Is there any way to highlight multiple searches in (g)Vim?

Question

I want to search for multiple strings in Vim/gVim and have them highlighted in different colours. Is there a way of doing this with out-the-box Vim or with a plug-in?

Answer 1

Yes, out-of-the-box you can use matchadd().

To add a highlight, eg. for trailing whitespace:

:highlight ExtraWhitespace ctermbg=grey guibg=grey
:call matchadd('ExtraWhitespace', '\s\+$', 11)

To view all matches:

:echo getmatches()

To remove matches use matchdelete(). Eg.:

:call matchdelete(7)