Let me confirm this. Do you really want to access the memory of a different process, as the new title suggests?

If so, that's much more complicated and is even less likely to be useful. Only debuggers do that. I think it's possible with three ptrace and two wait* calls, but I'm not sure in the details.

If you want to access the meory of the same process (the process of the perl interpreter), that's simpler, but it's probably still not what you want. Do read the references tutorial someone suggested, or this Q&A entry, or perldoc perlref, or perldoc perlreftut or other things about references.