Okay, now I'm nervous ;-) My reason for asking is purely academic--I'm trying to REALLY learn Perl (yes I have read the Llama book and am plowing through the Camel tome). However, instead of starting with what I don't understand, let me start with what I do (I do understand your first reply to this post and even much of the Linux article referenced).

It appears that in the first line:

my %hash = map { my $item = pop @$_; map { $_, $item } @$_ }
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you are mapping a key and value to %hash from an array. Next, it looks like a string of "HELP" redirects flow to a sub (as does the last line "QUIT"...).

Now, what I don't understand, specifically, how are the keys and values being mapped into the hash (where are they coming from)? What does pop @$_ do (couldn't find @$_ explained anywhere)? How does the last bit on that first line work? map { $_, $item } @$_

Lastly, why are there square brackets bookending lines 2 and 3?

I may not be ready for this heady stuff, but I'm willing to try. Thanks merlyn.

Update:
Thanks to runrig and his reply. I get it in theory, but not in practice. Though it has encouraged a more thorough understanding of map. I'll look at this in a couple of months and probably get it fine. Thanks.