sudo update-alternatives --config editor


#There are 5 choices for the alternative editor (providing /usr/bin/editor).
#
#  Selection    Path                Priority   Status
#------------------------------------------------------------
#* 0            /bin/nano            40        auto mode
#  1            /bin/ed             -100       manual mode
#  2            /bin/nano            40        manual mode
#  3            /usr/bin/mcedit      25        manual mode
#  4            /usr/bin/vim.basic   30        manual mode
#  5            /usr/bin/vim.tiny    10        manual mode
#
#Press enter to keep the current choice[*], or type selection number: 4
#update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/editor (editor) in manual mode

References

1. http://www.howtogeek.com/howto/ubuntu/change-the-default-editor-from-nano-on-ubuntu-linux/

Ubuntu – set default text editor

References