Ping a range of addresses

pinger.sh

#!/bin/sh

# source http://www.stealthcopter.com/blog/2010/01/bash-script-to-find-active-computers-in-a-subnet-using-ping/

: ${1?"Usage: $0 ip subnet to scan. eg '192.168.1.'"}

subnet=$1
for addr in `seq 0 1 255 `; do
#   ( echo $subnet$addr)
( ping -c 3 -t 5 $subnet$addr > /dev/null && echo $subnet$addr is Alive ) &
done