NAME

sysconf - get configurable system variables

SYNOPSIS

#include <unistd.h>

long sysconf(int name);

DESCRIPTION

The sysconf function provides a method for  the  application
to  determine  the  current  value  of a configurable system
limit or option (variable).  The  name  argument  represents
the  system  variable  to  be  queried.  The following table
lists the minimal set of system  variables  from  <limits.h>
and <unistd.h> that can be returned by sysconf, and the sym-
bolic  constants,  defined  in  <unistd.h>  that   are   the
corresponding_values_used_for_____._______________
         |                                       |
         |       NAME             RETURN VALUE   |
         |_______________________________________|
         | _SC_ARG_MAX         ARG_MAX           |
         | _SC_CHILD_MAX       CHILD_MAX         |
         | _SC_CLK_TCK         CLK_TCK           |
         | _SC_NGROUPS_MAX     NGROUPS_MAX       |
         | _SC_OPEN_MAX        OPEN_MAX          |
         | _SC_PASS_MAX        PASS_MAX          |
         | _SC_PAGESIZE        PAGESIZE          |
         | _SC_JOB_CONTROL     _POSIX_JOB_CONTROL|
         | _SC_SAVED_IDS       _POSIX_SAVED_IDS  |
         | _SC_VERSION         _POSIX_VERSION    |
         | _SC_XOPEN_VERSION   _XOPEN_VERSION    |
         | _SC_LOGNAME_MAX     LOGNAME_MAX       |
         |_______________________________________|
The value of CLK_TCK may be variable and it  should  not  be
assumed  that CLK_TCK is a compile-time constant.  The value
of CLK_TCK is the same as the value of sysconf(_SC_CLK_TCK).

SEE ALSO

fpathconf(3C).

DIAGNOSTICS

If name is an invalid value, sysconf will return -1 and  set
errno  to  indicate  the  error.   If sysconf fails due to a
value of name that is not defined on the system,  the  func-
tion will return a value of -1 without changing the value of
errno.

NOTES

A call to setrlimit may  cause  the  value  of  OPEN_MAX  to
change.