ADV - _POSIX_ADVISORY_INFO - _SC_ADVISORY_INFO¶

The following advisory functions are present:

posix_fadvise(),
posix_fallocate(),
posix_memalign(),
posix_madvise().

AIO - _POSIX_ASYNCHRONOUS_IO - _SC_ASYNCHRONOUS_IO¶

The header <aio.h> is present. The following functions are present:

aio_cancel(),
aio_error(),
aio_fsync(),
aio_read(),
aio_return(),
aio_suspend(),
aio_write(),
lio_listio().

BAR - _POSIX_BARRIERS - _SC_BARRIERS¶

This option implies the _POSIX_THREADS and _POSIX_THREAD_SAFE_FUNCTIONS options. The following functions are present:

pthread_barrier_destroy(),
pthread_barrier_init(),
pthread_barrier_wait(),
pthread_barrierattr_destroy(),
pthread_barrierattr_init().

--- - POSIX_CHOWN_RESTRICTED¶

If this option is in effect (as it always is under POSIX.1-2001) then only root may change the owner of a file, and nonroot can set the group of a file only to one of the groups it belongs to. This affects the functions chown(), fchown().

CS - _POSIX_CLOCK_SELECTION - _SC_CLOCK_SELECTION¶

This option implies the _POSIX_TIMERS option. The following functions are present:

pthread_condattr_getclock(),
pthread_condattr_setclock(),
clock_nanosleep().

If CLOCK_REALTIME is changed by the function clock_settime(), then this affects all timers set for an absolute time.

CPT - _POSIX_CPUTIME - _SC_CPUTIME¶

The clockID CLOCK_PROCESS_CPUTIME_ID is supported. The initial value of this clock is 0 for each process. This option implies the _POSIX_TIMERS option. The function clock_getcpuclockid() is present.

--- - _POSIX_FILE_LOCKING - _SC_FILE_LOCKING¶

This option has been deleted. Not in final XPG6.

FSC - _POSIX_FSYNC - _SC_FSYNC¶

The function fsync() is present.

IP6 - _POSIX_IPV6 - _SC_IPV6¶

Internet Protocol Version 6 is supported.

--- - _POSIX_JOB_CONTROL - _SC_JOB_CONTROL¶

If this option is in effect (as it always is under POSIX.1-2001) then the system implements POSIX-style job control, and the following functions are present:

setpgid(),
tcdrain(),
tcflush(),
tcgetpgrp(),
tcsendbreak(),
tcsetattr(),
tcsetpgrp().

MF - _POSIX_MAPPED_FILES - _SC_MAPPED_FILES¶

Shared memory is supported. The include file <sys/mman.h> is present. The following functions are present: mmap(), msync(), munmap().

ML - _POSIX_MEMLOCK - _SC_MEMLOCK¶

Shared memory can be locked into core. The functions mlockall(), munlockall() are present.

MR/MLR - _POSIX_MEMLOCK_RANGE - _SC_MEMLOCK_RANGE¶

More precisely, ranges can be locked into core. The functions mlock(), munlock() are present.

MPR - _POSIX_MEMORY_PROTECTION - _SC_MEMORY_PROTECTION¶

The function mprotect() is present.

MSG - _POSIX_MESSAGE_PASSING - _SC_MESSAGE_PASSING¶

The include file <mqueue.h> is present. The following functions are present:

mq_close(),
mq_getattr(),
mq_notify(),
mq_open(),
mq_receive(),
mq_send(),
mq_setattr(),
mq_unlink().

MON - _POSIX_MONOTONIC_CLOCK - _SC_MONOTONIC_CLOCK¶

CLOCK_MONOTONIC is supported. This option implies the _POSIX_TIMERS option. Affected functions are

aio_suspend(),
clock_getres(),
clock_gettime(),
clock_settime(),
timer_create().

--- - _POSIX_MULTI_PROCESS - _SC_MULTI_PROCESS¶

This option has been deleted. Not in final XPG6.

--- - _POSIX_NO_TRUNC¶

If this option is in effect (as it always is under POSIX.1-2001) then pathname components longer than NAME_MAX are not truncated, but give an error. This property may be dependent on the path prefix of the component.

PIO - _POSIX_PRIORITIZED_IO - _SC_PRIORITIZED_IO¶

This option says that one can specify priorities for asynchronous I/O. This affects the functions

aio_read(),
aio_write().

