DBG$HELP.HLB  —  DEBUG  MONITOR
    Displays the current value of a program variable or language
    expression in the monitor view of the VSI DECwindows Motif for
    OpenVMS user interface.

                                   NOTE

       Requires the VSI DECwindows Motif for OpenVMS user interface.

    Format

      MONITOR  expression

1  –  Parameters

 expression

    Specifies an entity to be monitored. With high-level languages,
    this is typically the name of a variable. Currently, MONITOR does
    not handle composite expressions (language expressions containing
    operators).

    If you specify the name of an aggregate variable (a composite
    data structure such as an array or record structure), the monitor
    view lists "Aggregate" for the value of the variable. You can
    then double-click on the variable name to get the values of all
    the elements (see context-sensitive Help).

    To specify an individual array element, array slice, or record
    component, follow the syntax of the current language.

2  –  Qualifiers

2.1    /ASCIC

       /ASCIC
       /AC

    Interprets each monitored entity as a counted ASCII string
    preceded by a 1-byte count field that gives the length of the
    string. The string is then displayed.

2.2    /ASCID

       /ASCID
       /AD

    Interprets each monitored entity as the address of a string
    descriptor pointing to an ASCII string. The CLASS and DTYPE
    fields of the descriptor are not checked, but the LENGTH and
    POINTER fields provide the character length and address of the
    ASCII string. The string is then displayed.

2.3    /ASCII

       /ASCII:n

    Interprets and displays each monitored entity as an ASCII string
    of length n bytes (n characters). If you omit n, the debugger
    attempts to determine a length from the type of the address
    expression.

2.4    /ASCIW

       /ASCIW
       /AW

    Interprets each monitored entity as a counted ASCII string
    preceded by a 2-byte count field that gives the length of the
    string. The string is then displayed.

2.5    /ASCIZ

       /ASCIZ
       /AZ

    Interprets each monitored entity as a zero-terminated ASCII
    string. The ending zero byte indicates the end of the string.
    The string is then displayed.

2.6    /BINARY

    Displays each monitored entity as a binary integer.

2.7    /BYTE

    Displays each monitored entity in the byte integer type (length 1
    byte).

2.8    /DATE_TIME

    Interprets each monitored entity as a quadword integer (length 8
    bytes) containing the internal OpenVMS representation of date and
    time. Displays the value in the format dd-mmm-yyyy hh:mm:ss.cc.

2.9    /DECIMAL

    Displays each monitored entity as a decimal integer.

2.10    /DEFAULT

    Displays each monitored entity in the default radix.

2.11    /EXTENDED_FLOAT

    (Alpha and Integrity servers only) Displays each monitored entity
    in the IEEE X_floating type (length 16 bytes).

2.12    /FLOAT

    On VAX processors, displays each monitored entity in the F_
    floating type (length 4 bytes).

    On Alpha processors, displays each monitored entity in the IEEE
    T_floating type (double precision, length 8 bytes).

2.13    /G_FLOAT

    Displays each monitored entity in the G_floating type (length 8
    bytes).

2.14    /HEXADECIMAL

    Displays each monitored entity as a hexadecimal integer.

2.15    /INSTRUCTION

    Displays each monitored entity as an assembly-language
    instruction (variable length, depending on the number of
    instruction operands and the kind of addressing modes used).
    See also the /OPERANDS qualifier.

2.16    /INT

    Same as /LONGWORD qualifier.

2.17    /LONG_FLOAT

    (Alpha and Integrity servers only) Displays each monitored entity
    in the IEEE S_floating type (single precision, length 4 bytes).

2.18    /LONG_LONG_FLOAT

    (Alpha and Integrity servers only) Displays each monitored entity
    in the IEEE T_floating type (double precision, length 8 bytes).

2.19    /LONGWORD

       /LONGWORD
       /INT
       /LONG

    Displays each monitored entity in the longword integer type
    (length 4 bytes). This is the default type for program locations
    that do not have a compiler-generated type.

2.20    /OCTAL

    Displays each monitored entity as an octal integer.

2.21    /OCTAWORD

    Displays each monitored entity in the octaword integer type
    (length 16 bytes).

2.22    /QUADWORD

    Displays each monitored entity in the quadword integer type
    (length 8 bytes).

2.23    /REMOVE

    Removes a monitored item or items with the address expression
    specified from the Monitor View.

2.24    /SHORT

    Same as /WORD qualfier.

2.25    /TASK

    Applies to tasking (multithread) programs. Interprets each
    monitored entity as a task (thread) object and displays the task
    value (the name or task ID) of that task object. When monitoring
    a task object, use /TASK only if the programming language does
    not have built-in tasking services.

2.26    /WORD

       /WORD
       /SHORT

    Displays each monitored entity in the word integer type (length 2
    bytes).

3  –  Description

    You can use the MONITOR command only with the debugger's VSI
    DECwindows Motif for OpenVMS user interface, because the output
    of that command is directed at the monitor view. With the command
    interface, you typically use the EVALUATE, EXAMINE or SET WATCH
    command instead.

    The MONITOR command does the following:

    1. Displays the monitor view (if it is not already displayed by a
       previous MONITOR command).

    2. Puts the name of the specified variable or expression and its
       current value in the monitor view.

    The debugger updates the monitor view whenever the debugger
    regains control from the program, regardless of whether the value
    of the variable or location you are monitoring has changed. (By
    contrast, a watchpoint halts execution when the value of the
    watched variable changes.)

    For more information about the monitor view and the MONITOR
    command, see context-sensitive Help.

    Related commands:

       DEPOSIT
       EVALUATE
       EXAMINE
       SET WATCH

4  –  Example

  DBG> MONITOR COUNT

      This command displays the name and current value of the
      variable COUNT in the monitor view of the debugger's VSI
      DECwindows Motif for OpenVMS user interface. The value is
      updated whenever the debugger regains control from the program.
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