#define SYS_BASE		0x10
#define SYS_MAC			SYS_BASE+1
#define SYS_LINUX		SYS_BASE+2
#define SYS_FREEBSD		SYS_BASE+3
#define SYS_NETBSD		SYS_BASE+4
#define SYS_OPENBSD		SYS_BASE+5
#define SYS_MINT		SYS_BASE+6
#define SYS_BSD_BASED		SYS_BASE+7
#define SYS_SOLARIS		SYS_BASE+8
#define SYS_HPUX		SYS_BASE+9
#define SYS_RISC_OS		SYS_BASE+10
#define SYS_OS2			SYS_BASE+11
#define SYS_IRIX		SYS_BASE+12
#define SYS_AIX			SYS_BASE+13
#define SYS_BEOS		SYS_BASE+14
#define SYS_CYGWIN		SYS_BASE+15
#define SYS_OPENVMS		SYS_BASE+16
#define SYS_OSF			SYS_BASE+17
#define SYS_QNXNTO		SYS_BASE+18
#define SYS_WINDOWS		SYS_BASE+19
#define SYS_DREAMCAST		SYS_BASE+20

#if defined(__APPLE__) || defined(MAC_OS_CLASSIC) \
	|| defined(MAC_OS_X) || defined(macintosh)
#	define SYSTEM		SYS_MAC
#elif defined(linux) || defined(__linux) || defined(__linux__)
#	define SYSTEM		SYS_LINUX
#elif defined(__FreeBSD__) || defined(__DragonFly__)
#	define SYSTEM		SYS_FREEBSD
#elif defined(__NetBSD__)
#	define SYSTEM		SYS_NETBSD
#elif defined(__OpenBSD__)
#	define SYSTEM		SYS_OPENBSD
#elif defined(__MINT__)
#	define SYSTEM		SYS_MINT
#elif defined(bsdi) || defined(__bsdi) || defined(__bsdi__)
#	define SYSTEM		SYS_BSD_BASED
#elif defined(sun) || defined(__SVR4)
#	define SYSTEM		SYS_SOLARIS
#elif defined(hpux) || defined(__hpux) || defined(__hpux__)
#	define SYSTEM		SYS_HPUX
#elif defined(riscos) || defined(__riscos) || defined(__riscos__)
#	define SYSTEM		SYS_RISC_OS
#elif defined(__OS2__) || defined(__EMX__)
#	define SYSTEM		SYS_OS2
#elif defined(osf) || defined(__osf) \
	|| defined(__osf__) || defined(_OSF_SOURCE)
#	define SYSTEM_		SYS_OSF
#elif defined(sgi) || defined(__sgi) \
	|| defined(__sgi__) || defined(_SGI_SOURCE)
#	define SYSTEM		SYS_IRIX
#elif defined(_AIX)
#	define SYSTEM		SYS_AIX
#elif defined(__BEOS__)
#	define SYSTEM		SYS_BEOS
#elif defined(__CYGWIN__)
#	define SYSTEM		SYS_CYGWIN
#elif defined(__VMS)
#	define SYSTEM		SYS_OPENVMS
#elif defined(__osf__)
#	define SYSTEM		SYS_OSF
#elif defined(__QNXNTO__)
#	define SYSTEM		SYS_QNXNTO
#elif defined(_arch_dreamcast)
#	define SYSTEM		SYS_DREAMCAST
#elif defined(WINDOWS) || defined(WIN32) || defined(_WIN32)
#	define SYSTEM		SYS_WINDOWS
#endif