PS - _POSIX_PRIORITY_SCHEDULING - _SC_PRIORITY_SCHEDULING¶

The include file <sched.h> is present. The following functions are present:

sched_get_priority_max(),
sched_get_priority_min(),
sched_getparam(),
sched_getscheduler(),
sched_rr_get_interval(),
sched_setparam(),
sched_setscheduler(),
sched_yield().

If also _POSIX_SPAWN is in effect, then the following functions are present:

posix_spawnattr_getschedparam(),
posix_spawnattr_getschedpolicy(),
posix_spawnattr_setschedparam(),
posix_spawnattr_setschedpolicy().

RS - _POSIX_RAW_SOCKETS¶

Raw sockets are supported. Affected functions are getsockopt(), setsockopt().

--- - _POSIX_READER_WRITER_LOCKS - _SC_READER_WRITER_LOCKS¶

This option implies the _POSIX_THREADS option. Conversely, under POSIX.1-2001 the _POSIX_THREADS option implies this option.

The following functions are present:


pthread_rwlock_destroy(),
pthread_rwlock_init(),
pthread_rwlock_rdlock(),
pthread_rwlock_tryrdlock(),
pthread_rwlock_trywrlock(),
pthread_rwlock_unlock(),
pthread_rwlock_wrlock(),
pthread_rwlockattr_destroy(),
pthread_rwlockattr_init().

RTS - _POSIX_REALTIME_SIGNALS - _SC_REALTIME_SIGNALS¶

Realtime signals are supported. The following functions are present:

sigqueue(),
sigtimedwait(),
sigwaitinfo().

--- - _POSIX_REGEXP - _SC_REGEXP¶

If this option is in effect (as it always is under POSIX.1-2001) then POSIX regular expressions are supported and the following functions are present:

regcomp(),
regerror(),
regexec(),
regfree().

--- - _POSIX_SAVED_IDS - _SC_SAVED_IDS¶

If this option is in effect (as it always is under POSIX.1-2001) then a process has a saved set-user-ID and a saved set-group-ID. Affected functions are

exec(),
kill(),
seteuid(),
setegid(),
setgid(),
setuid().

SEM - _POSIX_SEMAPHORES - _SC_SEMAPHORES¶

The include file <semaphore.h> is present. The following functions are present:

sem_close(),
sem_destroy(),
sem_getvalue(),
sem_init(),
sem_open(),
sem_post(),
sem_trywait(),
sem_unlink(),
sem_wait().

SHM - _POSIX_SHARED_MEMORY_OBJECTS - _SC_SHARED_MEMORY_OBJECTS¶

The following functions are present:

mmap(),
munmap(),
shm_open(),
shm_unlink().

--- - _POSIX_SHELL - _SC_SHELL¶

If this option is in effect (as it always is under POSIX.1-2001), the function system() is present.

SPN - _POSIX_SPAWN - _SC_SPAWN¶

This option describes support for process creation in a context where it is difficult or impossible to use fork(), for example, because no MMU is present. If _POSIX_SPAWN is in effect, then the include file <spawn.h> and the following functions are present:

posix_spawn(),
posix_spawn_file_actions_addclose(),
posix_spawn_file_actions_adddup2(),
posix_spawn_file_actions_addopen(),
posix_spawn_file_actions_destroy(),
posix_spawn_file_actions_init(),
posix_spawnattr_destroy(),
posix_spawnattr_getsigdefault(),
posix_spawnattr_getflags(),
posix_spawnattr_getpgroup(),
posix_spawnattr_getsigmask(),
posix_spawnattr_init(),
posix_spawnattr_setsigdefault(),
posix_spawnattr_setflags(),
posix_spawnattr_setpgroup(),
posix_spawnattr_setsigmask(),
posix_spawnp().

If also _POSIX_PRIORITY_SCHEDULING is in effect, then the following functions are present:

posix_spawnattr_getschedparam(),
posix_spawnattr_getschedpolicy(),
posix_spawnattr_setschedparam(),
posix_spawnattr_setschedpolicy().

SPI - _POSIX_SPIN_LOCKS - _SC_SPIN_LOCKS¶

This option implies the _POSIX_THREADS and _POSIX_THREAD_SAFE_FUNCTIONS options. The following functions are present:

pthread_spin_destroy(),
pthread_spin_init(),
pthread_spin_lock(),
pthread_spin_trylock(),
pthread_spin_unlock().

SS - _POSIX_SPORADIC_SERVER - _SC_SPORADIC_SERVER¶

The scheduling policy SCHED_SPORADIC is supported. This option implies the _POSIX_PRIORITY_SCHEDULING option. Affected functions are

sched_setparam(),
sched_setscheduler().

