Update Index
git update-index --no-assume-unchanged path/to/file.txt
List files
git ls-tree -r --name-only master
git ls-tree --full-tree -r HEAD
Create a global .gitignore
git config --global core.excludesfile ~/.gitignore_global
Git force a pull to overwrite
git fetch origin master
git reset --hard FETCH_HEAD
git clean -df
Git ignore to remove cache
git rm -rf --cached .
git add .
Reset to previous origin head
git reset --hard ORIG_HEAD