:update is like :w but only writes when changes are made.
While we're at it :earlier and :later are undo/redo but instead of using an undo stack they use change points in time, so your undo history is never overwritten :)
While we're at it :earlier and :later are undo/redo but instead of using an undo stack they use change points in time, so your undo history is never overwritten :)
I need it so rarely that I have a hard time remembering what the command was again whenever I need it. Needed it a few weeks ago, so now it's at the front of my mind again :D