oldcatY 不要用hostname获取IP，这样不准确，会获取到IPv6，用下面命令获取：
getIP(){
local serverIP=
serverIP=$(curl -s -4 http://www.cloudflare.com/cdn-cgi/trace | grep "ip" | awk -F "[=]" '{print $2}')
if [[ -z "${serverIP}" ]]; then
serverIP=$(curl -s -6 http://www.cloudflare.com/cdn-cgi/trace | grep "ip" | awk -F "[=]" '{print $2}')
fi
echo "${serverIP}"
}
