The CLI$GET_VALUE routine retrieves a value associated with a
    specified qualifier, parameter, keyword, or keyword path from the
    parsed command string.

                                   NOTE

       Only use the CLI$GET_VALUE routine to retrieve values from
       parsed command strings (through DCL or CLI$DCL_PARSE). When
       you use a foreign command to activate an image, the DCL
       parsing process is interrupted. As a result, CLI$GET_VALUE
       returns either values from the previously parsed command
       string or a status of CLI$_ABSENT if it is the first command
       string parsed.

    You can use the following label names with CLI$GET_VALUE to
    retrieve special strings:

    $VERB  Describes the verb in the command string (the first four
           letters of the spelling as defined in the command table,
           instead of the string that was actually typed).
    $LINE  Describes the entire command string as stored internally
           by DCL. In the internal representation of the command
           string, multiple spaces and tabs are removed, alphabetic
           characters are converted to uppercase, and comments are
           stripped. Integers are converted to decimal. If dates and
           times are specified in the command string, DCL fills in
           any defaulted fields. Also, if date-time strings (such
           as YESTERDAY) are used, DCL substitutes the corresponding
           absolute time value.

    To obtain the values for a list of entities, call CLI$GET_
    VALUE repeatedly until all values have been returned. After
    each CLI$GET_VALUE call, the returned condition value indicates
    whether there are more values to be obtained. Call CLI$GET_VALUE
    until you receive a condition value of CLI$_ABSENT.

    When you are using CLI$GET_VALUE to obtain a list of qualifier
    or keyword values, get all values in the list before starting to
    parse the next entity.