while using,
sed -i '122 i <button type="button" onclick="window.open('https://localhost:$ctrl','_blank')">CTRL01</button>' SCP_PortForwarding.html;
in SCP_PortForwarding.html i am getting,
<button type="button" onclick="window.open(https://localhost:10941,_blank)">CTRL01</button>
but want to print,
<button type="button" onclick="window.open('https://localhost:10941','_blank')">CTRL01</button>
where $ctrl is randomly assigned port number.