https://invisible-island.net/ncurses/man/
mitem_value(3x) Library calls mitem_value(3x)
set_item_value, item_value - set and get menu item values
#include <menu.h> int set_item_value(ITEM *item, bool value); bool item_value(const ITEM *item);
If you turn off the menu option O_ONEVALUE (e.g., with set_menu_opts or menu_opts_off; see menu_opts(3x)), the menu becomes multi-valued; that is, more than one item may simultaneously be selected. In a multi_valued menu, you can used set_item_value to select the given menu item (second argument TRUE) or deselect it (second argument FALSE).
The function set_item_value returns one of the following: E_OK The routine succeeded. E_SYSTEM_ERROR System error occurred (see errno(3)). E_REQUEST_DENIED The menu driver could not process the request.
These routines emulate the System V menu library. They were not supported on Version 7 or BSD versions.
Juergen Pfeifer. Manual pages and adaptation for new curses by Eric S. Raymond.
curses(3x), menu(3x) ncurses 6.5 2024-03-16 mitem_value(3x)