title: Eliminate partially duplicate lines by column and keep the last one
body: <p>I have a file that looks like this:</p>
  
  <pre><code>2011-03-21 name001 line1
  2011-03-21 name002 line2
  2011-03-21 name003 line3
  2011-03-22 name002 line4
  2011-03-22 name001 line5
  </code></pre>
  
  <p>for each name, I only want its last appearance. So, I expect the result to be:</p>
  
  <pre><code>2011-03-21 name003 line3
  2011-03-22 name002 line4
  2011-03-22 name001 line5
  </code></pre>
  
  <p>Could someone give me a solution with bash/awk/sed?</p>