dialog

DIALOG(3)                  Library Functions Manual                  DIALOG(3)



NAME
       dialog - widgets and utilities for the dialog program

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

       #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
       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.

   .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
       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.

   .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).

   .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: 0
       through 7 are the ANSI codes used in curses: black, red, green, yellow,
       blue, magenta, cyan and white respectively.  Bold is set by 'b', reset
       by 'B'.  Reverse is set by 'r', reset by 'R'.  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.

   .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 --nocancel 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.

   .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.

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

   .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:

       •   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>.

       •   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:

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

       •   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)
       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_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 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,
       subject to the --cr-wrap option.

   .nook
       This corresponds to the command-line option "--nook.  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.

   .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
       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

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

       •   the special value “locale” (this works with systems using glibc,
           providing an extension to the locale command, the first_weekday
           value).

       •   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_".

       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.

       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.

       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.

       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,
       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.

       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.

       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.

       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
            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.

   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.

       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.

       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.  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 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.

       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.

       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.

       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)

            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.

       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.

       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:

            •   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.

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

            •   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:

            •   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.

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

            •   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
       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:

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

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

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

       •   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.

       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
            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.

       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.

       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.

   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.

       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 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_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.

   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.

       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.

       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.

       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.

       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.  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

       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>
            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
       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.

       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_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.

       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_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

       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.

       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.

       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.

       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)

       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.

       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

   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
            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

       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.

       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

       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).

       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
       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.

       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:

       •   Blanks between arguments are replaced by nulls.

       •   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.

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

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

       •   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.

       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()));

   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.

       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:

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

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

           •   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.

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

       •   Otherwise, if dialog_vars.trim_whitespace is set:

           •   This function strips all extra spaces to simplify
               justification.

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

       •   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):

           •   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.

   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



$Date: 2020/03/24 00:26:28 $                                         DIALOG(3)