sysconf(2)

(Value for name Argument)

(_SC_AES_OS_VERSION)

Version number of OSF/AES OSC supported.

(_SC_AIO_LISTIO_MAX)

Maximum number of aio operations that can be specified in a lio_listio() call (see lio_listio(2)).

(_SC_AIO_MAX)

Maximum number of aio operations that can be queued at any time (see aio(5)).

(_SC_AIO_PRIO_DELTA_MAX

Maximum slowdown factor that can be specified in the aio_reqprio field of a aiocb structure (see aio(5)).

(_SC_ARG_MAX)

Maximum total length of the arguments for exec() in bytes, including environment data (see exec(2)).

(_SC_ATEXIT_MAX)

Maximum number of functions that can be registered with atexit() (see atexit(3)).

(_SC_BC_BASE_MAX)

Maximum ibase (input number radix) and obase (output number radix) allowed by bc (see bc(1)).

(_SC_BC_DIM_MAX)

Maximum number of elements in an array permitted by bc (see bc(1)).

(_SC_BC_SCALE_MAX)

Maximum scale factor (number of digits to the right of the decimal point) allowed by bc (see bc(1)).

(_SC_BC_STRING_MAX)

Maximum length of strings allowed by bc (see bc(1)).

(_SC_CCNUMA_SUPPORT)

Positive if the implementation supports multiple locality domains; -1 otherwise (see mpctl(2)).

(_SC_CHILD_MAX)

Maximum number of simultaneous processes per user ID (see fork(2)).

(_SC_CLK_TCK)

Number of clock intervals per second for times() (see times(2)).

(_SC_CLOCKS_PER_SEC)

Number of clock ticks per second for clock() (see clock(3C)).

(_SC_COLL_WEIGHTS_MAX)

Maximum number of weights that can be assigned to an entry of the LC_COLLATE order keyword in a localedef input file (see localedef(1M)).

(_SC_CPU_CHIP_TYPE)

Itanium®-based systems: CPUID Register 3 of the Itanium-based processor identification registers. See the Itanium-based architecture definition for this platform for the meaning of each bit.

(_SC_CPU_KEYBITS1)

Itanium-based systems: CPUID Register 4 of the Itanium-based processor identification registers. See the Itanium-based architecture definition for this platform for the meaning of each bit.

PA-RISC: Processor Extensions. The availability of architecture specific instructions is indicated by the key bit data returned by sysconf(_SC_CPU_KEYBITS1). Upon successful completion, the data returned will be the logical OR of the defined values for the features supported.

The possible values returned by sysconf(_SC_CPU_KEYBITS1) and their meanings for PA-RISC platforms are shown in the following table.

(_SC_CPU_VERSION)

Version of CPU architecture.

The possible values of the CPU_VERSION variable returned by sysconf(_SC_CPU_VERSION) and their meanings are:

The CPU_IS_PA_RISC() function classifies cpuvers, a value of the CPU_VERSION variable, as to its processor family.

(_SC_DELAYTIMER_MAX)

Maximum timer overrun count.

(_SC_EXPR_NEST_MAX)

Maximum parenthesis nesting level for expr expressions (see expr(1)).

(_SC_GETGR_R_SIZE_MAX)

Maximum getgrgid_r(), getgrnam_r() data buffer size.

(_SC_GETPW_R_SIZE_MAX)

Maximum getpwuid_r(), getpwnam_r() data buffer size.

(_SC_HOST_NAME_MAX)

Maximum length of a host name (not including the terminating null) (see gethostname(2)).

(_SC_HT_CAPABLE)

(_SC_HT_ENABLED)

(_SC_HW_32_64_CAPABLE)

Returns which kernel is supported on the hardware. The value returned is an encoding that may be interpreted using the _SYSTEM_SUPPORTS_ILP32OS() and _SYSTEM_SUPPORTS_LP64OS() macros defined in <unistd.h>.

For example:

(_SC_IO_TYPE)

Type of I/O drivers the kernel supports; currently, only the value IO_TYPE_CDIO

(_SC_KERNEL_BITS)

Returns the number of bits used by the kernel for pointer and long data types. Current values include 32 and 64.

(_SC_LIBC_VERSION)

The version of libc that is in use by the application that is requesting this information.

The format of the value returned by sysconf(_SC_LIBC_VERSION) is XXyyZZZZqN,

where:

(_SC_LINE_MAX)

Maximum number of bytes in an input line (including the newline) for POSIX.2 utilities.

(_SC_LOGIN_NAME_MAX)

Maximum length of user name in bytes.

