posixoptions man page
posixoptions ā optional parts of the POSIX standard The POSIX standard (the information below is from POSIX.1-2001) describes a set of behaviors and interfaces for a compliant system. However, many interfaces are optional and there are feature test macros to test the availability of interfaces at compile time, and functions sysconf(3), fpathconf(3), pathconf(3), confstr(3) to do this at run time. From shell scripts one can use getconf(1). For more detail, see sysconf(3). We give the name of the POSIX abbreviation, the option, the name of the sysconf(3) parameter used to inquire about the option, and possibly a very short description. Much more precise detail can be found in the POSIX standard itself, versions of which can nowadays be accessed freely on the web. The following advisory functions are present: The header <aio.h> is present. The following functions are present: This option implies the _POSIX_THREADS and _POSIX_THREAD_SAFE_FUNCTIONS options. The following functions are present: 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 following functions This option implies the _POSIX_TIMERS option. The following functions are present: If CLOCK_REALTIME is changed by the function clock_settime(), then this affects all timers set for an absolute time. The CLOCK_PROCESS_CPUTIME_ID clock 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. This option has been deleted. Not in final XPG6. The function fsync() is present. Internet Protocol Version 6 is supported. 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: Shared memory is supported. The include file <sys/mman.h> is present. The following functions are present: Shared memory can be locked into core. The following functions are present: More precisely, ranges can be locked into core. The following functions are present: The function mprotect() is present. The include file <mqueue.h> is present. The following functions are present: CLOCK_MONOTONIC is supported. This option implies the _POSIX_TIMERS option. The following functions are affected: This option has been deleted. Not in final XPG6. 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. This option says that one can specify priorities for asynchronous I/O. This affects the functions The include file <sched.h> is present. The following functions are present: If also _POSIX_SPAWN is in effect, then the following functions are present: Raw sockets are supported. The following functions are affected: This option implies the _POSIX_THREADS option. Conversely, under POSIX.1-2001 the _POSIX_THREADS option implies this option. The following functions are present: Realtime signals are supported. The following functions are present: 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: 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: The include file <semaphore.h> is present. The following functions are present: If this option is in effect (as it always is under POSIX.1-2001), the function system() is present. 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: If also _POSIX_PRIORITY_SCHEDULING is in effect, then the following functions are present: This option implies the _POSIX_THREADS and _POSIX_THREAD_SAFE_FUNCTIONS options. The following functions are present: The scheduling policy SCHED_SPORADIC is supported. This option implies the _POSIX_PRIORITY_SCHEDULING option. The following functions are affected: The following functions are affected: The following functions are affected: The following functions are affected: The clockID CLOCK_THREAD_CPUTIME_ID is supported. This option implies the _POSIX_TIMERS option. The following functions are affected: The following functions are affected: The following functions are affected: 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: The following functions are affected: This option implies the _POSIX_THREAD_PRIORITY_SCHEDULING option. The following functions are affected: Basic support for POSIX threads is available. The following functions are present: The following functions are present: The following functions are present: POSIX tracing is