>perl -wMstrict -le
"use Data::Dumper;
 my %hash = qw(a 1  b 2  c 3);
 print Dumper \%hash;
 init(\%hash);
 print Dumper \%hash;
 sub init {
   my $h = shift;
   $h = { foo => 'bar' };
   }
"
$VAR1 = {
          'c' => '3',
          'a' => '1',
          'b' => '2'
        };

$VAR1 = {
          'c' => '3',
          'a' => '1',
          'b' => '2'
        };