REXX Programming for z/OS (OS/390)

Overview
A highly practical workshop showing how to use REXX within an OS/390 environment. Machine-based practical exercises are provided.

Course objectives
The course is designed to provide a solid grounding in the REXX language within OS/390.

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 use advanced OS/390 functions.

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 an OS/390 environment.

Pre-requisites
TSO & ISPF Introduction or equivalent experience. An understanding of programming concepts is desirable, but not mandatory.

Course synopsis

• Introduction to REXX
• Simple REXX programs
  Syntax; variables; parsing; how to execute host commands; batch execution
• Selection
  IF and SELECT instructions
• Iteration
  DO instructions; introduction to stem variables
• Arithmetic
  How to use REXX maths and handle the results
• Subroutines and functions
• How to use the stack
• Advanced parse
• REXX input/output
  How to use EXECIO to read and write files
• Advanced REXX
  Functions SYSDSN, LISTDSI, OUTTRAP, SYSVAR; sample ISPF dialogue exec