When we compile some cross -platform programs, we will inevitably encounter _win32 , Linux What are the macroscopic macro of the compiler environment.There are many differences between _win32 and win32 before.But there is a list here, making a memo.

For example, a code that can only be compiled under the Unix-Like platform in a set.If you compile the wrong error on the non-Unix-Like platform, then my code can add a macro to check whether it is a UNIX environment.If it is normally compiled, the error is thrown directly.

#ifndef __unix__
#error This program should be complied and work in UNIX-LIKE platform.
#endif

The complete code is as follows:

#ifndef __unix__
#error This program should be complied and work in UNIX-LIKE platform.
#endif

#include <stdio.h>

int main()
{
    printf("this is unix-like platform");
    return 0;
}

This code can be compiled normally in the Mac OS and Linux environments, and an error will be reported under Windows.

Below is a macro list of a detection environment.

Please send updates/corrections to predef-contribute.

AIX

Example
If _AIX is defined, then the following macros can be used to determine the version. Notice that the macros indicates the mentioned version or higher. For example, if _AIX43 is defined, then _AIX41 will also be defined.

Android

Notice that Android is based on Linux, and that the Linux macros also are defined for Android.
Example

Amdahl UTS

AmigaOS

Apollo AEGIS

Apollo Domain/OS

Bada
Based on Nucleus OS.

BeOS

Blue Gene

BSD Environment

Example

BSD/OS

ConvexOS

Cygwin Environment

DG/UX

DragonFly

DYNIX/ptx

eCos

EMX Environment

FreeBSD

Example

For more information see the FreeBSD porters handbook.
GNU aka GNU/Hurd
The official name of this operating system is GNU. Hurd is the kernel in the GNU operating system. It is often listed as GNU/Hurd since there is also GNU/Linux and GNU/kFreeBSD, which are most of the GNU operating system with the Linux and FreeBSD kernels respectively.

GNU/kFreeBSD
GNU/kFreeBSD is one of the Debian distros that is based on the FreeBSD kernel rather than the Linux or Hurd kernels.

Notice that FreeBSD also defines __FreeBSD_kernel__ so the __GLIBC__ macro must be checked to distinguish it.
GNU/Linux

HI-UX MPP

HP-UX

IBM OS/400

INTEGRITY

Interix Environment

IRIX

Linux kernel
Systems based on the Linux kernel define these macros. There are two major Linux-based operating systems: GNU/Linux andAndroid, and numerous others like Ångström or OpenEmbedded

LynxOS

MacOS

Microware OS-9

MINIX

MorphOS

MPE/iX

MSDOS

NetBSD

Example

NonStop

Nucleus RTOS

OpenBSD

Example

OS/2

Palm OS

Plan 9

Pyramid DC/OSx

QNX

Example

Reliant UNIX

SCO OpenServer

Solaris

Use the SVR4 macros to distinguish between Solaris and SunOS.
#if defined(sun) || defined(**sun) # if defined(**SVR4) || defined(svr4) /_ Solaris / # else / SunOS _/ # endif #endif
Example

Stratus VOS

Notice that the __VOS__ macro is defined by the compiler, but as several compilers can co-exist in the same OS release, the version number is not reliable.
SVR4 Environment

Syllable

Symbian OS

Tru64 (OSF/1)

Ultrix

UNICOS

UNICOS/mp

UNIX Environment

Notice that not all compilers defines these macros, e.g. the xlC or the DEC C/C++ compiler, so it may be better to use the POSIX or X/Open standard macros instead.
UnixWare

U/Win Environment

VMS

Example

VxWorks

Example

Windows

Windows CE

Example

Wind/U Environment

Example

z/OS