title: Bash : extracting date from file
body: <p>I am new to bash and I have a file like this :</p>
  
  <pre><code>2012-11-22 11:36:55,909 1353551815756 1353551815909 0 true myapi 10 203051 203051:ShopDb:ShopDb
  2012-11-22 11:37:00,292 1353551820146 1353551820292 0 true myapi 10 201897 201897:ShopDb:ShopDb
  2012-11-22 11:38:01,824 1353551881672 1353551881824 0 true myapi 10 203051 203051:ShopDb:ShopDb
  </code></pre>
  
  <p>In a loop,line I want to extract date part (2012-11-22 11:36:55) convert to time-stamp and assign to a variable(or simply dis
  How to achieve this in bash ?</p>