my %hash = (f => 'd', c => 'a', b => 'e');
my @keys_ordered_by_value = sort { $hash{$a} cmp $hash{$b} } keys %has
+h;
#                                            ^^^
#                                            \|/
#  to sort numeric values use <=> here -------+
#  to sort in reverse order swap $a and $b:  { $hash{$a} cmp $hash{$b}
+ }

foreach my $key (@keys_ordered_by_value) {
    print "key = $key, value = $hash{$key}\n";
}
[download]

--shmem

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}