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OpenSolaris 2009.06 - man page for sysconf (opensolaris section 3c)

sysconf(3C)						   Standard C Library Functions 					       sysconf(3C)

sysconf - get configurable system variables
#include <unistd.h> long sysconf(int name);
The sysconf() function provides a method for an application to determine the current value of a configurable system limit or option (vari- able). The name argument represents the system variable to be queried. The following table lists the minimal set of system variables from <lim- its.h> and <unistd.h> that can be returned by sysconf() and the symbolic constants defined in <unistd.h> that are the corresponding values used for name on the SPARC and x86 platforms. Name Return Value Meaning _______________________________________________________________________ _SC_2_C_BIND _POSIX2_C_BIND Supports the C lang- uage binding option _SC_2_C_DEV _POSIX2_C_DEV Supports the C lang- uage development utilities option _SC_2_C_VERSION _POSIX2_C_VERSION Integer value indicates version of ISO POSIX-2 standard (Commands) _SC_2_CHAR_TERM _POSIX2_CHAR_TERM Supports at least one terminal _SC_2_FORT_DEV _POSIX2_FORT_DEV Supports FORTRAN Development Utilities Option _SC_2_FORT_RUN _POSIX2_FORT_RUN Supports FORTRAN Run-time Utilities Option _SC_2_LOCALEDEF _POSIX2_LOCALEDEF Supports creation of locales by the localedef utility _SC_2_SW_DEV _POSIX2_SW_DEV Supports Software Development Utility Option _SC_2_UPE _POSIX2_UPE Supports User Portability Utilities Option _SC_2_VERSION _POSIX2_VERSION Integer value indicates version of ISO POSIX-2 standard (C language binding) _SC_AIO_LISTIO_MAX AIO_LISTIO_MAX Max number of I/O operations in a single list I/O call supported _SC_AIO_MAX AIO_MAX Max number of outstanding asynchronous I/O operations supported _SC_AIO_PRIO_DELTA_MAX AIO_PRIO_DELTA_MAX Max amount by which process can decrease its asynchronous I/O priority level from its own scheduling priority _SC_ARG_MAX ARG_MAX Max size of argv[] plus envp[] _SC_ASYNCHRONOUS_IO _POSIX_ASYNCHRONOUS_IO Supports Asynchronous I/O _SC_ATEXIT_MAX ATEXIT_MAX Max number of functions that can be registered with atexit() _SC_AVPHYS_PAGES Number of physical memory pages not currently in use by system _SC_BARRIERS _POSIX_BARRIERS Supports Barriers option _SC_BC_BASE_MAX BC_BASE_MAX Maximum obase values allowed by bc _SC_BC_DIM_MAX BC_DIM_MAX Max number of elements permitted in array by bc _SC_BC_SCALE_MAX BC_SCALE_MAX Max scale value allowed by bc _SC_BC_STRING_MAX BC_STRING_MAX Max length of string constant allowed by bc _SC_CHILD_MAX CHILD_MAX Max processes allowed to a UID _SC_CLK_TCK CLK_TCK Ticks per second (clock_t) _SC_CLOCK_SELECTION _POSIX_CLOCK_SELECTION Supports Clock Selection option _SC_COLL_WEIGHTS_MAX COLL_WEIGHTS_MAX Max number of weights that can be assigned to entry of the LC_COLLATE order keyword in locale definition file _SC_CPUID_MAX Max possible processor ID _SC_DELAYTIMER_MAX DELAYTIMER_MAX Max number of timer expiration overruns _SC_EXPR_NEST_MAX EXPR_NEST_MAX Max number of parentheses by expr _SC_FSYNC _POSIX_FSYNC Supports File Synchronization _SC_GETGR_R_SIZE_MAX Max size of group entry buffer _SC_GETPW_R_SIZE_MAX Max size of password entry buffer _SC_HOST_NAME_MAX _POSIX_HOST_NAME_MAX Maximum length of a host name (excluding terminating null) _SC_IOV_MAX IOV_MAX Max number of iovec structures available to one process for use with readv() and writev() _SC_JOB_CONTROL _POSIX_JOB_CONTROL Job control supported? _SC_LINE_MAX LINE_MAX Max length of input line _SC_LOGIN_NAME_MAX LOGNAME_MAX + 1 Max length of login name _SC_LOGNAME_MAX LOGNAME_MAX _SC_MAPPED_FILES _POSIX_MAPPED_FILES Supports Memory Mapped Files _SC_MAXPID Max pid value _SC_MEMLOCK _POSIX_MEMLOCK Supports Process Memory Locking _SC_MEMLOCK_RANGE _POSIX_MEMLOCK_RANGE Supports Range Memory Locking _SC_MEMORY_PROTECTION _POSIX_MEMORY_PROTECTION Supports Memory Protection _SC_MESSAGE_PASSING _POSIX_MESSAGE_PASSING Supports Message Passing _SC_MONOTONIC_CLOCK _POSIX_MONOTONIC_CLOCK Supports Monotonic Clock option _SC_MQ_OPEN_MAX MQ_OPEN_MAX Max number of open message queues a process can hold _SC_MQ_PRIO_MAX MQ_PRIO_MAX Max number of message priorities supported _SC_NGROUPS_MAX NGROUPS_MAX Max simultaneous groups to which one can belong _SC_NPROCESSORS_CONF Number of processors configured _SC_NPROCESSORS_MAX Max number of processors supported by platform _SC_NPROCESSORS_ONLN Number of processors online _SC_OPEN_MAX OPEN_MAX Max open files per process _SC_PAGESIZE PAGESIZE System memory page size _SC_PAGE_SIZE PAGESIZE Same as _SC_PAGESIZE _SC_PASS_MAX PASS_MAX Max number of significant bytes in a password _SC_PHYS_PAGES Total number of pages of physical memory in system _SC_PRIORITIZED_IO _POSIX_PRIORITIZED_IO Supports Prioritized I/O _SC_PRIORITY_SCHEDULING _POSIX_PRIORITY_SCHEDULING Supports Process Scheduling _SC_RAW_SOCKETS _POSIX_RAW_SOCKETS Supports Raw Sockets option _SC_RE_DUP_MAX RE_DUP_MAX Max number of repeated occurrences of a regular expression permitted when using interval notation \{m,n\} _SC_READER_WRITER_LOCKS _POSIX_READER_WRITER_LOCKS Supports IPV6 option _SC_REALTIME_SIGNALS _POSIX_REALTIME_SIGNALS Supports Realtime Signals _SC_REGEXP _POSIX_REGEXP Supports Regular Expression Handling option _SC_RTSIG_MAX RTSIG_MAX Max number of realtime signals reserved for application use _SC_SAVED_IDS _POSIX_SAVED_IDS Saved IDs (seteuid()) supported? _SC_SEM_NSEMS_MAX SEM_NSEMS_MAX Max number of POSIX semaphores a process can have _SC_SEM_VALUE_MAX SEM_VALUE_MAX Max value a POSIX semaphore can have _SC_SEMAPHORES _POSIX_SEMAPHORES Supports Semaphores _SC_SHARED_MEMORY_ _POSIX_SHARED_MEMORY_ Supports Shared OBJECTS OBJECTS Memory Objects _SC_SHELL _POSIX_SHELL Supports POSIX shell _SC_SIGQUEUE_MAX SIGQUEUE_MAX Max number of queued signals that a process can send and have pending at receiver(s) at a time _SC_SPAWN _POSIX_SPAWN Supports Spawn option _SC_SPIN_LOCKS _POSIX_SPIN_LOCKS Supports Spin Locks option _SC_STACK_PROT Default stack protection _SC_STREAM_MAX STREAM_MAX Number of streams one process can have open at a time _SC_SYMLOOP_MAX _POSIX_SYMLOOP_MAX Max number of symbolic links that can be reliably traversed in the resolution of a pathname in the absence of a loop _SC_SYNCHRONIZED_IO _POSIX_SYNCHRONIZED_IO Supports Synchronized I/O _SC_THREAD_ATTR_ _POSIX_THREAD_ATTR_ Supports Thread STACKADDR STACKADDR Stack Address Attribute option _SC_THREAD_ATTR_ _POSIX_THREAD_ATTR_ Supports Thread