Mac上解决访问github慢之懒人版

写了一个简单脚本用来解决Mac上访问github慢的问题，基本思路如下：

1. 访问 http://github.global.ssl.fastly.net.ipaddress.com/#ipinfo 获取github的IP地址
2. 在/etc/hosts中加入查询到的IP和域名 （需要root 权限）
3. 在终端在输以下指令刷新DNS（需要root 权限）

运行以下shell脚本即可，需要root权限。

#get the fastest github ip
fast_ip=`curl http://github.global.ssl.fastly.net.ipaddress.com/#ipinfo 2>/dev/null| grep -E -o "([0-9]{1,3}[.]){3}[0-9]{1,3}" |sed -n '2p'`;
echo $fast_ip;

#Add or replace the $fast_ip in /etc/hosts
if grep "www.github.com" /etc/hosts >/dev/null;then
	echo "github dns exists, replace it with the latest one $fast_ip";
	sed -i -e "s|[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}  *www.github.com|$fast_ip www.github.com|"  /etc/hosts;
else
	echo "github dns does not exist, replace it with the latest one $fast_ip";
	echo -e "
#Github
$fast_ip www.github.com
" >> /etc/hosts;
fi

killall -HUP mDNSResponder;say DNS cache has been flushed;