SYSCONF(2P) SYSCONF(2P)
NAME
sysconf - get configurable system variables
SYNOPSIS
#include <unistd.h>
long sysconf(name)
init name;
DESCRIPTION
Sysconf allows an application to determine the current value
of a configurable system variable. Name represents the
system variable to be queried. Allowable values for name
are:
_SC_ARG_MAX 1 Maximum length of argument
list on exec(2)
_SC_CHILD_MAX 2 Maximum number of child
processes
_SC_CLK_TCK 3 Clock ticks per second
_SC_NGROUPS_MAX 4 Maximum supplementary groups
per user
_SC_OPEN_MAX 5 Maximum open files per
process
_SC_JOB_CONTROL 6 POSIX job control supported
if non zero
_SC_SAVED_IDS 7 POSIX saved set-uid/gid
feature supported
_SC_VERSION 8 POSIX version number
_SC_BCS_VERSION 9 Binary Compatibility Standard
version number
_SC_BCS_VENDOR_STAMP 10 Is vendor stamp of system
_SC_BCS_SYS_ID 11 Unique System ID of this
machine (if supported)
_SC_MAXUMEMV 12 Maximum user process size (in
kilobytes)
_SC_MAXUPROC 13 Maximum number of processes
per user
Maximum size of a message
[see msgct1(2)]
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SYSCONF(2P) SYSCONF(2P)
_SC_MAXMSGSZ 14
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SYSCONF(2P) SYSCONF(2P)
_SC_NMSGHDRS 15 Total number of message
headers in system [see
msgctl(2)]
_SC_SHMMAXSZ 16 Maximum size of shared
segment [see shmct1(2)]
_SC_SHMMINSZ 17 Minimum size of shared
segment [see shmct1(2)]
_SC_SHMSEGS 18 Maximum number of attached
segments per process [see
shmct1(2)]
_SC_NMSYSSEM 19 Total number of semaphores in
system [see semctl(2)]
_SC_MAXSEMVL 20 Maximum semaphore value [see
semctl(2)]
_SC_NSEMMAP 21 Number of semaphore sets [see
semctl(2)]
_SC_NSEMMSL 22 Number of semaphores per set
[see semctl(2)]
_SC_NSCMMNI 23 Number of shared segments per
system [see shmctl(2)]
_SC_ITIMER_VIRT 24 System supports a virtual
timer [see setitimer(2)]
_SC_ITIMER_PROF 25 System supports a profiling
timer [see setitimer(2)]
_SC_TIMER_GRAN 26 If non zero, specifies the
granularity of the real time
clock in microseconds. If
zero, specifies that 1 second
granularity is all that is
available.
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SYSCONF(2P) SYSCONF(2P)
_SC_PHSYMEM 27 Total physical memory of the
system in kilobytes
_SC_AVAILMEM 28 Physical memory available to
user processes in kilobytes
_SC_NICE 29 Nice prioritization available
_SC_MEMCTL_UNIT 30 Specifies the number of bytes
that comprise a memory unit
for the memctl(2) function.
_SC_SHMLBA 31 Memory address rounding used
in the shmsys(2) system call
_SC_SVSTREAMS 32 System V style STREAMS are
supported
_SC_CPUID 33 Returns the value of the
MC88100 processor
identification register
sysconf will fail if one of the following is true:
[EINVAL]
name is not equal to one of the allowable values
specified above.
DIAGNOSTICS
Upon successful completion, the specified system variable is
returned, if it is available. If the specified system
variable is not available, a value of -1 is returned, but
errno remains unchanged. Otherwise a value of -1 is
returned and errno is set to indicate the error.
SEE ALSO
intro(2), msgctl(2), shmctl(2), semctl(2), shmsys(2),
setitimer(2), pathconf(2), and exec(2).
Page 4 May 1989