NAME
posixoptions - optional parts of the POSIX standard DESCRIPTION
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.
ADV - POSIXADVISORYINFO - SCADVISORYINFO The following advisory functions are present: posixfadvise(), posixfallocate(), posixmemalign(), posixmadvise().
AIO - POSIXASYNCHRONOUSIO - SCASYNCHRONOUSIO The header
is present. The following functions are present: aiocancel(), aioerror(), aiofsync(), aioread(), aioreturn(), aiosuspend(), aiowrite(), liolistio(). BAR - POSIXBARRIERS - SCBARRIERS This option implies the POSIXTHREADS and POSIXTHREADSAFEFUNCTIONS options. The following functions are present: pthreadbarrierdestroy(), pthreadbarrierinit(), pthreadbarrierwait(), pthreadbarrierattrdestroy(), pthreadbarrierattrinit().
- - POSIXCHOWNRESTRICTED
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 - POSIXCLOCKSELECTION - SCCLOCKSELECTION This option implies the POSIXTIMERS option. The following functions are present: pthreadcondattrgetclock(), pthreadcondattrsetclock(), clocknanosleep(). If CLOCKREALTIME is changed by the function clocksettime(), then this affects all timers set for an absolute time.
CPT - POSIXCPUTIME - SCCPUTIME The clockID CLOCKPROCESSCPUTIMEID is supported. The initial value of this clock is 0 for each process. This option implies the POSIXTIMERS option. The function clockgetcpuclockid() is present.
- - POSIXFILELOCKING - SCFILELOCKING This option has been deleted. Not in final XPG6.
FSC - POSIXFSYNC - SCFSYNC The function fsync() is present.
IP6 - POSIXIPV6 - SCIPV6 Internet Protocol Version 6 is supported.
- - POSIXJOBCONTROL - SCJOBCONTROL
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 func‐ tions are present: setpgid(), tcdrain(), tcflush(), tcgetpgrp(), tcsendbreak(), tcsetattr(), tcsetpgrp().
MF - POSIXMAPPEDFILES - SCMAPPEDFILES Shared memory is supported. The include file
is present. The following functions are present: mmap(), msync(), munmap(). ML - POSIXMEMLOCK - SCMEMLOCK Shared memory can be locked into core. The functions mlockall(), munlockall() are present.
MR/MLR - POSIXMEMLOCKRANGE - SCMEMLOCKRANGE More precisely, ranges can be locked into core. The functions mlock(), munlock() are present.
MPR - POSIXMEMORYPROTECTION - SCMEMORYPROTECTION The function mprotect() is present.
MSG - POSIXMESSAGEPASSING - SCMESSAGEPASSING The include file
is present. The following functions are present: mqclose(), mqgetattr(), mqnotify(), mqopen(), mqreceive(), mqsend(), mqsetattr(), mqunlink(). MON - POSIXMONOTONICCLOCK - SCMONOTONICCLOCK CLOCKMONOTONIC is supported. This option implies the POSIXTIMERS option. Affected functions are aiosuspend(), clockgetres(), clockgettime(), clocksettime(), timercreate().
- - POSIXMULTIPROCESS - SCMULTIPROCESS This option has been deleted. Not in final XPG6.
- - POSIXNOTRUNC
If this option is in effect (as it always is under POSIX.1-2001) then pathname components longer than NAMEMAX are not truncated, but give an error. This property may be dependent on the path prefix of the compo‐ nent.
PIO - POSIXPRIORITIZEDIO - SCPRIORITIZEDIO This option says that one can specify priorities for asynchronous I/O. This affects the functions aioread(), aiowrite().
PS - POSIXPRIORITYSCHEDULING - SCPRIORITYSCHEDULING The include file
is present. The following functions are present: schedgetprioritymax(), schedgetprioritymin(), schedgetparam(), schedgetscheduler(), schedrrgetinterval(), schedsetparam(), schedsetscheduler(), schedyield(). If also POSIXSPAWN is in effect, then the following functions are present: posixspawnattrgetschedparam(), posixspawnattrgetschedpolicy(), posixspawnattrsetschedparam(), posixspawnattrsetschedpolicy(). RS - POSIXRAWSOCKETS Raw sockets are supported. Affected functions are getsockopt(), set‐ sockopt().
- - POSIXREADERWRITERLOCKS - SCREADERWRITERLOCKS This option implies the POSIXTHREADS option. Conversely, under
POSIX.1-2001 the POSIXTHREADS option implies this option. The following functions are present: pthreadrwlockdestroy(), pthreadrwlockinit(), pthreadrwlockrdlock(), pthreadrwlocktryrdlock(), pthreadrwlocktrywrlock(), pthreadrwlockunlock(), pthreadrwlockwrlock(), pthreadrwlockattrdestroy(), pthreadrwlockattrinit().
RTS - POSIXREALTIMESIGNALS - SCREALTIMESIGNALS Realtime signals are supported. The following functions are present: sigqueue(), sigtimedwait(), sigwaitinfo().
- - POSIXREGEXP - SCREGEXP
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().
