How to automatically prepend git commit with a branch name

prepare-commit-msg.sh

#!/bin/bash

# per @madeindjs's suggestion:
# For a quick install, into your project folder enter this command line:
#
#     curl https://gist.githubusercontent.com/thealexbaron/fd2a390dc6f8958d1b1ffe8b66b676bb/raw/5f5ed22c281a8488116a41e4496075f8b28d106a/prepare-commit-msg.sh > .git/hooks/prepare-commit-msg && chmod u+x .git/hooks/prepare-commit-msg
#
# which does: 
# - get Gist
# - copy into .git/hooks/prepare-commit-msg file
# - make it executable
#

# forked from https://gist.github.com/bartoszmajsak/1396344/97081e76ab275f5fe526347908503febd1340495

# This way you can customize which branches should be skipped when
# prepending commit message. 
if [ -z "$BRANCHES_TO_SKIP" ]; then
  BRANCHES_TO_SKIP=(master dev ec_rc ec_master)
fi

BRANCH_NAME=$(git symbolic-ref --short HEAD)
BRANCH_NAME="${BRANCH_NAME##*/}"

BRANCH_EXCLUDED=$(printf "%s\n" "${BRANCHES_TO_SKIP[@]}" | grep -c "^$BRANCH_NAME$")
BRANCH_IN_COMMIT=$(grep -c "\[$BRANCH_NAME\]" $1)

if [ -n "$BRANCH_NAME" ] && ! [[ $BRANCH_EXCLUDED -eq 1 ]] && ! [[ $BRANCH_IN_COMMIT -ge 1 ]]; then 
  sed -i.bak -e "1s/^/$BRANCH_NAME: /" $1
fi