Exit codes (passed back to the main program for its use) are defined with a "DLG_EXIT_ prefix. The defined 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.

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.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.

DIALOG_STATE.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.

DIALOG_STATE.getc_callbacks This is setup 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.

DIALOG_STATE.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.

DIALOG_STATE.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.

DIALOG_STATE.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.

DIALOG_STATE.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.

DIALOG_STATE.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.

DIALOG_STATE.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).

DIALOG_STATE.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.

DIALOG_STATE.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.

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

DIALOG_STATE.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. 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.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.

DIALOG_VARS.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.

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 It is obsolete.

DIALOG_VARS.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.

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

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

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

DIALOG_VARS.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.

DIALOG_VARS.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 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".

DIALOG_VARS.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.

DIALOG_VARS.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.

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

DIALOG_VARS.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.

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

DIALOG_VARS.extra_button This corresponds to the command-line option "--extra-button". If true, some widgets show an extra button, between "OK" and "Cancel" buttons.

DIALOG_VARS.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".

DIALOG_VARS.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.

DIALOG_VARS.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.

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

DIALOG_VARS.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.

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

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

DIALOG_VARS.input_result If DIALOG_VARS.input_length is zero, this is a pointer to user buffer (on the stack, or static). 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.

DIALOG_VARS.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.

DIALOG_VARS.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.

DIALOG_VARS.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.

DIALOG_VARS.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.

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

DIALOG_VARS.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.

DIALOG_VARS.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.

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

DIALOG_VARS.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.

DIALOG_VARS.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.

DIALOG_VARS.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. That requires occasional use of backslashes to make the output useful in shell scripts.

DIALOG_VARS.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).

DIALOG_VARS.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.

DIALOG_VARS.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.

DIALOG_VARS.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.

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

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

DIALOG_VARS.visit_items This corresponds to the command-line option "--visit-items". Modify the tab-traversal of checklist, radiobox, menubox and inputmenu 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.

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

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_calendar

implements the "--calendar option.

title

is the title on the top of the widget.

subtitle

is the prompt text shown within the widget.

height

is the height excluding the fixed-height calendar grid.

width

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

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.

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.

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.

title

is the title on the top of the widget.

cprompt

is the prompt text shown within the widget.

height

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

width

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

list_height

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

item_no

is the number of rows in items.

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_form

implements the "--form option.

title

is the title on the top of the widget.

cprompt

is the prompt text shown within the widget.

height

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

width

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

form_height

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

item_no

is the number of rows in items.

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.

title

is the title on the top of the widget.

path

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

height

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

width

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

dialog_gauge

implements the "--gauge option.

title

is the title on the top of the widget.

cprompt

is the prompt text shown within the widget.

height

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

width

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

percent

is the percentage to show in the progress bar.

dialog_inputbox

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

title

is the title on the top of the widget.

cprompt

is the prompt text shown within the widget.

height

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

width

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

init

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

password

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

dialog_menu

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

title

is the title on the top of the widget.

cprompt

is the prompt text shown within the widget.

height

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

width

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

menu_height

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

item_no

is the number of rows in items.

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_msgbox

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

title

is the title on the top of the widget.

cprompt

is the prompt text shown within the widget.

height

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

width

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

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.

title

is the title on the top of the widget.

height

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

width

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

seconds

is the timeout to use for the progress bar.

dialog_tailbox

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

title

is the title on the top of the widget.

file

is the name of the file to display in the dialog.

height

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

width

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

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.

title

is the title on the top of the widget.

file

is the name of the file to display in the dialog.

height

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

width

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

dialog_timebox

implements the "--timebox option.

title

is the title on the top of the widget.

subtitle

is the prompt text shown within the widget.

height

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

width

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

hour

is the initial hour shown. If the value is negative, the current hour is used.

minute

is the initial minute shown. If the value is negative, the current minute is used.

second

is the initial second shown. If the value is negative, the current second is used.

dialog_yesno

implements the "--yesno option.

title

is the title on the top of the widget.

cprompt

is the prompt text shown within the widget.

height

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

width

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

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_quoted

Add a quoted string to the result buffer (see dlg_add_result).

char * string is the string to add.

dlg_add_result

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

char * string is the string to add.

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

Automatically size the window used for a widget. If the given height or width are zero, justify the prompt text and return the actual limits.

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.

int * height is the nominal height.

int * width is the nominal width.

