shell 监控局域网的主机是否up（转）

#!/bin/bash
for ((i=;i<;i++)) ;do
ping -c  172.31..$i>/dev/null
#ping -c 172.31.0.30 ~172.31.0.59
if [[ $? -eq  ]]                  #if up $?==0
then echo "172.31.0.$i is alive"
else
echo "172.31.0.$i isn't up"
fi
done

#!/bin/bash
for ((i=;i<;i++)) ;do
if ping -c  172.31..$i>/dev/null ;  then
echo "172.31.0.$i is alive"
else
echo "172.31.0.$i isn't up"
fi
done

监控局域网的主机是否up，可以使用ping命令，如果ping 通$?等于0，ping不通 返回非0