— Function: long int sysconf (int parameter)

This function is used to inquire about runtime system parameters. The parameter argument should be one of the ‘_SC_’ symbols listed below.

The normal return value from sysconf is the value you requested. A value of -1 is returned both if the implementation does not impose a limit, and in case of an error.

The following errno error conditions are defined for this function:

EINVAL

The value of the parameter is invalid.