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     NAME
          dialog - widgets and utilities for the dialog program

     SYNOPSIS
          cc [ flag ... ] file
             or
          cc $(dialog-config --cflags) file ... $(dialog-config

          #include <dialog.h>

          Dialog is a program that will let you present a variety of questions or
          display messages using dialog boxes from a shell script.  It is built
          from the dialog library, which consists of several widgets as well as
          utility functions that are used by the widgets or the main program.

     DESCRIPTION
          This manpage documents the features from <dialog.h> which are likely
          to be important to developers using the widgets directly.  Some hints
          are also given for developing new widgets.

          Here is a dialog version of Hello World/:
               int main(void)
               {
                    int status;
                    init_dialog(stdin, stdout);
                    status = dialog_yesno(
                              "Hello, in dialog-format",
                              "Hello World!",
                              0, 0);
                    end_dialog();
                    return status;
               }

     DEFINITIONS
          Exit codes (passed back to the main program for its use) are defined
          with a "DLG_EXIT_ prefix.  The efined constants can be mapped using
          environment variables as described in dialog(1), e.g., DLG_EXIT_OK
          corresponds to $DIALOG_OK.

          Useful character constants which correspond to user input are named
          with the "CHR_" prefix, e.g., CHR_BACKSPACE.

          Colors and video attributes are categorized and associated with
          settings in the configuration file (see the discussion of $DIALOGRC in
          dialog/(1)).  The DIALOG_ATR(n) macro is used for defining the
          references to the combined color and attribute table
          dlg_color_table[].

          The dialog application passes its command-line parameters to the
          widget functions.  Some of those parameters are single values, but
          some of the widgets accept data as an array of values.  Those include

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          checklist/radiobox, menubox and formbox.  When the --item-help option
          is given, an extra column of data is expected.  The USE_ITEM_HELP(),
          CHECKBOX_TAGS, MENUBOX_TAGS and FORMBOX_TAGS macros are used to hide
          this difference from the calling application.

          Most of the other definitions found in <dialog.h> are used for
          convenience in building the library or main program.  These include
          definitions based on the generated <dlg_config.h> header.

     DATA STRUCTURES
          All of the global data for the dialog library is stored in a few
          structures: DIALOG_STATE, DIALOG_VARS and DIALOG_COLORS.  The
          corresponding dialog_state, dialog_vars and dlg_color_table global
          variables should be initialized to zeros, and then populated with the
          data to use.  A few of these must be nonzero for the corresponding
          widgets to function.  As as the case with function names, variables
          beginning with "dialog_" are designed for use by the calling
          application while variables beginning with "dlg_" are intended for
          lower levels, e.g., by the dialog library.

     DIALOG_STATE
          The state variables are dialog's working variables.  It initializes
          those, uses them to manage the widgets.

        .all_subwindows
          This is a linked list of all subwindows created by the library.  The
          dlg_del_window function uses this to free storage for subwindows when
          deleting a window.

        .all_windows
          This is a linked list of all windows created by the library.  The
          dlg_del_window function uses this to locate windows which may be
          redrawn after deleting a window.

        .aspect_ratio
          This corresponds to the command-line option "--aspect-ratio".  The
          value gives the application some control over the box dimensions when
          using auto sizing (specifying 0 for height and width).  It represents
          width / height.  The default is 9, which means 9 characters wide to
          every 1 line high.

        .finish_string
          When set to true, this allows calls to dlg_finish_string to discard
          the corresponding data which is created to speed up layout
          computations for the given string parameter.  The gauge widget uses
          this feature.

        .getc_callbacks
          This is set up in ui_getc.c to record windows which must be polled for
          input, e.g., to handle the background tailbox widget.  One window is
          designated as the foreground or control window.

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        .getc_redirect
          If the control window for DIALOG_STATE.getc_callbacks is closed, the
          list is transferred to this variable.  Closing all windows causes the
          application to exit.

        .had_resize
          This is set to TRUE in dlg_will_resize or dlg_result_key when
          KEY_RESIZE is read, to tell dialog to ignore subsequent ERRs.

        .no_mouse
          This corresponds to the command-line option "--no-mouse".  If true,
          dialog will not initialize (and enable) the mouse in init_dialog.

        .output
          This is set in the dialog application to the stream on which the
          application and library functions may write text results.  Normally
          that is the standard error, since the curses library prefers to write
          its data to the standard output.  Some scripts, trading portability
          for convenience, prefer to write results to the standard output, e.g.,
          by using the "--stdout" option.

        .output_count
          This is incremented by dlg_does_output, which is called by each widget
          that writes text to the output.  The dialog application uses that to
          decide if it should also write a separator, i.e.,
          DIALOG_STATE.separate_str, between calls to each widget.

        .pipe_input
          This is set in init_dialog to a stream which can be used by the gauge
          widget, which must be the application's standard input.  The dialog
          application calls init_dialog normally with input set to the standard
          input, but optionally based on the "--input-fd" option.  Since the
          application cannot read from a pipe (standard input) and at the same
          time read the curses input from the standard input, it must allow for
          reopening the latter from either a specific file descriptor, or
          directly from the terminal.  The adjusted pipe stream value is stored
          in this variable.

        .screen_height
          The text-formatting functions use this for the number of rows used for
          formatting a string.  It is used by dialog for the command-line
          options "--print-text-size" and "--print-text-only".

        .screen_initialized
          This is set in init_dialog and reset in end_dialog.  It is used to
          check if curses has been initialized, and if the endwin function must
          be called on exit.

        .screen_output
          This is set in init_dialog to the output stream used by the curses
          library.  Normally that is the standard output, unless that happens to

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          not be a terminal (and if init_dialog can successfully open the
          terminal directly).

        .screen_width
          The text-formatting functions use this for the number of columns used
          for formatting a string.  It is used by dialog for the command-line
          options "--print-text-size" and "--print-text-only".

        .separate_str
          This corresponds to the command-line option "--separate-widget".  The
          given string specifies a string that will separate the output on
          dialog's output from each widget.  This is used to simplify parsing
          the result of a dialog with several widgets.  If this option is not
          given, the default separator string is a tab character.

        .tab_len
          This corresponds to the command-line option "--tab-len number/".
          Specify the number of spaces that a tab character occupies if the
          "--tab-correct" option is given.  The default is 8.

        .text_height
          The text-formatting functions set this to the number of lines used for
          formatting a string.  It is used by dialog for the command-line
          options "--print-text-size" and "--print-text-only".

        .text_only
          Dialog uses this in the command-line option "--print-text-only".  The
          text-formatting functions (dlg_print_text, dlg_print_line, and
          dlg_print_autowrap) check this to decide whether to print the
          formatted text to dialog's output or to the curses-display.  Also,
          dlg_auto_size checks the flag, allowing it to be used before
          init_dialog is called.

        .text_width
          The text-formatting functions set this to the number of columns used
          for formatting a string.  It is used by dialog for the command-line
          options "--print-text-size" and "--print-text-only".

        .trace_output
          This corresponds to the command-line option "--trace file".  It is the
          file pointer to which trace messages are written.

        .use_colors
          This is set in init_dialog if the curses implementation supports
          color.

        .use_scrollbar
          This corresponds to the command-line option "--scrollbar".  If true,
          draw a scrollbar to make windows holding scrolled data more readable.

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        .use_shadow
          This corresponds to the command-line option "--no-shadow".  This is
          set in init_dialog if the curses implementation supports color.  If
          true, suppress shadows that would be drawn to the right and bottom of
          each dialog box.

        .visit_items
          This corresponds to the command-line option "--visit-items".  Modify
          the tab-traversal of the list-oriented widgets (buildlist, checklist,
          radiobox, menubox, inputmenu, and treeview) to include the list of
          items as one of the states.  This is useful as a visual aid, i.e., the
          cursor position helps some users.

          The dialog application resets the dialog_vars data before accepting
          options to invoke each widget.  Most of the DIALOG_VARS members are
          set directly from dialog's command-line options:

          DIALOG_VARS

          In contrast to DIALOG_STATE, the members of DIALOG_VARS are set by
          command-line options in dialog.

        .ascii_lines
          This corresponds to the command-line option "--ascii-lines.  It causes
          line-drawing to be done with ASCII characters, e.g., "+" and "-".  See
          DIALOG_VARS.no_lines.

        .backtitle
          This corresponds to the command-line option "--backtitle backtitle/".
          It specifies a backtitle string to be displayed on the backdrop, at
          the top of the screen.

        .beep_after_signal
          This corresponds to the command-line option "--beep-after".  If true,
          beep after a user has completed a widget by pressing one of the
          buttons.

        .beep_signal
          This corresponds to the command-line option "--beep".  It is obsolete.

        .begin_set
          This is true if the command-line option "--begin y x/" was used.  It
          specifies the position of the upper left corner of a dialog box on the
          screen.

        .begin_x
          This corresponds to the x value from the command-line option "--begin
          y x/" (second value).

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        .begin_y
          This corresponds to the y value from the command-line option "--begin
          y x/" (first value).

        .cancel_label
          This corresponds to the command-line option "--cancel-label string/".
          The given string overrides the label used for ``Cancel'' buttons.

        .cant_kill
          This corresponds to the command-line option "--no-kill".  If true,
          this tells dialog to put the tailboxbg box in the background, printing
          its process id to dialog's output.  SIGHUP is disabled for the
          background process.

        .colors
          This corresponds to the command-line option "--colors".  If true,
          interpret embedded "\Z" sequences in the dialog text by the following
          character, which tells dialog to set colors or video attributes:

          o   0 through 7 are the ANSI codes used in curses: black, red, green,
              yellow, blue, magenta, cyan and white respectively.

          o   Bold is set by 'b', reset by 'B'.

          o   Reverse is set by 'r', reset by 'R'.

          o   Underline is set by 'u', reset by 'U'.

          The settings are cumulative, e.g., "\Zb\Z1" makes the following text
          bright red.  Restore normal settings with "\Zn".

        .column_separator
          This corresponds to the command-line option "--column-separator".
          Dialog splits data for radio/checkboxes and menus on the occurrences
          of the given string, and aligns the split data into columns.

        .cr_wrap
          This corresponds to the command-line option "--cr-wrap".  If true,
          interpret embedded newlines in the dialog text as a newline on the
          screen.  Otherwise, dialog will only wrap lines where needed to fit
          inside the text box.  Even though you can control line breaks with
          this, dialog will still wrap any lines that are too long for the width
          of the box.  Without cr-wrap, the layout of your text may be formatted
          to look nice in the source code of your script without affecting the
          way it will look in the dialog.

        .cursor_off_label
          This corresponds to the command-line option "--cursor-off-label".  If
          true, place the terminal cursor at the end of a button instead of on
          the first character of the button label.  This is useful to reduce
          visual confusion when the cursor coloration interacts poorly with the

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          button-label text colors.

        .date_format
          This corresponds to the command-line option "--date-format string/".
          If the host provides strftime, and the value is nonnull, the calendar
          widget uses this to format its output.

        .default_button
          This is set by the command-line option "--default-button.  It is used
          by dlg_default_button.

