一、提要
数据源有两种：1）ubuntu相关数据源，2）特殊软件数据源（如docker、ros等软件专门数据源）。
本篇讲的是1）ubuntu相关数据源。ubuntu系统刚装好，修改数据源，这也是最好的修改ubuntu数据源机会。
至于2）特殊软件数据源，是不允许用户修改的。
二、 数据源的要点
2.1 ubuntu数据源的五个源
我们分析了source.list文件，发现在新装ubuntu下，只有五个关键词：
- bionic/
- bionic-backports/
- bionic-proposed/
- bionic-security/
- bionic-updates/
以上五个关键词对应10条语句，只要把这10条语句替换成其它源，就全部完成，没有遗漏。而国内数据源不到五家，因此挑一个就可以了。但是，以阿里源最为稳定可靠。
2.2 需要Ubuntu的具体别名
所谓ubuntu的别名，就是ubuntu为每个版本起了一个英文名称，如ubuntu18.04 名为focal，ubuntu22.04名为jammy。
如果不知道你的ubuntu到底别名是啥，可以用指令查询：
lsb_release -a举例：
三、修改新数据源（以阿里源为例）
3.1 修改前保护原始文件
cd /etc/apt
sudo cp ./source.list ./source.list.bak3.2 如何修改/etc/apt/sources.list
sudo vim /etc/apt/source.list此时按快捷键：ggdG（gg是到光标首行，dG是删除到尾部），这样清空文件，将以下文本全部粘贴入。保存完成。
比如：对于ubuntu20.04，粘贴内容为：
deb http://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universemultiverse
比如：对于ubuntu22.04， jammy 粘贴内容为：
deb http://mirrors.aliyun.com/ubuntu/ jammy main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ jammy main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ jammy-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ jammy-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ jammy-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ jammy-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ jammy-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ jammy-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ jammy-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ jammy-backports main restricted universe multiverse
以上就是aliyun的，关于focal版本的数据源已经做好。至于清华源、科大源可以同样做成。
3.3 数据源刷新
然后执行命令：
sudo apt-get update
sudo apt-get upgrade进行测试！阿里数据源修改完成。
四、其它数据源
上面提供了ubuntu20.04下下修改为阿里源。如果修改成：清华、科大、163 数据源。下面列出，主要是方便大家拷贝粘贴和修改。
4.1 清华源
# 默认注释了源码镜像以提高 apt update 速度，如有需要可自行取消注释
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-updates main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-backports main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-backports main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-security main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-security main restricted universe multiverse
# 预发布软件源，不建议启用
# deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-proposed main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-proposed main restricted universe multiverse
4.2 中科大源
deb https://mirrors.ustc.edu.cn/ubuntu/ focal main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ focal main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ focal-updates main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ focal-updates main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ focal-backports main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ focal-backports main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ focal-security main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ focal-security main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ focal-proposed main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ focal-proposed main restricted universe multiverse
4.3 网易163源
deb http://mirrors.163.com/ubuntu/ focal main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ focal-security main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ focal-updates main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ focal-proposed main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ focal-backports main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ focal main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ focal-security main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ focal-updates main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ focal-proposed main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ focal-backports main restricted universe multiverse
五、后记
以上所说是ubuntu刚装好需要修改的数据源，这些数据源与国外ubuntu开发团队是同步的。因此可以放心用。以后安装软件还会追加source.list或追加数据源文件，这些数据源是特殊安装的通道，不允许修改。