available. The following functions are present: This option implies the _POSIX_TRACE option. The following functions are present: Tracing children of the traced process is supported. This option implies the _POSIX_TRACE option. The following functions are present: This option implies the _POSIX_TRACE option. The following functions are present: The following functions are present: Always present (probably 0). Value to set a changeable special control character to indicate that it is disabled. The following functions are present: This option implies the following options: _POSIX_ASYNCHRONOUS_IO==200112L _POSIX_FSYNC _POSIX_MAPPED_FILES _POSIX_MEMLOCK==200112L _POSIX_MEMLOCK_RANGE==200112L _POSIX_MEMORY_PROTECTION _POSIX_MESSAGE_PASSING==200112L _POSIX_PRIORITIZED_IO _POSIX_PRIORITY_SCHEDULING==200112L _POSIX_REALTIME_SIGNALS==200112L _POSIX_SEMAPHORES==200112L _POSIX_SHARED_MEMORY_OBJECTS==200112L _POSIX_SYNCHRONIZED_IO==200112L _POSIX_TIMERS==200112L The Advanced Realtime option group implies that the following options are all defined to 200112L: (implies _POSIX_TIMERS) (implies _POSIX_TIMERS) (implies _POSIX_TIMERS) (implies _POSIX_PRIORITY_SCHEDULING) _POSIX_TIMEOUTS _POSIX_TYPED_MEMORY_OBJECTS This option implies that the following options are all defined to 200112L: _POSIX_THREAD_PRIO_INHERIT _POSIX_THREAD_PRIO_PROTECT _POSIX_THREAD_PRIORITY_SCHEDULING This option implies that the following options are all defined to 200112L: (implies _POSIX_THREADS, _POSIX_THREAD_SAFE_FUNCTIONS) (implies _POSIX_THREADS, _POSIX_THREAD_SAFE_FUNCTIONS) (implies _POSIX_TIMERS) (implies _POSIX_THREAD_PRIORITY_SCHEDULING) This option implies that the following options are all defined to 200112L: _POSIX_TRACE _POSIX_TRACE_EVENT_FILTER _POSIX_TRACE_LOG _POSIX_TRACE_INHERIT The following functions are present: Functions included in the legacy option group were previously mandatory, but are now optional in this version. The following functions are present: The following functions are present: This option implies the following options: _POSIX_FSYNC _POSIX_MAPPED_FILES _POSIX_MEMORY_PROTECTION _POSIX_THREAD_ATTR_STACKADDR _POSIX_THREAD_ATTR_STACKSIZE _POSIX_THREAD_PROCESS_SHARED _POSIX_THREAD_SAFE_FUNCTIONS _POSIX_THREADS This option may imply the following options from the XSI option groups: Encryption (_XOPEN_CRYPT) Realtime (_XOPEN_REALTIME) Advanced Realtime (ADB) Realtime Threads (_XOPEN_REALTIME_THREADS) Advanced Realtime Threads (ADVANCED REALTIME THREADS) Tracing (TRACING) XSI Streams (STREAMS) Legacy (_XOPEN_LEGACY) This page is part of release 5.04 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/. procenv(1), standards(7), sysconf(3).Description
Adv - _posix_advisory_info - _sc_advisory_info
posix_fadvise()
posix_fallocate()
posix_memalign()
posix_madvise()
Aio - _posix_asynchronous_io - _sc_asynchronous_io
aio_cancel()
aio_error()
aio_fsync()
aio_read()
aio_return()
aio_suspend()
aio_write()
lio_listio()
Bar - _posix_barriers - _sc_barriers
pthread_barrier_destroy()
pthread_barrier_init()
pthread_barrier_wait()
pthread_barrierattr_destroy()
pthread_barrierattr_init()
--- - Posix_chown_restricted
chown()
fchown()
CS - _posix_clock_selection - _sc_clock_selection
pthread_condattr_getclock()
pthread_condattr_setclock()
clock_nanosleep()
CPT - _posix_cputime - _sc_cputime
--- - _posix_file_locking - _sc_file_locking
FSC - _posix_fsync - _sc_fsync
Ip6 - _posix_ipv6 - _sc_ipv6
--- - _posix_job_control - _sc_job_control
setpgid()
tcdrain()
tcflush()
tcgetpgrp()
tcsendbreak()
tcsetattr()
tcsetpgrp()
MF - _posix_mapped_files - _sc_mapped_files
mmap()
msync()
munmap()
ML - _posix_memlock - _sc_memlock
mlockall()
munlockall()
Mr/Mlr - _posix_memlock_range - _sc_memlock_range
mlock()
munlock()
MPR - _posix_memory_protection - _sc_memory_protection
MSG - _posix_message_passing - _sc_message_passing
mq_close()
mq_getattr()
mq_notify()
mq_open()
mq_receive()
mq_send()
mq_setattr()
mq_unlink()
Mon - _posix_monotonic_clock - _sc_monotonic_clock
aio_suspend()
clock_getres()
clock_gettime()
clock_settime()
timer_create()
--- - _posix_multi_process - _sc_multi_process
