portable code between windows and linux

I have an aplication written for lin开发者_StackOverflow社区ux,and i want to make it to execute under windows too. So how can i make a specific line in code to execute only if the programs runs under windows ? I know its somehting with #ifdef... Thanks

You're looking for:

#if defined(_WIN32)
    // Your Windows specific code here
#endif

Edit based on comment:

There is a good discussion of _WIN32 vs WIN32 here: Whats the difference between the win32 defines

It depends on the code. You might be able to just re-compile it and go. If not, the effort involved in porting may be trivial (a few minor details here or there) or it might be next to impossible (e.g., trying to port valgrind).

Before you jump into using #ifdef, read Henry Spencer's paper on the subject.

I use #ifdef _MSC_VER to know if it's a Microsoft compiler, but I'm sure there are other ways.

Usually #ifdef _WIN32, but #ifdef WIN32 also works.