On Thu, Mar 6, 2008 at 10:50 AM, yitzle <[EMAIL PROTECTED]> wrote:
> I don't know much about how Perl deals with this stuff, but what
> you've done is made a copy of the pointer/reference.
> Both variables are referencing the same memory/hash.
> What you want to do is copy the hash, not copy the reference to it.
> I /think/ this ought to work:
> my %hash = %{$fileSize};
>
> __CODE__
> my $h1 = {a=>1,b=>2};
> print join(", ", keys %{$h1}), "\n";
> my $h2 = $h1; # References same object
> $$h2{c} = 3;
> print join(", ", keys %{$h1}), "\n";
> %copy = %{$h1}; # Copy to a new has
> $copy{d} = 4; # Doesn't affect the original object
> print join(", ", keys %{$h1}), "\n";
> print join(", ", keys %copy), "\n";
> __OUTPUT__
> a, b
> c, a, b
> c, a, b
> c, a, b, d
> __END__
>
> You can then reference the new copy if you so desire.
> my $refToCopy = \%copy;
As Chas points out, you need something more ___ than this. My code
would simply produce a "shallow copy" where the hash's elements are
still referencing the same final location. If this was a simple hash
that did not contain references, it would suffice. However, for a HoH,
the children hashed also need to be copied ("deep copy") which my
solution does not do.
Thanks, Chas!
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