.BR getconf (1).
For more detail, see
.BR sysconf (3).
-.PP
+.P
We give the name of the POSIX abbreviation, the option, the name of the
.BR sysconf (3)
parameter used to inquire about the option, and possibly
versions of which can nowadays be accessed freely on the web.
.SS ADV - _POSIX_ADVISORY_INFO - _SC_ADVISORY_INFO
The following advisory functions are present:
-.PP
+.P
.nf
.in +4n
.IR posix_fadvise ()
.I <aio.h>
is present.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR aio_cancel ()
.B _POSIX_THREAD_SAFE_FUNCTIONS
options.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR pthread_barrier_destroy ()
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 following functions
-.PP
+.P
.nf
.in +4n
.IR chown ()
.B _POSIX_TIMERS
option.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR pthread_condattr_getclock ()
.IR clock_nanosleep ()
.in
.fi
-.PP
+.P
If
.B CLOCK_REALTIME
is changed by the function
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:
-.PP
+.P
.nf
.in +4n
.IR setpgid ()
.I <sys/mman.h>
is present.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR mmap ()
.SS ML - _POSIX_MEMLOCK - _SC_MEMLOCK
Shared memory can be locked into core.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR mlockall ()
.SS MR/MLR - _POSIX_MEMLOCK_RANGE - _SC_MEMLOCK_RANGE
More precisely, ranges can be locked into core.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR mlock ()
.I <mqueue.h>
is present.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR mq_close ()
.B _POSIX_TIMERS
option.
The following functions are affected:
-.PP
+.P
.nf
.in +4n
.IR aio_suspend ()
.SS PIO - _POSIX_PRIORITIZED_IO - _SC_PRIORITIZED_IO
This option says that one can specify priorities for asynchronous I/O.
This affects the functions
-.PP
+.P
.nf
.in +4n
.IR aio_read ()
.I <sched.h>
is present.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR sched_get_priority_max ()
.IR sched_yield ()
.in
.fi
-.PP
+.P
If also
.B _POSIX_SPAWN
is in effect, then the following functions are present:
-.PP
+.P
.nf
.in +4n
.IR posix_spawnattr_getschedparam ()
.SS RS - _POSIX_RAW_SOCKETS
Raw sockets are supported.
The following functions are affected:
-.PP
+.P
.nf
.in +4n
.IR getsockopt ()
under POSIX.1-2001 the
.B _POSIX_THREADS
option implies this option.
-.PP
+.P
The following functions are present:
-.PP
+.P
.in +4n
.nf
.IR pthread_rwlock_destroy ()
.SS RTS - _POSIX_REALTIME_SIGNALS - _SC_REALTIME_SIGNALS
Realtime signals are supported.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR sigqueue ()
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:
-.PP
+.P
.nf
.in +4n
.IR regcomp ()
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.
The following functions are affected:
-.PP
+.P
.nf
.in +4n
.IR exec ()
.I <semaphore.h>
is present.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR sem_close ()
.fi
.SS SHM - _POSIX_SHARED_MEMORY_OBJECTS - _SC_SHARED_MEMORY_OBJECTS
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR mmap ()
it is difficult or impossible to use
.IR fork (),
for example, because no MMU is present.
-.PP
+.P
If
.B _POSIX_SPAWN
is in effect, then the include file
.I <spawn.h>
and the following functions are present:
-.PP
+.P
.nf
.in +4n
.IR posix_spawn ()
.IR posix_spawnp ()
.in
.fi
-.PP
+.P
If also
.B _POSIX_PRIORITY_SCHEDULING
is in effect, then
the following functions are present:
-.PP
+.P
.nf
.in +4n
.IR posix_spawnattr_getschedparam ()
.B _POSIX_THREAD_SAFE_FUNCTIONS
options.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR pthread_spin_destroy ()
.B _POSIX_PRIORITY_SCHEDULING
option.
The following functions are affected:
-.PP
+.P
.nf
.in +4n
.IR sched_setparam ()
.fi
.SS SIO - _POSIX_SYNCHRONIZED_IO - _SC_SYNCHRONIZED_IO
The following functions are affected:
-.PP
+.P
.nf
.in +4n
.IR open ()
.fi
.SS TSA - _POSIX_THREAD_ATTR_STACKADDR - _SC_THREAD_ATTR_STACKADDR
The following functions are affected:
-.PP
+.P
.nf
.in +4n
.IR pthread_attr_getstack ()
.fi
.SS TSS - _POSIX_THREAD_ATTR_STACKSIZE - _SC_THREAD_ATTR_STACKSIZE
The following functions are affected:
-.PP
+.P
.nf
.in +4n
.IR pthread_attr_getstack ()
.B _POSIX_TIMERS
option.