        .default_item
          This corresponds to the command-line option "--default-item string/".
          The given string is used as the default item in a checklist, form or
          menu box.  Normally the first item in the box is the default.

        .defaultno
          This corresponds to the command-line option "--defaultno".  If true,
          make the default value of the yes/no box a No.  Likewise, treat the
          default button of widgets that provide ``OK'' and ``Cancel'' as a
          Cancel.  If --no-cancel was given that option overrides this, making
          the default button always ``Yes'' (internally the same as ``OK'').

        .dlg_clear_screen
          This corresponds to the command-line option "--clear".  This option is
          implemented in the main program, not the library.  If true, the screen
          will be cleared on exit.  This may be used alone, without other
          options.

        .erase_on_exit
          This corresponds to the command-line option "--erase-on-exit".  If
          true, remove the dialog widget on program exit, erasing the entire
          screen to its native background color, and place the terminal cursor
          at the lower left corner of the screen.

          This is useful for making the window contents invisible at the end of
          a series of dialog boxes.  It can also be used at earlier stages of a
          series of invocations of dialog, if the series may be aborted before
          it is fully completed.

        .exit_label
          This corresponds to the command-line option "--exit-label string".
          The given string overrides the label used for ``EXIT'' buttons.

        .extra_button
          This corresponds to the command-line option "--extra-button".  If
          true, some widgets show an extra button, between ``OK'' and ``Cancel''
          buttons, or ``Yes'' and ``No'' buttons.

        .extra_label
          This corresponds to the command-line option "--extra-label string/".

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          The given string overrides the label used for ``Extra'' buttons.
          Note: for inputmenu widgets, this defaults to ``Rename''.

        .formitem_type
          This is set by the command-line option "--passwordform" to tell the
          form widget that its text fields should be treated like password
          widgets.

        .help_button
          This corresponds to the command-line option "--help-button".  If true,
          some widgets show a help-button after ``OK'' and ``Cancel'' buttons,
          i.e., in checklist, radiolist and menu boxes, or the ``Yes'' and
          ``No'' buttons for the yesno box.

          If --item-help is also given, on exit the return status will be the
          same as for the ``OK'' button, and the item-help text will be written
          to dialog's output after the token ``HELP''.  Otherwise, the return
          status will indicate that the Help button was pressed, and no message
          printed.

        .help_file
          This corresponds to the command-line option "--hfile string/".  The
          given filename is passed to dialog_helpfile when the user presses F1.

        .help_label
          This corresponds to the command-line option "--help-label string/".
          The given string overrides the label used for ``Help'' buttons.

        .help_line
          This corresponds to the command-line option "--hline string/".  The
          given string is displayed in the bottom of dialog windows, like a
          subtitle.

        .help_status
          This corresponds to the command-line option "--help-status".  If true,
          and the the help-button is selected, writes the checklist or radiolist
          information after the item-help ``HELP'' information.  This can be
          used to reconstruct the state of a checklist after processing the help
          request.

        .help_tags
          This corresponds to the command-line option "--help-tags".  If true,
          dlg_add_help_formitem and dlg_add_help_listitem use the item's tag
          value consistently rather than using the tag's help-text value when
          DIALOG_VARS.item_help is set.

        .input_length
          This is nonzero if DIALOG_VARS.input_result is allocated, versus being
          a pointer to the user's local variables.

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        .input_menu
          This flag is set to denote whether the menubox widget implements a
          menu versus a inputmenu widget.

        .input_result
          This may be either a user-supplied buffer, or a buffer dynamically
          allocated by the library, depending on DIALOG_VARS.input_length:

          o   If DIALOG_VARS.input_length is zero, this is a pointer to user
              buffer (on the stack, or static).  The buffer size is assumed to
              be MAX_LEN, which is defined in <dialog.h>.

          o   When DIALOG_VARS.input_length is nonzero, this is a dynamically-
              allocated buffer used by the widgets to return printable results
              to the calling application.  Certain widgets copy a result to this
              buffer.  If the pointer is NULL, or if the length is insufficient
              for the result, then the dialog library allocates a buffer which
              is large enough, and sets DIALOG_VARS.input_length.  Callers
              should check for this case if they have supplied their own buffer.

        .insecure
          This corresponds to the command-line option "--insecure".  If true,
          make the password widget friendlier but less secure, by echoing
          asterisks for each character.

        .in_helpfile
          This variable is used to prevent dialog_helpfile from showing
          anything, e.g., if F1 were pressed within a help-file display.

        .iso_week
          This corresponds to the command-line option "--iso-week".  It is used
          in the calendar widget to tell how to compute the starting week for
          the year:

          o   by default, the calendar treats January 1 as the first week of the
              year.

          o   If this variable is true, the calendar uses ISO 8601's convention.
              ISO 8601 numbers weeks starting with the first week in January
              with a Thursday in the current year.  January 1 may be in the
              previous year.

        .item_help
          This corresponds to the command-line option "--item-help".  If true,
          interpret the tags data for checklist, radiolist and menu boxes adding
          a column whose text is displayed in the bottom line of the screen, for
          the currently selected item.

        .keep_tite
          This is set by the command-line option "--keep-tite" to tell dialog to
          not attempt to cancel the terminal initialization (termcap ti//,te/)

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          sequences which correspond to xterm's alternate-screen switching.
          Normally dialog does this to avoid flickering when run several times
          in a script.

        .keep_window
          This corresponds to the command-line option "--keep-window".  If true,
          do not remove/repaint the window on exit.  This is useful for keeping
          the window contents visible when several widgets are run in the same
          process.  Note that curses will clear the screen when starting a new
          process.

        .last_key
          This corresponds to the command-line option "--last-key".

        .max_input
          This corresponds to the command-line option "--max-input size/".
          Limit input strings to the given size.  If not specified, the limit is
          2048.

        .no_hot_key
          This corresponds to the command-line option "--no-hot-list".  Some
          widgets (buildlist, checklist, inputmenu, menu, radiolist, treeview)
          display a list for which the leading capital letter in each entry is
          accepted as a hot-key, to quickly move the focus to that entry.
          Setting this variable to TRUE disables the feature.

        .no_items
          This corresponds to the command-line option "--no-items".  Some
          widgets (checklist, inputmenu, radiolist, menu) display a list with
          two columns (a ``tag'' and ``item'', i.e., ``description'').  This
          tells dialog to read shorter rows from data, omitting the ``list''.

        .no_label
          This corresponds to the command-line option "--no-label string/".  The
          given string overrides the label used for ``No'' buttons.

        .no_lines
          This corresponds to the command-line option "--no-lines.  It
          suppresses line-drawing.  See DIALOG_VARS.ascii_lines.

        .no_nl_expand
          This corresponds to the command-line option "--no-nl-expand".  If
          false, dlg_trim_string converts literal "\n" substrings in a message
          into newlines.

        .no_tags
          This corresponds to the command-line option "--no-tags".  Some widgets
          (checklist, inputmenu, radiolist, menu) display a list with two
          columns (a ``tag'' and ``item'', also known as ``description'').  The
          tag is useful for scripting, but may not help the user.  The --no-tags
          option (from Xdialog) may be used to suppress the column of tags from

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          the display.  Normally dialog allows you to quickly move to entries on
          the displayed list, by matching a single character to the first
          character of the tag.  When the --no-tags option is given, dialog
          matches against the first character of the description.  In either
          case, the matchable character is highlighted.  Here is a table showing
          how the no_tags and no_items values interact:
          Widget      Fields Shown   Fields Read   .no_items   .no_tags
          _____________________________________________________________
          buildlist   item           tag,item          0          0*
          buildlist   item           tag,item          0          1
          buildlist   tag            tag               1          0*
          buildlist   tag            tag               1          1
          checklist   tag,item       tag,item          0          0
          checklist   item           tag,item          0          1
          checklist   tag            tag               1          0
          checklist   tag            tag               1          1
          inputmenu   tag,item       tag,item          0          0
          inputmenu   item           tag,item          0          1
          inputmenu   tag            tag               1          0
          inputmenu   tag            tag               1          1
          menu        tag,item       tag,item          0          0
          menu        item           tag,item          0          1
          menu        tag            tag               1          0
          menu        tag            tag               1          1
          radiolist   tag,item       tag,item          0          0
          radiolist   item           tag,item          0          1
          radiolist   tag            tag               1          0
          radiolist   tag            tag               1          1
          treeview    item           tag,item          0          0*
          treeview    item           tag,item          0          1
          treeview    tag            tag               1          0*
          treeview    tag            tag               1          1
          _____________________________________________________________

          * Xdialog does not display the tag column for the analogous buildlist
            and treeview widgets.  Dialog does the same on the command-line.
            However the library interface defaults to displaying the tag column.
            Your application can enable or disable the tag column as needed for
            each widget.

        .nocancel
          This corresponds to the command-line option "--no-cancel".  If true,
          suppress the ``Cancel'' button in checklist, inputbox and menu box
          modes.  A script can still test if the user pressed the ESC key to
          cancel to quit.

        .nocollapse
          This corresponds to the command-line option "--no-collapse".  Normally
          dialog converts tabs to spaces and reduces multiple spaces to a single
          space for text which is displayed in a message boxes, etc.  It true,
          that feature is disabled.  Note that dialog will still wrap text,

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          subject to the --cr-wrap option.

        .nook
          This corresponds to the command-line option "--no-ok.  Dialog will
          suppress the ``ok'' (or ``yes'') button from the widget.

        .ok_label
          This corresponds to the command-line option "--ok-label string/".  The
          given string overrides the label used for ``OK'' buttons.

        .pause_secs
          When set, force dlg_set_timeout to use 10 milliseconds rather than
          using the DIALOG_VARS.timeout_secs value.

        .print_siz
          This corresponds to the command-line option "--print-size".  If true,
          each widget prints its size to dialog's output when it is invoked.

        .quoted
          This corresponds to the command-line option "--quoted.  Normally
          dialog quotes the strings returned by checklist's as well as the
          item-help text.  If true, dialog will quote all string results.

        .reorder
          This corresponds to the command-line option "--reorder.  By default,
          the buildlist widget uses the same order for the output (right) list
          as for the input (left).  If true, dialog will use the order in which
          a user adds selections to the output list.

        .separate_output
          This corresponds to the command-line option "--separate-output".  If
          true, checklist widgets output result one line at a time, with no
          quoting.  This facilitates parsing by another program.

        .single_quoted
          This corresponds to the command-line option "--single-quoted".  If
          true, use single-quoting as needed (and no quotes if unneeded) for the
          output of checklist's as well as the item-help text.  If this option
          is not set, dialog uses double quotes around each item.  The latter
          requires occasional use of backslashes to make the output useful in
          shell scripts.

        .size_err
          This corresponds to the command-line option "--size-err".  If true,
          check the resulting size of a dialog box before trying to use it,
          printing the resulting size if it is larger than the screen.  (This
          option is obsolete, since all new-window calls are checked).

        .sleep_secs
          This corresponds to the command-line option "--sleep secs/".  This
          option is implemented in the main program, not the library.  If

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          nonzero, this is the number of seconds after to delay after processing
          a dialog box.

