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OperatingSystems

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AIX

Type Macro Description
Identification _AIX
Version _AIX'VR' V = Version
R = Revision
Identification __TOS_AIX__ Defined by xlC
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.

AIX Version Macro
3.2.x _AIX3
_AIX32
4.1 _AIX41
4.3 _AIX43

Android

Type Macro Format Description
Identification __ANDROID__
Version __ANDROID_API__ V V = API Version

Must be included from <android/api-level.h>

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

Example
Android Version __ANDROID_API__
1.0 1
1.1 2
1.5 3
1.6 4
2.0 5
2.0.1 6
2.1 7
2.2 8
2.3 9
2.3.3 10
3.0 11

Amdahl UTS

Type Macro
Identification UTS

AmigaOS

Type Macro Description
Identification AMIGA
Identification __amigaos__ Defined by GNU C

Apollo AEGIS

Type Macro
Identification aegis

Apollo Domain/OS

Type Macro
Identification apollo

Bada

Based on Nucleus OS.

BeOS

Type Macro
Identification __BEOS__

BSD Environment

Type Macro Format Description
Identification __FreeBSD__
__NetBSD__
__OpenBSD__
__bsdi__
__DragonFly__
Version BSD YYYYMM YYYY = Year
MM = Month

Must be included from <sys/param.h>
Version BSD4_2
BSD4_3
BSD4_4
Must be included from <sys/param.h>
Identification _SYSTYPE_BSD Defined by DEC C
Example
Version BSD Macro
4.3 Net2 199103
4.4 199306 BSD4_4
4.4BSD-Lite2 199506

BSD/OS

Type Macro
Identification __bsdi__

ConvexOS

Type Macro
Identification __convex__

Cygwin Environment

Type Macro
Identification __CYGWIN__

DG/UX

Type Macro
Identification DGUX
Identification __DGUX__
Identification __dgux__

DragonFly

Type Macro
Identification __DragonFly__

DYNIX/ptx

Type Macro
Identification _SEQUENT_
Identification sequent

eCos

Type Macro
Identification __ECOS

EMX Environment

Type Macro
Identification __EMX__

FreeBSD

Type Macro Format Description
Identification __FreeBSD__
Version BSD
Version __FreeBSD__ V V = Version
Version __FreeBSD_version ? Must be included from <osreldate.h>
Example
FreeBSD __FreeBSD__ __FreeBSD_version
1.x 1
2.0-RELEASE 2 119411
2.2-RELEASE 2 220000
3.0-RELEASE 3 300005
4.0-RELEASE 4 400017
4.5-RELEASE 4 450000

For more information see the FreeBSD porters handbook.

GNU Hurd

Type Macro
Identification __GNU__

GNU/Linux

Type Macro
Identification __gnu_linux__

HI-UX MPP

Type Macro
Identification __hiuxmpp

HP-UX

Type Macro Description
Identification _hpux Defined by HP UPC
Identification hpux
Identification __hpux

IBM OS/400

Type Macro
Identification __OS400__

INTEGRITY

Type Macro
Identification __INTEGRITY

Interix Environment

Type Macro Description
Identification __INTERIX Defined by GNU C and Visual Studio

IRIX

Type Macro
Identification sgi
Identification __sgi

Linux kernel

Systems based on the Linux kernel define these macros. There are two major Linux-based operating systems: GNU/Linux and Android.

Type Macro Description
Identification __linux__
Identification linux Obsolete
Identification __linux Obsolete

LynxOS

Type Macro
Identification __Lynx__

MacOS

Type Macro Description
Identification macintosh Mac OS 9
Identification Macintosh Mac OS 9
Identification __APPLE__ & __MACH__ Mac OS X

Defined by GNU C and Intel C++

Microware OS-9

Type Macro Description
Identification __OS9000 Defined by Ultimate C/C++
Identification _OSK Defined by Ultimate C/C++

MINIX

Type Macro
Identification __minix

MorphOS

Type Macro
Identification __MORPHOS__

MPE/iX

Type Macro
Identification mpeix
Identification __mpexl

MSDOS

Type Macro
Identification MSDOS
Identification __MSDOS__
Identification _MSDOS
Identification __DOS__

NetBSD

Type Macro Format Description
Identification __NetBSD__
Version BSD
Version NetBSD'V'_'R' V = Version
R = Revision

Must be included from <sys/param.h>
Version __NetBSD_Version__ VVRRAAPP00 VV = Version
RR = Revision
AA = Release
PP = Patch

From NetBSD 1.2D (?) until NetBSD 2.0H

Must be included from <sys/param.h>
Version __NetBSD_Version__ VVRR00PP00 VV = Version
RR = Revision
PP = Patch

