title: How to check if running as root in a bash script
body: <p>I'm writing a script that requires root level permissions, and I want to make it so that if the script is not run as root, it simply echoes "Please run as root." and exits.</p>
  
  <p>Here's some pseudocode for what I'm looking for:</p>
  
  <pre><code>if (whoami != root)
    then echo "Please run as root"
  
    else (do stuff)
  fi
  
  exit
  </code></pre>
  
  <p>How could I best (cleanly and securely) accomplish this? Thanks!</p>
  
  <p>Ah, just to clarify: the (do stuff) part would involve running commands that in-and-of themselves require root. So running it as a normal user would just come up with an error. This is just meant to cleanly run a script that requires root commands, without using sudo inside the script, I'm just looking for some syntactic sugar. </p>