How do I find the name of an operating system?

Question

The questions pretty simple. I want want a function (C++) or method which will, on call, returun something like

\"Windows\" //or
\"Unix\"

Noth

Answer 1

Since you can not have a single binary file which runs over all operating systems, and you need to re-compile your code again. It's OK to use MACROs.

Use macros such as

_WIN32
_WIN64
__unix
__unix__
__APPLE__
__MACH__
__linux__
__FreeBSD__

like this

std::string getOsName()
{
    #ifdef _WIN32
    return "Windows 32-bit";
    #elif _WIN64
    return "Windows 64-bit";
    #elif __APPLE__ || __MACH__
    return "Mac OSX";
    #elif __linux__
    return "Linux";
    #elif __FreeBSD__
    return "FreeBSD";
    #elif __unix || __unix__
    return "Unix";
    #else
    return "Other";
    #endif
}                      

You should read compiler's manuals and see what MACROS they provided to detect the OS on compile time.

Answer 2

From the Poco source code:

Win32:

std::string EnvironmentImpl::osNameImpl()
{
    OSVERSIONINFO vi;
    vi.dwOSVersionInfoSize = sizeof(vi);
    if (GetVersionEx(&vi) == 0) throw SystemException("Cannot get OS version information");
    switch (vi.dwPlatformId)
    {
    case VER_PLATFORM_WIN32s:
        return "Windows 3.x";
    case VER_PLATFORM_WIN32_WINDOWS:
        return vi.dwMinorVersion == 0 ? "Windows 95" : "Windows 98";
    case VER_PLATFORM_WIN32_NT:
        return "Windows NT";
    default:
        return "Unknown";
    }
}

Unix:

std::string EnvironmentImpl::osNameImpl()
{
    struct utsname uts;
    uname(&uts);
    return uts.sysname;
}