Ubuntu 下安装 gcc/g++-4.8

安装 gcc/g++-4.8

mkdir install_g++-4.8
cd install_g++-4.8/
sudo apt update
wget http://mirrors.kernel.org/ubuntu/pool/universe/g/gcc-4.8/g++-4.8_4.8.5-4ubuntu8_amd64.deb 
wget http://mirrors.kernel.org/ubuntu/pool/universe/g/gcc-4.8/libstdc++-4.8-dev_4.8.5-4ubuntu8_amd64.deb 
wget http://mirrors.kernel.org/ubuntu/pool/universe/g/gcc-4.8/gcc-4.8-base_4.8.5-4ubuntu8_amd64.deb 
wget http://mirrors.kernel.org/ubuntu/pool/universe/g/gcc-4.8/gcc-4.8_4.8.5-4ubuntu8_amd64.deb 
wget http://mirrors.kernel.org/ubuntu/pool/universe/g/gcc-4.8/libgcc-4.8-dev_4.8.5-4ubuntu8_amd64.deb 
wget http://mirrors.kernel.org/ubuntu/pool/universe/g/gcc-4.8/cpp-4.8_4.8.5-4ubuntu8_amd64.deb 
wget http://mirrors.kernel.org/ubuntu/pool/universe/g/gcc-4.8/libasan0_4.8.5-4ubuntu8_amd64.deb  
sudo apt install ./gcc-4.8_4.8.5-4ubuntu8_amd64.deb ./gcc-4.8-base_4.8.5-4ubuntu8_amd64.deb ./libstdc++-4.8-dev_4.8.5-4ubuntu8_amd64.deb ./cpp-4.8_4.8.5-4ubuntu8_amd64.deb ./libgcc-4.8-dev_4.8.5-4ubuntu8_amd64.deb ./libasan0_4.8.5-4ubuntu8_amd64.deb ./g++-4.8_4.8.5-4ubuntu8_amd64.deb

查看当前系统所有版本号

ls /usr/bin/gcc* -al

当前所用版本为 gcc-9

将 gcc-4.8 的优先级设置为 100

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.8 100
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.8 100

切换并查看当前 gcc 版本

sudo update-alternatives --config gcc
sudo update-alternatives --config g++

gcc -v