title: setuid bit result
body: <p>I have a shell script that I want to set uid bit.
  I set the owner to root and set uid bit.
  I added 'whoami'in the shell to check if it is working properly
  but when I executed the script, whoami returned user's name, not root.
  Then this is wrong, right? I should have gotten root if uid was set correctly, right?</p>