A RegEx to highlight trailing whitespaces in Vim

Today I had a very interesting chat with Timothy Mukaibo about vim, and of course we ended up exchanging .vimrc tips.

One of the interesting bits of his .vimrc is that any extra whitespace at the end of a line are highlighted. I found this very useful and added it to mine straightaway!

Improving my vimrc cherry picking from @TimothyMukaibo's one. Thanks mate for sharing! 👍 https://t.co/vBornRfIeJ

— Giovanni Lodi (@mokagio) February 6, 2015

The extra whitespaces are picked through a RegEx, and in my ongoing quest to sharpen my RegEx skills I’m now gonna look at it:

/\s\+\$/

• \s is the matcher for a single whitespace character
• \+ is the “greedy” one or more quantifier
• \$ matches the end of the line

Summing it all up we get “match one or more whitespace characters at the end of the line”, which is exactly what we want.

Food for thoughts

• Understand the syntax used to set this in the .vimrc
• Understand why if the hi instruction comes after the match one then the trick doesn’t work
• Try to find out if it’s possible to have it running only in normal mode