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

##</code><code>##

open my $FH2, '<', '/tmp/fileread' or die "unable to open file 'file' for reading : $!";
open my $FH6, '>', '/tmp/tst.txt' or die "unable to open file 'file' for reading : $!";

my %duplicates;
while (<$FH2>) {
    chomp;
    my ($column_1, $column_2, $column_3) = split /,/;
    print {$FH6} "$column_1\n" if defined $duplicates{$column_2} &&    $duplicates{$column_3};
    $duplicates{$column_2}++;
}
close $FH6;
close $FH2;
open my $fh, '<', '/tmp/tst.txt' or die "unable to open file 'file' for reading : $!";
while (my $line = <$fh>) {
print $line;
}
close $fh;

##</code><code>##

 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?