title: Extracting IP addresses from text file with batch
body: <p>I have a text file with data like this:</p>
  
  <p>Aug 21 [10.23.5.5] Teardown dynamic</p>
  
  <p>Aug 18 [10.150.1.45] Aug 21 15:28:34 otoldc</p>
  
  <p>Aug 24 [10.96.5.10] Aug 21 2012 18:58:26 HYD</p>
  
  <p>Aug 24 [10.96.5.10] Aug 22 2012 18:58:26 HYD</p>
  
  <p>Aug 21 [192.168.15.231] sendmail[18831]</p>
  
  <p>I need to remove everything except IP addresses surrounded by "[" and "]". String length before "[" is fixed. String length after "]" varied.
  I tried use one of existing solutions here but couldn't get success. Is it possible to do it using batch?
  Thanks:-)</p>