#! perl -slw
use strict;
use Data::Dumper;


my $href = {
    '1'     => { key1 => 'val1' },
    '1.0'     => { key2 => 'val2' },
    '0001'     => { key3 => 'val3' },
    '2'     => { key1 => 'val1' },
    '0002'     => { key2 => 'val2' },
    '2.1'     => { key1 => 'val1'    },
    '2.10'    => { key2 => 'val2' },
    '2.1  '    => { key3 => 'val3' },
    '  2.1'    => { key4 => 'val4' },
    fred    => { key1 => 'val1' },
    '  fred'=> { key2 => 'val2' },
    'fred  '=> { key3 => 'val3' },
};

sub trim{
    $_[0] =~ s[^\s+|\s+$][]g; 
    $_[0] += 0 if $_[0] =~ m[^[\d|.]+$];
    $_[0]; 
}

my( %new, $k, $v );
@{ $new{ trim $k } }{ keys %$v } = ( values %$v ) 
    while ( $k, $v ) = each %$href;

print Dumper \%new;
__END__
P:\test>321690
$VAR1 = {
          '1' => {
                   'key2' => 'val2',
                   'key1' => 'val1',
                   'key3' => 'val3'
                 },
          '2' => {
                   'key2' => 'val2',
                   'key1' => 'val1'
                 },
          '2.1' => {
                     'key2' => 'val2',
                     'key1' => 'val1',
                     'key4' => 'val4',
                     'key3' => 'val3'
                   },
          'fred' => {
                      'key2' => 'val2',
                      'key1' => 'val1',
                      'key3' => 'val3'
                    }
        };
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