title: remove rows in file - Ruby
body: <p>What is a clever way to remove rows from a CSV file in ruby where a particular value exists in a particular row?</p>
  
  <p>Here's an example of a file:</p>
  
  <pre><code>350 lbs., Outrigger Footprint, 61" x 53", Weight, 767 lbs., 300-2080
  350 lbs., Outrigger Footprint, 61" x 53", Weight, 817 lbs., 300-2580
  350 lbs., Outrigger Footprint, 61" x 53", Weight, 817 lbs., 300-2580
  350 lbs., Outrigger Footprint, 69" x 61", Weight, 867 lbs., 300-3080
  350 lbs., Outrigger Footprint, 69" x 61", Weight, 867 lbs., 300-3080
  </code></pre>
  
  <p>Ideally, I'd want a new file created with only this:</p>
  
  <pre><code>350 lbs., Outrigger Footprint, 61" x 53", Weight, 767 lbs., 300-2080
  350 lbs., Outrigger Footprint, 61" x 53", Weight, 817 lbs., 300-2580
  350 lbs., Outrigger Footprint, 69" x 61", Weight, 867 lbs., 300-3080
  </code></pre>
  
  <p>when given this:</p>
  
  <pre><code>300-2580
  300-3080
  300-2080
  </code></pre>
  
  <p>so I know i can do this with <code>sort filename|uniq -d</code> but I'm trying to learn Ruby (somewhat painfully).  </p>
  
  <p>Thanks in advance,
  M</p>