Node:Constants for Sysconf,
Next:Examples of Sysconf,
Previous:Sysconf Definition,
Up:Sysconf
Constants for sysconf Parameters
Here are the symbolic constants for use as the parameter argument
to sysconf.  The values are all integer constants (more
specifically, enumeration type values).
_SC_ARG_MAX
- Inquire about the parameter corresponding to 
ARG_MAX.
 _SC_CHILD_MAX
- Inquire about the parameter corresponding to 
CHILD_MAX.
 _SC_OPEN_MAX
- Inquire about the parameter corresponding to 
OPEN_MAX.
 _SC_STREAM_MAX
- Inquire about the parameter corresponding to 
STREAM_MAX.
 _SC_TZNAME_MAX
- Inquire about the parameter corresponding to 
TZNAME_MAX.
 _SC_NGROUPS_MAX
- Inquire about the parameter corresponding to 
NGROUPS_MAX.
 _SC_JOB_CONTROL
- Inquire about the parameter corresponding to 
_POSIX_JOB_CONTROL.
 _SC_SAVED_IDS
- Inquire about the parameter corresponding to 
_POSIX_SAVED_IDS.
 _SC_VERSION
- Inquire about the parameter corresponding to 
_POSIX_VERSION.
 _SC_CLK_TCK
- Inquire about the parameter corresponding to 
CLOCKS_PER_SEC;
see CPU Time.
 _SC_CHARCLASS_NAME_MAX
- Inquire about the parameter corresponding to maximal length allowed for
a character class name in an extended locale specification.  These
extensions are not yet standardized and so this option is not standardized
as well.
 _SC_REALTIME_SIGNALS
- Inquire about the parameter corresponding to 
_POSIX_REALTIME_SIGNALS.
 _SC_PRIORITY_SCHEDULING
- Inquire about the parameter corresponding to 
_POSIX_PRIORITY_SCHEDULING.
 _SC_TIMERS
- Inquire about the parameter corresponding to 
_POSIX_TIMERS.
 _SC_ASYNCHRONOUS_IO
- Inquire about the parameter corresponding to 
_POSIX_ASYNCHRONOUS_IO.
 _SC_PRIORITIZED_IO
- Inquire about the parameter corresponding to 
_POSIX_PRIORITIZED_IO.
 _SC_SYNCHRONIZED_IO
- Inquire about the parameter corresponding to 
_POSIX_SYNCHRONIZED_IO.
 _SC_FSYNC
- Inquire about the parameter corresponding to 
_POSIX_FSYNC.
 _SC_MAPPED_FILES
- Inquire about the parameter corresponding to 
_POSIX_MAPPED_FILES.
 _SC_MEMLOCK
- Inquire about the parameter corresponding to 
_POSIX_MEMLOCK.
 _SC_MEMLOCK_RANGE
- Inquire about the parameter corresponding to 
_POSIX_MEMLOCK_RANGE.
 _SC_MEMORY_PROTECTION
- Inquire about the parameter corresponding to 
_POSIX_MEMORY_PROTECTION.
 _SC_MESSAGE_PASSING
- Inquire about the parameter corresponding to 
_POSIX_MESSAGE_PASSING.
 _SC_SEMAPHORES
- Inquire about the parameter corresponding to 
_POSIX_SEMAPHORES.
 _SC_SHARED_MEMORY_OBJECTS
- Inquire about the parameter corresponding to
_POSIX_SHARED_MEMORY_OBJECTS.
 _SC_AIO_LISTIO_MAX
- Inquire about the parameter corresponding to 
_POSIX_AIO_LISTIO_MAX.
 _SC_AIO_MAX
- Inquire about the parameter corresponding to 
_POSIX_AIO_MAX.
 _SC_AIO_PRIO_DELTA_MAX
- Inquire the value by which a process can decrease its asynchronous I/O
priority level from its own scheduling priority.  This corresponds to the
run-time invariant value 
AIO_PRIO_DELTA_MAX.
 _SC_DELAYTIMER_MAX
- Inquire about the parameter corresponding to 
_POSIX_DELAYTIMER_MAX.
 _SC_MQ_OPEN_MAX
- Inquire about the parameter corresponding to 
_POSIX_MQ_OPEN_MAX.
 _SC_MQ_PRIO_MAX
- Inquire about the parameter corresponding to 
_POSIX_MQ_PRIO_MAX.
 _SC_RTSIG_MAX
- Inquire about the parameter corresponding to 
_POSIX_RTSIG_MAX.
 _SC_SEM_NSEMS_MAX
- Inquire about the parameter corresponding to 
_POSIX_SEM_NSEMS_MAX.
 _SC_SEM_VALUE_MAX
- Inquire about the parameter corresponding to 
_POSIX_SEM_VALUE_MAX.
 _SC_SIGQUEUE_MAX
- Inquire about the parameter corresponding to 
_POSIX_SIGQUEUE_MAX.
 _SC_TIMER_MAX
- Inquire about the parameter corresponding to 
_POSIX_TIMER_MAX.
 _SC_PII
- Inquire about the parameter corresponding to 
_POSIX_PII.
