git_hook_prefix_commit_msg

gistfile1.txt

#!/usr/bin/env python
import sys, re
from subprocess import check_output

commit_msg_filepath = sys.argv[1]

branch = check_output(['git', 'symbolic-ref', '--short', 'HEAD']).strip()
regex = '(STRY.\d+)'
if re.search(regex, branch):
    issue = re.search(regex, branch).group()
    with open(commit_msg_filepath, 'r+') as fh:
        commit_msg = fh.read()
        fh.seek(0, 0)
        fh.write('[%s] %s' % (issue, commit_msg))