1 2 3 4 5 6 | highlight ExtraWhitespace ctermbg=red guibg=red match ExtraWhitespace /\s\+$/ autocmd BufWinEnter * match ExtraWhitespace /\s\+$/ autocmd InsertEnter * match ExtraWhitespace /\s\+\%#\@<!$/ autocmd InsertLeave * match ExtraWhitespace /\s\+$/ autocmd BufWinLeave * call clearmatches() |