sysconf(2) SDK R4.11 sysconf(2)
NAME
sysconf - get configurable system values
SYNOPSIS
#include <unistd.h>
#include <sys/m88kbcs.h>
long sysconf (name)
int name;
DESCRIPTION
Use sysconf(2) to get the current value of a system limit or option
specified by name. The valid arguments you can enter for name are
listed and described below:
_SC_2_C_BIND Find out whether the system supports the C
language binding option of X/Open; -1 means no.
_SC_2_C_DEV Find out whether the system supports the C
language development utilities option of X/Open;
-1 means no.
_SC_2_C_VERSION Get the version of the ISO POSIX-2 DIS supported
on this system. When the ISO POSIX-2 DIS and
therefore the X/Open POSIX2 C-language Binding
Feature Group is not supported, a value of -1 is
returned.
_SC_2_CHAR_TERM Find out whether the system supports at least
one terminal type (as defined by X/Open); -1
means no.
_SC_2_FORT_DEV Find out whether the system supports the FORTRAN
Development Utilities Option of X/Open; -1 means
no.
_SC_2_FORT_RUN Find out whether the system supports the FORTRAN
Run-time Utilities Option of X/Open; -1 means
no.
_SC_2_LOCALEDEF Find out whether the system supports the
creation of locales by the localedef utility; -1
means no.
_SC_2_SW_DEV Find out whether the system supports the
Software Development Utilities Option of X/Open;
-1 means no.
_SC_2_UPE Find out whether the system supports the User
Portability Utilities Option of X/Open; -1 means
no.
_SC_ACL Find out whether the access control list (ACL)
security feature, a form of discretionary access
control (DAC), is configured; -1 means no. The
DG/UX system optionally supports security
features.
_SC_AIO Find out whether the BCS Interim Asynchronous
I/O Extension is supported; -1 means no. The
DG/UX system supports the extension.
_SC_AIO_MAX Get the max supported size of a single aysnc I/O
request, if the async I/O extension is
supported.
_SC_ARG_MAX Get the maximum length of the exec(2) argument
list (ARG_MAX, as defined by POSIX and SVID3).
_SC_AUD Find out whether the auditing security feature
is configured; -1 means no. The DG/UX system
optionally supports security features.
_SC_AVAILMEM Get the amount (KB) of physical memory available
to user processes.
_SC_BC_BASE_MAX Get the maximum obase value allowed by the bc
utility.
_SC_BC_STRING_MAX Get the maximum length of a string constant
accepted by the bc utility.
_SC_BC_DIM_MAX Get the maximum number of elements permitted in
an array by the bc utility.
_SC_BC_SCALE_MAX Get the maximum scale value allowed by the bc
utility.
_SC_BCS_SYS_ID Get the BCS system identifier. If available,
this ID combined with the BCS vendor stamp
uniquely identifies the system on which an
application is running.
_SC_BCS_VENDOR_STAMP Get the BCS vendor stamp.
_SC_BCS_VERSION Get the number of the 88open BCS version to
which the system conforms
_SC_BSDNETWORK Find out whether the BSD Networking Extension is
supported: -1 means no. The DG/UX system
supports the extension.
_SC_CAP Find out whether the capability security feature
is configured; -1 means no. The DG/UX system
optionally supports security features.
_SC_CHILD_MAX Get the maximum number of simultaneous processes
allowed for each real user ID (CHILD_MAX, as
defined by POSIX and SVID3).
_SC_CLK_TCK Get the number of clock ticks per second
(CLK_TCK, as defined by POSIX and SVID3).
_SC_COLL_WEIGHTS_MAX Get the maximum number of weights that can be
assigned to an entry of the LC_COLLATE order
keyword in the locale definition file.
_SC_CPUID Get the value of the MC88100 Processor
Identification Register (cr0).
_SC_DATAKEYS_MAX Get the maximum number of Posix 1003.4a data
keys supported, if any. See note 2.
_SC_DELAYTIMER_MAX Get the maximum number of realtime timer
overruns that can be returned by
timer_getoverrun(2) (DELAYTIMER_MAX, as defined
by POSIX). See note 1.
