REXX Programming under TSO/ISPF

Virtual Classroom Environment dates - click to book!

UK Start Times

What do I need?

• webcam
• headphones with microphone
• sufficient bandwidth, at least 1.5 Mb/s in each direction.

What you will learn

On successful completion of this course you will be able to:

• describe the concepts and structure of the REXX language environment
• write and debug REXX programs executing in the TSO environment
• use the tracing and debugging aids effectively
• use the loop control and decision making instructions
• identify and put into practice the most commonly used REXX built in functions
• parse data strings
• use TSO commands and functions within REXX EXECS
• manage I/O using data stacks and stems
• use sub-routines and functions.

Who Should Attend

Systems programmers, operations analysts, senior operators, operations support staff and application programmers who will be writing and/or maintaining TSO REXX programs.

Prerequisites

An understanding of programming at a conceptual level and a good knowledge of TSO and its commands. A superficial knowledge of ISPF/PDF is insufficient for those who wish to gain full value from this course.

Duration

3 days

Fee (per attendee)

£1850 (ex VAT)

This includes free online 24/7 access to course notes.

Hard copy course notes are available on request from rsmshop@rsm.co.uk

at £50.00 plus carriage per set.

Course Code

RT

Contents

Introduction to REXX

Executing REXX EXECs; elements of the REXX language: Clauses, Tokens, Labels, Assignments, Instructions and Commands; constant and variable symbols; Simple, Compound & Stem variable symbols; operators for concatenation, arithmetic, comparison & logical operations.
This segment introduces the terminology associated with REXX and shows how data fields are defined and initialised.

Tracing and Debugging

Using TRACE instruction for debugging; using immediate commands HI, HT, TS and TE; use of EXECUTIL; interpreting TRACE output.
This segment describes the tracing facilities available in REXX to enable more rapid problem determination.

Parsing Strings

Parsing variables and strings; basic parsing techniques; special templates; place holders, literal patterns and numeric patterns.
Explains how input from any source can be split into useable entities using various techniques.

Control Instructions

Decisions: IF, THEN, ELSE, SELECT, WHEN, OTHERWISE; creating and controlling loops: DO WHILE, UNTIL, FOREVER, LEAVE, ITERATE; introduction to sub-routines.
This segment describes the IF, THEN, ELSE logic used in REXX.

Sub-routines and Functions

Internal and external sub-routines; how to create internal and external functions; passing arguments and results to and from sub-routines and functions; CALL; RETURN; EXIT; PROCEDURE; RESULT.
This segment shows how to create subroutines and functions, and identifies the difference between them

REXX Built-in Functions

Introduction to REXX supplied built in functions; how to use the most useful ones: ARG, DATE, TIME, DATATYPE, LENGTH, POS, WORDS, LEFT, RIGHT, STRIP, SPACE, COPIES and WORD.
This segment explains the commonly used REXX built-in functions, and indicates their use in REXX programs.

Data Stack Management

LIFO and FIFO stacking; avoiding the stack; writing to the stack: PUSH and QUEUE; reading from the stack: PARSE PULL; creating and managing extensions to the stack: MAKEBUF, QBUF and DROPBUF; interrogating the stack: QUEUE, QELEM; creating and managing private stacks: NEWSTACK, DELSTACK and QSTACK.
This segment describes the stack mechanisms used by TSO and REXX.

Using TSO Commands & Functions

Using TSO commands and functions: SYSDSN, LISTDSI, MSG, OUTTRAP, PROMPT and SYSVAR; reading and writing datasets with EXECIO.
Shows how to invoke and use TSO commands from a REXX program.