CHECK GUI CLIENT

This subroutine checks to see if the current engine is connected to a GUI-enabled client. No arguments are passed to the subroutine. It simply sets the predefined field RETURN CODE to 1 if running under a GUI-enabled client.

The subroutine can be invoked via SUBR or GOSUB. However, if invoked via SUBR, it must not be invoked DETACHED.

The following example generates a message or warning depending on whether or not the user is running under a GUI-enabled client.

        *
        SUBR     --- CHECK GUI CLIENT SUBPROCESS   END? N  FAIL 0
        *
        IF       --- RETURN CODE                EQ     1
  T     MESSAGE      User is running under GUI-enabled client.
  F     WARNING      User is not running under GUI-enabled client.