Windows Console/MS-DOS keyboard input tester

README.md

Windows Console/MS-DOS keyboard input tester

• To build for Windows, any compiler can be used.
• To build for MS-DOS, use Borland C++.

keytest.cpp

// Program to test keyboard input in the Windows Console or MS-DOS.
// To build for MS-DOS, use Borland C++.

#include <stdlib.h>
#include <stdio.h>

const unsigned short
    kbCtrlC = 0x2e03;

static void init();
static void restore();
static int readKey(unsigned short &keyCode, unsigned short &controlKeyState);

int main()
{
    init();
    atexit(restore);
    
    puts("Press Ctrl+C to exit");
    
    unsigned long counter = 0;
    unsigned short keyCode, controlKeyState;
    do {
        if (readKey(keyCode, controlKeyState))
            printf("Event #%lu:\t{0x%04hx, 0x%04hx}\n", ++counter, keyCode, controlKeyState);
    } while (keyCode != kbCtrlC);

    return 0;
}

#if defined(_WIN32) || (defined(__BORLANDC__) && defined(__FLAT__))

#include <windows.h>

static DWORD oldConsoleMode;

static void init()
{
    puts("Using Win32 Console API");
    HANDLE console = GetStdHandle(STD_INPUT_HANDLE);
    DWORD consoleMode;
    if (!GetConsoleMode(console, &consoleMode))
    {
        printf("GetConsoleMode error: %lu\n", GetLastError());
        exit(1);
    }
    oldConsoleMode = consoleMode;
    consoleMode &= ~ENABLE_PROCESSED_INPUT; // Report Ctrl+C and Shift+Arrow events.
    consoleMode &= ~(ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT); // Report Ctrl+S.
    if (!SetConsoleMode(console, consoleMode))
    {
        printf("SetConsoleMode error: %lu\n", GetLastError());
        exit(1);
    }
}

static void restore()
{
    HANDLE console = GetStdHandle(STD_INPUT_HANDLE);
    if (!SetConsoleMode(console, oldConsoleMode))
    {
        printf("SetConsoleMode error: %lu\n", GetLastError());
        exit(1);
    }
}

static int readKey(unsigned short &keyCode, unsigned short &controlKeyState)
{
    HANDLE console = GetStdHandle(STD_INPUT_HANDLE);
    INPUT_RECORD irBuffer;
    unsigned long eventsRead;
    if (!ReadConsoleInput(console, &irBuffer, 1, &eventsRead))
    {
        printf("ReadConsoleInput error: %lu\n", GetLastError());
        exit(1);
    }
    if (irBuffer.EventType != KEY_EVENT || !irBuffer.Event.KeyEvent.bKeyDown)
        return 0;

    keyCode = (irBuffer.Event.KeyEvent.wVirtualScanCode << 8) | (irBuffer.Event.KeyEvent.uChar.AsciiChar);
    controlKeyState = (unsigned short) irBuffer.Event.KeyEvent.dwControlKeyState;
    return 1;
}

#elif defined(__BORLANDC__) && defined(__MSDOS__)

#include <dos.h>

const unsigned biosSel = 0x0040;
const unsigned short far * const biosKeyShiftStatus = 
    (const unsigned short far *) MK_FP(biosSel, 0x17);

static void init()
{
    puts("Using DOS interrupts");
}

static void restore()
{
}

int readKey(unsigned short &keyCode, unsigned short &controlKeyState)
{
    _AH = 0x10; // Get extended keystroke.
    geninterrupt(0x16);

    keyCode = _AX;
    controlKeyState = *biosKeyShiftStatus;

    return 1;
}

#else

#error Unknown system. MS-DOS (with Borland C++) or Win32 are supported.

#endif

Prebuilt executables (built with Borland C++ 4.52): https://github.com/user-attachments/files/18907005/keytest.zip