In Mercurial I can do this with the bundled Purge Extension and executing the following command:
Also good to get rid of ignored files:
hg purge --all
I'm curious about the most practical/used equivalent solution in git.
Edit: I want to just get rid of the untracked files, not reset everything (e.g. suppose I have a program generating cache files or generated code and I want to delete them with git's help)