1  –  DBG$DECW$DISPLAY

    Specifies the debugger interface (DECwindows Motif or command)
    or the display device (if you are displaying the interface on a
    workstation).

    By default, DBG$DECW$DISPLAY is either undefined or has the same
    definition as the application-wide logical name DECW$DISPLAY.

    The DECwindows Motif interface is the default on workstations.
    To display the command interface instead of the DECwindows Motif
    interface, enter the following definition before starting the
    debugger:

    $ DEFINE DBG$DECW$DISPLAY " "

    For complete information about the DECwindows Motif interface,
    see the debugger's DECwindows Motif documentation.

2  –  DBG$INIT

    If the logical name DBG$INIT is defined at the start of a
    debugging session, then the file that it translates to is used
    as an initialization file. The commands in the file are executed
    as if the file had been called with the @ (Execute Procedure)
    command. This is useful if there is a particular set of commands
    that you always execute when you start up the debugger, for
    example to specify a source directory search list, enable screen
    mode, log the session.

    Example:

    $ CREATE MY_DEBUG.COM
    SET SOURCE SYS$DISK:[],SRC$
    SET MODE SCREEN
    SET STEP SILENT
         . . .
    $ DEFINE DBG$INIT [JONES.CMD]DEBUG_INIT.COM

3  –  DBG$INPUT and DBG$OUTPUT

    The value of the logical name DBG$INPUT determines the debugger
    input device. By default, this is SYS$INPUT.

    The value of the logical name DBG$OUTPUT determines the debugger
    output device. By default, this is SYS$OUTPUT.

    If you plan to debug a program that takes its input from a
    file and your debugger input from the terminal, establish the
    following definitions before starting the debugger:

    $ DEFINE SYS$INPUT program-input-file
    $ DEFINE/PROCESS DBG$INPUT 'F$LOGICAL("SYS$COMMAND")

    That is, define DBG$INPUT to point to the translation of
    SYS$COMMAND.

    If you define DBG$INPUT to point to SYS$COMMAND, the debugger
    will try to get its input from the file.

4  –  DBG$PROCESS

    The value of the logical name DBG$PROCESS determines the
    debugging configuration as follows:

    DBG$PROCESS
    Definition             Configuration

    DEFAULT or undefined   Default
    MULTIPROCESS           Multiprocess

    Use the default configuration to debug programs that normally run
    (without the debugger) in only one process. Use the multiprocess
    configuration to debug programs that normally run in more than
    one process.

    When defining DBG$PROCESS for a multiprocess configuration, make
    the definition job wide. This ensures that any processes that are
    in the same job tree as the program being debugged (for example,
    processes spawned by the program) can be controlled from the same
    debugging session.

    For more information, see help on Debugging_Configurations.