Difference between `git rm --cached` and `git upda

Question

I do not understand the difference between git rm --cached and git update-index --assume-unchanged.

I'm aware that git rm --cached <file> will remove a file from the staging area.

And, I know that git update-index --assume-unchanged <file> also does this.

I've also seen both commands offered as suggestions to similar questions here on SO.

Is there another affect of either of these two commands that makes them different?

Answer 1

The command

git rm --cached <file>

is used to untrack files in a Git branch. This command will remove the file from the staging area and also will remove the file from the repository next time you commit.

The command

git update-index --assume-unchanged <file>

will also make the file disappear from the staging area. However, this command is different because it tells Git to only temporarily ignore any changes made to the file. So when you commit the file it will remain a part of the repository assuming it were already there. When you want Git to see the changes made to the file again, you can run this:

git update-index --no-assume-unchanged <file>

This will return the file to the staging area, if it were there when you ran assume-unchanged earlier.

Here is a link for git rm --cached, and here is a link for git update-index --assume-unchanged.