Git gives you the power to do just about everything. Unfortunately, it sometimes results in commands that look like this (I even broke it into lines for easier digestion): 

git filter-branch -d /tmp/tmpfs/git-filter --env-filter \
    "export GIT_AUTHOR_NAME='Dan McGee' GIT_AUTHOR_EMAIL='email@example.com' \
        GIT_COMMITTER_NAME='Dan McGee' GIT_COMMITTER_EMAIL='email@example.com'" \
    --index-filter "git rm --cached --ignore-unmatch miniterm.c" \
    --msg-filter "cat - && echo && echo 'Signed-off-by: Dan McGee <email@example.com>'" HEAD

I had been keeping a local git repository with this mini-project of mine, but hadn't really cared to keep the author correct on the commits, let alone have signoff lines. Because I wanted to get this out there to see if there was any interest, I wanted to clean up my repository a bit by fixing the author and committer, along with removing a file that really didn't need to be there. The above command performed the magic necessary to do this.