my ($column_1, $column_2) = split /,/;
    print {$FH6} "$column_1\n" if defined duplicates{$column_2};
    $duplicates{$column_2}++;

But this only causes the last 2 lines of the file to be deleted, and I want the last line deleted because on the last line both columns 2 and 3 are the same.

So what I am really looking for is to print the # in the first column which corresponds to both column 2 and 3 being the same.

161248,/vol/filelist,CABINET
161200,/vol/filelist,INVENTORY
161400,/vol/filelist,INVENTORY

In the last line, column 2 (/vol/filelis) and column3 (INVENTORY) are the same.

Does anyone have a suggestion?