I know this doesn't address your original question but is there a reason you aren't calling system like this... system ($RUN_PROC2, @ARGV); Just asking. Now, if I understand, you 2 questions

• Will your arguments, like $ARGV5, change before your second program gets to it?
• How do you do interprocess communication with perl

I don't think that your arguments will get toasted by system. If system did something like $_[5]='blown away'; you'd be screwed but, without checking, I'm pretty confident it operates on copies of your variables, not directly on @_.

As for the second question check out pipes rather than shared memory for IPC. Not that my opinion matters much but I thinks pipes are easier to deal with and more stable than shared memory.

"So... What do all these little arrows mean?"
~unknown