pythonwindowsconsoleprompt

How to enable Windows console QuickEdit Mode from python?


I'd like to force QuickEdit Mode in the console when running a python script and then disable it right before terminating. Is there a way to do that?


Solution

  • You can use ctypes to call GetConsoleMode and SetConsoleMode.

    ctypes definitions:

    import msvcrt
    import atexit
    import ctypes
    from ctypes import wintypes
    
    kernel32 = ctypes.WinDLL('kernel32', use_last_error=True)
    
    # input flags
    ENABLE_PROCESSED_INPUT = 0x0001
    ENABLE_LINE_INPUT      = 0x0002
    ENABLE_ECHO_INPUT      = 0x0004
    ENABLE_WINDOW_INPUT    = 0x0008
    ENABLE_MOUSE_INPUT     = 0x0010
    ENABLE_INSERT_MODE     = 0x0020
    ENABLE_QUICK_EDIT_MODE = 0x0040
    ENABLE_EXTENDED_FLAGS  = 0x0080
    
    # output flags
    ENABLE_PROCESSED_OUTPUT   = 0x0001
    ENABLE_WRAP_AT_EOL_OUTPUT = 0x0002
    ENABLE_VIRTUAL_TERMINAL_PROCESSING = 0x0004 # VT100 (Win 10)
    
    def check_zero(result, func, args):    
        if not result:
            err = ctypes.get_last_error()
            if err:
                raise ctypes.WinError(err)
        return args
    
    if not hasattr(wintypes, 'LPDWORD'): # PY2
        wintypes.LPDWORD = ctypes.POINTER(wintypes.DWORD)
    
    kernel32.GetConsoleMode.errcheck= check_zero
    kernel32.GetConsoleMode.argtypes = (
        wintypes.HANDLE,   # _In_  hConsoleHandle
        wintypes.LPDWORD,) # _Out_ lpMode
    
    kernel32.SetConsoleMode.errcheck= check_zero
    kernel32.SetConsoleMode.argtypes = (
        wintypes.HANDLE, # _In_  hConsoleHandle
        wintypes.DWORD,) # _Out_ lpMode
    

    The following wraps the underlying WinAPI functions as get_console_mode and set_console_mode. I've limited the wrappers to operating on just the console's active input buffer or active output buffer, i.e. \\.\CONIN$ and \\.\CONOUT$. I think this is simpler than having to worry about file descriptors and handles. Notably sys.stdin and sys.stdout may be redirected elsewhere, as may also be the case for the C runtime's standard I/O FILE streams, file descriptors, and the Windows standard handles that you can get from GetStdHandle. In these cases you can still open CONIN$ and CONOUT$, as long as the process is attached to a console.

    def get_console_mode(output=False):
        '''Get the mode of the active console input or output
           buffer. Note that if the process isn't attached to a
           console, this function raises an EBADF IOError.
        '''
        device = r'\\.\CONOUT$' if output else r'\\.\CONIN$'
        with open(device, 'r+') as con:
            mode = wintypes.DWORD()
            hCon = msvcrt.get_osfhandle(con.fileno())
            kernel32.GetConsoleMode(hCon, ctypes.byref(mode))
            return mode.value
    
    def set_console_mode(mode, output=False):
        '''Set the mode of the active console input or output
           buffer. Note that if the process isn't attached to a
           console, this function raises an EBADF IOError.
        '''
        device = r'\\.\CONOUT$' if output else r'\\.\CONIN$'
        with open(device, 'r+') as con:
            hCon = msvcrt.get_osfhandle(con.fileno())
            kernel32.SetConsoleMode(hCon, mode)
    

    update_console_mode combines the latter functions to let you pass in the flags you want to set and the mask of flags to modify. This includes flags to clear. It also allows restoring the previous mode by registering an atexit function.

    def update_console_mode(flags, mask, output=False, restore=False):
        '''Update a masked subset of the current mode of the active
           console input or output buffer. Note that if the process
           isn't attached to a console, this function raises an
           EBADF IOError.
        '''
        current_mode = get_console_mode(output)
        if current_mode & mask != flags & mask:
            mode = current_mode & ~mask | flags & mask
            set_console_mode(mode, output)
        else:
            restore = False
        if restore:
            atexit.register(set_console_mode, current_mode, output)
    

    Example:

    if __name__ == '__main__':
        import os
        import sys
        import time
    
        if sys.stderr is None:
            os.close(2)
            sys.stderr = open('stderr.txt', 'w', buffering=1)
    
        print("%#06x, %#06x" % (get_console_mode(),
                                get_console_mode(output=True)))    
    
        flags = mask = ENABLE_EXTENDED_FLAGS | ENABLE_QUICK_EDIT_MODE
        update_console_mode(flags, mask, restore=True)
    
        print("%#06x, %#06x" % (get_console_mode(),
                                get_console_mode(output=True)))    
    
        time.sleep(10) # check console properties