title: Shell script to accept optional parameters
body: <p>How do I take optional parameters in my shell script.</p>
  
  <blockquote>
    <blockquote>
      <p>Command Line argument would be: <strong>./abc.sh parm1 parm2 parm3 parm4</strong></p>
    </blockquote>
  </blockquote>
  
  <p>Here parm3 and parm4 are optional depending upon parm1(config)</p>
  
  <blockquote>
    <p>How to write a shell script which will take mandatorily parm1 and parm2 as argument and treat the other two as optional parameters</p>
  </blockquote>