通过subprocess.check_output调用的可执行文件会在控制台上打印，但不会返回结果

------- ------- ------- /printing result ------- ------- ------- subprocess.check_output命令本身以某种方式将预期的输出打印到控制台，它返回的仅包含在@echo再次打开后的批处理文件的输出.The subprocess.check_output command itself somehow prints the intended output to the console, what it returns only contains the batch file's outputs after @echo is on again. 如何访问可执行文件的输出并将其保存到字符串中以进行进一步的工作? 还是我必须以某种方式修改批处理文件以捕获并打印输出，以使它最终出现在check_output的结果中?如果是这样，我该怎么做呢?Or do I have to somehow modify the batch file to catch and print the output, so that it will end upt in check_output's results? If so, how could I go about doing that?推荐答案如果程序直接写入控制台(例如，通过打开CONOUT$设备)而不是写入过程标准句柄，则唯一的选择是读取控制台屏幕缓冲区直接.为了简化此过程，请从新的空白屏幕缓冲区开始.通过以下功能创建，调整大小，初始化和激活新的屏幕缓冲区:If a program writes directly to the console (e.g. by opening the CONOUT$ device) instead of to the process standard handles, the only option is to read the console screen buffer directly. To make this simpler, start with a new, empty screen buffer. Create, size, initialize, and activate a new screen buffer via the following functions: CreateConsoleScreenBuffer GetConsoleScreenBufferInfoEx (支持的最低客户端:Windows Vista) SetConsoleScreenBufferInfoEx (支持的最低客户端:Windows Vista) SetConsoleWindowInfo FillConsoleOutputCharacter SetConsoleActiveScreenBuffer CreateConsoleScreenBufferGetConsoleScreenBufferInfoEx (Minimum supported client: Windows Vista)SetConsoleScreenBufferInfoEx (Minimum supported client: Windows Vista)SetConsoleWindowInfoFillConsoleOutputCharacterSetConsoleActiveScreenBuffer确保在调用CreateConsoleScreenBuffer时请求访问GENERIC_READ | GENERIC_WRITE.您稍后需要读取权限才能读取屏幕内容. Make sure to request GENERIC_READ | GENERIC_WRITE access when calling CreateConsoleScreenBuffer. You'll need read access later in order to read the contents of the screen. 专门针对Python，请使用 ctypes 来调用Windows控制台API中的函数.同样，如果通过msvcrt.open_osfhandle用C文件描述符包装句柄，则可以将其作为subprocess.Popen的stdout或stderr参数传递. Specifically for Python, use ctypes to call functions in the Windows console API. Also, if you wrap the handle with a C file descriptor via msvcrt.open_osfhandle, then you can pass it as the stdout or stderr argument of subprocess.Popen. 无法直接通过read，ReadFile甚至ReadConsole读取屏幕缓冲区的文件描述符或句柄.如果您有文件描述符，请通过msvcrt.get_osfhandle获取基础句柄.给定屏幕缓冲区句柄，请调用 ReadConsoleOutputCharacter 以从屏幕中读取内容.下面的示例代码中的read_screen函数演示了从屏幕缓冲区的开始到光标位置的读取.The file descriptor or handle for the screen buffer can't be read directly via read, ReadFile, or even ReadConsole. If you have a file descriptor, get the underlying handle via msvcrt.get_osfhandle. Given a screen buffer handle, call ReadConsoleOutputCharacter to read from the screen. The read_screen function in the sample code below demonstrates reading from the beginning of the screen buffer up to the cursor position.一个过程需要附加到控制台上才能使用控制台API.为此，我提供了一个简单的allocate_console上下文管理器来临时打开控制台.这在GUI应用程序中很有用，而GUI应用程序通常不附加在控制台上.A process needs to be attached to a console in order to use the console API. To that end, I've included a simple allocate_console context manager to temporarily open a console. This is useful in a GUI application, which normally isn't attached to a console.