|No such thing as a small change|
In "C" there are ways to "map" a piece of physical memory ... Since Perl ... cannot access an actual physical memory address.
Sorry, but I think you are just muddying the waters with this post. The OP didn't ask how to do that.
Nowhere in the OP did he mention "physical memory", just a specific memory address & the memory address of a given variable & a given memory address; all of which are generically taken to mean: addresses within the virtual address space of the current process unless explicitly qualified otherwise.
Outside the auspices of deep technical discussion at the operating system or hardware level, this -- along with your other occasional overreach in to technicalities: there's no such thing as a file -- just come across as clever dickiness rather than constructive attempts to help.
With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.