Linux - Script dialog using xmessage

Using xmessage to display a text dialog with a question: "Are you sure you want to reboot?" If you user clicked, on yes, it will reboot your computer by issuing the command systemctl reboot.

#!/bin/sh
 
answer=$(xmessage  "Are you sure you want to reboot?" -buttons yes,no -print)
if [ "$answer" == "yes" ];then
   systemctl reboot
fi

Output