The Env interface allows you to access the values of environment variables.
INTERFACE Env; PROCEDURE Get(nm: TEXT): TEXT; (* Return the value of the environment variable whose name is equal to "nm", or "NIL" if there is no such variable. *) VAR (*CONST*) Count: CARDINAL; (* Environment variables are indexed from "0" to "Count-1". *) PROCEDURE GetNth(n: CARDINAL; VAR (*OUT*) nm, val: TEXT); (* Set "nm" and "val" to the name and value of the environment variable with index "n". It is a checked runtime error if "n >= Count". *) END Env.