#!/usr/bin/env python
from ConfigParser import RawConfigParser as Parser
from ConfigParser import MissingSectionHeaderError
from StringIO import StringIO
import sys

def main(source_ini, update_ini):
    parser = Parser()
    # parser.read() will "fail" silently if the file is
    # not found; use open() and parser.readfp() to fail
    # on missing (or unreadable, etc.) file
    parser.readfp(open(source_ini))
    with open(update_ini) as f:
        updates = f.read()
    try:
        # Existing *.update files don't include section
        # headers; inject a [DEFAULT] header if the parsing
        # fails
        parser.readfp(StringIO(updates))
    except MissingSectionHeaderError:
        updates = "[DEFAULT]\n" + updates
        parser.readfp(StringIO(updates))
    parser.write(sys.stdout)

if __name__ == '__main__':
    args = sys.argv
    if len(args) != 3:
        print 'usage: %s [source] [update]' % sys.argv[0]
        sys.exit(1)
    else:
        main(sys.argv[1], sys.argv[2])