问题解决：curl: (7) Failed to connect to raw.githubusercontent.com port 443: 拒绝连接
https://qiuhaidong.github.io/blog/2022/04/05/octopress2-on-ubuntu-22-dot-04/
sudo apt install curl
curl -sSL https://get.rvm.io | bash -s stable
提示：
curl: (7) Failed to connect to raw.githubusercontent.com port 443 after 28 ms: 拒绝连接
解决：
Failed to connect to raw.githubusercontent.com
到这个网址：https://www.ipaddress.com/，输入：raw.githubusercontent.com，查询，得到IP地址，选择其中一个或多个，修改本地HOSTS：Ubuntu下打开/etc/hosts，添加 IP地址：185.199.108.133 raw.githubusercontent.com，重试，不行就重启再试。