- - POSIXSAVEDIDS - SCSAVEDIDS
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 - POSIXSEMAPHORES - SCSEMAPHORES The include file
is present. The following functions are present: semclose(), semdestroy(), semgetvalue(), seminit(), semopen(), sempost(), semtrywait(), semunlink(), semwait(). SHM - POSIXSHAREDMEMORYOBJECTS - SCSHAREDMEMORYOBJECTS The following functions are present: mmap(), munmap(), shmopen(), shmunlink().
- - POSIXSHELL - SCSHELL
If this option is in effect (as it always is under POSIX.1-2001), the function system() is present.
SPN - POSIXSPAWN - SCSPAWN 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 POSIXSPAWN is in effect, then the include file
and the following functions are present: posixspawn(), posixspawnfileactionsaddclose(), posixspawnfileactionsadddup2(), posixspawnfileactionsaddopen(), posixspawnfileactionsdestroy(), posixspawnfileactionsinit(), posixspawnattrdestroy(), posixspawnattrgetsigdefault(), posixspawnattrgetflags(), posixspawnattrgetpgroup(), posixspawnattrgetsigmask(), posixspawnattrinit(), posixspawnattrsetsigdefault(), posixspawnattrsetflags(), posixspawnattrsetpgroup(), posixspawnattrsetsigmask(), posixspawnp(). If also POSIXPRIORITYSCHEDULING is in effect, then the following functions are present: posixspawnattrgetschedparam(), posixspawnattrgetschedpolicy(), posixspawnattrsetschedparam(), posixspawnattrsetschedpolicy(). SPI - POSIXSPINLOCKS - SCSPINLOCKS This option implies the POSIXTHREADS and POSIXTHREADSAFEFUNCTIONS options. The following functions are present: pthreadspindestroy(), pthreadspininit(), pthreadspinlock(), pthreadspintrylock(), pthreadspinunlock().
SS - POSIXSPORADICSERVER - SCSPORADICSERVER The scheduling policy SCHEDSPORADIC is supported. This option implies the POSIXPRIORITYSCHEDULING option. Affected functions are schedsetparam(), schedsetscheduler().
SIO - POSIXSYNCHRONIZEDIO - SCSYNCHRONIZEDIO Affected functions are open(), msync(), fsync(), fdatasync().
TSA - POSIXTHREADATTRSTACKADDR - SCTHREADATTRSTACKADDR Affected functions are pthreadattrgetstack(), pthreadattrgetstackaddr(), pthreadattrsetstack(), pthreadattrsetstackaddr().
TSS - POSIXTHREADATTRSTACKSIZE - SCTHREADATTRSTACKSIZE Affected functions are pthreadattrgetstack(), pthreadattrgetstacksize(), pthreadattrsetstack(), pthreadattrsetstacksize().
TCT - POSIXTHREADCPUTIME - SCTHREADCPUTIME The clockID CLOCKTHREADCPUTIMEID is supported. This option implies the POSIXTIMERS option. Affected functions are pthreadgetcpuclockid(), clockgetres(), clockgettime(), clocksettime(), timercreate().
TPI - POSIXTHREADPRIOINHERIT - SCTHREADPRIOINHERIT Affected functions are pthreadmutexattrgetprotocol(), pthreadmutexattrsetprotocol().
TPP - POSIXTHREADPRIOPROTECT - SCTHREADPRIOPROTECT Affected functions are pthreadmutexgetprioceiling(), pthreadmutexsetprioceiling(), pthreadmutexattrgetprioceiling(), pthreadmutexattrgetprotocol(), pthreadmutexattrsetprioceiling(), pthreadmutexattrsetprotocol().
TPS - POSIXTHREADPRIORITYSCHEDULING - SCTHREADPRIORITYSCHEDULING If this option is in effect, the different threads inside a process can run with different priorities and/or different schedulers. Affected functions are pthreadattrgetinheritsched(), pthreadattrgetschedpolicy(), pthreadattrgetscope(), pthreadattrsetinheritsched(), pthreadattrsetschedpolicy(), pthreadattrsetscope(), pthreadgetschedparam(), pthreadsetschedparam(), pthreadsetschedprio().
TSH - POSIXTHREADPROCESSSHARED - SCTHREADPROCESSSHARED Affected functions are pthreadbarrierattrgetpshared(), pthreadbarrierattrsetpshared(), pthreadcondattrgetpshared(), pthreadcondattrsetpshared(), pthreadmutexattrgetpshared(), pthreadmutexattrsetpshared(), pthreadrwlockattrgetpshared(), pthreadrwlockattrsetpshared().
TSF - POSIXTHREADSAFEFUNCTIONS - SCTHREADSAFEFUNCTIONS Affected functions are readdirr(), getgrgidr(), getgrnamr(), getpwnamr(), getpwuidr(), flockfile(), ftrylockfile(), funlockfile(), getcunlocked(), getcharunlocked(), putcunlocked(), putcharunlocked(), randr(), strerrorr(), strtokr(), asctimer(), ctimer(), gmtimer(), localtimer().
