text: #!/usr/bin/env python3
  # 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.
  """Prints the lowest locally available SDK version greater than or equal to a
  given minimum sdk version to standard output.
  
  Usage:
    python3 find_sdk.py 10.6  # Ignores SDKs < 10.6
  """
  
  import os
  import re
  import subprocess
  import sys
  
  from optparse import OptionParser
  
  
  # sdk/build/xcode_links
  ROOT_SRC_DIR = os.path.join(
      os.path.dirname(
          os.path.dirname(os.path.dirname(os.path.realpath(__file__)))))
  
  
  def CreateSymlinkForSDKAt(src, dst):
      """
      Create symlink to Xcode directory at target location, which can be absolute or
      relative to `ROOT_SRC_DIR`.
      """
  
      # If `dst` is relative, it is assumed to be relative to src root.
      if not os.path.isabs(dst):
          dst = os.path.join(ROOT_SRC_DIR, dst)
  
      if not os.path.isdir(dst):
          os.makedirs(dst)
  
      dst = os.path.join(dst, os.path.basename(src))
  
      # Update the symlink if exists.
      if os.path.islink(dst):
          current_src = os.readlink(dst)
          if current_src == src:
              return dst
  
          os.unlink(dst)
          sys.stderr.write('existing symlink %s points %s; want %s. Removed.' %
                           (dst, current_src, src))
  
      os.symlink(src, dst)
      return dst
  
  
  def parse_version(version_str):
      """'10.6' => [10, 6]"""
      return list(map(int, re.findall(r'(\d+)', version_str)))
  
  
  def main():
      parser = OptionParser()
      parser.add_option(
          "--verify",
          action="store_true",
          dest="verify",
          default=False,
          help="return the sdk argument and warn if it doesn't exist")
      parser.add_option(
          "--sdk_path",
          action="store",
          type="string",
          dest="sdk_path",
          default="",
          help="user-specified SDK path; bypasses verification")
      parser.add_option(
          "--print_sdk_path",
          action="store_true",
          dest="print_sdk_path",
          default=False,
          help="Additionaly print the path the SDK (appears first).")
      parser.add_option(
          "--create_symlink_at",
          action="store",
          dest="create_symlink_at",
          help=
          "Create symlink to SDK at given location and return symlink path as SDK "
          "info instead of the original location.")
      (options, args) = parser.parse_args()
      min_sdk_version = args[0]
  
      job = subprocess.Popen(['xcode-select', '-print-path'],
                             stdout=subprocess.PIPE,
                             stderr=subprocess.STDOUT,
                             universal_newlines=True)
      out, err = job.communicate()
      if job.returncode != 0:
          print(out, file=sys.stderr)
          print(err, file=sys.stderr)
          raise Exception((
              'Error %d running xcode-select, you might have to run '
              '|sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer| '
              'if you are using Xcode 4.') % job.returncode)
      # The Developer folder moved in Xcode 4.3.
      xcode43_sdk_path = os.path.join(out.rstrip(),
                                      'Platforms/MacOSX.platform/Developer/SDKs')
      if os.path.isdir(xcode43_sdk_path):
          sdk_dir = xcode43_sdk_path
      else:
          sdk_dir = os.path.join(out.rstrip(), 'SDKs')
      sdks = [
          re.findall('^MacOSX(1[01]\.\d+)\.sdk$', s) for s in os.listdir(sdk_dir)
      ]
      sdks = [s[0] for s in sdks if s]  # [['10.5'], ['10.6']] => ['10.5', '10.6']
      sdks = [
          s for s in sdks  # ['10.5', '10.6'] => ['10.6']
          if parse_version(s) >= parse_version(min_sdk_version)
      ]
      if not sdks:
          raise Exception('No %s+ SDK found' % min_sdk_version)
      best_sdk = sorted(sdks, key=parse_version)[0]
  
      if options.verify and best_sdk != min_sdk_version and not options.sdk_path:
          print('''
                                             vvvvvvv
  
  This build requires the %s SDK, but it was not found on your system.
  
  Either install it, or explicitly set mac_sdk in your GYP_DEFINES.
  
                                             ^^^^^^^'
  ''' % min_sdk_version,
                file=sys.stderr)
          return min_sdk_version
  
      if options.print_sdk_path:
          sdk_path = subprocess.check_output(
              ['xcodebuild', '-version', '-sdk', 'macosx' + best_sdk, 'Path'],
              universal_newlines=True).strip()
          if options.create_symlink_at:
              print(CreateSymlinkForSDKAt(sdk_path, options.create_symlink_at))
          else:
              print(sdk_path)
  
      return best_sdk
  
  
  if __name__ == '__main__':
      if sys.platform != 'darwin':
          raise Exception("This script only runs on Mac")
      print(main())
  