SIO - _POSIX_SYNCHRONIZED_IO - _SC_SYNCHRONIZED_IO¶

Affected functions are open(), msync(), fsync(), fdatasync().

TSA - _POSIX_THREAD_ATTR_STACKADDR - _SC_THREAD_ATTR_STACKADDR¶

Affected functions are

pthread_attr_getstack(),
pthread_attr_getstackaddr(),
pthread_attr_setstack(),
pthread_attr_setstackaddr().

TSS - _POSIX_THREAD_ATTR_STACKSIZE - _SC_THREAD_ATTR_STACKSIZE¶

Affected functions are

pthread_attr_getstack(),
pthread_attr_getstacksize(),
pthread_attr_setstack(),
pthread_attr_setstacksize().

TCT - _POSIX_THREAD_CPUTIME - _SC_THREAD_CPUTIME¶

The clockID CLOCK_THREAD_CPUTIME_ID is supported. This option implies the _POSIX_TIMERS option. Affected functions are

pthread_getcpuclockid(),
clock_getres(),
clock_gettime(),
clock_settime(),
timer_create().

TPI - _POSIX_THREAD_PRIO_INHERIT - _SC_THREAD_PRIO_INHERIT¶

Affected functions are

pthread_mutexattr_getprotocol(),
pthread_mutexattr_setprotocol().

TPP - _POSIX_THREAD_PRIO_PROTECT - _SC_THREAD_PRIO_PROTECT¶

Affected functions are

pthread_mutex_getprioceiling(),
pthread_mutex_setprioceiling(),
pthread_mutexattr_getprioceiling(),
pthread_mutexattr_getprotocol(),
pthread_mutexattr_setprioceiling(),
pthread_mutexattr_setprotocol().

TPS - _POSIX_THREAD_PRIORITY_SCHEDULING - _SC_THREAD_PRIORITY_SCHEDULING¶

If this option is in effect, the different threads inside a process can run with different priorities and/or different schedulers. Affected functions are

pthread_attr_getinheritsched(),
pthread_attr_getschedpolicy(),
pthread_attr_getscope(),
pthread_attr_setinheritsched(),
pthread_attr_setschedpolicy(),
pthread_attr_setscope(),
pthread_getschedparam(),
pthread_setschedparam(),
pthread_setschedprio().

TSH - _POSIX_THREAD_PROCESS_SHARED - _SC_THREAD_PROCESS_SHARED¶

Affected functions are

pthread_barrierattr_getpshared(),
pthread_barrierattr_setpshared(),
pthread_condattr_getpshared(),
pthread_condattr_setpshared(),
pthread_mutexattr_getpshared(),
pthread_mutexattr_setpshared(),
pthread_rwlockattr_getpshared(),
pthread_rwlockattr_setpshared().

TSF - _POSIX_THREAD_SAFE_FUNCTIONS - _SC_THREAD_SAFE_FUNCTIONS¶

Affected functions are

readdir_r(),
getgrgid_r(),
getgrnam_r(),
getpwnam_r(),
getpwuid_r(),
flockfile(),
ftrylockfile(),
funlockfile(),
getc_unlocked(),
getchar_unlocked(),
putc_unlocked(),
putchar_unlocked(),
rand_r(),
strerror_r(),
strtok_r(),
asctime_r(),
ctime_r(),
gmtime_r(),
localtime_r().

TSP - _POSIX_THREAD_SPORADIC_SERVER - _SC_THREAD_SPORADIC_SERVER¶

This option implies the _POSIX_THREAD_PRIORITY_SCHEDULING option. Affected functions are

sched_getparam(),
sched_setparam(),
sched_setscheduler().

THR - _POSIX_THREADS - _SC_THREADS¶

Basic support for POSIX threads is available. The following functions are present:

