Ubuntu20.04更换软件源

一、参考网址：

https://developer.aliyun.com/mirror/ubuntu?spm=a2c6h.13651102.0.0.52901b11Xsy9XH

二、具体步骤

1：lsb_release -a,获取codename

2：进入/etc/apt目录下

3：备份sources.list

cp  sources.list sources.lis.bak

4：修改系统源

1	`sudo vi sources.list`

清除原文件所有内容并添加以下内容：注意，每一行的trusty应该用第一步查看得到的Codename来代替，如我的系统查到的是focal

deb http://mirrors.aliyun.com/ubuntu/ trusty main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ trusty-backports main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ trusty-proposed main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ trusty-security main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ trusty-updates main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ trusty main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-backports main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-proposed main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-security main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-updates main multiverse restricted universe

5：保存并且sudo apt update，更新成功

三、快速更换系统源

新建脚本并添加以下内容：

Codename=$( (lsb_release -a)|awk '{print $2}'|tail -n 1 )
echo "\
deb http://mirrors.aliyun.com/ubuntu/ $Codename main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ $Codename-backports main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ $Codename-proposed main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ $Codename-security main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ $Codename-updates main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ $Codename main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ $Codename-backports main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ $Codename-proposed main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ $Codename-security main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ $Codename-updates main multiverse restricted universe ">sources.list
apt-get update