Overriding the default ADDRESS Environment

When writing an IDF macro, you may find that you need to issue a command to the underlying operating system, not a command to IDF. You do this by using the REXX ADDRESS statement.

For example:

address CMS CMS-command

This directs only this command to CMS, with subsequent commands directed to the default environment (ASM).

Compare this with:

address CMS
CMS-command

This directs all commands to CMS until a subsequent address command overrides it.

"Which addressing environment is best for the default?" is generally a decision based upon how many IDF commands are required versus how many host commands are required. And of course you are not restricted to setting one default environment and leaving it that way until the end of your macro; you can change it again at any time.

Of course in an IDF macro, it is expected that most of the commands are IDF commands. And in this case, it is probably best to just leave the default addressing environment (as supplied at entry to your macro) alone, and make "temporary overrides" to other names as you may require for the few (if any) host commands issued.