The system attribute command has been extended to provide information on the user's environment variables. These are set up at user login time and cannot be altered. If the direct parameter to system attribute is a four-character Gestalt code, it is executed as in Standard Additions 1.7; if not, it attempts to get an environment variable by that name, returning either the value of the variable or an empty string. (Note that system attribute now will not fail with an error; it simply returns an empty string.) If called with no parameters, system attribute returns a list of all currently-defined environment variables.