Cleanup after program failure

[Matthias Oertli <oertlim@xxxxxxxxxxxxxxxx>]

Hi guys,

I've been asked to code a call to program B from within program A.

The difficulty is that program B needs a different environment to
program A: A slight change in the library list and a modified data
area.

This is easily doable, make program A call a small CL which sets up
everything, then calls program B and when it returns undoes the
changes and finally returns to program A.

My problem is this: If program B (or the CL) fails for whatever
reason, program A regains control without the environment having been
restored to what it should be which could mean disaster.

How can I guard against this situation?

Thanks for your help.
Best regards,
Matthias

-- 

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Matthias Oertli   <oertlim@s054.aone.net.au>
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