hash_tapes(["t1", "pr1", "l1", "po1"],
           ["t2", "pr2", "l2", "po2"],
           ["t3", "pr3", "l3", "po3"],
           ["t1", "pr2", "l2", "po2"]);
[download]

%Tape_Cat should be hash whose keys are the tape labels Each key contains an array of refs. Each ref in this array is anarray ref containing Protection, Location, and Pool

Looks like:

%Tape_Cat->Label->Record1 { Protection, Location, Pool }
                 |->Record2 { Protection, Location, Pool }
                 .
                 .
                 |->Recordn {Protection, Location, Pool }

I want to determine the value n and elminate those tapelabels with onl
+y one record.
[download]

I think your suggestion will place only one record , whichever is found last in %Tape_Cat. Am I missing the point?

The problem is line 223. You've got your condition backwards.

# ***  Incorrect  ****
if ( @{$Tape_Cat{ $label}} < 2 ) {
  # Executes if there is only 1 (or 0) instances of $label
}


# ***  Correct  ***
if ( @{$Tape_Cat{ $label}} > 1 ) {
  # Executes if there is more than 1 (ie, any duplicates)
}
[download]

bbfu
Black flowers blossum
Fearless on my breath

However I want to delete ONLY those records that are singletons. I want to generate a list of tapes having more than one record. The problem is that every tape ... even ones I know have duplicate records are being treated as singletons.

Oh, heh. Delete non-duplicates. Right, sorry. :)

Anyway, what you have posted works fine (which is what I thought initially, before I got confused about which you were wanting to remove).

[johnsca@CORY tmp]$ cat tst.pl
#!/usr/bin/perl

my @Tapes = (
  ['Label 1', 'p', 'l', 'P'],
  ['Label 1', 'p', 'l', 'P'], # Duplicate
  ['Label 2', 'p', 'l', 'P'],
  ['Label 3', 'p', 'l', 'P'],
);

hash_tapes(@Tapes);

sub hash_tapes (@) {

    my @tapes = @_;
    my %Tape_Cat =();

    foreach my $tape (@tapes) {
        my ( $label, $protection, $location, $pool ) = @{$tape};
        push @{ $Tape_Cat{$label} }, [ $protection, $location, $pool ]
+;
    }

    # Get rid of non-duplicates
    my $count = 0;
    foreach my $tape (@tapes) {
        my ($label,$protection,$location,$pool) = @{$tape};
        if ( @{$Tape_Cat{ $label}} < 2 ) {
            print "Deleting ". $label.
                  "Because it has ".@{$Tape_Cat{ $label }}.
                  " record(s)\n";
            $count++;
            delete $Tape_Cat{$label}
        }
    }

    my @keys = keys %Tape_Cat;
    print "Deleted $count keys, keys: @keys\n";
    return \%Tape_Cat;
}
[johnsca@CORY tmp]$ ./tst.pl
Deleting Label 2Because it has 1 record(s)
Deleting Label 3Because it has 1 record(s)
Deleted 2 keys, keys: Label 1
[download]

Correct, no? You should probably double-check the data that this function is actually getting. Use Data::Dumper at the begining of the function, or the built-in perl debugger. Update: If the data is coming from an outside source, check for strange things like leading or trailing newlines or linebreaks, or non-printable characters, or such.

Good luck. :)

bbfu
Black flowers blossum
Fearless on my breath