The REXX Language on TSO

This book will teach you how to write programs in the REXX language on IBM mainframe computers.

It is useful for technical, applications, and maintenance programmers working on new or legacy code written in the REXX language.

It describes the REXX programming language for TSO, MVS, OS/390 and z/OS. (IBM mainframe operating system environments).

The book quickly gets you writing programs in REXX. It covers all REXX language elements, all TSO built-in functions, and the more important built-in REXX functions.

You will find URLs in the book linking to a set of practice problems on a public webpage, as well as additional information on setting up your TSO session to execute REXX programs.

This book was written and published by the author of "REXX in the TSO Environment."

The REXX Language on TSO improves on "REXX in the TSO Environment" in every way: it clarifies important points; it is better organized, and gives better examples.

REXX is a high-level scripting language created in the 1980's by IBM for the IBM mainframe operating systems CMS and MVS. It quickly gained popularity and expanded into other environments such as Netview, CICS, AIX, QMF, VSE.

REXX is often used for prototyping applications, front-ending operating system commands and TSO/ISPF panel applications. Its flexibility and clear straightforward syntax make it a welcome replacement for IBM utility programs.

REXX is generally not used for high-volume business applications because of its performance limitations with respect to compiled or assembled languages.

REXX is able to read and write sequential files and/or PDS members. It contains all programming language features, including the ability to do calculations with decimal numbers to any precision. It is especially useful in manipulating character strings in free-column format.

There is a chapter containing examples of REXX programs, macros, and user-written functions. Explanations of the code are shown on the facing page.
About the Author: I worked as a programmer for a major insurance company. In 1976 I aided in the introduction of TSO to the staff by testing it, creating a TSO user's guide, writing Clists, teaching classes in TSO, and making recommendations to the technical support personnel about TSO. I worked on TSO administration, managing user id's. I automated the administration by writing Clists, TSO native mode commands, utilities, JCL, Assembler language programs, and MVS utilities. At another major insurance company I was introduced to REXX on CMS, and there wrote a user guide for programmers on REXX. When TSO REXX became available in 1988, I began working with it. Several years of that led to the creation of my book "REXX in the TSO Environment." As a programming contractor, I automated the transfer of an entire data center's JCL and procedures to another data center, using REXX, IBM utilities, and TSO/ISPF panels. When the publisher decided to drop mainframe books in 1996, the book was no longer published. Shortly after that I created a course for TSO REXX, and began teaching it in various companies throughout the country, including at an IBM site. I turned the course into a book which I published and sold directly on one of my websites until 2004. When I became aware of On Demand publishing, I updated my book, converted it to electronic format and published it in 2012.