--- - _posix_no_trunc
Pio - _posix_prioritized_io - _sc_prioritized_io
aio_read()
aio_write()
PS - _posix_priority_scheduling - _sc_priority_scheduling
sched_get_priority_max()
sched_get_priority_min()
sched_getparam()
sched_getscheduler()
sched_rr_get_interval()
sched_setparam()
sched_setscheduler()
sched_yield()
posix_spawnattr_getschedparam()
posix_spawnattr_getschedpolicy()
posix_spawnattr_setschedparam()
posix_spawnattr_setschedpolicy()
RS - _posix_raw_sockets
getsockopt()
setsockopt()
--- - _posix_reader_writer_locks - _sc_reader_writer_locks
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
sigqueue()
sigtimedwait()
sigwaitinfo()
--- - _posix_regexp - _sc_regexp
regcomp()
regerror()
regexec()
regfree()
--- - _posix_saved_ids - _sc_saved_ids
exec()
kill()
seteuid()
setegid()
setgid()
setuid()
Sem - _posix_semaphores - _sc_semaphores
sem_close()
sem_destroy()
sem_getvalue()
sem_init()
sem_open()
sem_post()
sem_trywait()
sem_unlink()
sem_wait()
--- - _posix_shell - _sc_shell
SPN - _posix_spawn - _sc_spawn
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()
posix_spawnattr_getschedparam()
posix_spawnattr_getschedpolicy()
posix_spawnattr_setschedparam()
posix_spawnattr_setschedpolicy()
Spi - _posix_spin_locks - _sc_spin_locks
pthread_spin_destroy()
pthread_spin_init()
pthread_spin_lock()
pthread_spin_trylock()
pthread_spin_unlock()
SS - _posix_sporadic_server - _sc_sporadic_server
sched_setparam()
sched_setscheduler()
Sio - _posix_synchronized_io - _sc_synchronized_io
open()
msync()
fsync()
fdatasync()
Tsa - _posix_thread_attr_stackaddr - _sc_thread_attr_stackaddr
pthread_attr_getstack()
pthread_attr_getstackaddr()
pthread_attr_setstack()
pthread_attr_setstackaddr()
TSS - _posix_thread_attr_stacksize - _sc_thread_attr_stacksize
pthread_attr_getstack()
pthread_attr_getstacksize()
pthread_attr_setstack()
pthread_attr_setstacksize()
TCT - _posix_thread_cputime - _sc_thread_cputime
pthread_getcpuclockid()
clock_getres()
clock_gettime()
clock_settime()
timer_create()
Tpi - _posix_thread_prio_inherit - _sc_thread_prio_inherit
pthread_mutexattr_getprotocol()
pthread_mutexattr_setprotocol()
TPP - _posix_thread_prio_protect - _sc_thread_prio_protect
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
pthread_attr_getinheritsched()
pthread_attr_getschedpolicy()
pthread_attr_getscope()
pthread_attr_setinheritsched()
pthread_attr_setschedpolicy()
pthread_attr_setscope()
pthread_getschedparam()
pthread_setschedparam()
pthread_setschedprio()
TSF - _posix_thread_safe_functions - _sc_thread_safe_functions
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
sched_getparam()
sched_setparam()
sched_setscheduler()
THR - _posix_threads - _sc_threads
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
mq_timedreceive()
mq_timedsend()
pthread_mutex_timedlock()
pthread_rwlock_timedrdlock()
pthread_rwlock_timedwrlock()
sem_timedwait()
posix_trace_timedgetnext_event()
TMR - _posix_timers - _sc_timers
clock_getres()
clock_gettime()
clock_settime()
nanosleep()
timer_create()
timer_delete()
timer_gettime()
timer_getoverrun()
timer_settime()
TRC - _posix_trace - _sc_trace
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
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
posix_trace_attr_getinherited()
posix_trace_attr_setinherited()
TRL - _posix_trace_log - _sc_trace_log
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
posix_mem_offset()
posix_typed_mem_get_info()
posix_typed_mem_open()
--- - _posix_vdisable
X/Open System Interface Extensions
Xsi - _xopen_crypt - _sc_xopen_crypt
crypt()
encrypt()
setkey()
Xsi - _xopen_realtime - _sc_xopen_realtime
Adv - --- - ---
Xsi - _xopen_realtime_threads - _sc_xopen_realtime_threads
Advanced Realtime Threads - --- - ---
Tracing - --- - ---
Streams - _xopen_streams - _sc_xopen_streams
fattach()
fdetach()
getmsg()
getpmsg()
ioctl()
isastream()
putmsg()
putpmsg()
Xsi - _xopen_legacy - _sc_xopen_legacy
bcmp()
bcopy()
bzero()
ecvt()
fcvt()
ftime()
gcvt()
getcwd()
index()
mktemp()
rindex()
utimes()
wcswcs()
Xsi - _xopen_unix - _sc_xopen_unix
mmap()
munmap()
msync()
See Also
Colophon
Referenced By