gistfile1.txt

_checkSudo() {
  if [ -z "__INTERACTIVE" ]; then
    #don't check if it's not in an interactive shell
    return 0
  fi
  if [ "$SUDO_GID" ] && [ "$SUDO_COMMAND" ] && [ "$SUDO_USER" ] && [ "$SUDO_UID" ]; then
    if [ "$SUDO_USER" = "root" ] && [ "$SUDO_UID" = "0" ]; then
      #it's root using sudo, no matter it's using sudo or not, just fine
      return 0
    fi
    if [ -n "$SUDO_COMMAND" ]; then
      #it's a normal user doing "sudo su", or `sudo -i` or `sudo -s`, or `sudo su acmeuser1`
      _endswith "$SUDO_COMMAND" /bin/su || _contains "$SUDO_COMMAND" "/bin/su " || grep "^$SUDO_COMMAND\$" /etc/shells >/dev/null 2>&1
      return $?
    fi
    #otherwise
    return 1
  fi
  return 0
}