I think would prefer to use subs rather than string eval here. Eg. 

my %varlengths = (
    'that' => sub(){ 2 }, 
    'theother' = sub{ $v{this}*2 },
}
...
  $readlength = $varlengths{$var}->(); # compute it

[download]

Slightly more work, but worth it I think.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
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In reply to Re^2: Reading binary files - program structure by BrowserUk
in thread Reading binary files - program structure by Anonymous Monk

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