You're welcome!

Yes, there is a way to combine them into one. Add a use Data::Undump, and then change the the part between say Dumper($hash) and $data = <> so that you're not printing to STDOUT and reading from STDIN anymore:

#!usr/bin/perl

use feature qw/say/;
use Data::Dumper;
use Data::Undump;

$Data::Dumper::Terse = 1;

$hash = {
  'testing' => {
    'link' => "http://www.espn.com",
    'bandwidth' => "100",
    'r' => "2",
  },
};

$data = Dumper($hash);

$undump = undump($data);

die "'testing' not found!" unless($undump->{'testing'});

say $undump->{'testing'}->{'link'} // (die "'link' not found!");
say $undump->{'testing'}->{'bandwidth'} // (die "'bandwidth not found!
+");
[download]

But of course now you're dumping and undumping your data in the same script, which is basically a no-op. So you could further simplify this to the following:

#!usr/bin/perl

use feature qw/say/;

$hash = {
  'testing' => {
    'link' => "http://www.espn.com",
    'bandwidth' => "100",
    'r' => "2",
  },
};

die "'testing' not found!" unless($hash->{'testing'});

say $hash->{'testing'}->{'link'} // (die "'link' not found!");
say $hash->{'testing'}->{'bandwidth'} // (die "'bandwidth not found!")
+;
[download]

But that's got little to do with you original question anymore.