更改sudo的editor
ubuntu的默认编译器为nano，当一个命令，如’sudo visudo’时，就会弹出nano编辑器。
对于习惯vim的用户来说，得先来修改它，方法如下：
sudo update-alternatives --config editor
选择vim.basic选项或者nvim选项，回车即可。
此时再次打开时已经是vim编辑器。
其他发行版可以参靠archwiki
The default editor for visudo is vi. The
sudo package is compiled with --with-env-editor and honors the use of the SUDO_EDITOR, VISUAL and EDITOR variables. EDITOR is not used when VISUAL is set.
To establish
nano as the visudo editor for the duration of the current shell session, export EDITOR=nano; to use a different editor just once simply set the variable before calling visudo:
# EDITOR=nano visudo
Alternatively you may edit a copy of the /etc/sudoers file and check it using visudo -c _/copy/of/sudoers_. This might come in handy in case you want to circumvent locking the file with visudo.
To change the editor permanently, see
Environment variables#Per user. To change the editor of choice permanently system-wide only for visudo, add the following to /etc/sudoers (assuming
nano is your preferred editor):
# Reset environment by default
Defaults env_reset
# Set default EDITOR to restricted version of nano, and do not allow visudo to use EDITOR/VISUAL.
Defaults editor=/usr/bin/rnano, !env_editor