        .tab_correct
          This corresponds to the command-line option "--tab-correct".  If true,
          convert each tab character of the text to one or more spaces.
          Otherwise, tabs are rendered according to the curses library's
          interpretation.

        .time_format
          This corresponds to the command-line option "--time-format string/".
          If the host provides strftime, and the value is nonnull, the timebox
          widget uses this to format its output.

        .timeout_secs
          This corresponds to the command-line option "--timeout secs/".  If
          nonzero, timeout input requests (exit with error code) if no user
          response within the given number of seconds.

        .title
          This corresponds to the command-line option "--title title/".
          Specifies a title string to be displayed at the top of the dialog box.

        .trim_whitespace
          This corresponds to the command-line option "--trim".  If true,
          eliminate leading blanks, trim literal newlines and repeated blanks
          from message text.

        .week_start
          This corresponds to the command-line option "--week-start".  It is
          used in the calendar widget to set the starting day for the week.  The
          string value can be

          o   a number (0 to 6, Sunday through Saturday using POSIX) or

          o   the special value ``locale'' (this works with systems using glibc,
              providing an extension to the locale command, the first_weekday
              value).

          o   a string matching one of the abbreviations for the day of the week
              shown in the calendar widget, e.g., ``Mo'' for ``Monday''.

        .yes_label
          This corresponds to the command-line option "--yes-label string/".
          The given string overrides the label used for ``Yes'' buttons.

     WIDGETS
          Functions that implement major functionality for the command-line
          dialog program, e.g., widgets, have names beginning "dialog_".

                                       - 13 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          All dialog boxes have at least three parameters:

             title
                  the caption for the box, shown on its top border.

             height
                  the height of the dialog box.

             width
                  the width of the dialog box.

          Other parameters depend on the box type.

        dialog_buildlist
          implements the "--buildlist" option.

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is
               adjusted to use the available screen size.

          int width
               is the desired width of the box.  If zero, the height is adjusted
               to use the available screen size.

          int list_height
               is the minimum height to reserve for displaying the list.  If
               zero, it is computed based on the given height and width.

          int item_no
               is the number of rows in items.

          char ** items
               is an array of strings which is viewed either as a list of rows
               tag item status

               or
               tag item status help

               depending on whether dialog_vars.item_help is set.

          int order_mode
               is reserved for future enhancements

        dialog_calendar
          implements the "--calendar" option.

                                       - 14 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          const char * title
               is the title on the top of the widget.

          const char * subtitle
               is the prompt text shown within the widget.

          int height
               is the height excluding the fixed-height calendar grid.

          int width
               is the overall width of the box, which is adjusted up to the
               calendar grid's minimum width if needed.

          int day
               is the initial day of the week shown, counting zero as Sunday.
               If the value is negative, the current day of the week is used.

          int month
               is the initial month of the year shown, counting one as January.
               If the value is negative, the current month of the year is used.

          int year
               is the initial year shown.  If the value is negative, the current
               year is used.

        dialog_checklist
          implements the "--checklist" and "--radiolist" options depending on
          the flag parameter.

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is
               adjusted to use the available screen size.

          int width
               is the desired width of the box.  If zero, the height is adjusted
               to use the available screen size.

          int list_height
               is the minimum height to reserve for displaying the list.  If
               zero, it is computed based on the given height and width.

          int item_no
               is the number of rows in items.

                                       - 15 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int items
               is an array of strings which is viewed either as a list of rows
               tag item status

               or
               tag item status help

               depending on whether dialog_vars.item_help is set.

          flag is either FLAG_CHECK, for checklists, or FLAG_RADIO for
               radiolists.

        dialog_dselect
          implements the "--dselect" option.

          const char * title
               is the title on the top of the widget.

          const char * path
               is the preselected value to show in the input-box, which is used
               also to set the directory- and file-windows.

          int height
               is the height excluding the minimum needed to show the dialog box
               framework.  If zero, the height is based on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

        dialog_editbox
          implements the "--editbox" option.

          const char * title
               is the title on the top of the widget.

          const char * file
               is the name of the file from which to read.

          int height
               is the desired height of the box.  If zero, the height is
               adjusted to use the available screen size.

          int width
               is the desired width of the box.  If zero, the height is adjusted
               to use the available screen size.

        dialog_form
          implements the "--form" option.

                                       - 16 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is
               adjusted to use the available screen size.

          int width
               is the desired width of the box.  If zero, the height is adjusted
               to use the available screen size.

          int form_height
               is the minimum height to reserve for displaying the list.  If
               zero, it is computed based on the given height and width.

          int item_no
               is the number of rows in items.

          int items
               is an array of strings which is viewed either as a list of rows
               Name NameY NameX Text TextY TextX FLen ILen

               or
               Name NameY NameX Text TextY TextX FLen ILen Help

               depending on whether dialog_vars.item_help is set.

        dialog_fselect
          implements the "--fselect" option.

          const char * title
               is the title on the top of the widget.

          const char * path
               is the preselected value to show in the input-box, which is used
               also to set the directory- and file-windows.

          int height
               is the height excluding the minimum needed to show the dialog box
               framework.  If zero, the height is based on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

        dialog_gauge
          implements the "--gauge" option.  Alternatively, a simpler or
          customized gauge widget can be set up using dlg_allocate_gauge,

                                       - 17 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          dlg_reallocate_gauge, dlg_update_gauge and dlg_free_gauge.

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is based
               on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

          int percent
               is the percentage to show in the progress bar.

        dialog_inputbox
          implements the "--inputbox" or "--password" option, depending on the
          value of password.

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is based
               on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

          const char * init
               is the initial value of the input box, whose length is taken into
               account when auto-sizing the width of the dialog box.

          int password
               if true, causes typed input to be echoed as asterisks.

        dialog_helpfile
          implements the "--hfile" option.

          const char * title
               is the title on the top of the widget.

                                       - 18 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          const char * file
               is the name of a file containing the text to display.  This
               function is internally bound to F1 (function key ``1''), passing
               dialog_vars.help_file as a parameter.  The dialog program sets
               that variable when the --hfile option is given.

          int height
               is the desired height of the box.  If zero, the height is based
               on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

        dialog_menu
          implements the "--menu" or "--inputmenu" option depending on whether
          dialog_vars.input_menu is set.

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is based
               on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

          int menu_height
               is the minimum height to reserve for displaying the list.  If
               zero, it is computed based on the given height and width.

          int item_no
               is the number of rows in items.

          int items
               is an array of strings which is viewed either as a list of rows
               tag item

               or
               tag item help

               depending on whether dialog_vars.item_help is set.

        dialog_mixedform
          implements the "--mixedform" option.

                                       - 19 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is
               adjusted to use the available screen size.

          int width
               is the desired width of the box.  If zero, the height is adjusted
               to use the available screen size.

          int form_height
               is the minimum height to reserve for displaying the list.  If
               zero, it is computed based on the given height and width.

          int item_no
               is the number of rows in items.

          int items
               is an array of strings which is viewed either as a list of rows
               Name NameY NameX Text TextY TextX FLen ILen Ityp

               or
               Name NameY NameX Text TextY TextX FLen ILen Ityp Help

               depending on whether dialog_vars.item_help is set.

        dialog_mixedgauge
          implements the "--mixedgauge" option

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the caption text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is based
               on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

          int percent
               is the percentage to show in the progress bar.

                                       - 20 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int item_no
               is the number of rows in items.

          int items
               is an array of strings which is viewed as a list of tag and item
               values.  The tag values are listed, one per row, in the list at
               the top of the widget.

               The item values are decoded: digits 0 through 9 are the following
               strings

               0    Succeeded

               1    Failed

               2    Passed

               3    Completed

               4    Checked

               5    Done

               6    Skipped

               7    In Progress

               8    (blank)

               9    N/A

               A string with a leading "-" character is centered, marked with
               "%".  For example, "-75" is displayed as "75%".  Other strings
               are displayed as is.

        dialog_msgbox
          implements the "--msgbox" or "--infobox" option depending on whether
          pauseopt is set.

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is based
               on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on

                                       - 21 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

               the screen size.

          int pauseopt
               if true, an ``OK'' button will be shown, and the dialog will wait
               for it to complete.  With an ``OK'' button, it is denoted a
               ``msgbox'', without an ``OK'' button, it is denoted an
               ``infobox''.

        dialog_pause
          implements the "--pause" option.

          const char * title
               is the title on the top of the widget.

          int height
               is the desired height of the box.  If zero, the height is based
               on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

          int seconds
               is the timeout to use for the progress bar.

        dialog_prgbox
          implements the "--prgbox" option.

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.  If empty or null, no
               prompt is shown.

          const char * command
               is the name of the command to execute.

          int height
               is the desired height of the box.  If zero, the height is based
               on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

          int pauseopt
               if true, an ``OK'' button will be shown, and the dialog will wait
               for it to complete.

                                       - 22 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

        dialog_progressbox
          implements the "--progressbox" option.

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.  If empty or null, no
               prompt is shown.

          int height
               is the desired height of the box.  If zero, the height is based
               on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

        dialog_rangebox
          implements the "--rangebox" option.

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.  If empty or null, no
               prompt is shown.

          int height
               is the desired height of the widget.  If zero, the height is
               based on the screen size.

          int width
               is the desired width of the widget.  If zero, the height is based
               on the screen size.

          int min_value
               is the minimum value to allow.

          int max_value
               is the maximum value to allow.

          int default_value
               is the default value, if no change is made.

        dialog_tailbox
          implements the "--tailbox" or "--tailboxbg" option depending on
          whether bg_task is set.

          const char * title
               is the title on the top of the widget.

                                       - 23 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          const char * file
               is the name of the file to display in the dialog.

          int height
               is the desired height of the box.  If zero, the height is based
               on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

          int bg_task
               if true, the window is added to the callback list in
               dialog_state, and the application will poll for the window to be
               updated.  Otherwise an ``OK'' button is added to the window, and
               it will be closed when the button is activated.

        dialog_textbox
          implements the "--textbox" option.

          const char * title
               is the title on the top of the widget.

          const char * file
               is the name of the file to display in the dialog.

          int height
               is the desired height of the box.  If zero, the height is based
               on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

        dialog_timebox
          implements the "--timebox" option.  See dlg_auto_size for layout using
          height and width parameters.

          const char * title
               is the title on the top of the widget.

          const char * subtitle
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.

               o   If zero, the height is based on the screen size.

               o   If greater than zero, the requested height is added to the
                   minimum box size.

                                       - 24 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int width
               is the desired width of the box.

               o   If zero, the height is based on the screen size.

               o   If greater than zero, the requested width is constrained by
                   the minimum box size and the width of the buttons.

          int hour
               is the initial hour shown.  If the value is negative, the current
               hour is used.  Returns DLG_EXIT_ERROR if the value specified is
               greater than or equal to 24.

          int minute
               is the initial minute shown.  If the value is negative, the
               current minute is used.  Returns DLG_EXIT_ERROR if the value
               specified is greater than or equal to 60.

          int second
               is the initial second shown.  If the value is negative, the
               current second is used.  Returns DLG_EXIT_ERROR if the value
               specified is greater than or equal to 60.

        dialog_treeview
          implements the "--treeview" option.

