Definition of `sysconf'
-----------------------
- 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.