$ perl -e 'use Data::Dumper;
>
> my %hash =(
>           'script' => 'foo.pm',
>           'params' => {
>                              'err' => '99',
>                              'FILE' => 'fileA'
>                        },
>           'par_global' => {
>                                 'err' => '99',  # this value (99) is overwritten
>                                 'err' => '20',  # with (20)
>                                 'FILE_READ' => 'fileB',
>                            },
>            'testset' => ['test1']
>         );
>
> print Dumper( \%hash ) . "\n";'
$VAR1 = {
          'params' => {
                        'FILE' => 'fileA',
                        'err' => 99
                      },
          'script' => 'foopm',
          'par_global' => {
                            'FILE_READ' => 'fileB',
                            'err' => 20
                          },
          'testset' => [
                         'test1'
                       ]
        };