我有一个Windows
python3.7
功能,使用kernel32.dll
成功调用GetSystemPowerStatus
ctypes
功能来查询电源状态,看看我的笔记本电脑是使用交流还是电池供电。这是一个纯粹的python解决方案。
我想将此功能移植到cygwin
python3.7
。开箱即用,python3
的cygwin
的ctypes
似乎不允许调用windows dll。我更喜欢纯python解决方案,但如果需要我可以使用C / C ++。有没有人有如何做到这一点的例子?
编辑添加代码(第63-67行)和错误消息:
elif _os.name == 'posix' and _sys.platform == 'cygwin':
# c:\Windows\System32\kernel32.dll
kernel32_name = '/proc/cygdrive/c/Windows/System32/kernel32.dll'
kernel32 = CDLL(kernel32_name)
_GetSystemPowerStatus = kernel32.GetSystemPowerStatus
$ python3.7 GetSystemPowerStatus.py
Traceback (most recent call last):
File "GetSystemPowerStatus.py", line 82, in <module>
result, systemPowerStatus = GetSystemPowerStatus()
File "GetSystemPowerStatus.py", line 66, in GetSystemPowerStatus
kernel32 = CDLL(kernel32_name)
File "/usr/lib/python3.7/ctypes/__init__.py", line 356, in __init__
self._handle = _dlopen(self._name, mode)
OSError: Invalid argument
python2.7给出了相同的错误,但是在第366行。
解决了。请看下面我自己的答案。
因为你我无法得到kernel32.dll
(虽然它适用于其他DLL,如user32
,msvcrt
,kernelbase
等)
我找到了一种非常人为的方法......它使用kernelbase.dll(导出GetModuleHandle
)获取kernel32.dll
的句柄,然后使用handle可选关键字调用CDLL
:
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import sys
import ctypes
def main():
# the idea is to load kernelbase.dll which will allow us to call GetModuleHandleW() on kernel32.dll
try:
kernel_base = ctypes.CDLL("/cygdrive/c/windows/system32/kernelbase.dll")
except OSError:
print("Can't load kernelbase.dll...")
return -1
gmhw = kernel_base.GetModuleHandleW
gmhw.argtypes = (ctypes.c_wchar_p, )
gmhw.restype = ctypes.c_void_p
# call GetModuleHandleW on kernel32.dll (which is loaded by default in the Python process)
kernel32_base_addr = gmhw("kernel32.dll")
print(f"Got kernel32 base address: {kernel32_base_addr:#x}")
# now call CDLL with optional arguments
kernel32 = ctypes.CDLL("/cygdrive/c/windows/system32/kernel32.dll", handle=kernel32_base_addr, use_last_error=True)
# test with GetSystemPowerStatus
print(f"GetSystemPowerStatus: {kernel32.GetSystemPowerStatus}")
return 0
if __name__ == "__main__":
sys.exit(main())
在发现我可以轻松加载user32.dll
后,我对源和pdb
和ldd
做了一些调查。以下是我的解决方案。
elif _os.name == 'posix' and _sys.platform == 'cygwin':
RTLD_LOCAL = 0 # from /usr/include/dlfcn.h
RTLD_LAZY = 1
RTLD_NOW = 2
RTLD_GLOBAL = 4
RTLD_NODELETE = 8
RTLD_NOLOAD = 16
RTLD_DEEPBIND = 32
kernel32_name = '/proc/cygdrive/c/Windows/System32/kernel32.dll'
kernel32 = CDLL(kernel32_name, mode=RTLD_LAZY | RTLD_NOLOAD)
_GetSystemPowerStatus = kernel32.GetSystemPowerStatus
调用该函数的常用代码是:
_GetSystemPowerStatus.restype = c_bool
_GetSystemPowerStatus.argtypes = [c_void_p,]
_systemPowerStatus = _SystemPowerStatus() # not shown, see ctypes module doc
result = _GetSystemPowerStatus(byref(_systemPowerStatus))
return result, SystemPowerStatus(_systemPowerStatus)
这适用于Python 2.7,3.6和3.6
$ uname -a
CYGWIN_NT-10.0 host 3.0.1(0.338/5/3) 2019-02-20 10:19 x86_64 Cygwin
感谢所有人的帮助。