#!/bin/bash

 PREFIX=192.168.

  num=

  while [ "$num" -lt "" ]; do

  echo -en "Pinging ${PREFIX}.${num}..."

  ping -c1 -w1 -t5 ${PREFIX}.${num} >/dev/null >&

  if [ "$?" -eq "" ]; then

  echo "OK" && echo “${PREFIX}.${num}” >>ok.txt

  else

  echo "Failed" && echo “${PREFIX}.${num}” >>failed.txt

  fi

  let num=$num+

  done