How to ignore files in Git after being modified

This is useful when the .gitignore doesn't work as expected.

To ignore the change use:

$ git update-index --assume-unchanged /path/to/file

To revert the ignore attribute:

$ git update-index --no-assume-unchanged /path/to/file

So, this alias could be useful for your .gitconfig:

    hide = update-index --assume-unchanged
    unhide = update-index --no-assume-unchanged

Or adding the alias using:

$ git config --global alias.hide 'update-index --assume-unchanged'
$ git config --global alias.unhide 'update-index --no-assume-unchanged'

And use it:

$ git hide myfile.ext
$ git unhide myfile.ext