known-host

#!/bin/sh

function usage() {
  echo "usage: $0 <line number|IP>"
}

if [ -z "$1" ] ; then
  usage
  exit
elif [ "$1" = "-y" ] ; then
  FORCE=1
  shift
fi


IP=$(echo $1 |grep -E "[0-9]*\.[0-9]*\.")
LINENU=$(echo $1 |grep -E "^[0-9]*$")

if [ -n "$IP" ] ; then
  ipmsg="with ip"
elif [ -z "$LINENU" ] ; then
  usage
  exit
fi

if [ ! "$FORCE" = "1" ] ; then
  echo "Press ENTER to remove line $ipmsg $1 or CTRL-C to exit"
  read foo
fi

if [ -n "$IP" ] ; then
  ssh-keygen -R $IP
else
  sed -i "${LINENU}d" $HOME/.ssh/known_hosts
fi