寫了一個簡單腳本用來解決Mac上訪問github慢的問題，基本思路如下：

1. 訪問 http://github.global.ssl.fastly.net.ipaddress.com/#ipinfo 獲取github的IP地址
2. 在/etc/hosts中加入查詢到的IP和域名 （需要root 權(quán)限）
3. 在終端在輸以下指令刷新DNS（需要root 權(quán)限）

運(yùn)行以下shell腳本即可，需要root權(quán)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 $fast_ip";
    echo -e "\n#Github\n$fast_ip www.github.com\n" >> /etc/hosts;
fi

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