以下示例已在Windows 7和10，Python 2.7和3.5中进行了测试.The following example was tested in Windows 7 and 10, in Python 2.7 and 3.5.import osimport contextlibimport msvcrtimport ctypesfrom ctypes import wintypeskernel32 = ctypes.WinDLL('kernel32', use_last_error=True)GENERIC_READ = 0x80000000GENERIC_WRITE = 0x40000000FILE_SHARE_READ = 1FILE_SHARE_WRITE = 2CONSOLE_TEXTMODE_BUFFER = 1INVALID_HANDLE_VALUE = wintypes.HANDLE(-1).valueSTD_OUTPUT_HANDLE = wintypes.DWORD(-11)STD_ERROR_HANDLE = wintypes.DWORD(-12)def _check_zero(result, func, args): if not result: raise ctypes.WinError(ctypes.get_last_error()) return argsdef _check_invalid(result, func, args): if result == INVALID_HANDLE_VALUE: raise ctypes.WinError(ctypes.get_last_error()) return argsif not hasattr(wintypes, 'LPDWORD'): # Python 2 wintypes.LPDWORD = ctypes.POINTER(wintypes.DWORD) wintypes.PSMALL_RECT = ctypes.POINTER(wintypes.SMALL_RECT)class COORD(ctypes.Structure): _fields_ = (('X', wintypes.SHORT), ('Y', wintypes.SHORT))class CONSOLE_SCREEN_BUFFER_INFOEX(ctypes.Structure): _fields_ = (('cbSize', wintypes.ULONG), ('dwSize', COORD), ('dwCursorPosition', COORD), ('wAttributes', wintypes.WORD), ('srWindow', wintypes.SMALL_RECT), ('dwMaximumWindowSize', COORD), ('wPopupAttributes', wintypes.WORD), ('bFullscreenSupported', wintypes.BOOL), ('ColorTable', wintypes.DWORD * 16)) def __init__(self, *args, **kwds): super(CONSOLE_SCREEN_BUFFER_INFOEX, self).__init__( *args, **kwds) self.cbSize = ctypes.sizeof(self)PCONSOLE_SCREEN_BUFFER_INFOEX = ctypes.POINTER( CONSOLE_SCREEN_BUFFER_INFOEX)LPSECURITY_ATTRIBUTES = wintypes.LPVOIDkernel32.GetStdHandle.errcheck = _check_invalidkernel32.GetStdHandle.restype = wintypes.HANDLEkernel32.GetStdHandle.argtypes = ( wintypes.DWORD,) # _In_ nStdHandlekernel32.CreateConsoleScreenBuffer.errcheck = _check_invalidkernel32.CreateConsoleScreenBuffer.restype = wintypes.HANDLEkernel32.CreateConsoleScreenBuffer.argtypes = ( wintypes.DWORD, # _In_ dwDesiredAccess wintypes.DWORD, # _In_ dwShareMode LPSECURITY_ATTRIBUTES, # _In_opt_ lpSecurityAttributes wintypes.DWORD, # _In_ dwFlags wintypes.LPVOID) # _Reserved_ lpScreenBufferDatakernel32.GetConsoleScreenBufferInfoEx.errcheck = _check_zerokernel32.GetConsoleScreenBufferInfoEx.argtypes = ( wintypes.HANDLE, # _In_ hConsoleOutput PCONSOLE_SCREEN_BUFFER_INFOEX) # _Out_ lpConsoleScreenBufferInfokernel32.SetConsoleScreenBufferInfoEx.errcheck = _check_zerokernel32.SetConsoleScreenBufferInfoEx.argtypes = ( wintypes.HANDLE, # _In_ hConsoleOutput PCONSOLE_SCREEN_BUFFER_INFOEX) # _In_ lpConsoleScreenBufferInfokernel32.SetConsoleWindowInfo.errcheck = _check_zerokernel32.SetConsoleWindowInfo.argtypes = ( wintypes.HANDLE, # _In_ hConsoleOutput wintypes.BOOL, # _In_ bAbsolute wintypes.PSMALL_RECT) # _In_ lpConsoleWindowkernel32.FillConsoleOutputCharacterW.errcheck = _check_zerokernel32.FillConsoleOutputCharacterW.argtypes = ( wintypes.HANDLE, # _In_ hConsoleOutput wintypes.WCHAR, # _In_ cCharacter wintypes.DWORD, # _In_ nLength COORD, # _In_ dwWriteCoord wintypes.LPDWORD) # _Out_ lpNumberOfCharsWrittenkernel32.ReadConsoleOutputCharacterW.errcheck = _check_zerokernel32.ReadConsoleOutputCharacterW.argtypes = ( wintypes.HANDLE, # _In_ hConsoleOutput wintypes.LPWSTR, # _Out_ lpCharacter wintypes.DWORD, # _In_ nLength COORD, # _In_ dwReadCoord wintypes.LPDWORD) # _Out_ lpNumberOfCharsRead功能@contextlib.contextmanagerdef