Re: desire to pass file handles by value

[pg]

Besides what Roger said, if this is all what you want to do, you can:

use Data::Dumper;
use strict;
use warnings;

my @lines = <DATA>;
my $count = {};
map {chomp;$count->{$_} ++} @lines;
print Dumper($count);

__DATA__
a
a
a
c
d 
e