Open System Services Porting Guide (G06.24+, H06.03+)

Table Of Contents
Porting UNIX Applications to the OSS Environment
Open System Services Porting Guide520573-006
7-14
Defined Symbols and Header Files
_XOPEN_SOURCE When defined, all symbols defined by POSIX.1,
POSIX.2, and XPG4 are visible. The pragma
SYSTYPE OSS defines the _XOPEN_SOURCE
macro.
_XOPEN_SOURCE_EXTENDED When defined, all symbols defined by POSIX.1,
POSIX.2, XPG4, and XPG4 Version 2 are
visible. Because the pragma SYSTYPE OSS
defines the _XOPEN_SOURCE macro, the OSS
user must explicitly define
_XOPEN_SOURCE_EXTENDED to use the
XPG4V2 functions, such as strdup(),
readlink(), symlink(), and others.
Note that, even though the OSS sockets APIs
are defined in Version 1 of the XPG4
specification, you must define
_XOPEN_SOURCE_EXTENDED to use them.
_TANDEM_SOURCE When defined, all symbols defined by HP are
visible. The pragma SYSTYPE GUARDIAN
defines the _TANDEM_SOURCE macro.
__cplusplus The TNS/R and TNS/E native compilers define
this macro, signifying that they are invoked as
C++ compilers instead of as C compilers. The
user does not explicitly define this macro but
chooses it when supplying the file suffix of the
source code; for instance, .C or .cpp means the
file is compiled with the C++ compiler. (Note that
there are two underscores, “__”, before
“cplusplus.”)
Refer to the c89(1) reference page either
online or in the Open System Services Shell and
Utilities Reference Manual for acceptable file
suffixes on input files for the c89 utility.