menu1.c

#include <stdio.h>

#define MAX_TITLE 32
#define MAX_SUBMENUS 16

typedef struct _menu menu;
 
struct _menu {
    char title[MAX_TITLE];
    void (*command)(int data);
    int data;
    short num_submenus;
    struct _menu *submenu[10];
};

void negative_menu(menu *m,int level); 
void do_command (int data);


 menu sub1 = { "Submenu 1", do_command,1,0,0};
 menu sub3 = { "Submenu 3", NULL,3,0,0};
 menu sub2_1 = { "Submenu 2-1", do_command,21,0,0};
 menu sub2_2 = { "Submenu 2-2", do_command,22,0,0};
 menu sub2 = { "Submenu 2", do_command,2,2,{&sub2_1,&sub2_2}};

 menu main_menu = { "Main Menu", NULL,0,3,{ &sub1, &sub2, &sub3} };

int main()
{
    int level=0;
  negative_menu(&main_menu,level);
 // display_menu(main_menu.submenu[1]);
  
/*
   main_menu.submenu[1]->command(main_menu.submenu[0]->data);
   main_menu.submenu[1]->command(main_menu.submenu[1]->data);
*/
   getchar();
  
  return 0;
}

 
void do_command (int data)
{
  printf("%s:%d\n",__func__,data);
     
}
void negative_menu(menu *m,int level)
{ 
  int i;

//   display_menu(&main_menu);             
   if (m!=NULL) 
     printf("\n%s: submenu=%d\n",m->title,m->num_submenus);        
          
     for (i=0;i<MAX_SUBMENUS;i++)
       if (m->submenu[i]!=NULL && i<m->num_submenus) {
            printf("%*s %s\n",level," ",m->submenu[i]->title);    
            if (m->submenu[i]->submenu[0])     
                negative_menu(m->submenu[i],level+4); 
        }
    
   return ;
}