It happened to me countless times - forgetting to
sudo before I start editing a file I don’t have
permission on using Vim.
I used to save the edited file to a temporary location when the permission error prompt, and copy it back again.
Today I Learned this awesome command:
:w !sudo tee %
:w !cmd- write the current buffer piped through command
%- the filename associated with the buffer
tee- used to store and view (both at the same time) the output of any other command
:w !sudo tee % will pipe the contents of the buffer through
sudo tee FILENAME.