Many symbols have been added in <limits.h> and <unistd.h>
to support SUSv3. Some of these symbols are tested at compile time
by the preprocessor to allow differential compiles based on the values
found, while others are intended for use by sysconf(), pathconf(),
fpathconf(), and confstr() to test the version of the standard and
availability of options at run time.
Table 1 lists
the SUSv3 options and option groups supported by the XL C/C++ Runtime
Library:
Table 1. SUSv3 options and option groups| Description |
Symbol Name |
|---|
| File Synchronization |
_POSIX_FSYNC |
| Memory Mapped Files |
_POSIX_MAPPED_FILES |
| Memory Protection |
_POSIX_MEMORY_PROTECTION |
| Realtime Signals Extension |
_POSIX_REALTIME_SIGNALS |
| Thread Stack Address Attribute |
_POSIX_THREAD_ATTR_STACKADDR |
| Thread Stack Size Attribute |
_POSIX_THREAD_ATTR_STACKSIZE |
| Thread Process-Shared Synchronization |
_POSIX_THREAD_PROCESS_SHARED |
| Thread-Safe Functions |
_POSIX_THREAD_SAFE_FUNCTIONS |
| Threads |
_POSIX_THREADS |
| Encryption Option Group |
_XOPEN_CRYPT |
| Legacy Option Group |
_XOPEN_LEGACY |
| XSI Streams Option Group |
_XOPEN_STREAMS |
| XSI Extension |
_XOPEN_UNIX |