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is based
               on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

          int list_height
               is the minimum height to reserve for displaying the list.  If
               zero, it is computed based on the given height and width.

          int item_no
               is the number of rows in items.

          char ** items
               is the list of items, contain tag, name, and optionally help
               strings (if dialog_vars.item_help is set).  The initial selection
               state for each item is also in this list.

                                       - 25 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int flag

          flag is either FLAG_CHECK, for checklists (multiple selections), or
               FLAG_RADIO for radiolists (a single selection).

        dialog_yesno
          implements the "--yesno" option.

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is based
               on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

     UTILITY FUNCTIONS
          Most functions that implement lower-level functionality for the
          command-line dialog program or widgets, have names beginning "dlg_".
          Bowing to longstanding usage, the functions that initialize the
          display and end it are named init_dialog and end_dialog.

          The only non-widget function whose name begins with "dialog_" is
          dialog_version, which returns the version number of the library as a
          string.

          A few functions are prefixed "_dlg_", because they are required for
          internal use, but not intended as part of the library application
          programming interface.

          Here is a brief summary of the utility functions and their parameters:

        dlg_add_callback
          Add a callback, used to allow polling input from multiple tailbox
          widgets.

          DIALOG_CALLBACK *p
               contains the callback information.

        dlg_add_callback_ref
          Like dlg_add_callback, but passes a reference to the DIALOG_CALLBACK
          as well as a pointer to a cleanup function which will be called when
          the associated input ends.

                                       - 26 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          DIALOG_CALLBACK **p
               points to the callback information.  This is a reference to the
               pointer so that the caller's pointer can be zeroed when input
               ends.

          DIALOG_FREEBACK func
               function to call when input ends, e.g., to free caller's
               additional data.

        dlg_add_help_formitem
          This is a utility function used enforce consistent behavior for the
          DIALOG_VARS.help_tags and DIALOG_VARS.item_help variables.

          int *result
               this is updated to DLG_EXIT_ITEM_HELP if DIALOG_VARS.item_help is
               set.

          char **tag
               the tag- or help-text is stored here.

          DIALOG_FORMITEM *item
               contains the list item to use for tag- or help-text.

        dlg_add_help_listitem
          This is a utility function used enforce consistent behavior for the
          DIALOG_VARS.help_tags and DIALOG_VARS.item_help variables.

          int *result
               this is updated to DLG_EXIT_ITEM_HELP if DIALOG_VARS.item_help is
               set.

          char **tag
               the tag- or help-text is stored here.

          DIALOG_LISTITEM *item
               contains the list item to use for tag- or help-text.

        dlg_add_last_key
          Report the last key entered by the user.  This implements the
          --last-key command-line option, using dialog_vars.last_key.

          int mode
               controls the way the last key report is separated from other
               results:

               -2   (no separator)

               -1   (separator after the key name)

               0    (separator is optionally before the key name)

                                       - 27 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

               1    (same as -1)

        dlg_add_quoted
          Add a quoted string to the result buffer (see dlg_add_result).  If no
          quotes are necessary, none are used.  If dialog_vars.single_quoted is
          set, single-quotes are used.  Otherwise, double-quotes are used.

          char * string
               is the string to add.

        dlg_add_result
          Add a string to the result buffer dialog_vars.input_result.

          char * string
               is the string to add.

        dlg_add_separator
          Add an output-separator to the result buffer dialog_vars.input_result.
          If dialog_vars.output_separator is set, use that.  Otherwise, if
          dialog_vars.separate_output is set, use newline.  If neither is set,
          use a space.

        dlg_add_string
          Add a quoted or unquoted string to the result buffer (see
          dlg_add_quoted) and dlg_add_result), according to whether
          dialog_vars.quoted is true.

          char * string
               is the string to add.

        dlg_align_columns
          Copy and reformat an array of pointers to strings, aligning according
          to the column separator dialog_vars.column_separator.  If no column
          separator is set, the array will be unmodified; otherwise it is copied
          and reformatted.

               Caveat: This function is only implemented for 8-bit characters.

          char **target
               This is the array to reformat.  It points to the first string to
               modify.

          int per_row
               This is the size of the struct for each row of the array.

          int num_rows
               This is the number of rows in the array.

        dlg_allocate_gauge
          Allocates a gauge widget.  Use dlg_update_gauge to display the result.

                                       - 28 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          const char * title
               is the title string to display at the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is
               adjusted to use the available screen size.

          int width
               is the desired width of the box.  If zero, the height is adjusted
               to use the available screen size.

          int percent
               is the percentage to show in the progress bar.

        dlg_asciibox
          returns its parameter transformed to the corresponding "+" or "-",
          etc., for the line-drawing characters used in dialog.  If the
          parameter is not a line-drawing or other special character such as
          ACS_DARROW, it returns 0.

          chtype ch
               is the parameter, usually one of the ACS_xxx constants.

        dlg_attr_clear
          Set window to the given attribute.

          WINDOW * win
               is the window to update.

          int height
               is the number of rows to update.

          int width
               is the number of columns to update.

          chtype attr
               is the attribute, e.g., A_BOLD.

        dlg_auto_size
          Compute window size based on the size of the formatted prompt and
          minimum dimensions for a given widget.

          Dialog sets dialog_state.text_height and dialog_state.text_width for
          the formatted prompt as a side-effect.

          Normally dialog writes the formatted prompt to the curses window, but
          it will write the formatted prompt to the output stream if
          dialog_state.text_only is set.

                                       - 29 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          const char * title
               is the title string to display at the top of the widget.

          const char * prompt
               is the message text which will be displayed in the widget, used
               here to determine how large the widget should be.

               If the value is NULL, dialog allows the widget to use the whole
               screen, i.e., if the values referenced by height and/or width are
               zero.

          int * height
               is the nominal height.  Dialog checks the referenced value and
               may update it:

               o   if the value is negative, dialog updates it to the available
                   height of the screen, after reserving rows for the window
                   border and shadow, as well as taking into account
                   dialog_vars.begin_y and dialog_vars.begin_set.

               o   if the value is zero, dialog updates it to the required
                   height of the window, taking into account a (possibly)
                   multi-line prompt.

               o   if the value is greater than zero, dialog uses it internally,
                   but restores the value on return.

          int * width
               is the nominal width.  Dialog checks the referenced value and may
               update it:

               o   if the value is negative, dialog updates it to the available
                   width of the screen, after reserving rows for the window
                   border and shadow, as well as taking into account
                   dialog_vars.begin_x and dialog_vars.begin_set.

               o   if the value is zero, dialog updates it to the required width
                   of the window, taking into account a (possibly) multi-line
                   prompt.

               o   if the value is greater than zero, dialog uses it internally,
                   but restores the value on return.

          int boxlines
               is the number of lines to reserve in the vertical direction.

          int mincols
               is the minimum number of columns to use.

        dlg_auto_sizefile
          Like dlg_auto_size, but use a file contents to decide how large the

                                       - 30 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          widget should be.

          const char * title
               is the title string to display at the top of the widget.

          const char * file
               is the name of the file.

          int * height
               is the nominal height.

               If it is -1, use the screen's height (after subtracting
               dialog_vars.begin_y if dialog_vars.begin_set is true).

               If it is greater than zero, limit the referenced value to the
               screen-height after verifying that the file exists.

          int * width
               is the nominal width.

               If it is -1, use the screen's width (after subtracting
               dialog_vars.begin_x if dialog_vars.begin_set is true).

               If it is greater than zero, limit the referenced value to the
               screen-width after verifying that the file exists.

          int boxlines
               is the number of lines to reserve on the screen for drawing
               boxes.

          int mincols
               is the number of columns to reserve on the screen for drawing
               boxes.

        dlg_beeping
          If dialog_vars.beep_signal is nonzero, this calls beep once and sets
          dialog_vars.beep_signal to zero.

        dlg_boxchar
          returns its chtype parameter transformed as follows:

          o   if neither dialog_vars.ascii_lines nor dialog_vars.no_lines is
              set.

          o   if dialog_vars.ascii_lines is set, returns the corresponding "+"
              or "-", etc., for the line-drawing characters used in dialog.

          o   otherwise, if dialog_vars.no_lines is set, returns a space for the
              line-drawing characters.

                                       - 31 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          o   if the parameter is not a line-drawing or other special character
              such as ACS_DARROW, it returns the parameter unchanged.

        dlg_box_x_ordinate
          returns a suitable x-ordinate (column) for a new widget.  If
          dialog_vars.begin_set is 1, use dialog_vars.begin_x; otherwise center
          the widget on the screen (using the width parameter).

          int width
               is the width of the widget.

        dlg_box_y_ordinate
          returns a suitable y-ordinate (row) for a new widget.  If
          dialog_vars.begin_set is 1, use dialog_vars.begin_y; otherwise center
          the widget on the screen (using the height parameter).

          int height
               is the height of the widget.

        dlg_buildlist
          This is an alternate interface to the buildlist widget which allows
          the application to read the list item states back directly without
          putting them in the output buffer.

          const char * title
               is the title string to display at the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is
               adjusted to use the available screen size.

          int width
               is the desired width of the box.  If zero, the height is adjusted
               to use the available screen size.

          int list_height
               is the minimum height to reserve for displaying the list.  If
               zero, it is computed based on the given height and width.

          int item_no
               is the number of rows in items.

          DIALOG_LISTITEM * items
               is the list of items, contain tag, name, and optionally help
               strings (if dialog_vars.item_help is set).  The initial selection
               state for each item is also in this list.

                                       - 32 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          const char * states
               This is a list of characters to display for the given states.
               Normally a buildlist provides true (1) and false (0) values,
               which the widget displays as "*" and space, respectively.  An
               application may set this parameter to an arbitrary null-
               terminated string.  The widget determines the number of states
               from the length of this string, and will cycle through the
               corresponding display characters as the user presses the space-
               bar.

          int order_mode
               is reserved for future enhancements

          int * current_item
               The widget sets the referenced location to the index of the
               current display item (cursor) when it returns.

        dlg_button_count
          Count the buttons in the list.

          const char ** labels
               is a list of (pointers to) button labels terminated by a null
               pointer.

        dlg_button_key
          If a key was bound to one of the button-codes in dlg_result_key, fake
          a button-value and an ``Cancel''  key to cause the calling widget to
          return the corresponding status.

