Index

This is an introductory tutorial to the Rexx programming language.

Alphabetic instruction index Alphabetic built-in function index Syntax summary -- quick reference

The following links are organized to introduce concepts for new Rexx programmers. Proceed down the columns and then to the right. Advanced programmers can reference a specific link, as necessary.

Hint: you can use the Tab key to sequence through the links.

Program structure Instruction elements and tokens Instruction terminators Comments Line continuation Symbolic variables Expressions Expression operators Operator precedence Say instruction String concatenation Assignment instruction Instruction classification Introductory examples Labels Boolean expressions If instruction Do nothing instruction -- Nop

Do instruction -- simple group Iterative do instructions Conditional loops Iterate, advanced iteration instruction Leave, advanced iteration instruction Select instruction End instruction Procedure instruction Call instruction Function calls Built-in functions Interpret instruction Signal instruction Condition handling Symbol removal instruction -- Drop Procedure completion instructions -- Exit / Return Parse instructions -- Arg / Parse / Pull Parse templates Introductory tutorial to parsing

System command instruction Changing command environment -- Address instruction Changing numeric computation options -- Numeric instruction Changing interpretation options -- Options instruction Adding lines to the data queue -- Push / Queue instructions Trace instruction External data queue Special variables -- RC, RESULT, and SIGL Error codes Performance hints Advanced examples A hand of cards example Rexx control flow synopsis program

Introduction:

This tutorial describes classic features of the Rexx language. The intent of the tutorial is to enable you to become a proficient Rexx program developer, without any initial expense.

The tutorial is not a document of a specific Rexx implementation. Many implementation-specific considerations are highlighted within the tutorial.

Rexx is a programming language that was developed over a ten year period, with extensive personal effort by IBM's Michael Cowlishaw. Click here to review the background history of the Rexx language.

The tutorial is a condensation of details that are documented in Michael Cowlishaw's famous book:

The REXX Language A Practical Approach to Programming Second Edition Author: Michael Cowlishaw IBM UK Laboratories Ltd. Published in 1990 by Prentice-Hall, Englewood Cliffs, New Jersey 07632. ISBN 0-13-780651-5 Note: this book is commonly referenced within the Rexx programming community as TRL-2.

The Rexx language, as documented in TRL-2, has numerous syntactic and semantic intricacies and nuances which are beyond the scope of this tutorial. You should obtain the above book if you plan to be an expert Rexx program developer.

The TRL-2 book can be obtained at one of the following internet sites:

Amazon	http://www.amazon.com/
Barnes & Noble	https://www.bn.com/
Fat Brain	https://www.fatbrain.com/
SoftPro	https://www.softpro.com/

TRL-2 was the basis of the American National Standards Institute's effort to standardize the definition of the REXX language. This standardization effort was identified as the ANSI X3J18 project. The American National Standard (ANSI Standard) for Rexx is called "Programming Language - REXX", and its number is X3.274-1996. Click here to learn about the ANSI REXX standardization project.

A new 500 page Rexx's reference has just been written by Howard Fosdick. The book describes how to make the best use of Rexx tools and interfaces, with examples for both Linux and Windows. A tutorial is provided with lots of examples to help you get up and running with Rexx. This book (ISBN: 0764579967 ) will be published in April 2005 by Wiley at the following online bookstores: Amazon Barnes and Noble

Some other helpful Rexx language internet sites are:

Rexx Language Association	http://www.rexxla.org/
Rexx Language page at IBM Hursley	http://www2.hursley.ibm.com/rexx/
An online Rexx tutorial	http://www.kyla.co.uk/other/rexx1.htm
An online Rexx tutorial	http://www.ilook.fsnet.co.uk/index/rexx_idx.htm
A good source for other Rexx information	http://www.rexx.org.uk
A good source for other Rexx information	http://www.rexxfiles.com

Kilowatt Software now offers roo!(TM) --an object-oriented Rexx interpreter.