automatically sign-off new commits

prepare-commit-msg

#!/bin/sh

# usage:
#   run command
#   $ cd your-repo
#   $ curl -Ls https://gist.githubusercontent.com/dixudx/7d7edea35b4d91e1a2a8fbf41d0954fa/raw/prepare-commit-msg -o .git/hooks/prepare-commit-msg
#   $ chmod +x .git/hooks/prepare-commit-msg

NAME=$(git config user.name)
EMAIL=$(git config user.email)

if [ -z "$NAME" ]; then
    echo "empty git config user.name"
    exit 1
fi

if [ -z "$EMAIL" ]; then
    echo "empty git config user.email"
    exit 1
fi

git interpret-trailers --if-exists doNothing --trailer \
    "Signed-off-by: $NAME <$EMAIL>" \
    --in-place "$1"