IUMetric
IUMetric See if measurements should use metric units
#include <Packages.h> International Utilities Package
returns Does this country use metric units?
IUMetric checks 'INTL' resource 0 and returns an indication of whether the
country described therein uses the metric system.
Returns: a Boolean; it identifies the standard units of measurement for the
current country:
FALSE Use a system other than metric.
TRUE Use metric measurements.

Notes: If your application draws a ruler, or otherwise shows units of
measurement, you should call IUMetric to help you decide on a default style
of measurement.
This function echoes the value stored in the metricSys field of the Intl0Rec
structure obtained via IUGetIntl(0).