hi,

well, GrandFather has a point! An alternative to what you are asking is to create a tree structure and then walk through it (it is more memory efficient then building hash of hashes). something like this: 

use strict;

my %hash;
while (<DATA>){
    chomp;
    my @array = split(',',$_);
    my ($child, $parent) = ($2,$1);
    $hash{$array[1]} = [] unless (exists $hash{$array[1]});
    push @{$hash{$array[1]}}, $array[0];
}


#and now you do the Johnny Cash (walk the line)
my @line;
_Johnny(5);  # entry that you wish to query
foreach (@line){
  print $_ . ",";
}
#------------------------------------------------#
sub _Johnny {

my $x = shift;
push (@line,$x);
for (@{$hash{$x}}){
  _Johnny($_);
}
}
#------------------------------------------------#


__DATA__
3,1
5,1
4,3
2,7
6,4
8,2
7,6
11,5
12,5
43,11
15,11

[download]
but the question is

What do you want to achieve using the data structure?

cheers , baxy

In reply to Re: Generating recursive hash by baxy77bax
in thread Generating recursive hash by Anonymous Monk

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