(_SC_MAPPED_FILES)

Not supported.

(_SC_MEMLOCK)

Positive if the system supports POSIX memory locking (see mlockall(2), munlockall(2)).

(_SC_MEMLOCK_RANGE)

Positive if the system supports POSIX memory range locking.

(_SC_MEMORY_PROTECTION)

Not supported.

(_SC_MESSAGE_PASSING)

Positive if the system supports POSIX message queues.

(_SC_MQ_OPEN_MAX)

Maximum number of per-process open message queue descriptors.

(_SC_MQ_PRIO_MAX)

Maximum limit for message priority.

(_SC_NGROUPS_MAX)

Maximum number of simultaneous supplementary group IDs per process.

(_SC_OPEN_MAX)

Maximum number of files that one process can have open at one time.

(_SC_PAGE_SIZE)

Kernel memory page size.

(_SC_PASS_MAX)

Maximum number of significant bytes in a password.

(_SC_ADVISORY_INFO)

Equal to 200112 if the Advisory Information option is supported; -1 otherwise.

(_SC_ASYNCHRONOUS_IO)

Positive if the system supports POSIX Asynchronous Input and Output.

(_SC_BARRIERS)

Equal to 200112 if the Barriers option is supported; -1 otherwise.

(_SC_CLOCK_SELECTION)

Equal to 200112 if the Clock Selection option is supported; -1 otherwise.

(_SC_CPUTIME)

Equal to 200112 if the Process CPU-Time Clocks option is supported; -1 otherwise.

(_SC_FSYNC)

Positive if the File Synchronization option is supported (see fsync(2)).

(_SC_IPV6)

Equal to 200112 if the IPv6 option is supported; -1 otherwise.

(_SC_JOB_CONTROL)

Positive if the system supports POSIX job control; -1 otherwise.

(_SC_MAPPED_FILES)

Positive if the system supports POSIX memory locking (see mlockall(2), munlockall(2)).

(_SC_MEMLOCK)

Positive if the system supports POSIX memory mapped files.

(_SC_MEMLOCK_RANGE)

Positive if the system supports POSIX memory range locking.

(_SC_MEMORY_PROTECTION)

Positive if the system supports POSIX memory protection.

(_SC_MESSAGE_PASSING)

Positive if the system supports POSIX Prioritized Input and Output.

(_SC_MONOTONIC_CLOCK)

Equal to 200112 if the Monotonic Clock option is supported; -1 otherwise.

(_SC_PRIORITIZED_IO)

Positive if the system supports POSIX message queues.

(_SC_PRIORITY_SCHEDULING)

Positive if the system supports POSIX.4 priority scheduling; -1 otherwise.

(_SC_RAW_SOCKETS)

Equal to 200112 if the Raw Sockets option is supported; -1 otherwise.

(_SC_READER_WRITER_LOCKS)

Equal to 200112 if the Read-Write Locks option is supported; -1 otherwise.

(_SC_REALTIME_SIGNALS)

Positive if the system supports POSIX.4 real time signal extensions; -1 otherwise.

(_SC_REGEXP)

Equal to 200112 if the Regular Expression Handling option is supported; -1 otherwise.

(_SC_SAVED_IDS)

Positive if each process has a saved set-user-ID and a saved set-group-ID; -1 otherwise.

(_SC_SEMAPHORES)

Positive if the system supports POSIX semaphores.

(_SC_SHARED_MEMORY_OBJECTS)

Positive if the system supports POSIX shared memory.

(_SC_SHELL)

Equal to 200112 if the POSIX shell is supported; -1 otherwise.

(_SC_SPAWN)

Equal to 200112 if the Spawn option is supported; -1 otherwise.

(_SC_SPIN_LOCKS)

Equal to 200112 if the Spin Locks option is supported; -1 otherwise.

(_SC_SPORADIC_SERVER)

Equal to 200112 if the Process Sporadic Server option is supported; -1 otherwise.

(_SC_SS_REPL_MAX)

Not supported.

(_SC_SYNCHRONIZED_IO)

Positive if the Synchronized IO option is supported (see open(2)).

(_SC_THREAD_ATTR_STACKADDR))

Positive if the implementation supports the POSIX Thread Stack Address Attribute option; -1 otherwise.

(_SC_THREAD_ATTR_STACKSIZE)

Positive if the implementation supports the POSIX Thread Stack Size Attribute option; -1 otherwise.

(_SC_THREAD_CPUTIME)

Equal to 200112 if the Thread CPU-Time Clocks option is supported; -1 otherwise.