          See dlg_ok_buttoncode, which maps settings for ok/extra/help and
          button number into exit-code.

        dlg_button_layout
          Make sure there is enough space for the buttons by computing the width
          required for their labels, adding margins and limiting based on the
          screen size.

          const char ** labels
               is a list of (pointers to) button labels terminated by a null
               pointer.

          int * limit
               the function sets the referenced limit to the width required for
               the buttons (limited by the screen size) if that is wider than
               the passed-in limit.

        dlg_button_sizes
          Compute the size of the button array in columns.

          const char ** labels
               is a list of (pointers to) button labels terminated by a null

                                       - 33 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

               pointer.

          int vertical
               is true if the buttons are arranged in a column rather than a
               row.

          int * longest
               Return the total number of columns in the referenced location.

          int * length
               Return the longest button's columns in the referenced location.

        dlg_button_to_char
          Find the first uppercase character in the label, which we may use for
          an abbreviation.  If the label is empty, return -1.  If no uppercase
          character is found, return 0.  Otherwise return the uppercase
          character.  Normally dlg_draw_buttons and dlg_char_to_button use the
          first uppercase character.  However, they keep track of all of the
          labels and if the first has already been used in another label, they
          will continue looking for another uppercase character.  This function
          does not have enough information to make that check.

          const char * label
               is the label to test.

        dlg_button_x_step
          Compute the step-size needed between elements of the button array.

          const char ** labels
               is a list of (pointers to) button labels terminated by a null
               pointer.

          int limit
               is the maximum number of columns to allow for the buttons.

          int * gap
               store the nominal gap between buttons in the referenced location.
               This is constrained to be at least one.

          int * margin
               store the left+right total margins (for the list of buttons) in
               the referenced location.

          int * step
               store the step-size in the referenced location.

        dlg_calc_list_width
          Calculate the minimum width for the list, assuming none of the items
          are truncated.

                                       - 34 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int item_no
               is the number of items.

          DIALOG_LISTITEM * items
               contains a name and text field, e.g., for checklists or radiobox
               lists.  The function returns the sum of the widest columns needed
               for of each of these fields.

               If dialog_vars.no_items is set, the text fields in the list are
               ignored.

        dlg_calc_listh
          Calculate new height and list_height values.

          int * height
               on input, is the height without adding the list-height.  On
               return, this contains the total list-height and is the actual
               widget's height.

          int * list_height
               on input, is the requested list-height.  On return, this contains
               the number of rows available for displaying the list after taking
               into account the screen size and the dialog_vars.begin_set and
               dialog_vars.begin_y variables.

          int item_no
               is the number of items in the list.

        dlg_calc_listw
          This function is obsolete, provided for library-compatibility.  It is
          replaced by dlg_calc_list_width.

          int item_no
               is the number of items.

          char ** items
               is a list of character pointers.

          int group
               is the number of items in each group, e.g., the second array
               index.

        dlg_char_to_button
          Given a list of button labels, and a character which may be the
          abbreviation for one, find it, if it exists.  An abbreviation will be
          the first character which happens to be capitalized in the label.  If
          the character is found, return its index within the list of labels.
          Otherwise, return DLG_EXIT_UNKNOWN.

          int ch
               is the character to find.

                                       - 35 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          const char ** labels
               is a list of (pointers to) button labels terminated by a null
               pointer.

        dlg_checklist
          This entrypoint provides the --checklist or --radiolist functionality
          without the limitations of dialog's command-line syntax (compare to
          dialog_checklist).

          const char * title
               is the title string to display at the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is
               adjusted to use the available screen size.

          int width
               is the desired width of the box.  If zero, the height is adjusted
               to use the available screen size.

          int list_height
               is the minimum height to reserve for displaying the list.  If
               zero, it is computed based on the given height and width.

          int item_no
               is the number of items.

          DIALOG_LISTITEM * items
               This is a list of the items to display in the checklist.

          const char * states
               This is a list of characters to display for the given states.
               Normally a checklist provides true (1) and false (0) values,
               which the widget displays as "*" and space, respectively.  An
               application may set this parameter to an arbitrary null-
               terminated string.  The widget determines the number of states
               from the length of this string, and will cycle through the
               corresponding display characters as the user presses the space-
               bar.

          int flag
               This is should be one of FLAG_CHECK or FLAG_RADIO, depending on
               whether the widget should act as a checklist or radiobox.

          int * current_item
               The widget sets the referenced location to the index of the
               current display item (cursor) when it returns.

                                       - 36 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

        dlg_check_scrolled
          given a function key (or other key that was mapped to a function key),
          check if it is one of the up/down scrolling functions:

               DLGK_PAGE_FIRST,
               DLGK_PAGE_LAST,
               DLGK_GRID_UP,
               DLGK_GRID_DOWN,
               DLGK_PAGE_PREV or
               DLGK_PAGE_NEXT.
          Some widgets use these key bindings for scrolling the prompt-text up
          and down, to allow for display in very small windows.  The function
          returns 0 (zero) if it finds one of these keys, and -1 if not.

          int key
               is the function-key to check

          int last
               is the number of lines which would be used to display the
               scrolled prompt in an arbitrarily tall window.  It is used here
               to check limits for the offset value.

          int page
               this is the available height for writing scrolled text, which is
               smaller than the window if it contains buttons.

          bool * show
               on return, holds TRUE if dlg_print_scrolled should be used to
               redisplay the prompt text.

          int * offset
               on entry, holds the starting line number (counting from zero)
               last used for dlg_print_scrolled.  On return, holds the updated
               starting line number.

        dlg_clear
          Set window to the default dialog screen attribute.  This is set in the
          rc-file with screen_color.

        dlg_clr_result
          Free storage used for the result buffer (dialog_vars.input_result).
          The corresponding pointer is set to NULL.

        dlg_color_count
          Return the number of colors that can be configured in dialog.

        dlg_color_setup
          Initialize the color pairs used in dialog.

        dlg_count_argv
          Count the entries in an argument vector.

                                       - 37 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          argv Points to the argument vector.

        dlg_count_columns
          Returns the number of columns used for a string.  This is not
          necessarily the number of bytes in a string.

          const char * string
               is the string to measure.

        dlg_count_real_columns
          Returns the number of columns used for a string, accounting for "\Z"
          sequences which can be used for coloring the text if
          dialog_vars.colors is set.  This is not necessarily the number of
          bytes in a string.

          const char * string
               is the string to measure.

        dlg_count_wchars
          Returns the number of wide-characters in the string.

          const char * string
               is the string to measure.

        dlg_create_rc
          Create a configuration file, i.e., write internal tables to a file
          which can be read back by dialog as an rc-file.

          const char * filename
               is the name of the file to write to.

        dlg_ctl_size
          If dialog_vars.size_err is true, check if the given window size is too
          large to fit on the screen.  If so, exit with an error reporting the
          size of the window.

          int height
               is the window's height

          int width
               is the window's width

        dlg_default_button
          If dialog_vars.default_button is positive, return the button-index for
          that button code, using dlg_ok_buttoncode to test indices starting
          with zero.  Otherwise (or if no match was found for the button code),
          return zero.

        dlg_default_formitem
          If dialog_vars.default_item is not null, find that name by matching
          the name field in the list of form items.  If found, return the index

                                       - 38 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          of that item in the list.  Otherwise, return zero.

          DIALOG_FORMITEM * items
               is the list of items to search.  It is terminated by an entry
               with a null name field.

        dlg_default_item
          This function is obsolete, provided for library-compatibility.  It is
          replaced by dlg_default_formitem and dlg_default_listitem.

          char ** items
               is the list of items to search.

          int llen
               is the number of items in each group, e.g., the second array
               index.

        dlg_defaultno_button
          If dialog_vars.defaultno is true, and dialog_vars.nocancel is not,
          find the button-index for the ``Cancel'' button.  Otherwise, return
          the index for ``OK'' (always zero).

        dlg_del_window
          Remove a window, repainting everything else.

          WINDOW * win
               is the window to remove.

        dlg_der_window
          create a derived window, e.g., for an input area of a widget

          WINDOW * win
               is the parent window

          int height
               is the subwindow's height

          int width
               is the subwindow's width

          int y
               is the subwindow's top-row

          int x
               is the subwindow's left-column

        dlg_does_output
          This is called each time a widget is invoked which may do output.  It
          increments dialog_state.output_count, so the output function in dialog
          can test this and add a separator.

                                       - 39 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

        dlg_draw_arrows
          Draw up/down arrows on a window, e.g., for scrollable lists.  It calls
          dlg_draw_arrows2 using the menubox_color and menubox_border_color
          attributes.

          WINDOW * dialog
               is the window on which to draw an arrow.

          int top_arrow
               is true if an up-arrow should be drawn at the top of the window.

          int bottom_arrow
               is true if an down-arrow should be drawn at the bottom of the
               window.

          int x
               is the zero-based column within the window on which to draw
               arrows.

          int top
               is the zero-based row within the window on which to draw up-
               arrows as well as a horizontal line to show the window's top.

          int bottom
               is the zero-based row within the window on which to draw down-
               arrows as well as a horizontal line to show the window's bottom.

        dlg_draw_arrows2
          Draw up/down arrows on a window, e.g., for scrollable lists.

          WINDOW * dialog
               is the window on which to draw an arrow.

          int top_arrow
               is true if an up-arrow should be drawn at the top of the window.

          int bottom_arrow
               is true if an down-arrow should be drawn at the bottom of the
               window.

          int x
               is the zero-based column within the window on which to draw
               arrows.

          int top
               is the zero-based row within the window on which to draw up-
               arrows as well as a horizontal line to show the window's top.

          int bottom
               is the zero-based row within the window on which to draw down-
               arrows as well as a horizontal line to show the window's bottom.

                                       - 40 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          chtype attr
               is the window's background attribute.

          chtype borderattr
               is the window's border attribute.

        dlg_draw_bottom_box
          Draw a partial box at the bottom of a window, e.g., to surround a row
          of buttons.  It is designed to merge with an existing box around the
          whole window (see dlg_draw_box), so it uses tee-elements rather than
          corner-elements on the top corners of this box.

          WINDOW * win
               is the window to update.

        dlg_draw_bottom_box2
          Draw a partial box at the bottom of a window, e.g., to surround a row
          of buttons.  It is designed to merge with an existing box around the
          whole window (see dlg_draw_box2), so it uses tee-elements rather than
          corner-elements on the top corners of this box.

          WINDOW * win
               is the window to update.

          chtype on_left
               is used to color the upper/left edges of the box, i.e., the tee-
               element and horizontal line

          chtype on_right
               is used to color the right edge of the box, i.e., the tee-element

          chtype on_inside
               is used to fill-color the inside of the box

        dlg_draw_box
          Draw a rectangular box with line drawing characters.

          WINDOW * win
               is the window to update.

          int y
               is the top row of the box.

          int x
               is the left column of the box.

          int height
               is the height of the box.

          int width
               is the width of the box.

                                       - 41 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          chtype boxchar
               is used to color the right/lower edges.  It also is fill-color
               used for the box contents.

          chtype borderchar
               is used to color the upper/left edges.

        dlg_draw_box2
          Draw a rectangular box with line drawing characters.

          WINDOW * win
               is the window to update.

          int y
               is the top row of the box.

          int x
               is the left column of the box.

          int height
               is the height of the box.

          int width
               is the width of the box.

          chtype boxchar
               is used to fill-color for the box contents.

          chtype borderchar
               is used to color the upper/left edges.

          chtype borderchar2
               is used to color the right/lower edges.

        dlg_draw_buttons
          Print a list of buttons at the given position.

          WINDOW * win
               is the window to update.

          int y
               is the starting row.

          int x
               is the starting column.

          const char ** labels
               is a list of (pointers to) button labels terminated by a null
               pointer.

                                       - 42 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int selected
               is the index within the list of the selected button.

          int vertical
               is true if the buttons are arranged in a column rather than a
               row.

          int limit
               is the number of columns (or rows if vertical/) allowed for the
               display.

        dlg_draw_helpline
          draw the text in dialog_vars.help_line at the bottom of the given
          window.

