, which allows users on other machines access to a limited set of files without requiring an account. Some of the more interesting sites that offer this service are:

rexx.uwaterloo.ca General repository for REXX-related information, including free REXX interpreters for Unix and DOS. An XEDIT clone for Unix and OS/2 may also be found here. Look under /pub/rexx.

flipper.pvv.unit.no The official home of Regina, one of the free Unix interpreters. An archive of the messages in comp.lang.rexx is also maintained here. Check under /pub/rexx.

ftp-os2.cdrom.com, ftp.luth.se General OS/2 archives.

wuarchive.wustl.edu General Amiga archive. Look under /pub/aminet.

Mailing Lists

Mailing lists are similar to newsgroups but use normal electronic mail to deliver the messages. The following mailing lists are mostly BITNET-based but are accessible from the Internet as well:

List name BITNET Node Internet Address Discusses
REXXLIST UCF1VM ucf1vm.cc.ucf.edu REXX in general
AREXX-L UCF1VM ucf1vm.cc.ucf.edu Amiga REXX
PC-REXX UCF1VM ucf1vm.cc.ucf.edu Personal REXX
REXXCOMP UCF1VM ucf1vm.cc.ucf.edu IBM's REXX compiler
TSO-REXX UCF1VM ucf1vm.cc.ucf.edu TSO REXX
VM-REXX UCF1VM ucf1vm.cc.ucf.edu VM/SP REXX
UREXX-L (none) liverpool.ac.ak Unix REXX

To subscribe to any of these lists, send a one-line message to the address LISTSERV@node, where node is the BITNET node or Internet address for the list you wish to join. In the body of your message should be the line

SUBSCRIBE list-name your--full-name

as in

SUBSCRIBE UREXX-L Eric Giguere

You will then be subscribed to the list and messages will start arriving in your mailbox. To send a message to the list, simply mail it to listname@node, as in UREXX- L@liverpool.ac.uk. Note the distinction between the LISTSERV address and the listname address. You can receive help by sending a HELP message to the LISTSERV address. Note that some of these mailing lists may be available on Usenet in the form of newsgroups with names starting with "bit.listserv". Ask your system administrator if you're not sure.

Thanks to Scott Ophof for providing this summary.

Gopher Service

Gopher clients may find REXX-related information at the site gopher.pvv.unit.no (Europe) and index.almaden.ibm.com (N. America).

Free REXX Products

This sections contains information on some free REXX products.

Interpreters

There are at least three REXX interpreters available for free on the Internet. The first two are Unix based and are well-supported by their authors. The third is an MS-DOS interpreter.

Regina is Anders Christensen's REXX interpreter for various flavours of Unix and VMS. It is fairly complete and Anders even has an API for developers. It also apparently can be ported to OS/2. Anders can be reached at anders@pvv.unit.no. Regina's official home is ftp.pvv.unit.no.

REXX/imc is Ian Collier's REXX interpreter for SunOS, though it has also been ported to other Unix systems. Ian can be reached at imc@prg.ox.ac.uk.

BREXX is Bill Vlachoudis' REXX interpreter for MS-DOS. The interpreter is not complete but is quite small. Bill can be reached at bill@donoussa.physics.auth.gr.

All three interpreters are available for anonymous FTP on rexx.uwaterloo.ca in the /pub/freerexx directory, each interpreter in its own subdirectory. Regina and REXX/imc are in source form, BREXX is only available as binary.

REXX-Aware Text Editors

Also on rexx.uwaterloo.ca in the /pub/editors directory is the text editor THE by Mark Hessling (mark@snark.itc.gu.edu.au). THE is a full-featured XEDIT/KEDIT clone (by XEDIT here we mean the IBM mainframe text editor, not the X Windows editor xedit) with REXX support. THE is available in versions for OS/2 and Unix. THE's official home is on ftp.gu.edu.au in /src/THE.

Comercial REXX Products

This Section contains information on some commercial REXX products.

Interpreters

REXX interpreters are available commercially for a wide variety of systems and come standard on some operating platforms such as the Amiga, OS/2 and the IBM mainframes. The following vendors sell REXX interpreters:

The Workstation Group [Various UNIX platforms, also VMS]
6300 River Road
Rosemont, IL 60018
(800) 228-0255 (US only)
sales@wrkgrp.com
Quercus Systems [DOS, Windows, Windows NT, OS/2]
P.O. Box 2157
Saratoga, CA 95070
(408) 867-7399
(800) 440-5944 (US & Canada)
75300.2450@compuserve.com
Simware [Novell Netware]
2 Gurdwara Road
Ottawa, Ontario
Canada K2E 1A2
(613) 727-1779

IBM also sells REXX interpreters for AIX and Netware.

Visual Development Enviromemnts

There are three REXX-based visual development environments available for OS/2:

VX-REXX WATCOM International
415 Phillip Street
Waterloo, Ontario
Canada N2L 3X2
Phone: (519) 886-3700
Fax: (519) 747-4971
VisPro/REXX HockWare
315 N. Academy St., Suite 100
Cary, NC 27513
Phone: (919) 380-0616
Fax: (919) 380-0757
GpfRexx Gpf Systems
10 Falls Road
Moodus, Conn. 06469
Phone: (203) 873-3300
Fax: (203) 873-3302

REXX-Aware Text Editors

Clones of the popular XEDIT editor are available for Unix from the Workstation Group (see address above) and for DOS and OS/2 from Mansfield Software. Tritus sells an ISPF/PDF text editor with REXX support for OS/2. One Up sells SourceLink, an integrated development environment for OS/2 with REXX macro capabilities. Command Technology sells the SPF/PC editor.

