Remove .DS_Store tracking in all Git repositories

Every time we create a new folder and add some files in MacOS,
it generates a .DS_Store file in that folder,
which causes lots of .DS_Store files spreading all over the places in MacOS,
and it is pretty annoying to add **/.DS_Store into every .gitignore file every time we create a new Git repository,
so I find a way to prevent the .DS_Store file from being tracked in every Git repository.

The git config command

The git config command can be used to set a variety of settings for git.
The most famous ones are git config --global user.name and git config --global user.email,
which sets user.name and user.email globally,
so every git repositories can use these settings.

This command can also be used to set local settings for a single git repository.
If we wish to use a different user name or email under a specific repository,
we can use git config --local user.name and git config --local user.email to achieve the goal.

There is a core.excludesfile setting for git config,
which can be set to a ignore configuration file to specify files we want all git repositories to ignore.

So all we have to do is to write .DS_Store and **/.DS_Store into a file,
and set core.excludesfile to the file.
Then all the git repositories will ignore .DS_Store.

We can do that by using these commands:

echo ".DS_Store" >> ~/.gitignore_global
echo "**/.DS_Store" >> ~/.gitignore_global
git config --global core.excludesfile ~/.gitignore_global