          WINDOW * dialog
               is the window to modify.

          bool decorations
               if true, allow room for the scrolling arrows.

        dlg_draw_scrollbar
          If dialog_state.use_scrollbar is set, draw a scrollbar on the right
          margin of windows holding scrollable data.  Also (whether or not the
          scrollbar is drawn), annotate the bottom margin of the window with the
          percentage of data by the bottom of that window, and call
          dlg_draw_arrows2 to put markers on the window showing when more data
          is available.

          WINDOW * win
               is the window in which the data is scrolled.  Because left,
               right, top, bottom are passed as parameters, this window can
               contain additional data.

          long first_data
               is the zero-based index to the first row of data in the current
               window.

          long this_data
               is the zero-based index to the current row of data.

          long next_data
               is the zero-based index to the next data after the current row.

          long total_data
               is the total number of rows of data.

          int left
               is the zero-based left margin/column of the window.  The up/down
               arrows are draw inset by 5 columns from this point.

                                       - 43 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int right
               is the zero-based right margin/column of the window.  The
               scrollbar is drawn flush against this column.

          int top
               is the zero-based row within the window on which to draw up-
               arrows as well as a horizontal line to show the window's top.

          int bottom
               is the zero-based row within the window on which to draw down-
               arrows as well as a horizontal line to show the window's bottom.

          chtype attr
               is the window's background attribute.

          chtype borderattr
               is the window's border attribute.

        dlg_draw_shadow
          Draw shadows along the right and bottom edge of a window to give it a
          3-dimensional look.  (The height, etc., may not be the same as the
          window's actual values).

          WINDOW * win
               is the window to update.

          int height
               is the height of the window.

          int width
               is the width of the window.

          int y
               is the top row of the window.

          int x
               is the left column of the window.

        dlg_draw_title
          Draw a title centered at the top of the window.

          WINDOW * win
               is the window to update.

          const char * title
               is the title string to display at the top of the widget.

        dlg_dummy_menutext
          This is a utility function which supports the --inputmenu option of
          the dialog program.  If dialog_vars.input_menu is set, dialog_menu
          passes this pointer to dlg_menu as the rename_menutext parameter.

                                       - 44 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          Otherwise, it passes dlg_dummy_menutext.  The function should only
          return DLG_EXIT_ERROR.

          DIALOG_LISTITEM * items
               is the list of menu items

          int current
               is the index of the currently-selected item

          char * newtext
               is the updated text for the menu item

        dlg_dump_keys
          Write all user-defined key-bindings to the given stream, e.g., as part
          of dlg_create_rc.

          FILE * fp
               is the stream on which to write the bindings.

        dlg_dump_window_keys
          Write all user-defined key-bindings to the given stream, e.g., as part
          of dlg_create_rc.

          FILE * fp
               is the stream on which to write the bindings.

          WINDOW * win
               is the window for which bindings should be dumped.  If it is
               null, then only built-in bindings are dumped.

        dlg_eat_argv
          Remove one or more items from an argument vector.

          int * argcp
               in/out parameter giving the length of the argument vector.  char
               *** argvp in/out parameter pointing to the argument vector.  int
               start starting index.  int count number of arguments to remove.

        dlg_edit_offset
          Given the character-offset in the string, returns the display-offset
          where dialog should position the cursor.  In this context,
          ``characters'' may be multicolumn, since the string can be a multibyte
          character string.

          char * string
               is the string to analyze

          int offset
               is the character-offset

                                       - 45 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int x_last
               is a limit on the column positions that can be used, e.g., the
               window's size.

        dlg_edit_string
          Updates the string and character-offset, given various editing
          characters or literal characters which are inserted at the character-
          offset.  Returns true if an editing change was made (and the display
          should be updated), and false if the key was something like KEY_ENTER,
          which is a non-editing action outside this function.

          char * string
               is the (multibyte) string to update

          int * offset
               is the character-offset

          int key
               is the editing key

          int fkey
               is true if the editing key is a function-key

          bool force
               is used in a special loop case by calling code to force the
               return value of this function when a function-key code 0 is
               passed in.

        dlg_exit
          Given an internal exit code, check if the corresponding environment
          variable is set.  If so, remap the exit code to match the environment
          variable.  Finally call exit with the resulting exit code.

          int code
               is the internal exit code, e.g., DLG_EXIT_OK, which may be
               remapped.  The dialog program uses this function to allow shell
               scripts to remap the exit codes so they can distinguish ESC from
               ERROR.

        dlg_exitcode2s
          Returns the name of an exit-code, e.g., ``OK'' for DLG_EXIT_OK.

          int code
               is an exit-code for dialog as defined in <dialog.h>.

        dlg_exitname2n
          Returns an exit-code as the reverse of dlg_exitcode2n, e.g., 0
          (DLG_EXIT_OK) for the ``OK'' string.

          const char * name
               is the name of an exit-code for dialog as defined in <dialog.h>

                                       - 46 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

               but omitting the ``DLG_EXIT_'' prefix.

        dlg_exit_buttoncode
          Map the given button index for dlg_exit_label into dialog's exit-code.

          int button
               is the button index

        dlg_exit_label
          Return a list of button labels.  If dialog_vars.extra_button is true,
          return the result of dlg_ok_labels.  Otherwise, return a list with the
          ``Exit'' label and (if dialog_vars.help_button is set) the ``Help''
          button as well.

        dlg_exiterr
          Quit program killing all tailboxbg widgets.

          const char * fmt
               is the format of the printf-like message to write.

          ...
               are the variables to apply to the fmt format.

        dlg_find_index
          Given the character-offset to find in the list, return the
          corresponding array index.

          const int *list
               contains a list of character-offsets, i.e., indices into a string
               that denote the beginning of multibyte characters.

          int limit
               is the last index into list to search.

          int to_find
               is the character-offset to find.

        dlg_finish_string
          If DIALOG_STATE.finish_string is true, this function discards data
          used to speed up layout computations.

          const char * string
               is the address of the string whose data should be discarded.  The
               address rather than contents is used as the unique identifier
               because some of the caching is used for editable input-fields.

        dlg_flush_getc
          Cancel the local data saved by dlg_last_getc.

        dlg_editbox
          This entrypoint provides the --editbox functionality without the

                                       - 47 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          limitations of dialog's command-line syntax (compare to
          dialog_editbox).

          const char * title
               is the title string to display at the top of the widget.

          char *** list
               is a pointer to an array of char * pointers.  The array is
               allocated by the caller, and so are the strings to which it
               points.  The dlg_editbox function may reallocate the array and
               the strings.

          int * rows
               points to the nominal length of list.  The referenced value is
               updated iflist is reallocated.

          int height
               is the desired height of the box.  If zero, the height is
               adjusted to use the available screen size.

          int width
               is the desired width of the box.  If zero, the height is adjusted
               to use the available screen size.

        dlg_form
          This entrypoint provides the --form functionality without the
          limitations of dialog's command-line syntax (compare to dialog_form).

          const char * title
               is the title string to display at the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is
               adjusted to use the available screen size.

          int width
               is the desired width of the box.  If zero, the height is adjusted
               to use the available screen size.

          int form_height
               is the minimum height to reserve for displaying the list.  If
               zero, it is computed based on the given height and width.

          int item_no
               is the number of items.

          DIALOG_FORMITEM * items
               This is a list of the items to display in the form.

                                       - 48 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int * current_item
               The widget sets the referenced location to the index of the
               current display item (cursor) when it returns.

        dlg_free_columns
          Free data allocated by dlg_align_columns.

          char **target
               This is the array which was reformatted.  It points to the first
               string to free.

          int per_row
               This is the size of the struct for each row of the array.

          int num_rows
               This is the number of rows in the array.

        dlg_free_formitems
          Free memory owned by a list of DIALOG_FORMITEM's.

          DIALOG_FORMITEM * items
               is the list to free.

        dlg_free_gauge
          Remove the gauge widget from the screen and free its associated
          memory.

          void *objptr
               points to the gauge widget.

        dlg_getc
          Read a character from the given window.  Handle repainting here (to
          simplify things in the calling application).  Also, if input-
          callback(s) are set up, poll the corresponding files and handle the
          updates, e.g., for displaying a tailbox.  Returns the key-code.

          WINDOW * win
               is the window within which to read.

          int * fkey
               as a side-effect, set this to true if the key-code is really a
               function-key.

        dlg_getenv_num
          Get a number from the environment:

          o   If the caller provides a pointer in the second parameter, return
              success/failure for the function return, and the actual value via
              the pointer.  Use this for decoding arbitrary numbers, e.g.,
              negative or zero.

                                       - 49 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          o   If the caller does not provide a pointer, return the decoded value
              for the function-return.  Use this when only values greater than
              zero are useful.

          char * name
               is the name of the environment-variable to retrieve.

          int * value
               is the optional pointer to a return-value.

        dlg_getenv_str
          Get a string from the environment, rejecting those which are entirely
          blank.

          char * name
               is the name of the environment-variable to retrieve.

        dlg_get_attrs
          extract the video attributes from the given window.

          WINDOW * win
               is the window from which to get attributes.

        dlg_getc_callbacks
          passes the given key-code ch to the current window that has
          established a callback.  If the callback returns zero, remove it and
          try the next window.  If no more callbacks remain, return.  If any
          callbacks were found, return true, otherwise false.

          int ch
               is the key-code

          int fkey
               is true if the key is a function-key

          int * result
               is used to pass an exit-code to the caller, which should pass
               that via dlg_exit.

        dlg_index_columns
          Build a list of the display-columns for the given multibyte string's
          characters.

          const char * string
               is the string to analyze

        dlg_index_wchars
          Build an index of the wide-characters in the string, so the caller can
          easily tell which byte-offset begins a given wide-character.

                                       - 50 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          const char * string
               is the string to analyze

        dlg_item_help
          Draw the string for the dialog_vars.item_help feature.

          const char * txt
               is the help-message

        dlg_keep_tite
          This performs the check and modifications for the command-line option
          "--keep-tite", used in init_dialog as well as for the command-line
          option --erase-on-exit.

          FILE * output
               is the output stream used for displaying widgets.  It is either
               stdout or stderr, depending on the --stdout option.

        dlg_killall_bg
          If dialog has callbacks active, purge the list of all that are not
          marked to keep in the background.  If any remain, run those in a
          background process.

          int * retval
               stores the exit-code to pass back to the caller.

        dlg_last_getc
          returns the most recent character that was read via dlg_getc.

        dlg_limit_columns
          Given a column limit, count the number of wide characters that can fit
          into that limit.  The offset is used to skip over a leading character
          that was already written.

          const char * string
               is the string to analyze

          int limit
               is the column limit

          int offset
               is the starting offset from which analysis should continue

        dlg_lookup_key
          Check for a key-binding.  If there is no binding associated with the
          widget, it simply returns the given curses-key.  Otherwise, it returns
          the result of the binding

          WINDOW * win
               is the window on which the binding is checked

                                       - 51 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int curses_key
               is the curses key-code

          int * dialog_key
               is the corresponding dialog internal code (see DLG_KEYS_ENUM in
               dlg_key.h).

        dlg_max_input
          Limit the parameter according to dialog_vars.max_input

          int max_len
               is the value to limit

        dlg_match_char
          Match a given character against the beginning of the string, ignoring
          case of the given character.  The matching string must begin with an
          uppercase character.

          int ch
               is the character to check

          const char * string
               is the string to search

        dlg_menu
          This entrypoint provides the --menu functionality without the
          limitations of dialog's command-line syntax (compare to dialog_menu).

          const char * title
               is the title string to display at the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is
               adjusted to use the available screen size.

          int width
               is the desired width of the box.  If zero, the height is adjusted
               to use the available screen size.

          int menu_height
               is the minimum height to reserve for displaying the list.  If
               zero, it is computed based on the given height and width.

          int item_no
               is the number of items.

