title: Script to send alert mail if disk usage exceeds a percentage
body: <p>I am new to shell scripting, and want to implement a script on my server which will automatically send e-mail alerts if:</p>
  
  <ul>
  <li>Disk usage exceeds 90% </li>
  <li>Disk usage exceeds 95% (In addition to the previous e-mail)</li>
  </ul>
  
  <p>My filesystem is <code>abc:/xyz/abc</code> and my mount is <code>/pqr</code>. How can I set this up via scripts?</p>