ultrix man page for sysconf

sysconf(3)						     Library Functions Manual							sysconf(3)

Name
       sysconf - get configurable system variables (POSIX)

Syntax
       #include <unistd.h>

       long sysconf(name)
       int name;

Description
       The function provides a method for the application to determine the current value of a configurable system limit or option.

       The name argument represents the system variable to be queried. The following table lists the system variables which may be queried and the
       corresponding value for the name argument. The values for the name argument are defined in the <unistd.h> header file.
       Variable 		    name Value

       ARG_MAX			    _SC_ARG_MAX
       CHILD_MAX		    _SC_CHILD_MAX
       CLK_TCK			    _SC_CLK_TCK
       NGROUPS_MAX		    _SC_NGROUPS_MAX
       OPEN_MAX 		    _SC_OPEN_MAX
       PASS_MAX 		    _SC_PASS_MAX
       _POSIX_JOB_CONTROL	    _SC_JOB_CONTROL
       _POSIX_SAVED_IDS 	    _SC_SAVED_IDS
       _POSIX_VERSION		    _SC_VERSION
       _XOPEN_VERSION		    _SC_XOPEN_VERSION

Return Values
       Upon successful completion, the function returns the current variable value on the system.

       If name is an invalid value, returns -1 and errno is set to indicate the reason. If the variable corresponding to name is  not  defined	on
       the system, returns -1 without changing the value of errno.

Diagnostics
       The function fails if the following occurs:

       [EINVAL]       The value of the name argument is invalid.

																	sysconf(3)