Vim: Return the path to viminfo.

vim_viminfo_path.vim

" Language: Vim script
" Description: Return the path to viminfo.
" Author: James Cherti
" URL: https://gist.github.com/jamescherti/3651dfc40aac4181f01fffad4095094e
" License: MIT

function! VimInfoPath() abort
  if &viminfofile
    return fnamemodify(&viminfofile, ':p')
  endif

  for l:item in split(&viminfo, ',')
    if len(l:item) > 0 && l:item[0] ==# 'n'
      return fnamemodify(l:item[1:], ':p')
    endif
  endfor

  " :help viminfo-file-name
  if has('win32') && !has('win32unix')
    if exists('$HOME')
      return fnamemodify($HOME . '\_viminfo', ':p')
    elseif exists('$VIM')
      return fnamemodify($VIM . '\_viminfo', ':p')
    else
      return 'c:\_viminfo'
    endif
  else
    return fnamemodify('~/.viminfo', ':p')
  endif
endfunction