[Git] Ignore change of a file that is in an index

There is a command git update-index --assume-unchanged <file> for ignore.
And there is a command git update-index --no-assume-unchanged <file> for unignore.

For listing assume-unchanged files use git ls-files -v and see lower h in front of file name.
You can combine this with grep "h ". And you can also use git ls-files -v if you are interesting only a file.