title: how to use shell variables in xml file
body: <p>this is my xml file</p>
  
  <pre><code>`&lt;common&gt;
     &lt;ALL&gt;
        &lt;CollectTimestamps&gt;0&lt;/CollectTimestamps&gt;
        &lt;DefaultDatabaseInstance&gt;ZEH3104&lt;/DefaultDatabaseInstance&gt;
     &lt;/ALL&gt;
  &lt;/common&gt;`
  </code></pre>
  
  <p>my databaseinstance value ZEH3104 is hard coded value, the value keeps changing from release to release, i want to use a variable insteadt of hard coded value, i want to use a shell variable like</p>
  
  <pre><code>`&lt;DefaultDatabaseInstance&gt;$myShellVariable&lt;/DefaultDatabaseInstance&gt;`
  </code></pre>
  
  <p>where echo $myShellVariable gives ZEH3104</p>
  
  <p>but this is not working  tag is taking $myShellVariable as value for the tag instead of ZEH3104</p>
  
  <p>is there any method where i can get the result. please help.</p>
  
  <p>NOTE: the tags should not be modified</p>