Simple bash ping-sweeper

ping_sweeper.sh

#!/bin/bash

# Simple ping-sweeper scan to determine which
# devices on a subnet respond to ping.

# Non-responding to ping does not mean
# that device is not up !

TIMESTAMP="$(date +%Y-%m-%d.%H:%M:%S)"
OUT="scan_${TIMESTAMP}.txt"
RED="\033[0;31m"
WHITE="\033[0;37m"

trap 'echo; exit 2' INT

read -p 'Please enter subnet: ' SUBNET

echo "Writing to file: '${OUT}'"

for IP in $(seq 1 254)
do
	printf "%-15s ==> " "${SUBNET}.${IP}" | tee -a "${OUT}"
	ping -c 1 "${SUBNET}.${IP}" > /dev/null 2>&1 

	if [ $? -eq 0 ]
	then
		printf "${RED}up${WHITE}\n" | tee -a "${OUT}"
	else
		printf "down\n" | tee -a "${OUT}"
	fi
done