getenv

Definition: object x = getenv(string s)
Description: Return the value of a DOS environment variable.
If the variable is undefined return -1.
Comments: Because either a string or an atom (-1) might be returned, you should probably assign the result to a variable declared as object.

There is also a setenv() routine, as yet undocumented [DEV].
Example:
?getenv("ALLUSERSPROFILE")  -- "C:\ProgramData"
See Also: command_line