By default, vim seems to save a backup file ending in a tilde (see :help backup). For example, when editing foobar.txt, a backup file foobar.txt~ is saved. I would like to have it saved to .foobar.txt~ instead. On Linux, a file starting with a dot is considered a hidden file.
I can't use the option backupext because it only allows use to set an extension and not a prefix.
I'd recommend to keep all of Vim's backup and state files in their own directory:
set directory=$HOME/tmp/vim//
set backupdir=$HOME/tmp/vim//
set undodir=$HOME/tmp/vim//
The two slashes at the end are important to ensure names are unique:
For Unix and Win32, if a directory ends in two path separators, the swap file name will be built from the complete path to the file with all path separators substituted to percent '%' signs. This will ensure file name uniqueness in the preserve directory.
(:help directory)
It is possible to store these file in the current directory as well -- see the documentation :help directory.
