环境：ubuntu18.04

1.查看自己的源
在Debian/Ubuntu系列中，查看软件源列表：

cat /etc/apt/sources.list

在CentOS/RHEL系列中，列出所有仓库配置文件：

ls /etc/yum.repos.d/

2.换源
在Debian/Ubuntu系列中，换源也就是要修改/etc/apt/sources.list文件，代码如下（：

vi /etc/apt/sources.list

在CentOS/RHEL系列中，换源则需要修改/etc/yum.repos.d/CentOS-Base.repo文件，代码如下（：

vi /etc/yum.repos.d/CentOS-Base.repo

进入到目录下 新建sources.list 将原来的备份 使用docker cp /newdir2/  containID:/etc/apt/目录下 
apt-get update即可

cat /etc/issue   查看操作系统  百度搜索其国内源  

Debian 12 ：

deb https://mirrors.aliyun.com/debian/ bookworm main non-free non-free-firmware contrib
deb-src https://mirrors.aliyun.com/debian/ bookworm main non-free non-free-firmware contrib 
deb https://mirrors.aliyun.com/debian-security/ bookworm-security main 
deb-src https://mirrors.aliyun.com/debian-security/ bookworm-security main 
deb https://mirrors.aliyun.com/debian/ bookworm-updates main non-free non-free-firmware contrib 
deb-src https://mirrors.aliyun.com/debian/ bookworm-updates main non-free non-free-firmware contrib 
deb https://mirrors.aliyun.com/debian/ bookworm-backports main non-free non-free-firmware contrib 
deb-src https://mirrors.aliyun.com/debian/ bookworm-backports main non-free non-free-firmware contrib

如果换源后  安装gcc等失败   
用aptitude 代替     它是debian的包管理器