Use a hash slice.

knoppix@Microknoppix:~$ perl -E '
> @arr = (
>    {
>       keynum  => 50,
>       keyname => q{fruit},
>       name    => q{plum},
>    },
>    {
>       keynum  => 100,
>       keyname => q{fish},
>       name    => q{cod},
>    },
>    {
>       keynum  => 200,
>       keyname => q{fowl},
>       name    => q{duck},
>    },
>    );
> printf qq{%10s%10s%10s\n}, qw{ #keynum keyname name };
> printf qq{%10d%10s%10s\n}, @$_{ qw{ keynum keyname name } }
>    for @arr;'
   #keynum   keyname      name
        50     fruit      plum
       100      fish       cod
       200      fowl      duck
knoppix@Microknoppix:~$
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I hope this is helpful.