title: Command to find a string and delete it from a file
body: <p>I have a property file <code>mail.properties</code>. The content of the file is </p>
  
  <pre><code>ErrorEmailTo.server1=abc_1@gmail.com,bcd_1@gmail.com,efg_1@gmail.com 
  ErrorEmailFrom.server1=abc_1@gmail.com,bcd_1@gmail.com,efg_1@gmail.com
  ErrorEmailCC.server1=abc_1@gmail.com,efg_1@gmail.com,bcd_1@gmail.com
  </code></pre>
  
  <p>...and numerous such entries.  </p>
  
  <p>I want to find <code>bcd_1@gmail.com</code> and delete it wherever it is present.  The output property file (<code>mail.properties</code>) should look like :  </p>
  
  <pre><code>ErrorEmailTo.server1=abc_1@gmail.com,efg_1@gmail.com 
  ErrorEmailFrom.server1=abc_1@gmail.com,efg_1@gmail.com
  ErrorEmailCC.server1=abc_1@gmail.com,efg_1@gmail.com
  </code></pre>