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

const char * file

int * height

int *width

int boxlines

int mincols

dlg_beeping

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

dlg_box_x_ordinate

int width

dlg_box_y_ordinate

int height

dlg_button_count

const char ** labels

dlg_button_layout

const char ** labels

int * limit

dlg_button_sizes

const char ** labels

int vertical

int * longest

int * length

dlg_button_x_step

const char ** labels

int limit

int * gap

int * margin

int * step

dlg_button_to_char

const char * label

dlg_calc_list_width

int item_no

DIALOG_LISTITEM * items

dlg_calc_listh

int * height

int * list_height

int item_no

dlg_calc_listw

int item_no

char ** items

int group

dlg_char_to_button

int ch

const char ** labels

dlg_checklist

const char * title

const char * cprompt

int height

int width

int list_height

int item_no

DIALOG_LISTITEM * items

const char * states

int flag

int * current_item

dlg_clear

dlg_clr_result

dlg_color_count

dlg_color_setup

dlg_count_columns

const char * string

dlg_count_wchars

const char * string

dlg_create_rc

const char * filename

dlg_ctl_size

int height

int width

dlg_default_formitem

DIALOG_FORMITEM * items

dlg_default_item

char ** items

int llen

dlg_defaultno_button

dlg_del_window

WINDOW * win

dlg_does_output

dlg_draw_arrows

WINDOW * dialog

int top_arrow

int bottom_arrow

int x

int top

int bottom

dlg_draw_bottom_box

WINDOW * win is the window to update.

dlg_draw_box

WINDOW * win is the window to update.

int y

int x

int height

int width

chtype boxchar

chtype borderchar

dlg_draw_buttons

WINDOW * win is the window to update.

int y

int x

const char ** labels

int selected

int vertical

int limit

dlg_draw_shadow

WINDOW * win is the window to update.

int height

int width

int y

int x

dlg_draw_title

WINDOW * win is the window to update.

const char * title

dlg_dump_keys

FILE * fp

dlg_edit_offset

char * string

int offset

int x_last

dlg_edit_string

char * string

int * offset

int key

int fkey

bool force

dlg_exit

int code

dlg_exit_buttoncode

int button

dlg_exit_label

dlg_exiterr

Quit program killing all tailboxbg widgets.

const char * fmt

dlg_flush_getc

dlg_form

const char * title

const char * cprompt

int height

int width

int form_height

int item_no

DIALOG_FORMITEM * items

int * current_item

dlg_free_formitems

DIALOG_FORMITEM * items

dlg_getc

WINDOW * win

int * fkey

dlg_getc_callbacks

int ch

int fkey

int * result

dlg_index_columns

const char * string

dlg_index_wchars

const char * string

dlg_item_help

char * txt

dlg_killall_bg

int * retval

dlg_last_getc

dlg_limit_columns

const char * string

int limit

int offset

dlg_lookup_key

WINDOW * win

int curses_key

int * dialog_key

dlg_match_char

int ch

const char * string

dlg_menu

const char * title

const char * cprompt

int height

int width

int menu_height

int item_no

DIALOG_LISTITEM * items

int * current_item

DIALOG_INPUTMENU rename_menutext

dlg_mouse_bigregion

int y

int x

dlg_mouse_free_regions

dlg_mouse_mkbigregion

int y

int x

int height

int width

int code

int step_x

int step_y

int mode

dlg_mouse_mkregion

int y

int x

int height

int width

int code

dlg_mouse_region

int y

int x

dlg_mouse_setbase

int x

int y

dlg_mouse_wgetch

WINDOW * win

int * fkey

dlg_mouse_wgetch_nowait

WINDOW * win

int * fkey

dlg_new_window

int height

int width

int y

int x

dlg_next_button

const char ** labels

int button

dlg_next_ok_buttonindex

int current

int extra

dlg_ok_buttoncode

int button

dlg_ok_label

dlg_ok_labels

dlg_parse_bindkey

char * params

dlg_parse_rc

dlg_prev_button

const char ** labels

int button

dlg_prev_ok_buttonindex

int current

int extra

dlg_print_autowrap

WINDOW * win is the window to update.

const char * prompt

int height

int width

dlg_print_size

int height

int width

dlg_print_text

WINDOW * win is the window to update.

const char * txt

int len

chtype * attr

dlg_put_backtitle

dlg_register_buttons

WINDOW * win

const char * name

const char ** buttons

dlg_register_window

WINDOW * win

const char * name

DLG_KEYS_BINDING * binding

dlg_remove_callback

DIALOG_CALLBACK * p contains the callback information.

dlg_result_key

int dialog_key

int fkey

int * resultp

dlg_set_focus

WINDOW * parent

WINDOW * win

dlg_set_result

const char * string

dlg_show_string

WINDOW * win

const char * string

int offset

chtype attr

int y_base

int x_base

int x_last

bool hidden

bool force

dlg_strclone

const char * cprompt

dlg_strcmp

const char * a

const char * b

dlg_sub_window

WINDOW * win

int height

int width

int y

int x

dlg_tab_correct_str

char * prompt

dlg_trim_string

char * src

dlg_unregister_window

WINDOW * win

dlg_yes_buttoncode

int button

dlg_yes_labels