VM Rexx Programming

Overview
A highly practical workshop showing how to use REXX within a VM environment.

Course objectives
The course is designed to provide a solid grounding in the REXX language within VM.

By the end of this course you will have learned
Rexx syntax, the concepts of variables, instructions, functions and host commands. How to use TRACE to interactively debug Rexx code. How to perform arithmetic and control the scale of arithmetic values. How to write subroutines, procedures and functions. How to manage the Stack. How to use EXECIO to read and write files. How to trap CP and CMS command output. Rexx instructions covered are - ADDRESS, ARG, CALL, DO, DROP, EXIT, IF, ITERATE, LEAVE, NOP, PARSE, PROCEDURE, PULL, PUSH, QUEUE, RETURN, SAY, SELECT, SIGNAL and UPPER. Rexx built-in functions include - ABBREV, DATATYPE, DATE, FORMAT, LEFT, QUEUED, RANDOM, RIGHT, STRIP, SUBSTR and TIME.

Who should attend
Any IT staff who will be using REXX within a VM environment.

Pre-requisites
VM Overview or equivalent experience of using CMS and Xedit. An understanding of programming concepts is desirable, but not mandatory.

Course synopsis

• Introduction to REXX
• Simple REXX Programs
• Syntax, variables, simple parsing, executing host commands
• Selection
• IF and SELECT instructions
• Iteration
• DO instructions, introduction to Stem Variables
• Arithmetic
• How to use REXX maths and handle the results
• Program Design
• How to code subroutines and functions
• REXX Input/Output
• How to use the Program Stack and Stem Variables to hold file-based data. EXECIO and PARSE for record processing.
• Advanced REXX
• Error message suppression. Trap and process CP command output. ADDRESS COMMAND.