          DIALOG_LISTITEM * items
               This is a list of the items to display in the form.

                                       - 52 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int * current_item
               The widget sets the referenced location to the index of the
               current display item (cursor) when it returns.

          DIALOG_INPUTMENU rename_menutext
               If this is not dlg_dummy_menutext, the widget acts like an
               inputmenu widget, providing an extra ``Rename'' button, which
               activates an edit feature on the selected menu item.

        dlg_move_window
          Moves/resizes the given window to the given position and size.

          WINDOW *win
               is the window to move/resize.

          WINDOW *height
               is the height of the resized window.

          WINDOW *width
               is the width of the resized window.

          WINDOW *y
               y-ordinate to use for the repositioned window.

          WINDOW *x
               x-ordinate to use for the repositioned window.

        dlg_mouse_bigregion
          Retrieve the big-region under the pointer.

          int y
               is the row on which the mouse click occurred

          int x
               is the column on which the mouse click occurred

        dlg_mouse_free_regions
          Free the memory associated with mouse regions.

        dlg_mouse_mkbigregion
          Creates a region on which the mouse-clicks will return a specified
          code.

          int y
               is the top-row of the region.

          int x
               is the left-column of the region.

          int height
               is the height of the region.

                                       - 53 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int width
               is the width of the region.

          int code
               is a code used to make the region unique within a widget

          int step_x
               is used in modes 2 (columns) and 3 (cells) to determine the width
               of a column/cell.

          int step_y
               is currently unused

          int mode
               is used to determine how the mouse position is translated into a
               code (like a function-key):

               1  index by lines

               2  index by columns

               3  index by cells

        dlg_mouse_mkregion
          int y
               is the top-row of the region.

          int x
               is the left-column of the region.

          int height
               is the height of the region.

          int width
               is the width of the region.

          int code
               is a code used to make the region unique within a widget

        dlg_mouse_region
          Retrieve the frame under the mouse pointer

          int y
               is the row of the mouse-click

          int x
               is the column of the mouse-click

        dlg_mouse_setbase
          Sets a base for subsequent calls to dlg_mouse_mkregion, so they can
          make regions relative to the start of a given window.

                                       - 54 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int x
               is the left-column for the base

          int y
               is the top-row for the base

        dlg_mouse_setcode
          Sets a value used internally by dlg_mouse_mkregion which is added to
          the code parameter.  By providing different values, e.g., multiples of
          KEY_MAX, it is possible to support multiple ``big'' regions in a
          widget.  The buildlist widget uses this feature to recognize mouse-
          clicks in the left/right panes.

          int code
               is the value to add to dlg_mouse_mkregion's code parameter.

        dlg_mouse_wgetch
          is a wrapper for dlg_getc which additionally maps mouse-clicks (if the
          curses library supports those) into extended function-keys which
          encode the position according to the mode in dlg_mouse_mkbigregion.
          Returns the corresponding key-code.

          WINDOW * win
               is the window on which to perform the input

          int * fkey
               the referenced location is set to true if the key-code is an
               actual or extended (mouse) function-key.

        dlg_mouse_wgetch_nowait
          This is a non-blocking variant of dlg_mouse_wgetch.

          WINDOW * win
               is the window on which to perform the input

          int * fkey
               the referenced location is set to true if the key-code is an
               actual or extended (mouse) function-key.

        dlg_need_separator
          Check if an output-separator is needed.  If
          dialog_vars.output_separator is set, return true.  Otherwise, if
          dialog_vars.input_result is nonempty, return true.  If neither, return
          false.

        dlg_new_modal_window
          Create a modal window, optionally with a shadow.  The shadow is
          created if dialog_state.use_shadow is true.

          WINDOW * parent
               is the parent window (usually the top-level window of a widget)

                                       - 55 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int height
               is the window's height

          int width
               is the window's width

          int y
               is the window's top-row

          int x
               is the window's left-column

        dlg_new_window
          Create a window, optionally with a shadow.  The shadow is created if
          dialog_state.use_shadow is true.

          int height
               is the window's height

          int width
               is the window's width

          int y
               is the window's top-row

          int x
               is the window's left-column

        dlg_next_button
          Return the next index in the list of labels.

          const char ** labels
               is a list of (pointers to) button labels terminated by a null
               pointer.

          int button
               is the current button-index.

        dlg_next_ok_buttonindex
          Assuming that the caller is using dlg_ok_labels to list buttons, find
          the next index in the list of buttons.

          int current
               is the current index in the list of buttons

          int extra
               if negative, provides a way to enumerate extra active areas on
               the widget.

        dlg_ok_buttoncode
          Map the given button index for dlg_ok_labels into dialog's exit-code.

                                       - 56 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int button
               is the button-index (which is not necessarily the same as the
               index in the list of labels).

        dlg_ok_button_key
          Calls dlg_button_key with the ``Cancel'' button disabled, e.g., for
          the textbox widget.

        dlg_ok_label
          Returns a list with the ``Ok'' label, and if dialog_vars.help_button
          is true, the ``Help'' label as well.

        dlg_ok_labels
          Return a list of button labels for the OK/Cancel group of widgets.

        dlg_ordinate
          Decode the string as an integer, decrement if greater than zero to
          make a curses-ordinate from a dialog-ordinate.

        dlg_parse_bindkey
          Parse the parameters of the ``bindkeys'' configuration-file entry.
          This expects widget name which may be "*", followed by curses key
          definition and then dialog key definition.

          char * params
               is the parameter string to parse.

        dlg_parse_rc
          Parse the configuration file and set up variables.

        dlg_popen
          Open a pipe which ties the standard error and output together.  The
          popen function captures only the standard output of a command.

          const char *command
               The shell command to run.

          const char *type
               Like popen, "r" is used to read, and "w" is used to write.

        dlg_prev_button
          Return the previous index in the list of labels.

          const char ** labels
               is a list of (pointers to) button labels terminated by a null
               pointer.

          int button
               is the current button index

                                       - 57 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

        dlg_print_listitem
          This is a helper function used for the various ``list'' widgets, e.g.,
          checklist, menu, buildlist, treeview.  Each list-widget has ``tag''
          and ``description'' values for each item which can be displayed.  If
          dialog_vars.no_tags is true, the ``tag'' value is not shown.  The
          first character of the first value shown (tag or description) is
          highlighted to indicate that the widget will match it for quick
          navigation.

          WINDOW *win
               the window in which to display the text

          const char *text
               the value to display

          int climit
               the number of columns available for printing the text

          bool first
               true if this is the first call (for ``tag'' and ``description''),
               and the first character of the value should be highlighted.

          int selected
               nonzero if the text should be displayed using the ``selected''
               colors

        dlg_print_scrolled
          This is a wrapper for dlg_print_autowrap which allows the user to
          scroll too-long prompt text up/down.  See dlg_check_scrolled for a
          function which updates the offset variable used as a parameter here.
          It complements this function; you need both.  If pauseopt is set, this
          function returns an updated last parameter, needed for
          dlg_check_scrolled calls.

          WINDOW * win
               is the window to update.

          const char * prompt
               is the string to print

          int offset
               is the starting line-number to write wrapped text.

          int height
               is the available height for writing the wrapped text

          int width
               is the width that the wrapping should occur in

          int pauseopt
               is true if the extra functionality for scrolling should be

                                       - 58 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

               enabled.  If false, this calls dlg_print_autowrap without doing
               any scrolling.

        dlg_print_line
          Print one line of the prompt in the window within the limits of the
          specified right margin.  The line will end on a word boundary and a
          pointer to the start of the next line is returned, or a NULL pointer
          if the end of *prompt is reached.

          WINDOW *win
               is the window to update.

          chtype *attr
               holds the starting attributes, and is updated to reflect the
               final attributes applied to the string.

          const char *prompt
               is the string to print

          int lm
               is the left margin.

          int rm
               is the right margin

          int *x
               returns the ending x-ordinate.

        dlg_prev_ok_buttonindex
          Find the previous button index in the list from dlg_ok_labels.

          int current
               is the current index

          int extra
               if negative provides a way to enumerate extra active areas on the
               widget.

        dlg_print_autowrap
          Print a string of text in a window, automatically wrap around to the
          next line if the string is too long to fit on one line.  Note that the
          string may contain embedded newlines.  The text is written starting at
          the top of the window.

          WINDOW * win
               is the window to update.

          const char * prompt
               is the string to print

                                       - 59 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int height
               is the nominal height the wrapped string is limited to

          int width
               is the width that the wrapping should occur in

        dlg_print_size
          If dialog_vars.print_siz is true, print the given height/width (from a
          widget) to dialog_state.output, e.g., Size: height, width.

          int height
               is the window's height

          int width
               is the window's width

        dlg_print_text
          Print up to cols columns from text, optionally rendering dialog's
          escape sequences for attributes and color.

          WINDOW * win
               is the window to update.

          const char * txt
               is the string to print

          int col
               is the column limit

          chtype * attr
               holds the starting attributes, and is updated to reflect the
               final attributes applied to the string.

        dlg_progressbox
          implements the "--prgbox" and "--progressbox" options.

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.  If empty or null, no
               prompt is shown.

          int height
               is the desired height of the box.  If zero, the height is based
               on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

                                       - 60 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          int pauseopt
               if true, an ``OK'' button will be shown, and the dialog will wait
               for it to complete.  With an ``OK'' button, it is denoted a
               ``programbox'', without an ``OK'' button, it is denoted a
               ``progressbox''.

          FILE * fp
               is the file pointer, which may be a pipe or a regular file.

        dlg_put_backtitle
          Display the background title if dialog_vars.backtitle is non-null.
          The background title is shown at the top of the screen.

        dlg_reallocate_gauge
          Allocates or reallocates a gauge widget (see dlg_allocate_gauge).  Use
          dlg_update_gauge to display the result.

          void ** objptr
               If the pointer referenced by this parameter is null, the function
               creates a new gauge widget using dlg_allocate_gauge.  Otherwise,
               it updates the title and cprompt values, reusing the window from
               the previous call on this function.  As a side-effect, the
               function stores the updated object-pointer via the objptr
               parameter.

          const char * title
               is the title string to display at the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is
               adjusted to use the available screen size.

          int width
               is the desired width of the box.  If zero, the height is adjusted
               to use the available screen size.

          int percent
               is the percentage to show in the progress bar.

        dlg_register_buttons
          The widget developer should call this function after
          dlg_register_window, for the list of button labels associated with the
          widget.  One may bind a key to a button, e.g., ``OK'' for DLGK_OK,

          WINDOW * win
               is the window with which to associate the buttons

                                       - 61 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          const char * name
               is the widget's binding name (usually the name of the widget).

          const char ** buttons
               is the list of buttons

        dlg_register_window
          For a given named widget's window, associate a binding table.

