https://invisible-island.net/ncurses/man/
mitem_current(3x) Library calls mitem_current(3x)
       mitem_current - set and get current_menu_item
       #include <menu.h>
       int set_current_item(MENU *menu, ITEM *item);
       ITEM *current_item(const MENU *menu);
       int set_top_row(MENU *menu, int row);
       int top_row(const MENU *menu);
       int item_index(const ITEM *item);
       The  function set_current_item sets the current item (the item on which
       the menu cursor is positioned).  current_item returns a pointer to  the
       current item in the given menu.
       The function set_top_row sets the top row of the menu to show the given
       row  (the  top  row is initially 0, and is reset to this value whenever
       the O_ROWMAJOR option is toggled).  The item leftmost on the given  row
       becomes  current.   The  function top_row returns the number of the top
       menu row being displayed.
       The function item_index returns the (zero-origin) index of item in  the
       menu's item pointer list.
       current_item  returns  a  pointer (which may be NULL).  It does not set
       errno.
       top_row and item_index return ERR (the general curses error  value)  if
       their menu parameter is NULL.
       set_current_item and set_top_row return one of the following:
       E_OK The routine succeeded.
       E_BAD_ARGUMENT
            Routine detected an incorrect or out-of-range argument.
       E_BAD_STATE
            Routine was called from an initialization or termination function.
       E_NOT_CONNECTED
            No items are connected to the menu.
       E_SYSTEM_ERROR
            System error occurred (see errno(3)).
       These  routines  emulate  the  System  V  menu  library.  They were not
       supported on Version 7 or BSD versions.
       The  SVr4  menu  library  documentation  specifies  the   top_row   and
       index_item error value as -1 (which is the value of ERR).
       Juergen Pfeifer.  Manual pages and adaptation for new curses by Eric S.
       Raymond.
       curses(3x), menu(3x)
ncurses 6.5                       2024-12-28                 mitem_current(3x)