Open file in vertical split in Vim / netrw

Whilst Jonathan.Brink's answer works perfectly well, simply adding

let g:netrw_altv=1

to .vimrc also seems to do the trick...

See https://superuser.com/questions/1056929/open-file-in-vertical-split-in-vim-netrw/1062063#1062063 for more info.

Netrw v153 and later (May 28, 2014) gives you the :Lexplore command, which, by default, opens a directory listing on the left hand side and opens files to the right (by pressing <cr>).

I'm sure this could be improved upon you can write a custom mapping that target's the netrw filetype.

Stick this in your .vimrc:

" open file vertically to the right
augroup netrw_mappings
    autocmd!
    autocmd filetype netrw call Netrw_mappings()
augroup END
function! OpenToRight()
  :rightbelow vnew
  :wincmd p
  :normal P
endfunction
function! Netrw_mappings()
    noremap V :call OpenToRight()<cr>
endfunction

The only thing is that you need to use V rather than v. For some reason I was unable to override netrw's v command, but using the capital version seems better anyway since it's not overriding a default.