Check perlreftut; your primary mistakes are:
  1. Not sending %list by reference: change(\%list);
  2. shift()ing @_ and expecting an aggregate back; instead, use: my $href = shift @_;
Once you have $href, you use %$href wherever you used %A. 
foreach (keys %$href) {
  print "$_ = $href->{$_}\n";  # or $$href{$_}
  ...
}

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Jeff japhy Pinyan, P.L., P.M., P.O.D, X.S.: Perl, regex, and perl hacker
How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart

In reply to Re: referances of hashes, and subroutines by japhy
in thread referances of hashes, and subroutines by tempest

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