I have yet to play around much with map and grep. For practice, I wanted to see how you might best create a subset of a hash. The following code generates a hash containing entries whose keys begin with 't' and is a subset of a larger hash whose keys are random. Here's what I came up with: 
my %hash = (tom => 23, larry=> 't0', tina=> 23);

my @filteredhash = grep{/^t/} keys %hash;
my %newhash = map{$_, $hash{$_}} @filteredhash;

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Surely there's a more efficient way than my hackish two-step code. Perhaps nest the grep inside the map: 
my %newhash = map{$_, $hash{$_}} grep{/^t/} keys %hash;

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That seems a little weird too. Help me out and I'll buy you a beer at the 19th hole.

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In reply to Miniature golf question by nysus

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