[Info-vax] Looking into C-include files on VMS

[Joerg Schilling]

In article <7llbk1F3eetdpU1 at mid.individual.net>,
Bill Gunshannon <billg999 at cs.uofs.edu> wrote:

>Then, what exactly is the reason VMS can't do a Unix style fork()?

It would help a lot already if vfork() on VMS did work like vfork()
and did not share file descriptors between parent and child.

More then 90% of all calls to fork() do this with the intention to 
call exec*() soon, but many of these calls like to redirect I/O
for the new process. 

With a real vfork() you may use vfork() in all these cases as long as
you do not use stdio in the child and as long as you call _exit() 
instead of exit() in the child in case if a problem. On VMS, you would
need to dup2() descriptors 0/1/2 to other numbers before redirecting 
0/1/2 for the new process _and_ you would need to restore 0/1/2 in the 
parent. The latter makes it hard to suport I/O redirection in typical 
software.

-- 
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