git hook for added branch name to commit message

prepare-commit-msg

#!/bin/sh
PROJECT_NAME="PROJECT_NAME"
COMMIT_MSG=$1
IS_EXISTS=$(cat $COMMIT_MSG |grep -i "$PROJECT_NAME"|wc -l)
FULL_BRANCH_NAME=$(git branch | grep '*' | sed 's/* //')
BRANCH_NAME=${FULL_BRANCH_NAME##*/}

addBranchName() {
        echo "$BRANCH_NAME" "$(cat $COMMIT_MSG)" > $COMMIT_MSG
}

if [[ $BRANCH_NAME == *$PROJECT_NAME* ]]; then
        if [ $IS_EXISTS -eq 0 ] ; then
                addBranchName
        fi
fi