Vim: open the current file's location using file manager

.vimrc

" open the current editing file's location using file manager
function! s:open_with_filer()
  let cmd = s:get_command()
  let path = s:convert_path(expand('%:p:h'))

  if cmd is# ''
    call g:echohl('Error', 'Your system is not supported.')
    return
  endif

  execute printf('!%s %s', cmd, path)
endfunction
nnoremap <Leader>e :<C-u>call <SID>open_with_filer()<Cr>

function! s:convert_path(path)
  if has('win32') || has('win64')
    return '"' . substitute(a:path, '/', '\', 'g') . '"'
  else
    return a:path
  endif
endfunction

function! s:get_command()
  if has ('mac')
    return 'open -a Finder'
  elseif has('unix') && has('gui_gnome')
    return 'nautilus'
  elseif has('win32') || has('win64')
    return 'start explorer'
  else
    return ''
  endif
endfunction