It's also possible to ignore files of a repository without the .gitignore files. You can put your ignored files in a global ignore file, for example ~/.gitignore_global, and globally configure Git to also consider entries in this file to be ignored:

$ git config --global core.excludesfile ~/.gitignore_global

You can also do it per repository in the .git/info/exclude file. If you use either of these options, you won't be able to easily share the ignored file; they can't be added to the repository as they are stored outside it. Sharing .gitignore files is much easier; you just add and commit them to Git. But, let's see how the other options work:

$ echo "*.test" > .git/info/exclude
$ touch test.test
$ git status
On branch ignore
  Your branch is ahead of 'origin/ignore' by 1 commit.
    (use "git push" to publish your local commits)
    
  Untracked files:
    (use "git add <file>..." to include in what will be committed)
    
      test.txt
    
nothing added to commit but untracked files present (use "git add" to track)
$ ls
bar        bin       foo
test.test  test.txt  test.txt.bak

We can see that the .test file didn't show up in the status output and that the ignored files exist in the working directory.