###1. Highlight/Show trailing whitespaces in vi###
- highlight ExtraWhitespace ctermbg=darkgreen guibg=darkgreen
- Show trailing whitespace using match ExtraWhitespace /\s+$/
- Show trailing whitespace and spaces before a tab match ExtraWhitespace /\s+$| +\ze\t/
- Show tabs that are not at the start of a line match ExtraWhitespace /[^\t]\zs\t+/
- Show spaces used for indenting (so you use only tabs for indenting) match ExtraWhitespace /^\t\zs +/*
- Switch off :match highlighting match
- Match trailing whitespace, except when typing at the end of a line match ExtraWhitespace /\s+%#@<!$/