Do you ping constantly but only want to know when a host is down? Well this little script does just that.

host_down.sh

#!/usr/bin/env bash
# [email protected]
# host_down.sh

[[ $1 == "-a" ]] && audible='\a' && shift || audible=
address_1=$1
address_2=$2
[[ -z $address_1 ]] && read -p "Address #1 to ping: " address_1
[[ -z $address_2 ]] && read -p "Address #2 to ping: " address_2

localip="$(ifconfig | grep inet | grep -v inet6 | awk '{ print $2 }' | grep -v '^127' | tr '\n' ',' | sed 's/,$//')"
print_length="${address_1}${address_2}"
print_length="${#print_length}"
header_boarder="$(printf '%*s\n' "$(($print_length + 30))" '' | tr ' ' -)"
[[ $((${#header_boarder} % 2)) == 0 ]] && header_boarder="${header_boarder}-"
printf "\e[8;$((${#header_boarder} / 2 + $((${#header_boarder} / 4))));$(( ${#header_boarder} + 4 ))t"
sleep .2
COLUMNS=$(tput cols)
clear

echo "Pinging from $(hostname) ($localip)" | fmt -c -w $COLUMNS
echo "Address #1: $address_1 | Address #2: $address_2" | fmt -c -w $COLUMNS
echo "$header_boarder" | fmt -c -w $COLUMNS

while true; do
  if [[ $day_stamp != "$(date "+%A %b %d %Y")" ]]; then
    day_stamp="$(date "+%A %b %d %Y")"
    echo "$day_stamp" | fmt -c -w $COLUMNS
  fi
  
  if [[ $(ping -t 2 -c 1 $address_1 > /dev/null 2>&1 ; echo $?) == "0" ]]; then
    address_1_down=false
  else
    address_1_down=true
  fi
  
  if [[ $(ping -t 2 -c 1 $address_2 > /dev/null 2>&1 ; echo $?) == "0" ]]; then
    address_2_down=false
  else
    address_2_down=true
  fi
  
  time_stamp="$(date "+%r")"
  
  [[ $address_1_down == true ]] && notice=" drop @ $time_stamp" || notice="                   "
  [[ $address_1_down == true || $address_2_down == true ]] && notice="${notice} | "
  [[ $address_2_down == true ]] && notice="${notice}drop @ $time_stamp" || notice="${notice}                  "
  [[ $address_1_down == true || $address_2_down == true ]] && printf "%*s$audible\n" $(((${#notice}+$COLUMNS)/2)) "$notice"
  
  sleep 1
done

To quickly run, use:

bash <(curl -fsSL https://gist.github.com/redperadot/8715208/raw/host_down.sh)