STACKSIZE STACKSIZE Stack Size Attribute option _SC_THREAD_DESTRUCTOR_ PTHREAD_DESTRUCTOR_ Number attempts made ITERATIONS ITERATIONS to destroy thread- specific data on thread exit _SC_THREAD_KEYS_MAX PTHREAD_KEYS_MAX Max number of data keys per process _SC_THREAD_PRIO_ _POSIX_THREAD_PRIO_ Supports Priority INHERIT INHERIT Inheritance option _SC_THREAD_PRIO_ _POSIX_THREAD_PRIO_ Supports Priority PROTECT PROTECT Protection option _SC_THREAD_PRIORITY_ _POSIX_THREAD_PRIORITY_ Supports Thread SCHEDULING SCHEDULING Execution Scheduling option _SC_THREAD_PROCESS_ _POSIX_THREAD_PROCESS_ Supports SHARED SHARED Process-Shared Synchronization option _SC_THREAD_SAFE_ _POSIX_THREAD_SAFE_ Supports Thread-Safe FUNCTIONS FUNCTIONS Functions option _SC_THREAD_STACK_MIN PTHREAD_STACK_MIN Min byte size of thread stack storage _SC_THREAD_THREADS_MAX PTHREAD_THREADS_MAX Max number of threads per process _SC_THREADS _POSIX_THREADS Supports Threads option _SC_TIMEOUTS _POSIX_TIMEOUTS Supports Timeouts option _SC_TIMER_MAX TIMER_MAX Max number of timer per process supported _SC_TIMERS _POSIX_TIMERS Supports Timers _SC_TTY_NAME_MAX TTYNAME_MAX Max length of tty device name _SC_TZNAME_MAX TZNAME_MAX Max number of bytes supported for name of a time zone _SC_V6_ILP32_OFF32 _POSIX_V6_ILP32_OFF32 Supports X/Open ILP32 w/32-bit offset build environment _SC_V6_ILP32_OFFBIG _POSIX_V6_ILP32_OFFBIG Supports X/Open ILP32 w/64-bit offset build environment _SC_V6_LP64_OFF64 _POSIX_V6_LP64_OFF64 Supports X/Open LP64 w/64-bit offset build environment _SC_V6_LPBIG_OFFBIG _POSIX_V6_LPBIG_OFFBIG Same as _SC_V6_LP64_OFF64 _SC_VERSION _POSIX_VERSION POSIX.1 version supported _SC_XBS5_ILP32_OFF32 _XBS_ILP32_OFF32 Indicates support for X/Open ILP32 w/32-bit offset build environment _SC_XBS5_ILP32_OFFBIG _XBS5_ILP32_OFFBIG Indicates support for X/Open ILP32 w/64-bit offset build environment _SC_XBS5_LP64_OFF64 _XBS5_LP64_OFF64 Indicates support of X/Open LP64, 64-bit offset build environment _SC_XBS5_LPBIG_OFFBIG _XBS5_LP64_OFF64 Same as _SC_XBS5_LP64_OFF64 _SC_XOPEN_CRYPT _XOPEN_CRYPT Supports X/Open Encryption Feature Group _SC_XOPEN_ENH_I18N _XOPEN_ENH_I18N Supports X/Open Enhanced Internationalization Feature Group _SC_XOPEN_LEGACY _XOPEN_LEGACY Supports X/Open Legacy Feature Group _SC_XOPEN_REALTIME _XOPEN_REALTIME Supports X/Open POSIX Realtime Feature Group _SC_XOPEN_REALTIME_ _XOPEN_REALTIME_THREADS Supports X/Open THREADS POSIX Reatime Threads Feature Group _SC_XOPEN_SHM _XOPEN_SHM Supports X/Open Shared Memory Feature Group _SC_XOPEN_STREAMS _POSIX_XOPEN_STREAMS Supports XSI Streams option group _SC_XOPEN_UNIX _XOPEN_UNIX Supports X/Open CAE Specification, August 1994, System Interfaces and Headers, Issue 4, Version 2 _SC_XOPEN_VERSION _XOPEN_VERSION Integer value indicates version of X/Open Portability Guide to which implementation conforms _SC_XOPEN_XCU_VERSION _XOPEN_XCU_VERSION Integer value indicates version of XCU specification to which implementation conforms The following options are not supported and return -1: _SC_2_PBS _POSIX2_PBS _SC_2_PBS_ACCOUNTING _POSIX2_PBS_ACCOUNTING _SC_2_PBS_CHECKPOINT _POSIX2_PBS_CHECKPOINT _SC_2_PBS_LOCATE _POSIX2_PBS_LOCATE _SC_2_PBS_MESSAGE _POSIX2_PBS_MESSAGE _SC_2_PBS_TRACK _POSIX2_PBS_TRACK _SC_ADVISORY_INFO _POSIX_ADVISORY_INFO _SC_CPUTIME _POSIX_CPUTIME _SC_SPORADIC_SERVER _POSIX_SPORADIC_SERVER _SC_SS_REPL_MAX _POSIX_SS_REPL_MAX _SC_THREAD_CPUTIME _POSIX_THREAD_CPUTIME _SC_THREAD_SPORADIC_SERVER _POSIX_THREAD_SPORADIC_SERVER _SC_TRACE _POSIX_TRACE _SC_TRACE_EVENT_FILTER _POSIX_TRACE_EVENT_FILTER _SC_TRACE_EVENT_NAME_MAX _POSIX_TRACE_EVENT_NAME_MAX _SC_TRACE_INHERIT _POSIX_TRACE_INHERIT _SC_TRACE_LOG _POSIX_TRACE_LOG _SC_TRACE_NAME_MAX _POSIX_TRACE_NAME_MAX _SC_TRACE_SYS_MAX _POSIX_TRACE_SYS_MAX _SC_TRACE_USER_EVENT_MAX _POSIX_TRACE_USER_EVENT_MAX _SC_TYPED_MEMORY_OBJECTS _POSIX_TYPED_MEMORY_OBJECTS
Upon successful completion, sysconf() returns the current variable value on the system. The value returned will not be more restrictive than the corresponding value described to the application when it was compiled with the implementation's <limits.h>, <unistd.h> or <time.h>. With only a few obvious exceptions such as _SC_AVPHYS_PAGES and _SC_NPROCESSORS_ONLN, the value will not change during the life- time of the calling process. If name is an invalid value, sysconf() returns -1 and sets errno to indicate the error. If the variable corresponding to name is associated with functionality that is not supported by the system, sysconf() returns -1 without changing the value of errno. Calling sysconf() with the following returns -1 without setting errno, because no maximum limit can be determined. The system supports at least the minimum values and can support higher values depending upon system resources. Variable Minimum supported value _SC_AIO_MAX _POSIX_AIO_MAX _SC_ATEXIT_MAX 32 _SC_MQ_OPEN_MAX 32 _SC_THREAD_THREADS_MAX _POSIX_THREAD_THREADS_MAX _SC_THREAD_KEYS_MAX _POSIX_THREAD_KEYS_MAX _SC_THREAD_DESTRUCTOR_ITERATIONS _POSIX_THREAD_DESTRUCTOR_ITERATIONS The following SPARC and x86 platform variables return EINVAL: _SC_COHER_BLKSZ _SC_DCACHE_ASSOC _SC_DCACHE_BLKSZ _SC_DCACHE_LINESZ _SC_DCACHE_SZ _SC_DCACHE_TBLKSZ _SC_ICACHE_ASSOC _SC_ICACHE_BLKSZ _SC_ICACHE_LINESZ _SC_ICACHE_SZ _SC_SPLIT_CACHE
The sysconf() function will fail if: EINVAL The value of the name argument is invalid.
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Architecture |SPARC and x86 | +-----------------------------+-----------------------------+ |Interface Stability |Committed | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe, Async-Signal-Safe | +-----------------------------+-----------------------------+ |Standard |See standards(5). | +-----------------------------+-----------------------------+
pooladm(1M), zoneadm(1M), fpathconf(2), seteuid(2), setrlimit(2), confstr(3C), attributes(5), standards(5)
A call to setrlimit() can cause the value of OPEN_MAX to change. Multiplying sysconf(_SC_PHYS_PAGES) or sysconf(_SC_AVPHYS_PAGES) by sysconf(_SC_PAGESIZE) to determine memory amount in bytes can exceed the maximum values representable in a 32-bit signed or unsigned integer. The value of CLK_TCK can be variable and it should not be assumed that CLK_TCK is a compile-time constant. If the caller is in a non-global zone and the pools facility is active, sysconf(_SC_NPROCESSORS_CONF) and sysconf(_SC_NPROCESSORS_ONLN) return the number of processors in the processor set of the pool to which the zone is bound. SunOS 5.11 26 Mar 2008 sysconf(3C)