How to make git status show only staged files

Solution 1:

Use git diff --name-only (with --cached to get the staged files)

Solution 2:

The accepted answer won't let you know what kind of changes were there.

Yes, If you are not syntax checker but an ordinary person with a repository full of unstaged files, and you still want to know what will happen to staged files - there is another command:

git status --short | grep '^[MARCD]'

which leads to something like:

M  dir/modified_file
A  dir/new_file
R  dir/renamed -> dir/renamed_to
C  dir/copied_file
D  dir/deleted_file

Obviously, this files were staged, and after git commit:
deleted_file will be deleted,
new_file will be added,
renamed_file will become a renamed_to.

Here is an explanation of short-format output: https://git-scm.com/docs/git-status#_short_format