I have the following code intended to sort a hash of hashes by value: 

#!/usr/bin/perl -w
use strict;

my %hoh_test;


$hoh_test{foo1}{bar} = -0.12697;
$hoh_test{foo1}{baz} = -0.000398154;
$hoh_test{foo2}{bar} = -4.0183e-05;
$hoh_test{foo2}{baz} = 0;
$hoh_test{foo3}{bar} = 9.966003977e-06;
$hoh_test{foo3}{baz} = 0.0001939;

# sort descending by value
foreach my $foo (keys(%hoh_test))
{
    foreach my $ba (sort {$hoh_test{$foo}{$b} <=> $hoh_test{$foo}{$a}}
+ keys(%{$hoh_test{$foo}}))
    {
        printf("foo: $foo, ba: $ba, value: %s\n", $hoh_test{$foo}{$ba}
+);
    }
}

[download]

Here is the expected output: 

foo: foo3, ba: baz, value: 0.0001939
foo: foo3, ba: bar, value: 9.966003977e-06
foo: foo2, ba: baz, value: 0
foo: foo2, ba: bar, value: -4.0183e-05
foo: foo1, ba: baz, value: -0.000398154
foo: foo1, ba: bar, value: -0.12697

[download]

The actual output varies most times the program is run, so clearly my code doesn't work as intended. My two questions are:

1. How can I fix this to sort by values?
2. What exactly is it even doing now? Given that the output changes with most runs it doesn't appear to be sorting by anything.

In reply to help sorting hash of hashes by value by Special_K

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