Git hook parsing a branch name to get jira number and putting into message

prepare-commit-msg

#!/bin/bash

MSG_FILE=$1
branch_name=`git rev-parse --abbrev-ref HEAD`

issue_id=`echo ${branch_name} | grep -o "[0-9]\{4\}"`
# message=`echo ${branch_name} | sed -e 's/[-_]/ /g' -e 's/[0-9]\{4\}//g' -e 's/^[ \t]*//;s/[ \t]*$//'`

# remove all the strings between square brackets
sed -e "s/\[[^]]*]//g" -e 's/^[ \t]*//;s/[ \t]*$//' -i '' $MSG_FILE

if ! [[ -z ${issue_id} ]]; then
  sed -e "1s/./[${issue_id}] &/" -i '' $MSG_FILE
fi

Put it into .git/hooks and make executable with chmod a+x .git/hooks/prepare-commit-msg