#!/usr/bin/perl 
use strict ;
my %struct ;

$struct{foo}{1} = "one" ;
$struct{bar}{2} = "two" ;

foreach my $hash ( keys (%struct) )
{
    print "$hash \n";
    foreach my $key ( keys ( %{$struct{$hash}} ) )
    {
        print "\t$key \n" ;
    }
}
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#!/usr/bin/perl -w 
use Data::Dumper; 
my $hashtest; 
$hashtest->{'abc'}->{'filename'} = 'fred'; $hashtest->{'def'}->{'filen
+ame'} = 'harry'; 
 
foreach $v (values (%{$hashtest})) 
{ 
    $testhash->{$v->{'filename'}} = 1; 
} 
print Dumper($testhash);
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#!/usr/bin/perl 
use warnings ; # perl5 adn above
use strict ; # always! 
use Data::Dumper;  

my @files ;
my %hashtest;

# load some dummy data
$hashtest{'abc'}{'filename'} = 'fred';
$hashtest{'def'}{'filename'} = 'harry';

# unfold outter has keys
foreach my $key (keys (%hashtest))
{
    # push the file name ont @files. 
    # printing $hashtest{$key}{'filename'} etc would 
    # be apropriate as  well
    push @files, $hashtest{$key}{'filename'} ;
}

print Dumper(\@files);
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