_SC_EXPR_NEST_MAX Get the maximum number of expressions that can
be nested within parentheses by the expr
utility.
_SC_ITIMER_PROF Find out whether the system supports a profiling
timer; -1 means no. Provided by setitimer(2), a
profiling timer sends SIGPROF upon expiration.
The DG/UX system supports the timer.
_SC_ITIMER_VIRT Find out whether the system supports a virtual
timer; -1 means no. Provided by setitimer(2), a
virtual timer sends SIGVTALRM upon expiration.
The DG/UX system supports the timer.
_SC_JOB_CONTROL Find out whether the system supports job control
functions (_POSIX_JOB_CONTROL, as defined by
POSIX and SVID3); -1 means no. The DG/UX system
supports job control.
_SC_LINE_MAX Get the maximum length, in bytes, of a utility's
input line (either standard input or another
file), when the utility is described as
processing text files. The length includes room
for the trailing newline. The length returned
by this query may not apply if it is noted
otherwise for a given utility.
_SC_LOGNAME_MAX Get the maximum number of characters in a login
name.
_SC_MAC Find out whether the mandatory access control
(MAC) security feature is configured; -1 means
no. The DG/UX system optionally supports
security features.
_SC_MAXMSGSZ Get the maximum size in bytes of a message.
_SC_MAXSEMVL Get the maximum semaphore value.
_SC_MAXUMEMV Get the maximum user process size (KB).
_SC_MAXUPROC Get the number of simultaneous processes allowed
for each real user ID. Use POSIX argument
_SC_CHILD_MAX instead, which returns the same
number.
_SC_MEMCTL_UNIT Get the memory size unit in bytes.
_SC_NGROUPS_MAX Get the maximum number of simultaneous
supplementary group IDs (NGROUPS_MAX, as defined
by POSIX and SVID3).
_SC_NICE Find out whether the system supports nice(2)
process prioritization; -1 means no. The DG/UX
system supports this feature.
_SC_NMSGHDRS Get the maximum number of message headers.
_SC_NMSYSSEM Get the maximum number of semaphores.
_SC_NPTYS Get the number of BCS Networking Supplement type
pseudo-terminals.
_SC_SEM_NSEMS_MAX Get the maximum number of POSIX counting
semaphores that each process may open
simultaneously.
_SC_NSEMMAP Get the maximum number of semaphore sets.
_SC_NSEMMSL Get the maximum number of semaphores per set.
_SC_NSHMMNI Get the maximum number of shared memory
segments.
_SC_OPEN_MAX Get the maximum number of files that a process
can have open at one time (OPEN_MAX, as defined
by POSIX and SVID3).
_SC_PAGESIZE Get the system page size in bytes.
_SC_PASS_MAX Get the maximum number of significant
characters, excluding the terminating null
character, allowed in a password (PASS_MAX, as
defined by XPG3 and SVID3).
_SC_PHYSMEM Get the system's total physical memory size
(KB).
_SC_RE_DUP_MAX Get the maximum number of repeated occurrences
of a regular expression permitted when using the
interval notation \{m,n\} .
_SC_REENTRANT_FUNCTIONS
Get whether or not Posix 1003.4a reentrant
functions are supported. See note 2.
_SC_RWX_SUPPORT Find out whether the system supports
simultaneous read-write-execute access of memory
regions; -1 means no. The DG/UX system supports
this feature; see memctl(2).
_SC_SAVED_IDS Find out whether the system supports the saving
of set-user-ID and set-group-ID on a per-process
basis (_POSIX_SAVED_IDS, as defined by POSIX and
SVID3); -1 means no. The DG/UX system supports
this feature.
_SC_SEC_LEVEL Find out the security level supported by the
system; -1 means none. The DG/UX system
optionally supports security level DG_C2 and
security level DG_B1.
_SC_SEM_NSEMS_MAX Get the maximum number of POSIX Counting
Semaphores each process may have open
simultaneously. See note 1.
_SC_SEM_VALUE_MAX Get the maximum value a POSIX Counting Semaphore
may be. See note 1.