(_SC_THREAD_PRIORITY_SCHEDULING)

Positive if the implementation supports the POSIX Thread Priority Scheduling option; -1 otherwise.

(_SC_THREAD_PRIO_INHERIT)

Positive if the implementation supports the POSIX Thread Priority Inheritance option; -1 otherwise.

(_SC_THREAD_PRIO_PROTECT)

Positive if the implementation supports the POSIX Thread Priority Protection option; -1 otherwise.

(_SC_THREAD_PROCESS_SHARED)

Positive if the implementation supports the POSIX Thread Process-Shared Synchronization option; -1 otherwise.

(_SC_THREAD_SAFE_FUNCTIONS)

Positive if the implementation supports the POSIX Thread Thread-Safe Functions option; -1 otherwise.

(_SC_THREAD_SPORADIC_SERVER)

Equal to 200112 if the Thread Sporadic Server option is supported; -1 otherwise.

(_SC_THREADS)

Positive if the implementation supports POSIX threads; -1 otherwise.

(_SC_TIMEOUTS)

Equal to 200112 if the Timeouts option is supported; -1 otherwise.

(_SC_TIMERS)

Positive if the system supports POSIX.4 clocks and timers; -1 otherwise.

(_SC_TRACE)

Equal to 200112 if the Trace option is supported; -1 otherwise.

(_SC_TRACE_EVENT_FILTER)

Equal to 200112 if the Trace Event Filter option is supported; -1 otherwise.

(_SC_TRACE_EVENT_NAME_MAX)

Maximum length of the trace event name.

(_SC_TRACE_INHERIT)

Equal to 200112 if the Trace Inherit option is supported; -1 otherwise.

(_SC_TRACE_LOG)

Equal to 200112 if the Trace Log option is supported; -1 otherwise.

(_SC_TRACE_NAME_MAX)

Maximum length of the trace generation version string or of the trace stream name.

(_SC_TRACE_SYS_MAX)

Maximum number of trace streams that may simultaneously exist in the system.

(_SC_TRACE_USER_EVENT_MAX)

Maximum number of user trace event type identifiers that may simultaneously exist in a traced process

(_SC_TTY_NAME_MAX)

Maximum length of a terminal device name.

(_SC_TYPED_MEMORY_OBJECTS)

Equal to 200112 if the Typed Memory Objects option is supported; -1 otherwise.

(_SC_VERSION)

Approval date of the POSIX.1 Standard (such as 199009 for POSIX.1-1990) to which the system conforms. This value indicates the year (first four digits) and month (next two digits) that the standard was approved by the IEEE Standards Board.

(_SC_2_C_BIND)

Equal to 1 if the POSIX.2 C Language Bindings Option is available through the c89 utility; -1 otherwise.

(_SC_2_C_DEV)

Equal to 1 if the POSIX.2 C Language Development Utilities Option is supported; -1 otherwise.

(_SC_2_C_VERSION)

Current version of the POSIX.2 C Language Binding Option supported (same format as _POSIX_VERSION); -1 otherwise.

(_SC_2_FORT_DEV)

Equal to 1 if the POSIX.2 FORTRAN Development Utilities Option is supported; -1 otherwise.

(_SC_2_FORT_RUN)

Equal to 1 if the POSIX.2 Fortran Runtime Utilities Option is supported; -1 otherwise.

(_SC_2_LOCALEDEF)

Equal to 1 if locales can be created with the POSIX.2 localedef utility; -1 otherwise.

(_SC_2_PBS)

Equal to 200112 if the Batch Environment Services and Utilities option is supported; -1 otherwise.

(_SC_2_PBS_ACCOUNTING)

Equal to 200112 if the Batch Accounting option is supported; -1 otherwise.

(_SC_2_PBS_CHECKPOINT)

Equal to 200112 if the Batch Checkpoint/Restart option is supported; -1 otherwise.

(_SC_2_PBS_LOCATE)

Equal to 200112 if the Locate Batch job request option is supported; -1 otherwise.

(_SC_2_PBS_MESSAGE)

Equal to 200112 if the Batch Job Message Request option is supported; -1 otherwise.

(_SC_2_PBS_TRACK)

Equal to 200112 if the Track Batch Job Request option is supported; -1 otherwise.

(_SC_2_SW_DEV)

Equal to 1 if the POSIX.2 Software Development Utilities Option is supported; -1 otherwise.

(_SC_2_UPE)

Equal to 1 if the POSIX.2 User Portability Utilities Option is supported; -1 otherwise.

(_SC_2_VERSION)

Current version of POSIX.2 (same format as _POSIX_VERSION).

