Why [^\d\w\s,] matches "leonardo,davinci"?

Question

I can't understand why the regexp:

[^\d\s\w,]

Matches the string:

"leonardo,davinci"

That is my test:

$ echo "leonardo,davinci" | egrep '[^\d\w\s,]'
leonardo,davinci

While this works as expected:

$ echo "leonardo,davinci" | egrep '[\S\W\D]'
$ 

Thanks very much

Answer 1

It's because egrep doesn't have the predefined sets \d, \w, \s. Therefore, putting slash in front of them is just matching them literally:

leonardo,davinci

echo "leonardo,davinci" | egrep '[^a-zA-Z0-9 ,]'

Will indeed, not match.

---

If you have it installed, you can use pcregrep instead:

echo "leonardo,davinci" | pcregrep '[^\w\s,]'