_SC_SEMAPHORES Find out whether or not the system supports all
POSIX semaphore functions; -1 means no. In
accordance with POSIX requirements, until there
is an approved (not draft) POSIX realtime
extension document (1003.4), and the DG/UX
system complies with the approved document, this
will return -1. See note 1.
_SC_SHMLBA Get the number of bytes used as a rounding
factor on memory addresses by shmsys(2).
_SC_SHMMAXSZ Get the maximum size of a shared memory segment.
_SC_SHMMINSZ Get the minimum size of a shared memory segment.
_SC_SHMSEGS Get the maximum number of attached shared memory
segments per process.
_SC_STREAM_MAX Get the maximum number of streams one process
can have open.
_SC_SVSTREAMS Find out whether the system supports System V
style streams; -1 means no. The DG/UX system
supports streams.
_SC_THREAD_ATTR_STACKSIZE
Get whether or not Posix 1003.4a
pthread_attr_setstacksize() is supported. See
note 2.
_SC_THREAD_PRIORITY_SCHEDULING
Parameter to return whether or not Posix 1003.4a
fixed priority scheduling is supported. See
note 2.
_SC_THREADS Get whether or not Posix 1003.4a threads are
supported. See note 2.
_SC_THREADS_PRIO_INHERIT
Get whether or not Posix 1003.4a priority
inheritance for mutexes is supported. See note
2.
_SC_THREADS_PRIO_PROTECT
Get whether or not Posix 1003.4a priority
ceilings for mutexes are supported. See note 2.
_SC_THREADS_PROCESS_SHARED
Get whether or not Posix 1003.4a process-shared
(inter-process) mutexes and conditions are
supported. See note 2.
_SC_TIMER_GRAN Get the granularity of the system's real time
clock. A non-zero number indicates the
granularity in microseconds; zero indicates a
granularity of 1 second.
_SC_TIMER_MAX Get the maximum number of per-process timers
that may be created by the POSIX-defined
timer_create(2) call. See note 1.
_SC_TIMERS Find out whether the system supports all POSIX
realtime clock and timer functions; -1 means no.
The DG/UX system does not at present support all
clock and timer realtime extensions. In
accordance with POSIX requirements, until there
is an approved (not draft) POSIX realtime
extension document (1003.4), and the DG/UX
system complies with the approved document, this
will return -1. See note 1.
_SC_TZNAME_MAX Get the maximum number of bytes supported for
the name of a time zone.
_SC_VERSION Get the code of the POSIX.1 version supported
(_POSIX_VERSION, as defined by POSIX and SVID3):
198808 indicates the 1988 version and 199009 the
1990 version.
_SC_XOPEN_CRYPT Find out whether the system supports the X/Open
Encryption Feature Group; -1 means no.
_SC_XOPEN_ENH_I18N Find out whether the system supports the X/Open
Enhanced Internationalization Feature Group; -1
means no.
_SC_XOPEN_VERSION Get the version number of the supported X/Open
Portability Guide (_X_OPEN_VERSION, as defined
by XPG3 and SVID3).
RETURN VALUE
If name is invalid, sysconf(2) returns -1 and sets errno. If name is
valid but the associated feature is not applicable on the system,
sysconf(2) returns -1 without setting errno.
Otherwise, sysconf(2) returns the current value of the system
parameter indicated by name.
DIAGNOSTICS
EINVAL The value of the name argument is invalid.
SEE ALSO
pathconf(2), fpathconf(2).
NOTES
(1) Values marked with "Note 1" are based on POSIX realtime extension
document P1003.4 draft 14. They are therefore subject to change.
Compilation of a source file containing such a value requires that
feature macro _POSIX4_DRAFT_SOURCE be defined. This feature macro is
not enabled by any other feature macro, nor does it enable any other
feature macro.
(2) Values marked with "Note 2" are based on POSIX threads extension
document P1003.4a draft 6. It is anticipated that they may change in
order to support draft 8. Compilation of a source file containing
such a value requires that feature macro _POSIX4A_DRAFT6_SOURCE be
defined. This feature macro is not enabled by any other feature
macro. It enables the feature macro _POSIX4A_DRAFT_SOURCE.
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