(_SC_PRIORITIZED_IO)

Not supported.

(_SC_PSET_SUPPORT)

Positive if the implementation supports the Processor Set Functions; -1 otherwise.

(_SC_PROC_RSRC_MGR)

Equal to 1 if the optional HP Process Resource Management (PRM) software is installed and configured; 0 otherwise (see prmconfig(1)).

(_SC_THREAD_DESTRUCTOR_ITERATIONS)

The number of attempts made to destroy a pthread's thread-specific data values on thread exit.

(_SC_THREAD_KEYS_MAX)

The number of pthread data keys per process.

(_SC_THREAD_STACK_MIN)

Minimum size in bytes of pthread stack storage.

(_SC_THREAD_THREADS_MAX)

Maximum number of pthreads that can be created per process.

(_SC_RE_DUP_MAX)

Maximum number of repeated occurrences of a regular expression permitted when using the interval notation \{m,n\} (see regcomp(3C)).

(_SC_RTSIG_MAX)

Maximum number of realtime signals reserved for application use.

(_SC_SECURITY_CLASS)

SEC_CLASS-NONE (No DoD security level supported).

(_SC_SEMAPHORES)

Positive if the system supports POSIX semaphores.

(_SC_SEM_NSEMS_MAX)

Maximum number of open semaphores per process.

(_SC_SEM_VALUE_MAX)

Maximum semaphore value.

(_SC_SHARED_MEMORY_OBJECTS)

Positive if the system supports POSIX shared memory.

(_SC_SIGQUEUE_MAX)

Maximum number of queued signals that a process may send and have pending at the receivers at any time.

(_SC_STREAM_MAX)

Maximum number of stdio streams that one process can have open at one time.

(_SC_TIMER_MAX)

Maximum number of POSIX.4 timers per process, if POSIX.4 timers are supported; -1 otherwise.

(_SC_TTY_NAME_MAX)

Value of TTY_NAME_MAX.

(_SC_TZNAME_MAX)

Maximum number of bytes in a time zone name for the TZ environment variable.

(_SC_XOPEN_CRYPT)

Equal to 1 if the X/Open Encryption Feature Group is supported; -1 otherwise.

(_SC_XOPEN_ENH_I18N)

Equal to 1 if the X/Open Enhanced Internationalization Feature Group is supported; -1 otherwise.

(_SC_XOPEN_LEGACY)

Not supported.

(_SC_XOPEN_REALTIME)

Not supported.

(_SC_XOPEN_REALTIME_THREADS)

Not supported.

(_SC_XOPEN_SHM)

Equal to 1 if the X/Open Shared Memory Feature Group is supported; -1 otherwise.

(_SC_XOPEN_STREAMS)

Equal to 200112 if the Streams option is supported; -1 otherwise.

(_SC_XOPEN_VERSION)

Issue number of X/Open Portability Guide supported.

(_SC_XBS5_ILP32_OFF32)

A flag that denotes whether _CS_XBS5_ILP32_OFF32_CFLAGS, _CS_XBS5_ILP32_OFF32_LDFLAGS, _CS_XBS5_ILP32_OFF32_LIBS and _CS_XBS5_ILP32_OFF32_LINTFLAGS are supported by confstr(). A return value of -1 indicates they are not supported.

(_SC_XBS5_ILP32_OFFBIG)

A flag that denotes whether _CS_XBS5_ILP32_OFFBIG_CFLAGS, _CS_XBS5_ILP32_OFFBIG_LDFLAGS, _CS_XBS5_ILP32_OFFBIG_LIBS and _CS_XBS5_ILP32_OFFBIG_LINTFLAGS are supported by confstr(). A return value of -1 indicates they are not supported.

(_SC_XBS5_LP64_OFF64)

A flag that denotes whether _CS_XBS5_LP64_OFF64_CFLAGS, _CS_XBS5_LP64_OFF64_LDFLAGS, _CS_XBS5_LP64_OFF64_LIBS and _CS_XBS5_LP64_OFF64_LINTFLAGS are supported by confstr(). A return value of -1 indicates they are not supported.

(_SC_XBS5_LPBIG_OFFBIG)

A flag that denotes whether _CS_XBS5_LPBIG_OFFBIG_CFLAGS, _CS_XBS5_LPBIG_OFFBIG_LDFLAGS, _CS_XBS5_LPBIG_OFFBIG_LIBS and _CS_XBS5_LPBIG_OFFBIG_LINTFLAGS are supported by confstr(). A return value of -1 indicates they are not supported.

The value of name is not valid.