I wish i had more time to go over this with you, but right off the bat:

my @subjects = [];  # reference to empty array
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is wrong. That is an array that holds an empty array reference. Try this instead:

my @subjects;
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There is no need to assign anything, just declare the variable. Further more, this loop:

for (my $i = 0 ; $i<scalar @resultLine; $i++) {
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can be written in a more Perlish fashion like so:

for my $i (0 .. $#resultLine) {
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This is Perl, not C. :) Finally, do yourself a big favor. Slow down and read some material. I recommend davorg's excellent book, Data Munging With Perl.