pthread_atfork(),
pthread_attr_destroy(),
pthread_attr_getdetachstate(),
pthread_attr_getschedparam(),
pthread_attr_init(),
pthread_attr_setdetachstate(),
pthread_attr_setschedparam(),
pthread_cancel(),
pthread_cleanup_push(),
pthread_cleanup_pop(),
pthread_cond_broadcast(),
pthread_cond_destroy(),
pthread_cond_init(),
pthread_cond_signal(),
pthread_cond_timedwait(),
pthread_cond_wait(),
pthread_condattr_destroy(),
pthread_condattr_init(),
pthread_create(),
pthread_detach(),
pthread_equal(),
pthread_exit(),
pthread_getspecific(),
pthread_join(),
pthread_key_create(),
pthread_key_delete(),
pthread_mutex_destroy(),
pthread_mutex_init(),
pthread_mutex_lock(),
pthread_mutex_trylock(),
pthread_mutex_unlock(),
pthread_mutexattr_destroy(),
pthread_mutexattr_init(),
pthread_once(),
pthread_rwlock_destroy(),
pthread_rwlock_init(),
pthread_rwlock_rdlock(),
pthread_rwlock_tryrdlock(),
pthread_rwlock_trywrlock(),
pthread_rwlock_unlock(),
pthread_rwlock_wrlock(),
pthread_rwlockattr_destroy(),
pthread_rwlockattr_init(),
pthread_self(),
pthread_setcancelstate(),
pthread_setcanceltype(),
pthread_setspecific(),
pthread_testcancel().

TMO - _POSIX_TIMEOUTS - _SC_TIMEOUTS¶

The following functions are present:

mq_timedreceive(),
mq_timedsend(),
pthread_mutex_timedlock(),
pthread_rwlock_timedrdlock(),
pthread_rwlock_timedwrlock(),
sem_timedwait(),
posix_trace_timedgetnext_event().

TMR - _POSIX_TIMERS - _SC_TIMERS¶

The following functions are present:

clock_getres(),
clock_gettime(),
clock_settime(),
nanosleep(),
timer_create(),
timer_delete(),
timer_gettime(),
timer_getoverrun(),
timer_settime().

TRC - _POSIX_TRACE - _SC_TRACE¶

POSIX tracing is available. The following functions are present:

posix_trace_attr_destroy(),
posix_trace_attr_getclockres(),
posix_trace_attr_getcreatetime(),
posix_trace_attr_getgenversion(),
posix_trace_attr_getmaxdatasize(),
posix_trace_attr_getmaxsystemeventsize(),
posix_trace_attr_getmaxusereventsize(),
posix_trace_attr_getname(),
posix_trace_attr_getstreamfullpolicy(),
posix_trace_attr_getstreamsize(),
posix_trace_attr_init(),
posix_trace_attr_setmaxdatasize(),
posix_trace_attr_setname(),
posix_trace_attr_setstreamsize(),
posix_trace_attr_setstreamfullpolicy(),
posix_trace_clear(),
posix_trace_create(),
posix_trace_event(),
posix_trace_eventid_equal(),
posix_trace_eventid_get_name(),
posix_trace_eventid_open(),
posix_trace_eventtypelist_getnext_id(),
posix_trace_eventtypelist_rewind(),
posix_trace_flush(),
posix_trace_get_attr(),
posix_trace_get_status(),
posix_trace_getnext_event(),
posix_trace_shutdown(),
posix_trace_start(),
posix_trace_stop(),
posix_trace_trygetnext_event().

TEF - _POSIX_TRACE_EVENT_FILTER - _SC_TRACE_EVENT_FILTER¶

This option implies the _POSIX_TRACE option. The following functions are present:

posix_trace_eventset_add(),
posix_trace_eventset_del(),
posix_trace_eventset_empty(),
posix_trace_eventset_fill(),
posix_trace_eventset_ismember(),
posix_trace_get_filter(),
posix_trace_set_filter(),
posix_trace_trid_eventid_open().

TRI - _POSIX_TRACE_INHERIT - _SC_TRACE_INHERIT¶

Tracing children of the traced process is supported. This option implies the _POSIX_TRACE option. The following functions are present:

posix_trace_attr_getinherited(),
posix_trace_attr_setinherited().

TRL - _POSIX_TRACE_LOG - _SC_TRACE_LOG¶

This option implies the _POSIX_TRACE option. The following functions are present:

posix_trace_attr_getlogfullpolicy(),
posix_trace_attr_getlogsize(),
posix_trace_attr_setlogfullpolicy(),
posix_trace_attr_setlogsize(),
posix_trace_close(),
posix_trace_create_withlog(),
posix_trace_open(),
posix_trace_rewind().

TYM - _POSIX_TYPED_MEMORY_OBJECTS - _SC_TYPED_MEMORY_OBJECT¶

The following functions are present:

posix_mem_offset(),
posix_typed_mem_get_info(),
posix_typed_mem_open().

--- - _POSIX_VDISABLE¶

Always present (probably 0). Value to set a changeable special control character to indicate that it is disabled.