#!/usr/bin/bash

DEL=""

deletehost() {
  local host ip
  host=$(echo $1 | awk -F@ '{print $NF}')
  ip=$(host $host | awk '/has address/ {print $NF}' | head -1)
  ssh-keygen -R $host
  test -n "$ip" && ssh-keygen -R $ip
}

while getopts ":dh" OPT; do
  case "$OPT" in
    d) DEL=Y ;;
 \?|h) usage >&2 ; exit 0 ;;
  esac
done
shift $(expr $OPTIND - 1)

test -n "$DEL" && deletehost $@

ssh root@${1:-none}