Mansfield Software
P.O. Box 532
Storrs, CT 06268
Phone: (203) 429-8402
Fax: (203) 487-1185
Tritus
3300 Bee Caves Road, Suite 650
Austin, Texas 78746
Phone: (512) 794-5800
Fax: (512) 7940-3833
One Up
1603 LBJ Freeway, Suite 200
Dallas, Texas 75243
Phone: (800) 678-0187
Command Technology
1040 Marina Village Parkway
Alameda, CA 94501
Phone: (800) 336-3320

The OS/2 Enhanced Editor (EPM.EXE), which is bundled with OS/2, also has REXX support. Use its online help and search for the 'rx' command.

REXX Extensions

A number of vendors sell extensions to REXX:

  • Quercus Systems sells REXXLIB (a collection of over 150 REXX extension functions), REXXCOMM (a function package for accessing serial ports from REXX) and REXXTERM (a full-featured asynchronous communications program).
  • SofTouch Systems sells the GammaTech REXX SuperSet/2, a collection of over 300 REXX extension functions for OS/2.
Quercus Systems
P.O. Box 2157
Saratoga, CA 95070
(408) 867-7399
(800) 440-5944 (US & Canada)
75300.2450@compuserve.com
SofTouch Systems
1300 S. Meridian, Suite 600
Oklahoma City, Okla. 73108-1751
Phone: (405) 947-8080
Fax: (405) 632-6537

REXX and ANSI

The American National Standards Institute (ANSI) sets national standards for various things in the United States, including programming languages. The X3J18 REXX Standards Committee is currently defining a formal standard for the REXX language, using Mike Cowlishaw's book as its base document. The Committee meets 3 or 4 times a year and holds ongoing discussions throughout the year by electronic mail. Mgopher.pvv.unit.noembers of X3J18 are mostly REXX implementors, but anyone can participate. The Committee intends to release a draft standard next year. More information can be had from the vice-chair, Neil Milsted at nfnm@wrkgrp.com. Note that public ANSI documents relating to X3J18 can be had using the LISTSERV service at PSUVM on BITNET or by Gopher to gopher.pvv.unit.no on the Internet.

The REXX Language Association

The REXX Language Association is an independent organization dedicated to promoting the use of the REXX programming language, for more information see the REXX Language Association listing.

The REXX Symposium

The REXX Symposium is an annual conference devoted to REXX, attended both by users and vendors, held at the beginning of May. It is sponsored by the Stanford Linear Accelerator, with the cooperation of the RexxLA.

REXX Bibliography

Mike Cowlishaw and Linda Green have kindly provided the following partial bibliography of REXX books.

The REXX Language - M.F. Cowlishaw

English:  ISBN 0-13-780735-X  Prentice-Hall, 1985
          ISBN 0-13-780651-5  2nd edition, 1990
German:   ISBN 3-446-15195-8  Carl Hanser Verlag, 1988
          ISBN 0-13-780784-8  P-H International, 1988
Japanese: ISBN 4-7649-0136-6  Kindai-kagaku-sha, 1988

The REXX Reference Summary Handbook - Dick Goran

ISBN 0-9639854-1-8, CFS Nevada Inc., 1994

Modern Programming Using REXX - Robert P. O'Hara and David R. Gomberg

English:  ISBN 0-13-597311-2  Prentice-Hall, 1985
          ISBN 0-13-579329-5  2nd edition, 1988

REXX in the TSO Environment - Gabriel F. Gargiulo

ISBN 0-89435-354-3, QED Information Systems Inc.
320 pages, 1990

Using OS/2 REXX - Gabriel F. Gargiulo

ISBN 0-894-35449-3, QED Publishing Group

Practical Usage of REXX - Anthony S. Rudd

ISBN 0-13-682790-X, Ellis Horwood (Simon & Schuster), 1990

Using ARexx on the Amiga - Chris Zamara and Nick Sullivan

ISBN 1-55755-114-6, Abacus Books, 1991

The REXX Handbook - Edited by Gabe Goldberg and Phil Smith III

ISBN 0-07-023682-8, McGraw-Hill, 1991

Programming in REXX - Charles Daney

ISBN 0-07-015305-1, McGraw-Hill, 1992

Command Language Cookbook - Hallett German

ISBN 0-442-00801-5, Van Nostrand Reinhold, 1992

OS/2 2.1 REXX Handbook - Hallett German

ISBN 0-442-01734-0, Van Nostrand Reinhold, 1994

OS/2 REXX: From Bark to Byte - Inter. Technical Supp. Org. (IBM)

IBM Document Number GG24-4199-00, 1993

REXX: Advanced Techniques for Programmers - Peter Kiesel

ISBN 0-07-034600-3, McGraw Hill, 1992

REXX Tools and Techniques - Barry Nirmal

ISBN 0-89435-417-5, QED Publishing Group, 1993

The ARexx Cookbook - Merrill Callaway

ISBN 0-96-327730-8, Whitestone, 1992

Writing OS/2 REXX Programs - Ronny Richardson

ISBN 0-07-052372-X, McGraw Hill, 1992

Writing VX-REXX Programs - Ronny Richardson

ISBN 0-07-911911-5, McGraw Hill, 1994