Do you ever finish up editing a config file only to realize you forgot to open it with
sudo and therefore can't save? This simple one liner from Peteris Krumins’ blog is a godsend.
:w ! tells vim to pass the entire file in the buffer to
stdin of the next command. The command tee writes
stdin to a file. The character
% tells vim to pass the current file name so you end up using
tee running as root to write the vim buffer back to the original file.