Used to detect a forbidden pattern that you don't want to commit

pre-commit

FILES_PATTERN='\.(js|coffee)(\..+)?$'
FORBIDDEN='console.log'
git diff --cached --name-only | \
    grep -E $FILES_PATTERN | \
    GREP_COLOR='4;5;37;41' xargs grep --color --with-filename -n $FORBIDDEN && echo "COMMIT REJECTED. Found $FORBIDDEN references. Please remove them before commiting" && exit 1