Does it have to be map? 
my %sorted_msgs;
for (@lines) {
   my $key = obtain key here;
   my $value = [ value array items here ];
   push @{$sorted_msgs{$key}}, $value;
}

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In reply to Re: Using map to convert an array into a hash of array of arrays by moritz
in thread Using map to convert an array into a hash of array of arrays by rjoost

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