How do I check OS with a preprocessor directive?

Question

I need my code to do different things based on the operating system on which it gets compiled. I\'m looking for something like this:

#ifdef OSisWindows
// do         


        

Answer 1

You can use pre-processor directives as warning or error to check at compile time you don't need to run this program at all just simply compile it .

#if defined(_WIN32) || defined(_WIN64) || defined(__WINDOWS__)
    #error Windows_OS
#elif defined(__linux__)
    #error Linux_OS
#elif defined(__APPLE__) && defined(__MACH__)
    #error Mach_OS
#elif defined(unix) || defined(__unix__) || defined(__unix)
    #error Unix_OS
#else
    #error Unknown_OS
#endif

#include 
int main(void)
{
    return 0;
}