Edit file vi, not opened by sudo
Opened a file in vi without
sudo. Edited some stuff, realized you can't save it. You close the file, open with sudo, redo the edits.
How about, switching to sudo while vi is still open?
Here's what you got to do:
Open file and edit normally.
Try saving as you usually do.
:w. Meet the error
E212: Can't open file for writing
Press ENTER or type command to continue
Choose to type the command, just type
:w !sudo tee %
Press "O" for Ok. Exit vim with
Your edits are saved.