vaibhav07 has asked for the wisdom of the Perl Monks concerning the following question: 

 my %hash =(
          'script' => 'foo.pm',
          'params' => {
                             'err' => '99',
                             'FILE' => 'fileA'
                       },
          'par_global' => {
                                'err' => '99',
                                'err' => '20',
                                'FILE_READ' => 'fileB',
                           },
           'testset' => ['test1']
        );

[download]

I am extracting key value pairs from %hash, but in case if key=values are similar, it should pick only one entry of it rather than picking both the entries.

Output from my code FILE=fileA err=99 script:foo.pm foo.pm FILE_READ=fileB err=99 err=20 testset:test1

Output required FILE=fileA err=99 script:foo.pm foo.pm FILE_READ=fileB err=20 testset:test1

Should list only one entry of err=99 rather than two entries

Code used 

foreach my $key (keys %hash) {
    if ( ref $hash{$key} ne 'HASH' && ref $hash{$key} ne 'ARRAY' ) {
        print"$key:$hash{$key}\n";
        if( (defined $key) && ($key eq 'script') ) {
            print"$hash{$key}\n";
        }
    }
    if( ref $hash{$key} eq 'HASH' ) {
        foreach my $k (keys %{$hash{$key}}) {
            print"$k=$hash{$key}{$k}\n";
        }
    } elsif( ref $hash{$key} eq 'ARRAY' ) {
        print"$key:$hash{$key}[0]\n";
    }
}

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Replies are listed 'Best First'.
Re: Remove similar key=value pair from HOH
by LanX (Saint) on Apr 11, 2015 at 19:31 UTC
    Please wrap the output also in <code> tags, it's not readable

    anyway this part 

      'par_global' => {
                                'err' => '99',
                                'err' => '20',
                                'FILE_READ' => 'fileB',
                           },

    [download]

    doesn't make sense, b/c you can only have one key "err" , cause hash-keys are unique!

    update

    honestly I doubt the demonstrated output is really from your code, this doesn't make sense.

    Cheers Rolf
    (addicted to the Perl Programming Language and ☆☆☆☆ :)
    Je suis Charlie!

[reply]
[d/l]
[select]
Re: Remove similar key=value pair from HOH
by pme (Monsignor) on Apr 11, 2015 at 19:33 UTC
    Hi vaibhav07,

    Perl hash unable to store duplicated keys. See and run the code snippet below. 

    use Data::Dumper;

my %hash =(
          'script' => 'foo.pm',
          'params' => {
                             'err' => '99',
                             'FILE' => 'fileA'
                       },
          'par_global' => {
                                'err' => '99',  # this value (99) is o
+verwritten
                                'err' => '20',  # with (20)
                                'FILE_READ' => 'fileB',
                           },
           'testset' => ['test1']
        );

print Dumper( \%hash ) . "\n";

    [download]
[reply]
[d/l]
      Hmm, not convinced. 
      $ 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'
                       ]
        };

      [download]

      Je suis Charlie.
[reply]
[d/l]
[reply]

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