Library /sys$common/syshlp/dbg$help.hlb DEBUG, Built in Symbols, %ACTIVE TASK  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    (Applies only to tasking programs.) Gives you the currently
    active task (the one that was running when the debugger last
    took control). See the SET TASK/ACTIVE command.

    Example:

    DBG> EVALUATE %ACTIVE_TASK
    %TASK 2