How to delete password in vim without storing it in a register?

Question

I have a password in a text file. I'm editing the file in vim and I want to delete the password. If I just delete it, say with 'dw', it's stored in several registers. I want to avoid keeping any track of the password in vim.

The closest I managed to get is to use the black hole register: '"_dw' - this doesn't store the password in the usual registers, but it still remains in the '".' register.

Answer 1

The black hole register is the way to go. The "last inserted text register" ". contains the password only if it was the last text entered. Have in mind that the password although deleted still exists in the undo history. I would recommend the following:

:let old_undolevels = &undolevels
:set undolevels=-1                   
:exe "normal a \<BS>\<Esc>"
:let &undolevels = old_undolevels
:unlet old_undolevels

That will clear the undo history and the ". register.

Answer 2

You could delete something else into the black hole register, which would wipe out the previous contents, or you could directly assign something to it like this:

:let @_=""