How to relocate temporary Vim files

Vim has an annoying habit of littering your working directory with its own swap, backup, and undo files. You can relocate these temporary files to a central repository by adding the following lines to your .vimrc file:

" Relocate backup files, swap files, and undo files.
set backupdir=~/.cache/vim//
set directory=~/.cache/vim//
set undodir=~/.cache/vim//

(The trailing double slash tells Vim to encode the file's original path in its name so files from different directories can co-exist peacefully.)

You'll need to make sure the directory you specify exists or Vim will throw a mild fit. You can add the following snippet to your .vimrc file to create the directory automatically on startup if it doesn't already exist.

if !isdirectory($HOME . "/.cache/vim")
    call mkdir($HOME . "/.cache/vim", "p")

The "p" flag ensures that intermediary directories along the path will be created if necessary.