output_routine

    OpenVMS usage:procedure
    type:         procedure value
    access:       write only
    mechanism:    by reference
    Name of a routine that writes help text a line at a time. The
    output_routine argument is the address of the procedure value
    of the routine to call. You should specify either the address of
    LIB$PUT_OUTPUT or a routine of your own that has the same calling
    format as LIB$PUT_OUTPUT.

 output_width

    OpenVMS usage:longword_signed
    type:         longword (signed)
    access:       read only
    mechanism:    by reference
    Width of the help-text line to be passed to the user-supplied
    output routine. The output_width argument is the address of a
    longword containing the width of the text line to be passed to
    the user-supplied output routine. If you omit output_width or
    specify it as 0, the default output width is 80 characters per
    line.

 line_desc

    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor
    Contents of the help request line. The line_desc argument is the
    address of a string descriptor pointing to a character string
    containing one or more help keys defining the help requested, for
    example, the HELP command line minus the HELP command and HELP
    command qualifiers. The default is a string descriptor for an
    empty string.

 library_name

    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor
    Name of the main library. The library_name argument is the
    address of a string descriptor pointing to the main library
    file specification string. The default is a null string, which
    means you should use the default help libraries. If you omit the
    device and directory specifications, the default is SYS$HELP. The
    default file type is .HLB.

 flags

    OpenVMS usage:mask_longword
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    Flags specifying help output options. Each programming language
    provides an appropriate mechanism for accessing these flags.
    The flags argument is the address of an unsigned longword that
    contains the following flags, when set:

    Flag          Description

    HLP$M_PROMPT  Interactive help prompting is in effect.
    HLP$M_        The process logical name table is searched for
    PROCESS       default help libraries.
    HLP$M_GROUP   The group logical name table is searched for group
                  default help libraries.
    HLP$M_SYSTEM  The system logical name table is searched for
                  system default help libraries.
    HLP$M_        The list of default libraries available is output
    LIBLIST       with the list of topics available.
    HLP$M_HELP    The list of topics available in a help library is
                  preceded by the major portion of the text on help.

    If you omit this longword, the default is for prompting and all
    default library searching to be enabled, but no library list is
    generated and no help text precedes the list of topics.

 input_routine

    OpenVMS usage:procedure
    type:         procedure value
    access:       read only
    mechanism:    by reference
    Routine used for prompting. The input_routine argument is the
    address of the procedure value of the prompting routine. You
    should specify either the address of LIB$GET_INPUT or a routine
    of your own that has the same calling format as LIB$GET_INPUT.
    This argument must be supplied when the HELP command is run in
    prompting mode (that is, HLP$M_PROMPT is set or defaulted).