sysconf(3)

NAME

sysconf − get configurable system variables (POSIX)

SYNTAX

#include <unistd.h>

long sysconf(name);
int name;

DESCRIPTION

The sysconf() 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.

Variablename 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

_POSIX_JOB_CONTROL_SC_JOB_CONTROL

_POSIX_SAVED_IDS_SC_SAVED_IDS

_POSIX_VERSION_SC_VERSION

RETURN VALUE

Upon successful completion, the sysconf() function returns the current variable value on the system.

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

DIAGNOSTICS

The sysconf() function fails if the following occurs:

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