Can I include other .gitignore file in a .gitignore file? (like #include in c-like languages)

You could:

• Have a template repo with:
  • those xxx.gitignore files in it:
  • a .gitignore file with “xxx-gitignore-xxx” in it (in other word, with a content you can easily identify
  • a .gitattribute filter driver

(for each new repo, you clone it and can start with those files already there.
Then you remove the remote ‘origin‘, or replace it by whatever remote repo you want to push to)

^{(image shown in “Customizing Git – Git Attributes“, from “Pro Git book“)}

On any checkout of your repo, the filter driver will, through the smudge script:

• recognize the content of the .gitignore file
• check if the xxx.gitignore content isn’t already there (by looking for a specific string which only those files have)
• if their content isn’t there, it will append the content of those xxx.gitignore files
• if the content is already up-to-date, it wouldn’t modify the .gitignore.

Note that having a identifiable content is key here, since a filter driver script doesn’t have the name/path of the file it filters.

It is a bit convoluted, but seems to be the only way to implement the “include” feature you want.