ubuntu18.04配置（更新）

1 参考地址
https://blog.csdn.net/hymanjack/article/details/80285400
https://blog.csdn.net/github_36498175/article/details/80161362
https://www.linuxidc.com/Linux/2018-04/152109.htm
2 gfortran gcc g++切换(安装gamit需要切换低版本)

sudo apt-get install gcc-5 gcc-5-multilib
sudo apt-get install g++-5 g++-5-multilib
sudo apt-get install gcc-6 gcc-6-multilib
sudo apt-get install g++-6 g++-6-multilib
sudo apt-get install gcc-7 gcc-7-multilib
sudo apt-get install g++-7 g++-7-multilib

sudo apt-get install gfortran-5 gfortran-5-multilib
sudo apt-get install gfortran-6 gfortran-6-multilib
sudo apt-get install gfortran-7 gfortran-7-multilib

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-5 50
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-6 60
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-7 70
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-5 50
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-6 60
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-7 70

sudo update-alternatives --install /usr/bin/gfortran gfortran /usr/bin/gfortran-5 50
sudo update-alternatives --install /usr/bin/gfortran gfortran /usr/bin/gfortran-6 60
sudo update-alternatives --install /usr/bin/gfortran gfortran /usr/bin/gfortran-7 70

然后选择gcc和g++ gfortran

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

3 主题定制
主题
https://www.gnome-look.org/p/1167049/
https://www.gnome-look.org/p/1241688/

图标 papirus

sudo add-apt-repository ppa:papirus/papirus
sudo apt update 
sudo apt-get install papirus-icon-theme

pop系列

sudo add-apt-repository ppa:system76/pop
sudo apt-get update
sudo apt install pop-theme

扁平化系列

sudo add-apt-repository ppa:daniruiz/flat-remix
sudo apt-get update
sudo apt-get install flat-remix-gnome