How to pass current file name with a different path to the command line

Question

Is there any way to make the special symbol % work with path names on the command line? For instance, I'd like to do:

:diffsplit Path\to\other\directory\%

So that I can do a @: to quickly compare files of the same name. However, this just opens up a new buffer called %.

Of course I could do:

:exe 'diffsplit Path\to\other\directory\'.expand('%')

But this is cumbersome as I can't tab complete directories when typing the command.

Is there any other better way to do this?

Here's a related question, but it doesn't address my situation exactly.

Edit: Just to clarify, I would like to be able to re-use the command exactly for different files. So a solution that simply autofills the current file in the command line will not work. The same command needs to work for different file names.

Answer 1

Special characters (see :h cmdline-special) and filename modifiers (see :h filename-modifiers) are expanded on the command line, so:

:diffsplit Path/to/other/directory/%:t

Answer 2

So it turns out that it's a stupid Windows problem. The remedy to this is to simply use forward slashes in the path name. i.e. :diffsplit Path/to/other/directory/% works just fine.

I've remedied this on my system by using the option set shellslash which defaults to using forward slashes even on Windows.

Answer 3

I don't know if this is ok for you:

:diffsplit Path/to/somewhere/<c-r>%

Just one more keystroke to your original, the <C-r>, in order to fill the % register value.