git reset --hard
which is a synonym for "git reset --hard HEAD
" should be what you are looking for.
Use it with caution as it would effectively delete any current change in your working directory. See "Undoing in Git"
Note: as Charles Bailey mentions in the comment, and in his answer, this would not removed untracked files.
For that git clean is the right tool. See his answer for more, but also the SO question "How do you remove untracked files from your git working copy?", or the Git-Ready article "cleaning up untracked files".
So if we wanted to do a major cleanup:
$ git clean -n -d -x
That command would clean up files listed under the project’s .gitignore
file as well as removing other files and directories that aren’t necessary.
As always use precaution when running git clean, and make sure to double check what you’re really deleting.
Note, you might want to move your untracked files instead.