cpp_consoleattacher.cpp

// I was only able to make this thanks to https://stackoverflow.com/users/407438/jim-brissom
// and his answer here: https://stackoverflow.com/questions/3859276/get-console-handle
// as well as consulting the C# source code for ColorTool (https://github.com/Microsoft/console/tree/master/tools/ColorTool)
// and of course Microsoft documentation - thanks everyone!

#include <sstream>
#include <iostream>
#include <windows.h>

/*
    Possible return codes:
    EXIT_SUCCESS
    -1 = Failed to attach to console
    -2 = Failed to get handle of console
    -3 = Failed to get ScreenBufferInfoEx of console
    -4 = Failed to set ScreenBufferInfoEx of console
    -5 = Too few arguments supplied (minimum: [executable] PID COLOR0)
*/

int main (int argc, char *argv[]) {
    // Command line arguments:
    // 0 : name of executable
    // 1 : process ID of console
    // 2-17 : colors to apply
    if (argc < 3) {
        return -5;
    }

    DWORD process_id = atoi(argv[1]);
    COLORREF newColorTable[16] = {0};

    int count = 0;

    while (count < argc - 2) {
        newColorTable[count++] = strtoul(argv[count + 2], NULL, 0);
    }

    if (AttachConsole(process_id)) {
        HANDLE hStdOut = GetStdHandle(STD_OUTPUT_HANDLE);
        if (hStdOut != NULL) {
            CONSOLE_SCREEN_BUFFER_INFOEX console_buffer_info = { 96 };

            if (GetConsoleScreenBufferInfoEx(hStdOut, &console_buffer_info)) {
                for (int i = 0; i < count; i++) {
                    console_buffer_info.ColorTable[i] = newColorTable[i];
                }
                if (! SetConsoleScreenBufferInfoEx(hStdOut, &console_buffer_info)) {
                    return -4;
                }
            } else {
                return -3;
            }
        } else {
            return -2;
        }   
        FreeConsole();
    } else {
        return -1;
    }

    return EXIT_SUCCESS;
}