Filter
Top Products
Chapter 18. Procedure Language REXX
The REstructured eXtended eXecutor language, or REXX language, is a versatile,
easy to use structured procedure language that is part of:
•
VM/ESA
•
VSE/ESA
•
TSO/E
REXX was designed as a replacement for the EXEC and EXEC2 languages that
provided a way to bundle Conversational Monitor System (CMS) commands
together. REXX is an extremely versatile programming language in that it can be
intermixed with commands to host environments, it provides powerful functions,
and it has extensive mathematical capabilities.
18.1 REXX and VM/ESA
By far, the most vital role REXX plays is as a procedural language for VM/ESA.
That means a REXX procedure can be a kind of script for VM/ESA to follow. By
using REXX, you can reduce long and complex or repetitious tasks to a single
command or procedure that can be run from CMS.
REXX is a built-in feature of VM/ESA, so there is no installation process or
separate environment. Any REXX procedure can call CMS commands, XEDIT
macros, other subcommand environments, GCS and so on.
18.2 REXX and VSE/ESA
REXX programs can do many tasks, including the automation of VSE/Operations.
For example, if you use the JCL EXEC command to call a REXX program, you
can leave JCL statements on the stack for VSE/ESA to process. This enables you
to insert JCL statements or data into the current job stream. REXX programs can
run in any partition. They can communicate with POWER through the Spool
Access Support interface.
REXX/VSE is available for all VSE/ESA 2.1 and higher and is integrated closely
into the VSE/ESA central functions. It is implemented through:
•
The REXX/VSE interpreter
•
The Library for REXX/370 in REXX/VSE
18.3 REXX and TSO/E
The TSO/E implementation of the REXX language allows REXX execs to run in
any MVS address space. You can write a REXX exec that includes TSO/E
services and run it in a TSO/E address space, or you can write an application in
REXX to run outside of a TSO/E address space. REXX runs in an OS/390 system
in different environments: MVS, NetView, OE shell scripts, ... .
Copyright IBM Corp. 1998 369