When dealing with a large hash (the OP stated this was a small example) it may be better to use each rather than getting the overhead of a temporary list using keys. A skelton example:
while (my ($key,$value) = each %$hashref) {
    print "$key $value\n";
}

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In reply to Re^2: getting keys of multi-level hashrefs by cdarke
in thread getting keys of multi-level hashrefs by mask_man

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