REXX programming considerations

BCPii supports REXX execs being executed from the System REXX, TSO/E REXX, and independent software vendor (ISV) REXX programming environments. Each REXX environment is unique:

System REXX supports all BCPii APIs and provides the capability to write sophisticated BCPii applications by utilizing REXX and other programming languages as part of a single application.
Note:
- To use the HWIEVENT and HWICMD services, a non-REXX adjunct helper program is needed to call z/OS system services to prepare for events and to coordinate with an event exit. See Programming Examples for detailed information.
- The System REXX "MODIFY AXR" command is not supported by BCPii. See Executing a BCPii REXX exec in the System REXX environment.
TSO/E REXX execs are easy to execute from a TSO user. This environment supports all the BCPii APIs, except HWIEVENT and HWICMD.
ISV-provided REXX environments provide different features, depending on which ISV product is being used. These environments support all the BCPii APIs, except HWIEVENT and HWICMD.

The following table identifies the z/OS BCPii APIs supported in the three REXX environments:

Table 1. BCPii APIs supported in the REXX environment
BCPii APIs	System REXX environment	TSO/E REXX environment	ISV-provided REXX environment
HWICONN	X	X	X
HWIDISC	X	X	X
HWILIST	X	X	X
HWIQUERY	X	X	X
HWISET	X	X	X
HWIEVENT	X
HWICMD	X

The syntax of the BCPii REXX execs are identical in all three REXX environments. Therefore, a BCPii REXX exec written to be used in one REXX environment can be run in another REXX environment without change.