| #!/usr/bin/env python | 
 | # Copyright 2013 The Chromium Authors | 
 | # Use of this source code is governed by a BSD-style license that can be | 
 | # found in the LICENSE file. | 
 |  | 
 | """Chrome Version Tool | 
 |  | 
 | Scrapes Chrome channel information and prints out the requested nugget of | 
 | information. | 
 | """ | 
 |  | 
 | from __future__ import print_function | 
 |  | 
 | import json | 
 | import optparse | 
 | import os | 
 | import string | 
 | import sys | 
 | import urllib | 
 |  | 
 | URL = 'https://omahaproxy.appspot.com/json' | 
 |  | 
 |  | 
 | def main(): | 
 |   try: | 
 |     data = json.load(urllib.urlopen(URL)) | 
 |   except Exception as e: | 
 |     print('Error: could not load %s\n\n%s' % (URL, str(e))) | 
 |     return 1 | 
 |  | 
 |   # Iterate to find out valid values for OS, channel, and field options. | 
 |   oses = set() | 
 |   channels = set() | 
 |   fields = set() | 
 |  | 
 |   for os_versions in data: | 
 |     oses.add(os_versions['os']) | 
 |  | 
 |     for version in os_versions['versions']: | 
 |       for field in version: | 
 |         if field == 'channel': | 
 |           channels.add(version['channel']) | 
 |         else: | 
 |           fields.add(field) | 
 |  | 
 |   oses = sorted(oses) | 
 |   channels = sorted(channels) | 
 |   fields = sorted(fields) | 
 |  | 
 |   # Command line parsing fun begins! | 
 |   usage = ('%prog [options]\n' | 
 |            'Print out information about a particular Chrome channel.') | 
 |   parser = optparse.OptionParser(usage=usage) | 
 |  | 
 |   parser.add_option('-o', '--os', | 
 |                     choices=oses, | 
 |                     default='win', | 
 |                     help='The operating system of interest: %s ' | 
 |                          '[default: %%default]' % ', '.join(oses)) | 
 |   parser.add_option('-c', '--channel', | 
 |                     choices=channels, | 
 |                     default='stable', | 
 |                     help='The channel of interest: %s ' | 
 |                          '[default: %%default]' % ', '.join(channels)) | 
 |   parser.add_option('-f', '--field', | 
 |                     choices=fields, | 
 |                     default='version', | 
 |                     help='The field of interest: %s ' | 
 |                          '[default: %%default] ' % ', '.join(fields)) | 
 |   (opts, args) = parser.parse_args() | 
 |  | 
 |   # Print out requested data if available. | 
 |   for os_versions in data: | 
 |     if os_versions['os'] != opts.os: | 
 |       continue | 
 |  | 
 |     for version in os_versions['versions']: | 
 |       if version['channel'] != opts.channel: | 
 |         continue | 
 |  | 
 |       if opts.field not in version: | 
 |         continue | 
 |  | 
 |       print(version[opts.field]) | 
 |       return 0 | 
 |  | 
 |   print('Error: unable to find %s for Chrome %s %s.' % (opts.field, opts.os, | 
 |                                                         opts.channel)) | 
 |   return 1 | 
 |  | 
 | if __name__ == '__main__': | 
 |   sys.exit(main()) |