Why does `--exclude=node_modules` work but not `--exclude="**/node_modules/**"`?

[radiantshaw]

I ran ctags -R --exclude=node_modules and checked the generated tags file and found out that the node_modules folder was successfully excluded from the output. But when I do the same with ctags -R --exclude="**/node_modules/**, then some of the files inside the node_modules folder are still included in the generated tags file. I wanted to know why is this the case just so that I can understand how ctags work.

Notes

Version:

$ ctags --version
Universal Ctags 5.9.0, Copyright (C) 2015 Universal Ctags Team
Universal Ctags is derived from Exuberant Ctags.
Exuberant Ctags 5.8, Copyright (C) 1996-2009 Darren Hiebert
  Compiled: Oct 25 2021, 04:40:56
  URL: https://ctags.io/
  Optional compiled features: +wildcards, +regex, +gnulib_fnmatch, +gnulib_regex, +iconv, +option-directory, +xpath, +json, +interactive, +yaml, +case-insensitive-filenames, +packcc, +optscript

[masatake]

Doesn't the description of --exclude option of the man page of ctags help you?
https://docs.ctags.io/en/latest/man/ctags.1.html#input-output-file-options

If it is not enough, I must add more descriptions to the page.

[radiantshaw]

@masatake I did some digging and found out the scenarios. Assume that we have a file as foo/bar/baz/foobar.rb:

1. --exclude=foo, --exclude=bar, --exclude=bazall match the file -- that means the folder names provided to--exclude` will be compared against every folder in the path
2. --exclude=foobar.rb matches the file -- that means the file names are matched against the file name (the same is also documented well)
3. --exclude=foo/bar, --exclude=bar/baz also match the file -- that means if the --exclude option has slashes in between, then the matching also works
4. --exclude=baz/foobar.rb doesn't match -- that means if the --exclude option contains slashes but has a file name at the end, then it doesn't work
5. --exclude=fo, --exclude=oo, --exclude=ba, --exclude=ar, --exclude=az also doesn't match the file -- that means if the folder/file names are incomplete, then the matching doesn't work

This might be not an exhaustive list, as there might be more cases. But it would be good to add how the matching happens in the documentation.

[radiantshaw]

@masatake I found something else. --exclude="*/bar/*" works but --exclude="*/foo/*" doesn't. But it is because of how shell completions work; nothing to do with ctags. So feel free to close this issue after considering the comment above for updating the documentation.

Also, really great work on this tool. Really appreciate it. ✌️