old_contents: from . import diff
  
  import argparse
  
  
  def format_option(opt):
      """Return a formatted option in the form name=value."""
      return '{}={}\n'.format(opt.option, opt.value)
  
  
  def format_output(first, second):
      """Return a string showing the differences between two ini strings."""
      diffs = diff(first, second)
  
      out = ''
      for d in diffs:
          if d.first.value is not None:
              out += '-' + format_option(d.first)
          if d.second.value is not None:
              out += '+' + format_option(d.second)
  
      return out
  
  
  def main():
      """Run the main CLI."""
      parser = argparse.ArgumentParser()
      parser.add_argument('first')
      parser.add_argument('second')
      args = parser.parse_args()
  
      print(format_output(args.first, args.second))
  
new_contents: from __future__ import print_function
  
  from . import diff
  
  import argparse
  
  
  def format_option(opt):
      """Return a formatted option in the form name=value."""
      return '{}={}\n'.format(opt.option, opt.value)
  
  
  def format_output(first, second):
      """Return a string showing the differences between two ini strings."""
      diffs = diff(first, second)
  
      out = ''
      for d in diffs:
          if d.first.value is not None:
              out += '-' + format_option(d.first)
          if d.second.value is not None:
              out += '+' + format_option(d.second)
  
      return out
  
  
  def main():
      """Run the main CLI."""
      parser = argparse.ArgumentParser()
      parser.add_argument('first', type=argparse.FileType('r'))
      parser.add_argument('second', type=argparse.FileType('r'))
      args = parser.parse_args()
  
      first = args.first.read()
      second = args.second.read()
  
      print(format_output(first, second), end='')
  
subject: Add file reading