1.修改/etc/profile，增加以下内容
export http_proxy="http://10.5.3.9:80"
export https_proxy="http://10.5.3.9:80"
export ftp_proxy="http://10.5.3.9:80"
source /etc/profile
3.测试
curl http://2018.ip138.com/ic.asp
原文：https://www.cnblogs.com/bigcome/p/9944772.html