Perl. Отсортировать числовые значение ключей хеша по возрастанию

#!/usr/bin/perl -w
     
use strict;
     
my %tmp = (
    "key1" => 3,
    "key2" => 6,
    "key3" => 1,
    "key4" => 3,
);
     
my %sorted_by_values = ();
     
for my $key ( keys %tmp ) {
    my $value = $tmp{ $key };
     
    if ( exists $sorted_by_values{ $value } ) {
        push @{ $sorted_by_values{ $value } }, $key;
    } else {
        $sorted_by_values{ $value } = [ $key ];
    }
}
     
for my $value ( sort keys %sorted_by_values ) {
    for my $key ( sort @{ $sorted_by_values{ $value } } ) {
        printf "%s => %d\n", $key, $value;
    }
}

map {print "$_ $tmp{$_}\n"} sort {$tmp{$a} <=> $tmp{$b}} keys %tmp

my %tmp = (
  "key1" => 3,
  "key2" => 6,
  "key3" => 1,
);

print "$_\n" for sort { $tmp{$a} <=> $tmp{$b} } keys %tmp;

#!/usr/bin/perl -w

use strict;

my %tmp = (
  "key1" => 3,
  "key2" => 6,
  "key3" => 1,
  "key4" => 3,
);

# Это сортировка по убыванию
# По увеличению: заменить на $tmp{$a} <=> $tmp{$b}
for my $key ( sort { $tmp{$b} <=> $tmp{$a} } keys %tmp ) {
	printf "%s => %d\n", $key, $tmp{ $key };
}