REXX

REXX is an interpreted, procedural structured language that is included with every version of OS/2 EE 1.2 and later, IBM PC-DOS 7.0 and most AmigaOS variants and clones in addition to all current and recent IBM mainframe and minicomputer operating systems.

Although REXX is a generic programming language and can be (and has been) used to construct everything from simple utilities to large business applications, it is primarily used as a scripting or macro language, and as such is unusually easy to learn.

History

The REXX language was created by Mike Cowlishaw in 1979 under VM/CMS. The second implementation (2.00) was used inside IBM in 1980. Language level 3.20 was included in VM/SP Release 3 which was released in 1983.

Third party implementations started appearing in 1985.

In 1987 REXX was chosen to be the Systems Application Architecture (SAA) procedural language.

In 1989 the first version of IBM CMS REXX Compiler was released.

Object REXX is a different language that has been given object-oriented extensions modelled on those present in Smalltalk. While it is mostly compatible with Classic REXX there are some minor differences. It means that some REXX programs have to be modified to run correctly under Object REXX.

Amiga REXX is a clone of IBM's Classic REXX that has extensions to help its use as a mechanism for application to application and/or inter-application communication, Regina REXX supports those extensions.

Implementations

Vendor	Implementation	Operating environment
		OS/2	DOS	Win16	Win32
IBM	Procedures Language 2/REXX	X				(aka SAA REXX) shipped with OS/2
	REXXPC88		X			IBM internal (1987/88)
	PC DOS REXX		X			included in IBM PC DOS versions 7 and higher
Quercus	Personal REXX	X	X	X		Commercial
	Regina REXX	X	X			Compatible with Classic REXX - Open Source
	BREXX		X			Open Source
	Compact Rexx (CRX)		X			Open source
	Portable Rexx		X			Commercial
	WinREXX			X		Commercial
	WREXX			X		Commercial

Text editor support

• Boxer - Regina, IBM and BREXX support included by default
• FTE - support for syntax highlighting, code folding and syntax-aware autoindent.

Publications

For listings of REXX related books and general articles see the REXX Bibliography.

• Ian Collier's REXX tutorial
• Vladimír Zábrodský: An Introduction To The REXX Programming Language (OS/2.cz)
• Keith Watts: The Classic REXX tutorial - Teaches the language to "Language Level 4.00 (TRL-2)", that is roughly the same as the SAA REXX shipped with OS/2
• REXX: THE LANGUAGE - Introduction and tutorial by James Barry of Kyla Computing.
• Matt Slocum: Rexx Programming Guide - Nov 2005

Links

• The Rexx Language Association
• Style Guide for Rexx
• IBM REXX page
• Mark Hessling's Home Page - Lots of Rexx and Regina information and files from the gent behind Regina REXX, including a Rexx manual
• REXX Tips & Tricks - In English & German, not to be confused with our REXX Tips & Tricks, this is material collected by a mainframe REXX programmer and some of it does not apply to OS/2 REXX.
• Cosmos Grammaticus - REXX related blog

• USENET: comp.lang.REXX
• REXX LA forum - The official REXX Language Association forum
• REXXLIST - Long running list

Standards

• ANSI standard for Rexx (X3.274), Published in 1996.
• Extended REXX proposal - Published in 1998

Source code snippets, archives and collections

Small programs or routines that you can integrate into your own programs or study to learn from, but are not delivered in library form.

• Album of Algorithms and Techniques for Standard Rexx - Vladimír Zábrodský's collection of REXX code, mostly small snippets.
• Mark's MVS Utilities - While mostly XEDIT and MVS related there are a few worthwhile REXX programs in there as well.
• norrsken data teknik eCS tools - Helge Nordmann's REXX utility collection.
• PLEAC-REXX - Collection of common REXX rutines
• REXX examples from Rob van der Woude's Scripting homepage
• Rex Swain's B2MMDDYY.REX - Convert Base format date to MM/DD/YYYY
• Walter Pachl's REXX code, on rosettacode.org - Contains many REXX snippets.