GT09 - REXX Programming Workshop - 3 Days

Course Description

This course covers all aspects of programming with REXX. During the course the student is taught how to write programs that issue TSO commands, read and write to z/OS datasets, access the REXX Datastack, manipulate string data, perform conditional logic and use functions.

This course does not cover the REXX / ISPF (Diaglog Manager) interface. For REXX / Diaglog Manager training, please see course GT08 - Developing ISPF Applications using REXX.

Pre-requisites

The delegate should be familiar with the z/OS host environment, together with a working knowledge TSO / ISPF.

Objectives

The aim of this course is to provide the programmer with the necessary skills required to design, write, code and test REXX programs that interact with TSO and ISPF Dialog Manager.

On completion of this course the student will be able to:

  • develop Structured REXX Programs
  • understand and use REXX Verbs
  • use conditional logic in a REXX program
  • use REXX parsing commands
  • access the Data Stack
  • use REXX to access datasets
  • use REXX to run TSO commands
  • Develop and use REXX Functions
  • interactively test and debug REXX programs

Environment

Development will be performed using REXX running on a z/OS Platform.

Customisation

For on-site courses (i.e. at your premises), we are more than happy to tailor the course agenda to suit your exact requirements. In many cases, we are able to build your in-house standards and naming conventions into the delivered course.

Course Details

Introduction
What Is REXX?
Simple Examples
Building REXX Programs

Program Execution
On-Line Execution Of REXX Programs
System Definition Of REXX Programs
Dynamic Concatenation Of REXX Datasets
Batch Execution Of REXX Programs

Getting Started
Commencing A REXX Program - Comments
Terminating A REXX Program - Exit
Variables
Assigning Values To Variables
Use Of Quotation Marks
Compound Or Stem Variables (Arrays)
Re-Initialising Variables - Drop
Concatenating Variables
Sending Data To The Terminal - Say
Receiving Data From The Terminal - Pull
Statement Continuation
Variables And Arithmetic
Evaluation Sequence
Numbers Supported
Altering Precision
Altering Precision For Comparisons
Interpret

Text Parsing
Parsing Words Separated By Spaces
Parsing Words Separated By A Given String
Parsing Words By Specific Columns
Disregarding Portions Of A String
Parsing Instructions Summary
Splitting Data Using Arg

Program Flow And Control
Conditional Testing Variables - If / Then / Else
Nested If Statements
The Select Statement
Comparison Operators
Combining Comparisons - Logical Operators
Program Loops
Do
Do Forever
Do While
Do Until
Loop Summary
Iterate and Leave
Using Leave / Iterate Within Nested Loops
Interrupting Endless Loops

Subroutines
Passing Data to Subroutines
Sending Arguments To Subroutines
Receiving Arguments Into Subroutines
Receiving Arguments Into Main Line Programs
Sharing And Protecting Internal Variables
Returning Data To The Calling Program
Label Look-Aside Table

Functions
Built-in Function Summary
Abbrev
Abs
Address
Arg
B2X
C2D
C2X
Center
Compare
Copies
D2C
D2X
Datatype
Date
Delstr
Delword
Find
Format
Index
Insert
Justify
Lastpos
Left
Length
Listdsi
Max
Min
Msg
Outtrap
Overlay
Pos
Random
Reverse
Right
Sign
Space
Strip
Substr
Subword
Sysdsn
Sysvar
Time
Translate
Trunc
Upper
Userid
Verify
Word
Wordindex
Wordlength
Wordpos
Words
X2B
X2C
X2D

User Defined Functions
Subroutine / Function Search Order

The Data Stack
Datastack Manipulation
Queuing
Stacking
NEWSTACK And DELSTACK
MAKEBUF And DROPBUF
Data Stack Query Commands

External Commands
Executing TSO Commands
The Address Command
Allocating Datasets
Freeing Datasets
Execio - Reading And Writing To Files
Execio - Return Codes
Reading Records Into A Compound Variable
Writing Records From A Compound Variable
Reading Records Into The Data Stack
Writing Records From The Data Stack
Appending Data To A File
Copying A Dataset
Deleting And Renaming Datasets
Clearing The Screen
Editing And Browsing A Dataset
Suppression Of System Messages
TSO Command Reference Summary

Program Testing
Trapping Errors
Signal And Call
Trace
ISPF Dialog Testing

Course Format

The course contains many practical exercises to ensure familiarity with the product. Students create REXX programs that interact with TSO. On completion of this course students will be ready to start the development of REXX application programs.

The comprehensive Student Guide supplied is fully indexed serving as a useful reference tool long after the course has finished. Delegates will also be able to access a free help-line with technical questions relating to topics covered on the course.

Course Enquiry