unclear on exclude and glob

[lxnagel]

I ran lefthook to format files before committing

 commands:
  clang-formater:
    root: "source/app/"
    glob: "*.{c,cpp,h}"
    exclude: ".*$(?<!_evt\\.[h|c])"
    run: clang-format-9 --style=file -i {staged_files}

This left lefthook 1.2.9 still believing files ending in "_evt.c" should be passed to clang? Why?
In the meantime I was playing around with glob, solving it. Yet I would like to understand what my false assumtion was.
This works:

commands:
  clang-formater:
    root: "source/app/"
    glob: "*[!_evt].{c,cpp,h}"
    run: clang-format-9 --style=file -i {staged_files}

Just want to make sure I'm prepared for future challenges.

[mrexox]

Hey! This exclude value doesn't look like a regular expression 🤔

You can try this:

exclude: ".*_evt\.(h|c)"

Please note exclude expects a regular expression, not a glob. I hope this helps.

[mrexox]

Well, then try using single quotes, and please come back if something goes wrong :)

[lxnagel]

  exclude: '.*$(?<!_evt\.[h|c])'

Still doesnt work.

func filterExclude(vs []string, matcher string) []string {
	if matcher == "" {
		return vs
	}

	vsf := make([]string, 0)
	for _, v := range vs {
		if res, _ := regexp.MatchString(matcher, v); !res {
			vsf = append(vsf, v)
		}
	}
	return vsf
}

it really should be simple, right? I mean the root-filter can be removed and won't be an issue.

[mrexox]

I think it doesn't work because the regexp is wrong:

It doesn't compole. You can test it here: https://regex101.com/

'.*$(?<!_evt\.[h|c])'

Try this:

'.*_evt\.(h|c)'

[mrexox]

So, the config would look like this:

 commands:
  clang-formater:
    root: "source/app/"
    glob: "*.{c,cpp,h}"
    exclude: '.*_evt\.(h|c)'
    run: clang-format-9 --style=file -i {staged_files}

[lxnagel]

Oh! Been on regex101 - as usual, I had not explicitly switched to gelang as for python things the std setting worked. The negative lookahead is at least working in other variants.
Hope that this is Q&A is found by someone else. Now I can replay/confirm your statement.

[lxnagel]

Solution found and in the discussion