TSP - POSIXTHREADSPORADICSERVER - SCTHREADSPORADICSERVER This option implies the POSIXTHREADPRIORITYSCHEDULING option. Affected functions are schedgetparam(), schedsetparam(), schedsetscheduler().
THR - POSIXTHREADS - SCTHREADS Basic support for POSIX threads is available. The following functions are present: pthreadatfork(), pthreadattrdestroy(), pthreadattrgetdetachstate(), pthreadattrgetschedparam(), pthreadattrinit(), pthreadattrsetdetachstate(), pthreadattrsetschedparam(), pthreadcancel(), pthreadcleanuppush(), pthreadcleanuppop(), pthreadcondbroadcast(), pthreadconddestroy(), pthreadcondinit(), pthreadcondsignal(), pthreadcondtimedwait(), pthreadcondwait(), pthreadcondattrdestroy(), pthreadcondattrinit(), pthreadcreate(), pthreaddetach(), pthreadequal(), pthreadexit(), pthreadgetspecific(), pthreadjoin(), pthreadkeycreate(), pthreadkeydelete(), pthreadmutexdestroy(), pthreadmutexinit(), pthreadmutexlock(), pthreadmutextrylock(), pthreadmutexunlock(), pthreadmutexattrdestroy(), pthreadmutexattrinit(), pthreadonce(), pthreadrwlockdestroy(), pthreadrwlockinit(), pthreadrwlockrdlock(), pthreadrwlocktryrdlock(), pthreadrwlocktrywrlock(), pthreadrwlockunlock(), pthreadrwlockwrlock(), pthreadrwlockattrdestroy(), pthreadrwlockattrinit(), pthreadself(), pthreadsetcancelstate(), pthreadsetcanceltype(), pthreadsetspecific(), pthreadtestcancel().
TMO - POSIXTIMEOUTS - SCTIMEOUTS The following functions are present: mqtimedreceive(), mqtimedsend(), pthreadmutextimedlock(), pthreadrwlocktimedrdlock(), pthreadrwlocktimedwrlock(), semtimedwait(), posixtracetimedgetnextevent().
TMR - POSIXTIMERS - SCTIMERS The following functions are present: clockgetres(), clockgettime(), clocksettime(), nanosleep(), timercreate(), timerdelete(), timergettime(), timergetoverrun(), timersettime().
TRC - POSIXTRACE - SCTRACE POSIX tracing is available. The following functions are present: posixtraceattrdestroy(), posixtraceattrgetclockres(), posixtraceattrgetcreatetime(), posixtraceattrgetgenversion(), posixtraceattrgetmaxdatasize(), posixtraceattrgetmaxsystemeventsize(), posixtraceattrgetmaxusereventsize(), posixtraceattrgetname(), posixtraceattrgetstreamfullpolicy(), posixtraceattrgetstreamsize(), posixtraceattrinit(), posixtraceattrsetmaxdatasize(), posixtraceattrsetname(), posixtraceattrsetstreamsize(), posixtraceattrsetstreamfullpolicy(), posixtraceclear(), posixtracecreate(), posixtraceevent(), posixtraceeventidequal(), posixtraceeventidgetname(), posixtraceeventidopen(), posixtraceeventtypelistgetnextid(), posixtraceeventtypelistrewind(), posixtraceflush(), posixtracegetattr(), posixtracegetstatus(), posixtracegetnextevent(), posixtraceshutdown(), posixtracestart(), posixtracestop(), posixtracetrygetnextevent().
TEF - POSIXTRACEEVENTFILTER - SCTRACEEVENTFILTER This option implies the POSIXTRACE option. The following functions are present: posixtraceeventsetadd(), posixtraceeventsetdel(), posixtraceeventsetempty(), posixtraceeventsetfill(), posixtraceeventsetismember(), posixtracegetfilter(), posixtracesetfilter(), posixtracetrideventidopen().
TRI - POSIXTRACEINHERIT - SCTRACEINHERIT Tracing children of the traced process is supported. This option implies the POSIXTRACE option. The following functions are present: posixtraceattrgetinherited(), posixtraceattrsetinherited().
TRL - POSIXTRACELOG - SCTRACELOG This option implies the POSIXTRACE option. The following functions are present: posixtraceattrgetlogfullpolicy(), posixtraceattrgetlogsize(), posixtraceattrsetlogfullpolicy(), posixtraceattrsetlogsize(), posixtraceclose(), posixtracecreatewithlog(), posixtraceopen(), posixtracerewind().
TYM - POSIXTYPEDMEMORYOBJECTS - SCTYPEDMEMORYOBJECT The following functions are present: posixmemoffset(), posixtypedmemgetinfo(), posixtypedmemopen().
- - POSIXVDISABLE Always present (probably 0). Value to set a changeable special control character to indicate that it is disabled. XOPEN EXTENSIONS XOPENCRYPT, XOPENLEGACY, XOPENREALTIME, XOPENREALTIMETHREADS, XOPENUNIX. SEE ALSO sysconf(3), standards(7) COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
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2007-12-21 POSIXOPTIONS(7)