The following functions are affected:
-.PP
+.P
.nf
.in +4n
.IR pthread_getcpuclockid ()
.fi
.SS TPI - _POSIX_THREAD_PRIO_INHERIT - _SC_THREAD_PRIO_INHERIT
The following functions are affected:
-.PP
+.P
.nf
.in +4n
.IR pthread_mutexattr_getprotocol ()
.fi
.SS TPP - _POSIX_THREAD_PRIO_PROTECT - _SC_THREAD_PRIO_PROTECT
The following functions are affected:
-.PP
+.P
.nf
.in +4n
.IR pthread_mutex_getprioceiling ()
If this option is in effect, the different threads inside a process
can run with different priorities and/or different schedulers.
The following functions are affected:
-.PP
+.P
.nf
.in +4n
.IR pthread_attr_getinheritsched ()
.fi
.SS TSH - _POSIX_THREAD_PROCESS_SHARED - _SC_THREAD_PROCESS_SHARED
The following functions are affected:
-.PP
+.P
.nf
.in +4n
.IR pthread_barrierattr_getpshared ()
.fi
.SS TSF - _POSIX_THREAD_SAFE_FUNCTIONS - _SC_THREAD_SAFE_FUNCTIONS
The following functions are affected:
-.PP
+.P
.nf
.in +4n
.IR readdir_r ()
.B _POSIX_THREAD_PRIORITY_SCHEDULING
option.
The following functions are affected:
-.PP
+.P
.nf
.in +4n
.IR sched_getparam ()
.SS THR - _POSIX_THREADS - _SC_THREADS
Basic support for POSIX threads is available.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR pthread_atfork ()
.fi
.SS TMO - _POSIX_TIMEOUTS - _SC_TIMEOUTS
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR mq_timedreceive ()
.fi
.SS TMR - _POSIX_TIMERS - _SC_TIMERS
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR clock_getres ()
.SS TRC - _POSIX_TRACE - _SC_TRACE
POSIX tracing is available.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR posix_trace_attr_destroy ()
.B _POSIX_TRACE
option.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR posix_trace_eventset_add ()
.B _POSIX_TRACE
option.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR posix_trace_attr_getinherited ()
.B _POSIX_TRACE
option.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR posix_trace_attr_getlogfullpolicy ()
.fi
.SS TYM - _POSIX_TYPED_MEMORY_OBJECTS - _SC_TYPED_MEMORY_OBJECT
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR posix_mem_offset ()
.SH X/OPEN SYSTEM INTERFACE EXTENSIONS
.SS XSI - _XOPEN_CRYPT - _SC_XOPEN_CRYPT
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR crypt ()
.fi
.SS XSI - _XOPEN_REALTIME - _SC_XOPEN_REALTIME
This option implies the following options:
-.PP
+.P
.PD 0
.TP
.BR _POSIX_ASYNCHRONOUS_IO == 200112L
.SS ADV - --- - ---
The Advanced Realtime option group implies that the following options
are all defined to 200112L:
-.PP
+.P
.PD 0
.TP
.B _POSIX_ADVISORY_INFO
.SS XSI - _XOPEN_REALTIME_THREADS - _SC_XOPEN_REALTIME_THREADS
This option implies that the following options
are all defined to 200112L:
-.PP
+.P
.PD 0
.TP
.B _POSIX_THREAD_PRIO_INHERIT
.SS ADVANCED REALTIME THREADS - --- - ---
This option implies that the following options
are all defined to 200112L:
-.PP
+.P
.PD 0
.TP
.B _POSIX_BARRIERS
.SS TRACING - --- - ---
This option implies that the following options
are all defined to 200112L:
-.PP
+.P
.PD 0
.TP
.B _POSIX_TRACE
.PD
.SS STREAMS - _XOPEN_STREAMS - _SC_XOPEN_STREAMS
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR fattach ()
Functions included in the legacy option group were previously mandatory,
but are now optional in this version.
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR bcmp ()
.fi
.SS XSI - _XOPEN_UNIX - _SC_XOPEN_UNIX
The following functions are present:
-.PP
+.P
.nf
.in +4n
.IR mmap ()
.IR msync ()
.in
.fi
-.PP
+.P
This option implies the following options:
-.PP
+.P
.PD 0
.TP
.B _POSIX_FSYNC
.TP
.B _POSIX_THREADS
.PD
-.PP
+.P
This option may imply the following options from the XSI option groups:
-.PP
+.P
.PD 0
.TP
.RB "Encryption (" _XOPEN_CRYPT )