# Copyright (c) 2014 Google Inc. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""
TestWin.py: a collection of helpers
for testing on Windows.
"""
import errno
import os
import re
import sys
import subprocess
class Registry(object):
def _QueryBase(self, sysdir, key, value):
"""Use reg.exe to read a particular key.
While ideally we might use the win32 module, we would like gyp to be
python neutral, so
for instance cygwin python lacks this module.
Arguments:
sysdir: The system subdirectory to attempt to launch reg.exe
from.
key: The registry key to read
from.
value: The particular value to read.
Return:
stdout
from reg.exe,
or None for failure.
"""
# Skip if not on Windows or Python Win32 setup issue
if sys.platform
not in (
'win32',
'cygwin'):
return None
# Setup params to pass to and attempt to launch reg.exe
cmd = [os.path.join(os.environ.get(
'WINDIR',
''), sysdir,
'reg.exe'),
'query', key]
if value:
cmd.extend([
'/v', value])
p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
# Get the stdout from reg.exe, reading to the end so p.returncode is valid
# Note that the error text may be in [1] in some cases
text = p.communicate()[0].decode(
'utf-8',
'ignore')
# Check return code from reg.exe; officially 0==success and 1==error
if p.returncode:
return None
return text
def Query(self, key, value=
None):
r
"""Use reg.exe to read a particular key through _QueryBase.
First tries to launch
from %WinDir%\Sysnative to avoid WoW64 redirection.
If
that fails, it falls back to System32. Sysnative
is available on Vista
and
up
and available on Windows Server 2003
and XP through KB patch 942589. Note
that Sysnative will always fail
if using 64-bit python due to it being a
virtual directory
and System32 will work correctly
in the first place.
KB 942589 -
http://support.microsoft.com/kb/942589/en-us.
Arguments:
key: The registry key.
value: The particular registry value to read (optional).
Return:
stdout
from reg.exe,
or None for failure.
"""
text =
None
try:
text = self._QueryBase(
'Sysnative', key, value)
except OSError
as e:
if e.errno == errno.ENOENT:
text = self._QueryBase(
'System32', key, value)
else:
raise
return text
def GetValue(self, key, value):
"""Use reg.exe to obtain the value of a registry key.
Args:
key: The registry key.
value: The particular registry value to read.
Return:
contents of the registry key
's value, or None on failure.
"""
text = self.Query(key, value)
if not text:
return None
# Extract value.
match = re.search(r
'REG_\w+\s+([^\r]+)\r\n', text)
if not match:
return None
return match.group(1)
def KeyExists(self, key):
"""Use reg.exe to see if a key exists.
Args:
key: The registry key to check.
Return:
True if the key exists
"""
if not self.Query(key):
return False
return True
