Language Processor Environments

As described in TSO/E REXX customizing services, a language processor environment is the environment in which the language processor "interprets" or processes a REXX exec. Such an environment must exist before an exec can run.

The topics in this chapter explain language processor environments and the default parameters modules in more detail. They explain the various tasks you can perform to customize the environment in which REXX execs run. This chapter describes:

Different aspects of a language processor environment and the characteristics that make up such an environment. This chapter explains when the system invokes the initialization routine, IRXINIT, to initialize an environment and the values IRXINIT uses to define the environment. This chapter describes the values TSO/E provides in the default parameters modules and how to change the values. It also describes what values you can and cannot specify when the environment is integrated into TSO/E (TSOFL flag is on) and when the environment is not integrated into TSO/E (TSOFL flag is off).
The various control blocks that are defined when a language processor environment is initialized and how you can use the control blocks for REXX processing.
How language processor environments are chained together.
How the data stack is used in different language processor environments.

Rule: The control blocks created for a language processor environment provide information about the environment. You can obtain information from the control blocks. However, you must not change any of the control blocks. If you do, unpredictable results may occur.