title: Unix uniq, sort & cut command remove duplicate lines
body: <p>If we have the following result:</p>
  
  <pre><code>Operating System,50
  Operating System,40
  Operating System,30
  Operating System,23
  Data Structure,87
  Data Structure,21
  Data Structure,17
  Data Structure,8
  Data Structure,3
  Crypo,33
  Crypo,31
  C++,65
  C Language,39
  C Language,19
  C Language,4
  Java 1.6,16
  Java 1.6,11
  Java 1.6,10
  Java 1.6,2
  </code></pre>
  
  <p>I only want to compare the first field (book name), and remove duplicate lines except the first line of each book, which records the largest number. So the result is as below:</p>
  
  <pre><code>Operating System,50
  Data Structure,87
  Crypo,33
  C++, 65
  C Language,39
  Java 1.6,16
  </code></pre>
  
  <p>Can anyone help me out that how could I do using uniq, sort &amp; cut command? May be using tr, head or tail?</p>