Name

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      HELPFILE

Purpose

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      Display a file of help text.

Category

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Calling Sequence

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      helpfile, file

Inputs

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      file = name of help text file. in

Keyword Parameters

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Keywords

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        DIRECTORY=d give help text file directory.
          Default is the current directory.
        EXIT_CODE=excode. Exit code. If excode is 'QUIT'
          then do a return. Meant to exit recursively.
        /TXTMENU use TXTMENU type screen menus.

Outputs

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Common Blocks

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Notes

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      Notes: the simplest help text file is simply an
        ordinary text file. It will be displayed to the screen
        using the /MORE option. Lines must not start with *
        in column 1, such lines are not displayed (see below).
        Help text files may also have optional comment lines
        and setup a menu used to display other help text files.
        A help text file has the following format:
        There are 4 types of lines:
        1. Comment lines: have * in column 1. Not displayed.
        2. Text to display: must not have * in column 1.
        3. Menu control lines: must start in column 1.
            There are 2 menu control lines:
            .menu_start
            .menu_end
            Menus are optional.
        4. Menu lines: must be between .menu_start and .menu_end
            lines and have the following format:
            menu text | action code
            The menu text may be any text and will be displayed
            in a menu. The action code must be one of 5 options:
            title --- means use as menu title,
            noop --- no operation when selected,
            link filename --- means display filename as help text,
            back --- means go back to calling routine,
            quit --- means recursively exit all levels.

Example

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      *---- This is an example help text file ------
      *---- These two lines are comments and not displayed.
      A line of text to display.
        . . . any number of lines . . .
      .menu_start
      Example menu | title
      Go back to last menu | back
      Quit help | quit
      Overview | link overview.hlp
      Setting up defaults | link defaults.hlp
        . . . any number of menu lines . . .
      .menu_end
        May display more lines of text after returning from a
        menu call. . . .

Modification History

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      R. Sterner, 10 jan, 1992
      R. Sterner, 15 Jan, 1992 --- added DIRECTORY=
  Copyright (C) 1992, Johns Hopkins University/Applied Physics Laboratory
  This software may be used, copied, or redistributed as long as it is not
  sold and this copyright notice is reproduced on each copy made. This
  routine is provided as is without any express or implied warranties
  whatsoever. Other limitations apply as described in the file disclaimer.txt.