allocate_console(): allocated = kernel32.AllocConsole() try: yield allocated finally: if allocated: kernel32.FreeConsole()@contextlib.contextmanagerdef console_screen(ncols=None, nrows=None): info = CONSOLE_SCREEN_BUFFER_INFOEX() new_info = CONSOLE_SCREEN_BUFFER_INFOEX() nwritten = (wintypes.DWORD * 1)() hStdOut = kernel32.GetStdHandle(STD_OUTPUT_HANDLE) kernel32.GetConsoleScreenBufferInfoEx( hStdOut, ctypes.byref(info)) if ncols is None: ncols = info.dwSize.X if nrows is None: nrows = info.dwSize.Y elif nrows > 9999: raise ValueError('nrows must be 9999 or less') fd_screen = None hScreen = kernel32.CreateConsoleScreenBuffer( GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, None, CONSOLE_TEXTMODE_BUFFER, None) try: fd_screen = msvcrt.open_osfhandle( hScreen, os.O_RDWR | os.O_BINARY) kernel32.GetConsoleScreenBufferInfoEx( hScreen, ctypes.byref(new_info)) new_info.dwSize = COORD(ncols, nrows) new_info.srWindow = wintypes.SMALL_RECT( Left=0, Top=0, Right=(ncols - 1), Bottom=(info.srWindow.Bottom - info.srWindow.Top)) kernel32.SetConsoleScreenBufferInfoEx( hScreen, ctypes.byref(new_info)) kernel32.SetConsoleWindowInfo(hScreen, True, ctypes.byref(new_info.srWindow)) kernel32.FillConsoleOutputCharacterW( hScreen, u'\0', ncols * nrows, COORD(0,0), nwritten) kernel32.SetConsoleActiveScreenBuffer(hScreen) try: yield fd_screen finally: kernel32.SetConsoleScreenBufferInfoEx( hStdOut, ctypes.byref(info)) kernel32.SetConsoleWindowInfo(hStdOut, True, ctypes.byref(info.srWindow)) kernel32.SetConsoleActiveScreenBuffer(hStdOut) finally: if fd_screen is not None: os.close(fd_screen) else: kernel32.CloseHandle(hScreen)def read_screen(fd): hScreen = msvcrt.get_osfhandle(fd) csbi = CONSOLE_SCREEN_BUFFER_INFOEX() kernel32.GetConsoleScreenBufferInfoEx( hScreen, ctypes.byref(csbi)) ncols = csbi.dwSize.X pos = csbi.dwCursorPosition length = ncols * pos.Y + pos.X + 1 buf = (ctypes.c_wchar * length)() n = (wintypes.DWORD * 1)() kernel32.ReadConsoleOutputCharacterW( hScreen, buf, length, COORD(0,0), n) lines = [buf[i:i+ncols].rstrip(u'\0') for i in range(0, n[0], ncols)] return u'\n'.join(lines)示例if __name__ == '__main__': import io import textwrap import subprocess text = textwrap.dedent('''\ Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.''') cmd = ("python -c \"" "print('piped output');" "conout = open(r'CONOUT$', 'w');" "conout.write('''%s''')\"" % text) with allocate_console() as allocated: with console_screen(nrows=1000) as fd_conout: stdout = subprocess.check_output(cmd).decode() conout = read_screen(fd_conout) with io.open('result.txt', 'w', encoding='utf-8') as f: f.write(u'stdout:\n' + stdout) f.write(u'\nconout:\n' + conout)输出stdout:piped outputconout:Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed doeiusmod tempor incididunt ut labore et dolore magna aliqua. Utenim ad minim veniam, quis nostrud exercitation ullamco laborisnisi ut aliquip ex ea commodo consequat. Duis aute irure dolorin reprehenderit in voluptate velit esse cillum dolore eufugiat nulla pariatur. Excepteur sint occaecat cupidatat nonproident, sunt in culpa qui officia deserunt mollit anim id estlaborum. 这篇关于通过subprocess.check_output调用的可执行文件会在控制台上打印，但不会返回结果的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！