高版本Ubuntu(如22.02)修改apt源，快速安装低版本gcc/g++

Posted 2023-04-03 懵~

Ubuntu不同版本默认apt install gcc安装的gcc和g++版本不同，如Ubuntu22.04默认安装gcc/g++为11版本，高版本Ubuntu无法直接通过apt install gcc安装低版本编译器，可以通过离线安装（过于繁琐），本文推荐修改apt源，添加对应低版本ubuntu源即可，这里以Ubuntu22.04为例，给出安装gcc-5/gcc-7的简单方法，同时给出了常用的国内镜像源。

apt install gcc的会同时安装gcc和g++

1. 首先简单介绍常用国内apt源-->阿里云和清华云(此步骤只是参考可略过)

deb http://mirrors.aliyun.com/ubuntu/ jammy main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ jammy-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ jammy-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ jammy-backports main restricted universe multiverse
 
# deb-src http://mirrors.aliyun.com/ubuntu/ jammy main restricted universe multiverse
# deb-src http://mirrors.aliyun.com/ubuntu/ jammy-security main restricted universe multiverse
# deb-src http://mirrors.aliyun.com/ubuntu/ jammy-updates main restricted universe multiverse
# deb-src http://mirrors.aliyun.com/ubuntu/ jammy-backports main restricted universe multiverse
 
## Pre-released source, not recommended.
# 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 https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-backports main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-security main restricted universe multiverse
 
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-updates main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-backports main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-security main restricted universe multiverse
 
## Pre-released source, not recommended.
# deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-proposed main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-proposed main restricted universe multiverse

上面源中每一行中的jammy标识为ubuntu22.04，若为其他版本Ubuntu，将对应jammy改为其他版本标识，如focal即可，常用的Ubuntu版本代号如下：

Ubuntu 22.04：jammy
Ubuntu 20.04：focal
Ubuntu 18.04：bionic
Ubuntu 16.04：xenial

2. Ubuntu22.04默认安装gcc-11版本，如果需要安装低版本，可以修改apt源，添加低版本ubuntu源来安装

使用下面命令修改apt源

sudo vim /etc/apt/sources.list

如要安装gcc-7，在sources.list文件末尾添加Ubuntu 20.04：focal的源

deb https://mirrors.aliyun.com/ubuntu/ focal main universe

如要安装gcc-5，在sources.list文件末尾添加Ubuntu 16.04：focal的源

deb https://mirrors.aliyun.com/ubuntu/ xenial main universe

sources.list文件修改完毕后，执行以下命令加载源资源

sudo apt-get update

注意，有时update时会报错, 提示GPG error缺少公钥，多见于添加了xenial版本(Ubuntu16)源

W: GPG error: http://mirrors.aliyun.com/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
E: The repository 'http://mirrors.aliyun.com/ubuntu xenial InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

此时，解决办法根据报错信息“NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32”导入对应公钥即可

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 40976EAF437D05B5
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 3B4FE6ACC0B21F32

然后，再次sudo apt-get update，之后就可以直接apt安装gcc对应版本

sudo apt install gcc-5
sudo apt install gcc-7

Ubuntu 18.04修改默认源为国内源

安装Ubuntu 18.04后，使用国外源太慢了，修改为国内源会快很多。

修改阿里源为Ubuntu 18.04默认的源

备份/etc/apt/sources.list

备份

cp /etc/apt/sources.list /etc/apt/sources.list.bak

在/etc/apt/sources.list文件前面添加如下条目

添加阿里源

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

最后执行如下命令更新源

更新

sudo apt-get update
sudo apt-get upgrade

另外其他几个国内源如下：
中科大源

中科大源

deb https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse

163源

163源

deb http://mirrors.163.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ bionic-updates main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ bionic-backports main restricted universe multiverse

清华源

清华源

deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse