C++ preprocessor directive to identify OSX

It depends. WIN32 is probably going to be defined. MSC_VER is probably going to be defined too. Check for your documentation for your Windows compiler. I am hedging my answer a bit because the answer depends on what compiler you are using. If you are using GCC, then you may not have those symbols defined. But, if you are using GCC on Windows then you probably have this problem to begin with.

A better approach would be to write a "clear()" function for Windows that calls "cls". Then, your application doesn't need any OS identification. You would put the "clear()" function and all other Windows-specific code into a glue.c source file that is only linked into the Windows version.

A good goal to aim for is to make your core application logic independent of any operating system. Each build system for each OS would have a set of ancillary files (like the glue.c source) that enables it to build for that OS. You want to keep that ancillary set of files as small as possible. If you have a console application, that should be easy. Code to the curses library and install some Windows curses port.

Hi, try this:


cohi@tigger:/tmp> cat t.c
#ifdef _APPLE_
#error darwin detected
#else
#error other detected
#endif

cohi@tigger:/tmp> gcc t.c
t.c:2:2: error: #error darwin detected

cohi@tigger:/tmp> gcc -v
Using built-in specs.
Target: powerpc-apple-darwin8
Configured with: /private/var/tmp/gcc/gcc-5363.obj~28/src/configure --disable-checking -enable-werror --prefix=/usr --mandir=/share/man --enable-languages=c,objc,c +,obj-c+ --program-transform-name=/^[cg][^.-]*$/s/$/-4.0/ --with-gxx-include-dir=/include/c++/4.0.0 --with-slibdir=/usr/lib --build=powerpc-apple-darwin8 --host=powerpc-apple-darwin8 --target=powerpc-apple-darwin8
Thread model: posix
gcc version 4.0.1 (Apple Computer, Inc. build 5363)

PS: And you might want to try this, it's how I found out; it's also documented in the GCC manual on gcc.gnu.org.

echo | cpp -dM