ifconfig | awk ‘/inet addr/‘  | awk ‘!/127.0.0.1/‘ |awk -F ‘:‘ ‘{print $2}‘ |awk ‘{print $1}‘  (#centos6)

ifconfig | awk ‘/inet/‘|awk ‘!/inet6|127.0.0.1/‘|awk ‘{print $2}‘  (#centos7.3)

echo -e `for i in {1..254}; do  ping -W1 -c1 192.168.77.$i ;done` > /dev/null  &&    arp -n | awk ‘/:/‘ | sort -t. -k4 -n

(#循环｛a..b｝需求bash 4.0+)