OK, I think I see what you are trying to do, but a hash may not be what you want. A list might be better for your needs. List ex: 
use List::MoreUtils qw(any);  #instead of using: 
                              #     "if (grep( m/whatever/, @list)){}"
                              #use: "if (any { m/whatever/} @list){}" 
                              #this exits on the first occurrence.

if (!any {m/^\Q$record[3]\E$} @esList){ 
   #the \Q\E guarantees that the value held in the $record[3] 
   #is not interpreted as a regular expression

    push (@esList = $record[3]);
}
### @esList is now a unique list of the values you want...

[download]
But if you really want to use a hash, this is how you might do it: 
my %esList = ();
$esList{$record[3]) = 1;

### then to recall all the found records:
foreach my $result {sort(keys(%esList))){
    print "found record: $result \n"; 
}

[download]
Also, if you're interested, I started a discussion recently about how to best implement multidimensional hashes, they have some unique characterictics that you might not expect when trying to extending principals of a one dimensional hash. But there are some very good references listed there. It can be found at: Best Multidimensional Hash Practices? Good luck...

In reply to Re^3: Learning about hashes by DamianKaelGreen
in thread Learning about hashes by molson

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