 _SC_PII_XTI
- Inquire about the parameter corresponding to 
_POSIX_PII_XTI.
 _SC_PII_SOCKET
- Inquire about the parameter corresponding to 
_POSIX_PII_SOCKET.
 _SC_PII_INTERNET
- Inquire about the parameter corresponding to 
_POSIX_PII_INTERNET.
 _SC_PII_OSI
- Inquire about the parameter corresponding to 
_POSIX_PII_OSI.
 _SC_SELECT
- Inquire about the parameter corresponding to 
_POSIX_SELECT.
 _SC_UIO_MAXIOV
- Inquire about the parameter corresponding to 
_POSIX_UIO_MAXIOV.
 _SC_PII_INTERNET_STREAM
- Inquire about the parameter corresponding to 
_POSIX_PII_INTERNET_STREAM.
 _SC_PII_INTERNET_DGRAM
- Inquire about the parameter corresponding to 
_POSIX_PII_INTERNET_DGRAM.
 _SC_PII_OSI_COTS
- Inquire about the parameter corresponding to 
_POSIX_PII_OSI_COTS.
 _SC_PII_OSI_CLTS
- Inquire about the parameter corresponding to 
_POSIX_PII_OSI_CLTS.
 _SC_PII_OSI_M
- Inquire about the parameter corresponding to 
_POSIX_PII_OSI_M.
 _SC_T_IOV_MAX
- Inquire the value of the value associated with the 
T_IOV_MAX
variable.
 _SC_THREADS
- Inquire about the parameter corresponding to 
_POSIX_THREADS.
 _SC_THREAD_SAFE_FUNCTIONS
- Inquire about the parameter corresponding to
_POSIX_THREAD_SAFE_FUNCTIONS.
 _SC_GETGR_R_SIZE_MAX
- Inquire about the parameter corresponding to 
_POSIX_GETGR_R_SIZE_MAX.
 _SC_GETPW_R_SIZE_MAX
- Inquire about the parameter corresponding to 
_POSIX_GETPW_R_SIZE_MAX.
 _SC_LOGIN_NAME_MAX
- Inquire about the parameter corresponding to 
_POSIX_LOGIN_NAME_MAX.
 _SC_TTY_NAME_MAX
- Inquire about the parameter corresponding to 
_POSIX_TTY_NAME_MAX.
 _SC_THREAD_DESTRUCTOR_ITERATIONS
- Inquire about the parameter corresponding to
_POSIX_THREAD_DESTRUCTOR_ITERATIONS.
 _SC_THREAD_KEYS_MAX
- Inquire about the parameter corresponding to 
_POSIX_THREAD_KEYS_MAX.
 _SC_THREAD_STACK_MIN
- Inquire about the parameter corresponding to 
_POSIX_THREAD_STACK_MIN.
 _SC_THREAD_THREADS_MAX
- Inquire about the parameter corresponding to 
_POSIX_THREAD_THREADS_MAX.
 _SC_THREAD_ATTR_STACKADDR
- Inquire about the parameter corresponding to
a
_POSIX_THREAD_ATTR_STACKADDR.
 _SC_THREAD_ATTR_STACKSIZE
- Inquire about the parameter corresponding to
_POSIX_THREAD_ATTR_STACKSIZE.
 _SC_THREAD_PRIORITY_SCHEDULING
- Inquire about the parameter corresponding to
_POSIX_THREAD_PRIORITY_SCHEDULING.
 _SC_THREAD_PRIO_INHERIT
- Inquire about the parameter corresponding to 
_POSIX_THREAD_PRIO_INHERIT.
 _SC_THREAD_PRIO_PROTECT
- Inquire about the parameter corresponding to 
_POSIX_THREAD_PRIO_PROTECT.
 _SC_THREAD_PROCESS_SHARED
- Inquire about the parameter corresponding to
_POSIX_THREAD_PROCESS_SHARED.
 _SC_2_C_DEV
- Inquire about whether the system has the POSIX.2 C compiler command,
c89.
 _SC_2_FORT_DEV
- Inquire about whether the system has the POSIX.2 Fortran compiler
command, 
fort77.
 _SC_2_FORT_RUN
- Inquire about whether the system has the POSIX.2 
asa command to
interpret Fortran carriage control.
 _SC_2_LOCALEDEF
- Inquire about whether the system has the POSIX.2 
localedef
command.
 _SC_2_SW_DEV
- Inquire about whether the system has the POSIX.2 commands 
ar,
make, and strip.
 _SC_BC_BASE_MAX
- Inquire about the maximum value of 
obase in the bc
utility.
 _SC_BC_DIM_MAX
- Inquire about the maximum size of an array in the 
bc
utility.
 _SC_BC_SCALE_MAX
- Inquire about the maximum value of 
scale in the bc
utility.
 _SC_BC_STRING_MAX
- Inquire about the maximum size of a string constant in the
bc utility.
 _SC_COLL_WEIGHTS_MAX
- Inquire about the maximum number of weights that can necessarily
be used in defining the collating sequence for a locale.
 _SC_EXPR_NEST_MAX
- Inquire about the maximum number of expressions nested within
parentheses when using the 
expr utility.
