get_windows_ver_cli.cpp

// concise_safe_get_windows_edition.cpp
// Build (MSVC): cl /O2 /W4 concise_safe_get_windows_edition.cpp

#include <windows.h>
#include <cstdio>

static void print_last_error(const char *ctx) {
    DWORD err = GetLastError();
    LPSTR msg = nullptr;
    FormatMessageA(
        FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
        nullptr, err, 0, reinterpret_cast<LPSTR>(&msg), 0, nullptr
    );
    fprintf(stderr, "%s: error %lu: %s\n", ctx, (unsigned long)err, msg ? msg : "(no message)");
    if (msg) LocalFree(msg);
}

int main(void) {
    const char LABEL[] = "Windows edition: ";
    OSVERSIONINFOEXW osv = {}; osv.dwOSVersionInfoSize = sizeof(osv);

    HMODULE ntdll = GetModuleHandleW(L"ntdll.dll");
    if (!ntdll) { print_last_error("GetModuleHandleW"); return 1; }

    using RtlFn = LONG (WINAPI *)(OSVERSIONINFOW*);
    auto rtl = reinterpret_cast<RtlFn>(GetProcAddress(ntdll, "RtlGetVersion"));
    if (!rtl) { print_last_error("GetProcAddress(RtlGetVersion)"); return 2; }

    if (rtl(reinterpret_cast<OSVERSIONINFOW*>(&osv)) != 0) {
        fprintf(stderr, "RtlGetVersion failed\n"); return 3;
    }

    const char *edition = (osv.wProductType == VER_NT_WORKSTATION)
                            ? ((osv.wSuiteMask & VER_SUITE_PERSONAL) ? "Home" : "Pro")
                            : "Server";

    printf("%s%s\n", LABEL, edition);
    return 0;
}