How to get Vim to highlight non-ascii characters?

Question

I\'m trying to get Vim to highlight non-ASCII characters. Is there an available setting, regex search pattern, or plugin to do so?

Answer 1

This regex works as well. It was the first google hit for "vim remove non-ascii characters" from briceolion.com and with :set hlsearch will highlight:

/[^[:alnum:][:punct:][:space:]]/

Answer 2

Yes, there is a native feature to do highlighting for any matched strings. Inside Vim, do:

:help highlight
:help syn-match

syn-match defines a string that matches fall into a group. highlight defines the color used by the group. Just think about syntax highlighting for your vimrc files.

So you can use below commands in your .vimrc file:

syntax match nonascii "[^\x00-\x7F]"
highlight nonascii guibg=Red ctermbg=2