sysconf(1) for details. Conf is
a term Config(Value), where Value is always an integer. Config
is the sysconf() name after removing =_SC_= and conversion to
lowercase. Currently support the following configuration info:
arg_max, child_max, clk_tck, open_max, pagesize,
phys_pages, avphys_pages, nprocessors_conf and
nprocessors_onln. Note that not all values may be supported on
all operating systems.