use warnings
    FATAL => 'all'
    ;
use strict;


use Text::CSV_XS;
use Data::Dump;
use List::Util qw(max);


MAIN: {  # main execution loop

my $csv = Text::CSV_XS->new ({ binary => 1 }) or
    die qq{instantiating CSV: }, Text::CSV_XS->error_diag();

my %postings;

RECORD:
# for my $ar_record (@{ $csv->getline_all(*DATA) }) {  # works
while (my $ar_record = $csv->getline(*DATA)) {  # works

    my ($category, $posted) = @$ar_record;

    LEVEL:
    for (my $depth = 0;
         my ($sub_cat) = $category =~ m{ \A [^.]+ (?: [.] [^.]+){$dept
+h} }xmsg;
         ++$depth
        ) {

        # print qq{depth $depth: '$sub_cat' \n};  # FOR DEBUG

        next LEVEL unless $category =~ m{ \A \Q$sub_cat\E }xms;

        $postings{$sub_cat}{posted} += $posted;
        $postings{$sub_cat}{lowest}  = $sub_cat eq $category;

        }  # end for LEVEL

    }  # end for RECORD

# dd \%postings;  # FOR DEBUG

my $max_width = max map { length $_->{posted} } values %postings;

for my $sub_category (reverse sort keys %postings ) {
    printf qq{%*d for '$sub_category%s' \n},
        $max_width, $postings{$sub_category}{posted},
        $postings{$sub_category}{lowest} ? '' : '.*'
        ;
    }

exit(0);  # expected exit

}  # end MAIN loop

exit(1);  # unexpected MAIN loop exit


# subroutines ######################################################
# none


__DATA__
comp.lang.c,100
comp.lang.beta,23
comp.lang.java.help,123
comp.object,12
alt.3d,12
comp.object,3
comp.lang.beta,11
alt.animals.llama,1423
[download]

Output:

  15 for 'comp.object'
 123 for 'comp.lang.java.help'
 123 for 'comp.lang.java.*'
 100 for 'comp.lang.c'
  34 for 'comp.lang.beta'
 257 for 'comp.lang.*'
 272 for 'comp.*'
1423 for 'alt.animals.llama'
1423 for 'alt.animals.*'
  12 for 'alt.3d'
1435 for 'alt.*'
[download]

Update: The statement
    next LEVEL unless $category =~ m{ \A \Q$sub_cat\E }xms;
in the  LEVEL loop is totally useless: a sub-string extracted from beginning of a string must be present at the beginning of the string! Generated output is the same without this statement.