How do I track only specific files using .gitignore? [duplicate]

Question

What should I put in my Git repository's .gitignore to exclude all files and directories there except specific ones. For example if I have a large number of files and directories in a repo, and just want Git to track fileX, .fileY, and directoryZ, but completely ignore everything else, what should be in my .gitignore?

Answer 1

You should ignore content; but exclude folders.
That allows you to exclude files.

/**
!/**/
!fileX

That is because:

It is not possible to re-include a file if a parent directory of that file is excluded.

Check the effect of a .gitignore with git checkignore -v

git check-ignore -v -- afile