In a recent note, Charles Mills said:

> Date:         Tue, 28 Nov 2006 10:59:12 -0800
> 
> I am not 1% of an expert on UNIX S/S and/or fork, but the documentation
> implies that fork creates the child in a new address space, for example,
> under Usage Notes:
> 
> "3. If the calling address space uses the macro IARVSERV to capture storage,
> these pages are not copied to the child address space."
> 
> Other notes imply that BPX1FRK creates a new job -- and presumably therefore
> a jobstep task.
> 
There have been several good followups to this topic, but perhaps I can
contribute to the second 1%.

In some respects, the child address space is radically unlike a new job
in that it inherits from the parent attributes such as:

       o  real user ID, real group ID, effective user ID,  effec-
          tive group ID

       o  environment variables

       o  open file descriptors

       o  current working directory

       o  file mode creation mask (see umask(2))

       o  controlling terminal

... and others.  It appears the definition of "job" may be as
slippery as that of "reentrant".

-- gil
-- 
StorageTek
INFORMATION made POWERFUL

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