bash script to prepare release with git

release.sh

#!/bin/bash

CHANGELOG_FILENAME="CHANGELOG.rst"

LASTTAG=$(git tag| sort -V | tail -1)
echo "Last tag $LASTTAG"

TMPFILE=$(mktemp)
TODAY=$(date +%Y-%m-%d)

read -p "new tag : " NEWTAG

TAG_TITLE="$NEWTAG ($TODAY)"
TAG_TITLE_LENGTH=${#TAG_TITLE}

# file title
head  -n 3 $CHANGELOG_FILENAME >> $TMPFILE

# version title
echo $TAG_TITLE >> $TMPFILE
printf '=%.0s' `seq 1 $TAG_TITLE_LENGTH` >> $TMPFILE # print '-' x $TAG_TITLE_LENGTH
echo -e "\n" >> $TMPFILE

# list of commit started with '-'
git log $LASTTAG..HEAD --pretty=format:"%h %s (%an)"  | sed 's/^/- /' >> $TMPFILE
echo  >> $TMPFILE

# add history file (without title document)
tail -n +3 $CHANGELOG_FILENAME >> $TMPFILE # remove 3 first line

cp $TMPFILE $CHANGELOG_FILENAME
rm $TMPFILE

git diff

read -p "edit change log ? [YN]: " yn

case $yn in
        [Yy]* ) vim $CHANGELOG_FILENAME ;;

esac

git add $CHANGELOG_FILENAME

sed -i "s/$LASTTAG/$NEWTAG/g" app/config/version.yml
git add app/config/version.yml

git diff

read -p "commit & tag ? [YN]: " yn

case $yn in
        [Yy]* ) git add app/config/version ; git commit -m"version $NEWTAG" ; git tag $NEWTAG ;;
        [Nn]* ) exit;;
        * ) echo "Please answer yes or no.";;
esac