text: #!/usr/bin/env python
  # Copyright 2014 The Chromium Authors. All rights reserved.
  # Use of this source code is governed by a BSD-style license that can be
  # found in the LICENSE file.
  
  import fnmatch
  import os
  import subprocess
  
  def commit(message, cwd=None):
    subprocess.call(['git', 'commit', '-a', '-m', message], cwd=cwd)
  
  def system(command, cwd=None):
    return subprocess.check_output(command, cwd=cwd)
  
  def find(patterns, start='.'):
    for path, dirs, files in os.walk(start):
      for basename in files + dirs:
        if any([fnmatch.fnmatch(basename, pattern) for pattern in patterns]):
          filename = os.path.join(path, basename)
          yield filename
  
  def filter_file(path, predicate):
    with open(path, 'r+') as f:
      lines = f.readlines()
      new_lines = [line for line in lines if predicate(line)]
      f.seek(0)
      f.truncate()
      f.write(''.join(new_lines))
  