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 REXX built-in functions, and the more important TSO-only 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 in 2012 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 and OS/2. REXX is often used for prototyping applications, front-ending operating system commands and TSO/ISPF panel applications. Its flexibility and clear straightforward syntax makes 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.

REXX is a general purpose language which is easy to learn. It contains an extensive library of powerful functions which greatly reduces the amount of coding necessary to write applications. The use of REXX in a wide range of environments simplifies the writing of applications to run under different hardware and operating systems, and its expansibility allows other components to make sure of REXX facilities and vice versa. Practical Usage of TSO REXX provides a concise source of information for the development and implication of applications using the REXX language. The author adopts a practical approach, using lists and diagrams to illustrate relevant points. This third edition, (previously titled Practical Usage of MVS REXX), has been revised to include the new REXX features introduced for the OS/390 TSO/E environment.

The REXX programming language includes built-in functions that simplify programming. REXX Functions let you manipulate data strings or do mathematics simply with a minimum of programming effort. This book explains 72 REXX functions that you can use in your REXX programs. This book is about TSO REXX functions, but we have included a few that work in CMS only. A function is a built-in feature of the REXX language. Functions are always available to you when you are writing your program. They provide an easy way to manipulate data strings or to perform arithmetic on numbers. Using functions simplifies programming and provides reliability, because the functions were created and tested by the software manufacturer (IBM.)The Index is not like most indexes that list only language features alphabetically. They are no help if you don't know the name of the language feature. This index shows the common English language name for a feature, for example, "Convert decimal number" points you to the REXX equivalent D2C. You don't have to know that D2C means "Convert decimal number to character" in order to use the index.The examples are simple and clear and will show you the different ways to invoke, or use REXX functions in a REXX program.To aid you in finding the function that you need, one chapter is devoted to listing the functions, classified by what they do. Each of the built-in functions is shown in detail with examples of use. The functions are shown alphabetically.As a bonus, I've included several supplementary chapters to make life easier for the REXX programmer:1. How to write REXX macros.2. Compatibility Issues across platforms.3. Precedence of Operators. What REXX processes first, in complex expressions?4. How to execute TSO Commands, in Native Mode (Ready Mode) TSO, in ISPF Option 6, on the command line on ISPF panels, and in batch.5. How to specify Dataset names in TSO commands. An explanation of TSO naming conventions.6. Finally, the TSO commands that you are likely to use in your REXX programs, arranged by their function, with clear and simple examples.

Practical Usage of MVS REXX provides a concise and complete source of information for the development of applications using the REXX language - IBM's systems application architecture procedural language. The book adopts a highly practical approach and includes many lists and diagrams to make finding the relevant information as easy to find and use as possible. It particularly emphasises the interfacing capabilities of REXX. Both beginners and experts will find the book useful. Beginners are led through the steps required to develop REXX applications via a series of worked examples, and experts will find a complete and easy reference to the language.

This book is for the programmer who needs to convert a program written in TSO-CLIST to TSO-REXX in the z/OS TSO/ISPF environment. You need some familiarity with both languages in order to do a conversion. This book will show the correspondences, or lack of them, between CLIST language features and REXX language features. CLIST language features are shown on the left-hand page, with the corresponding REXX language feature on the facing, right-hand page.TSO-CLIST dates back to the beginning of TSO in 1971. It truly is a legacy language. IBM continues to support it, and even enhance it, because so many of its customers have active, functioning CLIST programs in use.CLIST language is found only in one environment, the z/OS TSO/ISPF environment. Experience programming with CLIST is not readily transferable to any other environment. The REXX language is found mostly in the z/OS TSO/ISPF environment, and in QMF, CICS, DOS/VSE, and Netview. Knowing REXX makes you more valuable to your employer.The number of programmers who can understand CLIST language is diminishing. It is a good business decision to convert CLIST programs, where possible, to REXX programs. I'm sure most programmers will remember the nightmare of having to fix a program that is so old that no one left alive knows what the program is expected to do.

&Quot;Whether you're new to Rexx or are an experienced Rexx programmer, this comprehensive reference offers you what you need to know in order to work with this easy yet powerful scripting language on any level. After a quick overview of the basics of Rexx, you'll move on to more advanced scripting topics such as portable code and optimal coding style.". "This book is for programmers on any platform who are either looking to learn Rexx or already use it and want to expand their knowledge of Rexx. A basic knowledge of programming is assumed."--BOOK JACKET.

The Restructured Extended Executor (REXX) language is a procedural language that allows you to write programs and algorithms in a clear and structural way. It is an interpreted and compiled language, and you do not have to compile a REXX command list before executing it. With IBM z/OS V1.9, you can harness the versatility of REXX to interface and interact with the power of SDSF. A new function called REXX with SDSF is available that provides access to SDSF functions through the use of the REXX programming language. This REXX support provides a simple and powerful alternative to using SDSF batch. This IBM Redbooks publication describes the new support and provides sample REXX execs that exploit the new function and that perform real-world tasks related to operations, systems programming, system administration, and automation. This book complements the SDSF documentation, which is primarily reference information. The audience for this book includes operations support, system programmers, automation support, and anyone with a desire to access SDSF using a REXX interface.