Eryk Sun added the comment: Kelvin is calling WlanScan [1], which returns an error code that apparently can include HRESULT (signed) values cast as DWORD (unsigned) values, including 0x80342002 (ERROR_NDIS_DOT11_POWER_STATE_INVALID).
ctypes.FormatError calls FormatMessage [2] with the flag FORMAT_MESSAGE_FROM_SYSTEM. About half of the system error codes defined in winerror.h consist of COM HRESULT codes. But, to clarify Kelvin's link [3], this does not include NTSTATUS values from kernel-mode system calls. NTSTATUS values require the ntdll.dll message table. [1]: https://msdn.microsoft.com/en-us/library/ms706783 [2]: https://msdn.microsoft.com/en-us/library/ms679351 [3]: https://msdn.microsoft.com/en-us/library/cc231196 A workaround in this case is to use the default c_int restype to return the error as a signed integer: >>> ctypes.FormatError(0x80342002 - 2**32) "The wireless local area network interface is powered down and doesn't support the requested operation." A similar workaround works for setting the exit code to an HRESULT or NTSTATUS error code: >>> hex(subprocess.call('python -c "import os; os._exit(0xC0000001)"')) Traceback (most recent call last): File "<string>", line 1, in <module> OverflowError: Python int too large to convert to C long '0x1' >>> hex(subprocess.call('python -c "import sys; sys.exit(0xC0000001)"')) '0xffffffff' >>> hex(subprocess.call('python -c "import os; os._exit(0xC0000001 - 2**32)"')) '0xc0000001' >>> hex(subprocess.call('python -c "import sys; sys.exit(0xC0000001 - 2**32)"')) '0xc0000001' ---------- nosy: +eryksun _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue28474> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