 _SC_LINE_MAX
- Inquire about the maximum size of a text line that the POSIX.2 text
utilities can handle.
 _SC_EQUIV_CLASS_MAX
- Inquire about the maximum number of weights that can be assigned to an
entry of the 
LC_COLLATE category order keyword in a locale
definition.  The GNU C library does not presently support locale
definitions.
 _SC_VERSION
- Inquire about the version number of POSIX.1 that the library and kernel
support.
 _SC_2_VERSION
- Inquire about the version number of POSIX.2 that the system utilities
support.
 _SC_PAGESIZE
- Inquire about the virtual memory page size of the machine. 
getpagesize returns the same value (see Query Memory Parameters).
 _SC_NPROCESSORS_CONF
- Inquire about the number of configured processors.
 _SC_NPROCESSORS_ONLN
- Inquire about the number of processors online.
 _SC_PHYS_PAGES
- Inquire about the number of physical pages in the system.
 _SC_AVPHYS_PAGES
- Inquire about the number of available physical pages in the system.
 _SC_ATEXIT_MAX
- Inquire about the number of functions which can be registered as termination
functions for 
atexit; see Cleanups on Exit.
 _SC_XOPEN_VERSION
- Inquire about the parameter corresponding to 
_XOPEN_VERSION.
 _SC_XOPEN_XCU_VERSION
- Inquire about the parameter corresponding to 
_XOPEN_XCU_VERSION.
 _SC_XOPEN_UNIX
- Inquire about the parameter corresponding to 
_XOPEN_UNIX.
 _SC_XOPEN_REALTIME
- Inquire about the parameter corresponding to 
_XOPEN_REALTIME.
 _SC_XOPEN_REALTIME_THREADS
- Inquire about the parameter corresponding to 
_XOPEN_REALTIME_THREADS.
 _SC_XOPEN_LEGACY
- Inquire about the parameter corresponding to 
_XOPEN_LEGACY.
 _SC_XOPEN_CRYPT
- Inquire about the parameter corresponding to 
_XOPEN_CRYPT.
 _SC_XOPEN_ENH_I18N
- Inquire about the parameter corresponding to 
_XOPEN_ENH_I18N.
 _SC_XOPEN_SHM
- Inquire about the parameter corresponding to 
_XOPEN_SHM.
 _SC_XOPEN_XPG2
- Inquire about the parameter corresponding to 
_XOPEN_XPG2.
 _SC_XOPEN_XPG3
- Inquire about the parameter corresponding to 
_XOPEN_XPG3.
 _SC_XOPEN_XPG4
- Inquire about the parameter corresponding to 
_XOPEN_XPG4.
 _SC_CHAR_BIT
- Inquire about the number of bits in a variable of type 
char.
 _SC_CHAR_MAX
- Inquire about the maximum value which can be stored in a variable of type
char.
 _SC_CHAR_MIN
- Inquire about the minimum value which can be stored in a variable of type
char.
 _SC_INT_MAX
- Inquire about the maximum value which can be stored in a variable of type
int.
 _SC_INT_MIN
- Inquire about the minimum value which can be stored in a variable of type
int.
 _SC_LONG_BIT
- Inquire about the number of bits in a variable of type 
long int.
 _SC_WORD_BIT
- Inquire about the number of bits in a variable of a register word.
 _SC_MB_LEN_MAX
- Inquire the maximum length of a multi-byte representation of a wide
character value.
 _SC_NZERO
- Inquire about the value used to internally represent the zero priority level for
the process execution.
 SC_SSIZE_MAX
- Inquire about the maximum value which can be stored in a variable of type
ssize_t.
 _SC_SCHAR_MAX
- Inquire about the maximum value which can be stored in a variable of type
signed char.
 _SC_SCHAR_MIN
- Inquire about the minimum value which can be stored in a variable of type
signed char.
 _SC_SHRT_MAX
- Inquire about the maximum value which can be stored in a variable of type
short int.
 _SC_SHRT_MIN
- Inquire about the minimum value which can be stored in a variable of type
short int.
 _SC_UCHAR_MAX
- Inquire about the maximum value which can be stored in a variable of type
unsigned char.
 _SC_UINT_MAX
- Inquire about the maximum value which can be stored in a variable of type
unsigned int.
 _SC_ULONG_MAX
- Inquire about the maximum value which can be stored in a variable of type
unsigned long int.
 _SC_USHRT_MAX
- Inquire about the maximum value which can be stored in a variable of type
unsigned short int.
 _SC_NL_ARGMAX
- Inquire about the parameter corresponding to 
NL_ARGMAX.
 _SC_NL_LANGMAX
- Inquire about the parameter corresponding to 
NL_LANGMAX.
 _SC_NL_MSGMAX
- Inquire about the parameter corresponding to 
NL_MSGMAX.
 _SC_NL_NMAX
- Inquire about  the parameter corresponding to 
NL_NMAX.
 _SC_NL_SETMAX
- Inquire about the parameter corresponding to 
NL_SETMAX.
 _SC_NL_TEXTMAX
- Inquire about the parameter corresponding to 
NL_TEXTMAX.