[NaCl SDK] Convert python scripts from optparse to argparse.

native_client_sdk/src/tools/getos.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 """Determine OS and various other system properties.
 
 Determine the name of the platform used and other system properties such as
 the location of Chrome.  This is used, for example, to determine the correct
 Toolchain to invoke.
 """
 
-import optparse
+import argparse
 import os
 import re
 import subprocess
 import sys
 
 import oshelpers
 
 
 SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
 CHROME_DEFAULT_PATH = {
@@ skipping 185 matching lines @@
   Raises:
     Error: The SDK version is older than required_version.
   """
   version = GetSDKVersion()[:2]
   if version < required_version:
     raise Error("SDK version too old (current: %d.%d, required: %d.%d)"
            % (version[0], version[1], required_version[0], required_version[1]))
 
 
 def main(args):
-  parser = optparse.OptionParser()
-  parser.add_option('--arch', action='store_true',
+  parser = argparse.ArgumentParser()
+  parser.add_argument('--arch', action='store_true',
       help='Print architecture of current machine (x86_32, x86_64 or arm).')
-  parser.add_option('--chrome', action='store_true',
+  parser.add_argument('--chrome', action='store_true',
       help='Print the path chrome (by first looking in $CHROME_PATH and '
            'then $PATH).')
-  parser.add_option('--nacl-arch', action='store_true',
+  parser.add_argument('--nacl-arch', action='store_true',
       help='Print architecture used by NaCl on the current machine.')
-  parser.add_option('--sdk-version', action='store_true',
+  parser.add_argument('--sdk-version', action='store_true',
       help='Print major version of the NaCl SDK.')
-  parser.add_option('--sdk-revision', action='store_true',
+  parser.add_argument('--sdk-revision', action='store_true',
       help='Print revision number of the NaCl SDK.')
-  parser.add_option('--sdk-commit-position', action='store_true',
+  parser.add_argument('--sdk-commit-position', action='store_true',
       help='Print commit position of the NaCl SDK.')
-  parser.add_option('--check-version',
+  parser.add_argument('--check-version',
       metavar='MAJOR.POSITION',
       help='Check that the SDK version is at least as great as the '
            'version passed in. MAJOR is the major version number and POSITION '
            'is the Cr-Commit-Position number.')
 
-  options, _ = parser.parse_args(args)
+  if len(args) > 1:
+    parser.error('Only one option can be specified at a time.')
+
+  options = parser.parse_args(args)
 
   platform = GetPlatform()
 
-  if len(args) > 1:
-    parser.error('Only one option can be specified at a time.')
-
-  if not args:
-    print platform
-    return 0
-
   if options.arch:
     out = GetSystemArch(platform)
   elif options.nacl_arch:
     out = GetNaClArch(platform)
   elif options.chrome:
     out = GetChromePath(platform)
   elif options.sdk_version:
     out = GetSDKVersion()[0]
   elif options.sdk_revision:
     out = GetSDKVersion()[1]
   elif options.sdk_commit_position:
     out = GetSDKVersion()[2]
   elif options.check_version:
     required_version = ParseVersion(options.check_version)
     CheckVersion(required_version)
     out = None
+  else:
+    out = platform
 
   if out:
     print out
   return 0
 
 
 if __name__ == '__main__':
   try:
     sys.exit(main(sys.argv[1:]))
   except Error as e:
     sys.stderr.write(str(e) + '\n')
     sys.exit(1)