          WINDOW * win
               is the window with which to associate the buttons

          const char * name
               is the widget's binding name (usually the name of the widget).

          DLG_KEYS_BINDING * binding
               is the binding table

        dlg_remove_callback
          Remove a callback.

          DIALOG_CALLBACK * p
               contains the callback information.

        dlg_renamed_menutext
          This is a utility function which supports the --inputmenu option of
          the dialog program.  If dialog_vars.input_menu is set, dialog_menu
          passes this pointer to dlg_menu as the rename_menutext parameter.
          Otherwise, it passes dlg_dummy_menutext.  The function should add
          ``RENAMED'' to dialog_vars.input_result , followed by the menu item's
          name and the newtext value (with a space separating the three items),
          and return DLG_EXIT_EXTRA.

          DIALOG_LISTITEM * items
               is the list of menu items

          int current
               is the index of the currently-selected item

          char * newtext
               is the updated text for the menu item

        dlg_reset_timeout
          Calls wtimeout with the value saved for a window in the last call to
          dlg_set_timeout.

        dlg_restore_vars
          Restore dialog's variables from the given variable (see
          dialog_save_vars).

                                       - 62 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          DIALOG_VARS * save
               is the variable from which to restore.  The
               DIALOG_VARS.input_length and DIALOG_VARS.input_result members are
               treated specially, since these are used by a widget to pass data
               to the caller.  They are not modified by this function.

        dlg_result_key
          Test a dialog internal keycode to see if it corresponds to one of the
          push buttons on the widget such as ``OK''.  This is only useful if
          there are user-defined key bindings, since there are no built-in
          bindings that map directly to DLGK_OK, etc.  Return true if a mapping
          was done.

          int dialog_key
               is the dialog key to test

          int fkey
               is true if this is a function key

          int * resultp
               store the result of the mapping in the referenced location.

        dlg_save_vars
          Save dialog's variables into the given variable (see
          dlg_restore_vars).

          DIALOG_VARS * save
               is the variable into which to save.

        dlg_set_focus
          Set focus on the given window, making it display above other windows
          on the screen.

          WINDOW * parent
               is the parent window (usually the top-level window of a widget)

          WINDOW * win
               is the window on which to place focus (usually a subwindow of a
               widget)

        dlg_set_result
          Setup a fixed-buffer for the result in dialog_vars.input_result

          const char * string
               is the new contents for the result

        dlg_set_timeout
          Calls wtimeout to establish a preferred timeout for nonblocking reads,
          e.g., to allow the gauge widget to handle window-resizing events.  The
          dlg_may_resize function temporarily overrides this value, to allow it
          to skip over the error codes returned while the ncurses library

                                       - 63 -      Formatted:  December 31, 2021

     DIALOG(3)              $Date: 2021/12/13 22:40:26 $               DIALOG(3)

          processes window-resizing events.  It restores the value established
          in this call by calling dlg_restore_timeout.

          WINDOW * win
               is the window whose input-timeout should be set

          bool will_getc
               is true if the widget is expected to read keyboard characters.
               Some (such as the gauge widget) do not.

        dlg_show_string
          Displays the string, shifted as necessary, to fit within the box and
          show the current character-offset.

          WINDOW * win
               is the window within which to display

          const char * string
               is the string to display

          int offset
               is the starting (character, not bytes) offset

          chtype attr
               is the window attribute to use for the string

          int y_base
               beginning row on screen

          int x_base
               beginning column on screen

          int x_last
               number of columns on screen

          bool hidden
               if true, do not echo input

          bool force
               if true, force repaint

        dlg_strclone
          duplicate the string, like strdup.

          const char * cprompt
               is the string to duplicate

        dlg_strcmp
          compare two strings, ignoring case.

                                       - 64 -      Formatted:  December 31, 2021

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          const char * a
               is one string

          const char * b
               is the other string

        dlg_string_to_argv
          Convert a string to an argument vector returning an index (which must
          be freed by the caller).  The string is modified:

          o   Blanks between arguments are replaced by nulls.

          o   Normally arguments are separated by blanks; however you can
              double-quote an argument to enclose blanks.  The surrounding
              double-quotes are removed from the string.

          o   A backslash preceding a double-quote within double-quotes is
              removed.

          o   A backslash preceding a newline outside double-quotes is removed.

          o   Except for special cases, backslashes are preserved in the
              strings, since other dialog functions interpret backslashes, e.g.,
              for colors.

          char *blob
               is the string to convert.

        dlg_sub_window
          create a subwindow, e.g., for an input area of a widget

          WINDOW * win
               is the parent window

          int height
               is the subwindow's height

          int width
               is the subwindow's width

          int y
               is the subwindow's top-row

          int x
               is the subwindow's left-column

        dlg_tab_correct_str
          If the dialog_vars.tab_correct is true, convert tabs to single spaces.
          Return the converted result.  The caller is responsible for freeing
          the string.

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          char * prompt
               is the string to convert

        dlg_trace
          If the parameter is non-null, opens a trace file with that name and
          stores the file pointer in dialog_state.trace.

        dlg_trace_2n
          logs a numeric value as a comment.

          char * name
               is the name to log in the comment.

          int value
               is the value to log in the comment.

        dlg_trace_2s
          logs a string value as a comment.  If the value contains embedded
          newlines, the comment is continued with ``#+'' markers.

          char * name
               is the name to log in the comment.

          int value
               is the value to log in the comment.

        dlg_trace_chr
          If dialog_state.trace is set, translate the parameters into a
          printable representation, log it on a ``chr'' line.

          int ch
               is the nominal keycode value.

          int fkey
               is nonzero if the value is really a function key.  Some of these
               may be values declared in the DLG_KEYS_ENUM.

        dlg_trace_msg
          Write a formatted message to the trace file.

          const char * fmt
               is the format of the printf-like message to write.

          ...
               are the variables to apply to the fmt format.  Use the DLG_TRACE
               macro for portability, in case the trace feature is not compiled
               into the library.  It uses an extra level of parentheses to work
               with a variable number of parameters, e.g.,

                 DLG_TRACE(("this is dialog version %s\n", dialog_version()));

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        dlg_trace_va_msg
          Write a formatted message to the trace file.

          const char *fmt
               is the format of the printf-like message to write.

          va_list ap
               are the variables to apply to the fmt format.  This is used in
               dlg_exiterr to capture error messages in the trace file:

                 va_start(ap, fmt);
                 dlg_trace_msg("## Error: ");
                 dlg_trace_va_msg(fmt, ap);
                 va_end(ap);
          Unlike dlg_trace_msg, an extra macro is not needed.

        dlg_ttysize
          Returns the screensize without using curses.  That allows the function
          to be used before initializing the screen.

        dlg_trace_win
          If dialog_state.trace is set, log a printable picture of the given
          window.

        dlg_treeview
          This is an alternate interface to 'treeview' which allows the
          application to read the list item states back directly without putting
          them in the output buffer.

          const char * title
               is the title on the top of the widget.

          const char * cprompt
               is the prompt text shown within the widget.

          int height
               is the desired height of the box.  If zero, the height is based
               on the screen size.

          int width
               is the desired width of the box.  If zero, the height is based on
               the screen size.

          int list_height
               is the minimum height to reserve for displaying the list.  If
               zero, it is computed based on the given height and width.

          int item_no
               is the number of rows in items.

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          DIALOG_LISTITEM * items
               is the list of items, contain tag, name, and optionally help
               strings (if dialog_vars.item_help is set).  The initial selection
               state for each item is also in this list.

          const char * states
               This is a list of characters to display for the given states.
               Normally a buildlist provides true (1) and false (0) values,
               which the widget displays as "*" and space, respectively.  An
               application may set this parameter to an arbitrary null-
               terminated string.  The widget determines the number of states
               from the length of this string, and will cycle through the
               corresponding display characters as the user presses the space-
               bar.

          int * depths
               This is a list of depths of each item in the tree.  It is a
               separate parameter from items to allow reuse of the existing
               functions.

          int flag
               is either FLAG_CHECK, for checklists (multiple selections), or
               FLAG_RADIO for radiolists (a single selection).

          int * current_item
               The widget sets the referenced location to the index of the
               current display item (cursor) when it returns.

        dlg_trim_string
          The dialog program uses this in each widget to adjust the message
          string, which may contain the newline character (referred to as '\n')
          and/or the special substring "\n" (which can be translated into a
          newline character).  There are several optional features:

          o   Unless dialog_vars.nocollapse is set, each tab is converted to a
              space before other processing.

          o   If dialog_vars.no_nl_expand is not set, and the string has "\n"
              substrings:

              o   The function changes embedded "\n" substrings to '\n'
                  characters.

                  The function preserves extra spaces after these substitutions.
                  For instance, spaces following a newline (substring or
                  character) are preserved to use as an indentation.

              o   If dialog_vars.cr_wrap is set, the function preserves '\n'
                  newline characters.  Otherwise, each '\n' newline character is
                  converted to a space.

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          o   Otherwise, if dialog_vars.trim_whitespace is set:

              o   This function strips all extra spaces to simplify
                  justification.

              o   If dialog_vars.cr_wrap is set, the function preserves '\n'
                  newline characters.  Otherwise, each '\n' newline character is
                  converted to a space.

          o   Finally (if dialog_vars.no_nl_expand is set, or the string does
              not contain "\n" substrings, and dialog_vars.trim_whitespace is
              not set):

              o   Unless dialog_vars.nocollapse is set, sequences of spaces are
                  reduced to a single space.

          char * src
               is the string to trim

        dlg_unregister_window
          Remove the bindings for a given window.

          WINDOW * win
               is the window from which to remove bindings

        dlg_update_gauge
          Update a gauge widget to show a different percentage value.

          void *objptr
               points to the gauge object to update.

          int percent
               is the new percentage value to display.

        dlg_will_resize
          This filters out bursts of KEY_RESIZE values.  Call this after
          dlg_getc returns KEY_RESIZE, to improve performance.

        dlg_yes_buttoncode
          Map the given button index for dlg_yes_labels into dialog's exit-code.

          int button
               is the button index

        dlg_yes_labels
          Return a list of buttons for Yes/No labels.

        end_dialog
          End use of dialog functions.

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        init_dialog
          Do some initialization for dialog.

          FILE *input
               is the real tty input of dialog.  Usually it is the standard
               input, but if --input-fd option is used, it may be anything.

          FILE *output
               is where dialog will send its result.  Usually it is the standard
               error, but if --stdout or --output-fd is used, it may be
               anything.

     SEE ALSO
          dialog (1).

     AUTHOR
          Thomas E. Dickey

                                       - 70 -      Formatted:  December 31, 2021