How to know the unit setting of the drawing, metric or English (feet and inches)?

Issue:

You want to know the unit setting for current drawing.

Solution:

Input command MEASUREMENT, if it prompts: “New current value for MEASUREMENT (Off or On) :” that mean the drawing is using English unit setting. If it prompts: “New current value for MEASUREMENT (Off or On) :”, that mean the drawing is using metric. This system variable controls the hatch pattern and linetype files when openning the existing drawings