title: How do I start reading at an offset in binary data?
body: <p>I have a C-like struct like this:</p>
  
  <pre><code>SomeStruct &lt;&lt; BinData::Record
  endian :little
  
  uint32 :offsetOfName
  uint32 :offsetOfLastname
  #...
  uint32 :lenVars
  struct :Person, :length =&gt; :lenVars
      string :name
      string :lname
      #...
  end
  </code></pre>
  
  <p>I have a bunch of offsets and lengths before <code>:Person</code>. All the offsets and lengths describe the data within the <code>:Person</code> struct. </p>
  
  <p>How can I start reading data at a specified offset, for the given length, or until the next offset?</p>