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Ask the Wizard Questions
Language: Interprocess communication
The Question is:
From a 'C' written program, I spawn a sub-process using
$CREPRC. Now, I need to be able to communicate between the
two processes (sub-process & the parent) via mailboxes
(or pipes). This would be simple if the image which is
executed in the sub-process knew about it, however I require
any executable image to be able to do that.
I supposed the question really is how do I redirect standard
input & output to the two mailboxes within the sub-process?
The Answer is:
>I supposed the question really is how do I redirect standard
>input & output to the two mailboxes within the sub-process?
Perhaps I'm missing something here. Why not:
$CREMBX(chan=OUT_CHAN,lognam="IN_MBX")
$CREMBX(chan=IN_CHAN2,lognam="OUT_MBX")
$CREPRC(...input="IN_MBX",output="OUT_MBX"...)
So the subprocess has IN_MBX as its primary SYS$INPUT and OUT_MBX as
its primary SYS$OUTPUT. From the parent process, you can send messages
to the subprocess as $QIOs to OUT_CHAN and receive responses from
IN_CHAN. Be careful not to get yourself deadlocked!
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