From NetBSD 2.99.9

Must be included from <sys/param.h>
Example
NetBSD __NetBSD_Version__ Macro
0.8 NetBSD0_8
0.9 NetBSD0_9
1.0 NetBSD1_0 = 1
1.0A NetBSD1_0 = 2
1.2D 102040000
1.2.1 102000100

NonStop

Type Macro
Identification __TANDEM

Nucleus RTOS

Type Macro
Identification __nucleus__

OpenBSD

Type Macro Format Description
Identification __OpenBSD__
Version BSD
Version OpenBSD'V'_'R' V = Version
R = Revision

Must be included from <sys/param.h>
Example
OpenBSD Macro
3.1 OpenBSD3_1
3.9 OpenBSD3_9

OS/2

Type Macro
Identification OS2
Identification _OS2
Identification __OS2__
Identification __TOS_OS2__

Palm OS

Type Macro Description
Identification __palmos__ Defined by GNU C in PRC-Tools

Pyramid DC/OSx

Type Macro
Identification pyr

QNX

Type Macro Format Description
Identification __QNX__ QNX 4.x
Identification __QNXNTO__ QNX 6.x
Version _NTO_VERSION VRR V = Version
RR = Revision

Only available when __QNXNTO__ is defined.

Must be included from <sys/neutrino.h>
Example
QNX _NTO_VERSION
6.2 620

Reliant UNIX

Type Macro
Identification sinux

SCO OpenServer

Type Macro Description
Identification M_I386 Defined by GNU C
Identification M_XENIX Defined by GNU C
Identification _SCO_DS

Solaris

Type Macro Description
Identification sun
Identification __sun
Version __'System'_'Version' System = uname -s
Version = uname -r
Any illegal character is replaced by an underscore.

Defined by Sun Studio

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
Solaris Macro
2.7 __SunOS_5_7
8 __SunOS_5_8

Stratus VOS

Type Macro Format Description
Identification __VOS__
Version __VOS__ V V = Version

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

Type Macro Description
Identification __sysv__
Identification __SVR4
Identification __svr4__
Identification _SYSTYPE_SVR4 Defined on IRIX

Symbian OS

Type Macro
Identification __SYMBIAN32__

Tru64 (OSF/1)

Type Macro
Identification __osf__
Identification __osf

Ultrix

Type Macro
Identification ultrix
Identification __ultrix
Identification __ultrix__
Identification unix & vax

UNICOS

Type Macro Format Description
Identification _UNICOS
Version _UNICOS V V = Version

UNIX Environment

Type Macro
Identification __unix__
Identification __unix

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

Type Macro
Identification sco
Identification _UNIXWARE7

U/Win Environment

Type Macro
Identification _UWIN

VMS

Type Macro Format Description
Identification VMS
Identification __VMS
Version __VMS_VER VVRREPPTT VV = Version
RR = Revision
E = Edit number
PP = Patch (01 = A, ... 26 = Z)
TT = Type (22 = official)
Example
VMS __VMS_VER
6.1 60100022
6.2 60200022
6.2-1I 60210922

Windows

Type Macro Description
Identification _WIN32 Defined for both 32-bit and 64-bit environments
Identification _WIN64 Defined for 64-bit environments.
Identification __WIN32__ Defined by Borland C++
Identification __TOS_WIN__ Defined by xlC
Identification __WINDOWS__ Defined by Watcom C/C++

Windows CE

Type Macro Format Description
Identification _WIN32_WCE Defined by Embedded Visual Studio C++
Version _WIN32_WCE VRR V = Version
R = Revision
Identification WIN32_PLATFORM_'P' P = Platform
Version WIN32_PLATFORM_'P' V P = Platform
V = Version
Example
Version _WIN32_WCE
2.01 201
2.11 211
3.0 300
4.0 400
4.1 410
4.2 420
5.0 501
Platform Macro Value
H/PC 2000 WIN32_PLATFORM_HPC2000
H/PC Pro 2.11 WIN32_PLATFORM_HPCPRO 211
H/PC Pro 3.0 WIN32_PLATFORM_HPCPRO 300
Pocket PC WIN32_PLATFORM_PSPC 1
Pocket PC 2002 WIN32_PLATFORM_PSPC 310
Windows Mobile 2003 WIN32_PLATFORM_PSPC 400
Smartphone 2002 WIN32_PLATFORM_WFSP 100

Wind/U Environment

Type Macro Format Description
Identification _WINDU_SOURCE
Version _WINDU_SOURCE 0xVVRRPP VV = Version
RR = Revision
PP = Patch
Example
Wind/U _WINDU_SOURCE
3.1.2 0x030102

z/OS

Type Macro Description
Identification __MVS__ Host
Identification __HOS_MVS__ Host
Identification __TOS_MVS__ Target