Re: std::cin and disabling canonical line processing (buffering)

It works perfectly! Thanks!

"Tom Widmer [VC++ MVP]" wrote:

> Harold Bamford wrote:
> > Tom,
> >
> > Oh, this is *so* close!
> >
> > I find that I have to set the console mode to 0 rather than
> > ENABLE_PROCESSED_INPUT in order to get a ^C char -- as expected. No surprise
> > there.
> >
> > And the text-binary translation is now gone, which is great! As an aside, I
> > also found that using:
> >
> > _setmode(0, _O_BINARY)
> >
> > turned off the text translation, but this is clearly an unreliable hack and
> > I prefer your method of opening up the console in binary mode from the get-go.
> >
> > But, (and you *knew* this was coming!):
> >
> > I cannot read the ESC character; it gets silently eaten. My suspicion is
> > that since ESC forms the prefix of several "special" keys that it is being
> > treated as part of a special sequence, such as:
> >
> > // Up Arrow ESC [ A
> > // Down Arrow ESC [ B
> > // Right Arrow ESC [ C
> > // Left Arrow ESC [ D
> > // Home ESC [ 1 ~
> > // Insert ESC [ 2 ~
> > // Delete ESC [ 3 ~
> > // End ESC [ 4 ~
> > // PageUp ESC [ 5 ~
> > // PageDn ESC [ 6 ~
> >
> > I would have thought that by NOT enabling mouse or window input modes that
> > these would be passed through raw. Apparently not. And just for grins, I
> > tried it with those modes enabled and still cannot get an ESC char.
> >
> > Ideas or suggestions?
> >
> > Thanks so much for your help!
>
> Ok, try this:
>
> #include <windows.h>
> #include <iostream>
> #include <fstream>
>
> class consolebuf: public std::streambuf
> {
> public:
> consolebuf(HANDLE consoleHandle)
> :m_handle(consoleHandle)
> {
> }
>
> protected:
> int underflow()
> {
> DWORD read = 0;
> INPUT_RECORD record;
>
> for(;;)
> {
> if (!ReadConsoleInput(m_handle, &record, 1, &read)
> || read != 1)
> {
> return EOF;
> }
> if (record.EventType == KEY_EVENT)
> {
> if (record.Event.KeyEvent.bKeyDown)
> {
> //here you need to decide what char to return
> if (record.Event.KeyEvent.uChar.AsciiChar != 0)
> {
> m_currentChar =
> record.Event.KeyEvent.uChar.AsciiChar;
> }
> else
> {
> //some kind of special key.
> //for now, just pass the key code
> m_currentChar =
> static_cast<char>(record.Event.KeyEvent.wVirtualKeyCode);
> }
> setg(&m_currentChar, &m_currentChar, &m_currentChar
> + 1);
> return traits_type::to_int_type(m_currentChar);
> }
> }
> }
> }
>
> private:
> HANDLE m_handle;
> char m_currentChar;
> };
>
> int main()
> {
> HANDLE inputHandle = GetStdHandle(STD_INPUT_HANDLE);
> SetConsoleMode(inputHandle, 0);
>
> consolebuf buf(inputHandle);
> std::istream is(&buf);
> char c;
> while(is.get(c))
> {
> if (c == 'x')
> break;
> std::cout << int(c) << std::endl;
> }
> }
>
> Obviously, not all virtual key codes have an obvious char value, so you
> may want to discard any key presses that you don't want to process (just
> continue the for loop).
>
> Tom
>
.