#!/usr/bin/env perl

use strict;
use warnings;

use Text::CSV;

my $csv = Text::CSV::->new();

while (my $row = $csv->getline(*DATA)) {
    # Do something with all elements, e.g.
    print 'Elements: ', 0+@$row, '; Last: |', $row->[-1], "|\n";
}

__DATA__
1,,3,4,,,
1,,3,4,,,not_empty

,
800,900,"1,000"