title: SSH: Don't prompt for password in shell script
body: <p>I'm using ssh and have a passwordless ssh setup for my system. Using ssh in a script works fine, but if the user specifies a host that don't has a passwordless ssh setup the script prompts for a password and hangs.</p>
  
  <p>How could I avoid the password prompt and return an error if passwordless ssh is not setup for the host?</p>