update-alternatives --config editor
Selection Path Priority Status
------------------------------------------------------------
0 /bin/nano 40 auto mode
* 1 /bin/nano 40 manual mode
2 /usr/bin/mcedit 25 manual mode
3 /usr/bin/vim.basic 30 manual mode
4 /usr/bin/vim.tiny 10 manual mode
ls -l /etc/alternatives/editor
lrwxrwxrwx 1 root root 9 Apr 3 09:18 /etc/alternatives/editor -> /bin/nano