commit https://github.com/vim/vim/commit/12c4492dd35e0cd83c8816be2ec849b836109882 Author: Bram Moolenaar <Bram@vim.org> Date: Sun Jan 8 13:26:03 2017 +0100 patch 8.0.0151: passing buffer content to system() is clumsy Problem: To pass buffer content to system() and systemlist() one has to first create a string or list. Solution: Allow passing a buffer number. (LemonBoy, closes #1240)

" Simplistic way to make spaces and Tabs visible

" This can be added to an already active syntax.

syn match Space " "
syn match Tab "\t"
if &background == "dark"
  hi def Space ctermbg=darkred guibg=#500000
  hi def Tab ctermbg=darkgreen guibg=#003000
else
  hi def Space ctermbg=lightred guibg=#ffd0d0
  hi def Tab ctermbg=lightgreen guibg=#d0ffd0
endif