uthash int

#include <stdio.h>   /* gets */  
#include <stdlib.h>  /* atoi, malloc */  
#include <string.h>  /* strcpy */  
#include "uthash.h"  
  
struct my_struct {  
    int ikey;                    /* key */  
    char value[10];  
    UT_hash_handle hh;         /* makes this structure hashable */  
};  
  
static struct my_struct *g_users = NULL;  
  
void add_user(int mykey, char *value) {  
    struct my_struct *s;  
  
    HASH_FIND_INT(g_users, &mykey, s);  /* mykey already in the hash? */  
    if (s==NULL) {  
      s = (struct my_struct*)malloc(sizeof(struct my_struct));  
      s->ikey = mykey;  
      HASH_ADD_INT( g_users, ikey, s );  /* ikey: name of key field */  
    }  
    strcpy(s->value, value);  
}  
  
struct my_struct *find_user(int mykey) {  
    struct my_struct *s;  
  
    HASH_FIND_INT( g_users, &mykey, s );  /* s: output pointer */  
    return s;  
}  
  
void delete_user(struct my_struct *user) {  
    HASH_DEL( g_users, user);  /* user: pointer to deletee */  
    free(user);  
}  
  
void delete_all() {  
  struct my_struct *current_user, *tmp;  
  
  HASH_ITER(hh, g_users, current_user, tmp) {  
    HASH_DEL(g_users,current_user);  /* delete it (users advances to next) */  
    free(current_user);            /* free it */  
  }  
}  
  
void print_users() {  
    struct my_struct *s;  
  
    for(s=g_users; s != NULL; s=(struct my_struct*)(s->hh.next)) {  
        printf("user ikey %d: value %s\n", s->ikey, s->value);  
    }  
}  
  
int name_sort(struct my_struct *a, struct my_struct *b) {  
    return strcmp(a->value,b->value);  
}  
  
int id_sort(struct my_struct *a, struct my_struct *b) {  
    return (a->ikey - b->ikey);  
}  
  
void sort_by_name() {  
    HASH_SORT(g_users, name_sort);  
}  
  
void sort_by_id() {  
    HASH_SORT(g_users, id_sort);  
}  
  
int main(int argc, char *argv[]) {  
    char in[10];  
    int ikey=1, running=1;  
    struct my_struct *s;  
    unsigned num_users;  
  
    while (running) {  
        printf(" 1. add user\n");  
        printf(" 2. add/rename user by id\n");  
        printf(" 3. find user\n");  
        printf(" 4. delete user\n");  
        printf(" 5. delete all users\n");  
        printf(" 6. sort items by name\n");  
        printf(" 7. sort items by id\n");  
        printf(" 8. print users\n");  
        printf(" 9. count users\n");  
        printf("10. quit\n");  
        gets(in);  
        switch(atoi(in)) {  
            case 1:  
                printf("name?\n");  
                add_user(ikey++, gets(in));  
                break;  
            case 2:  
                printf("id?\n");  
                gets(in); ikey = atoi(in);  
                printf("name?\n");  
                add_user(ikey, gets(in));  
                break;  
            case 3:  
                printf("id?\n");  
                s = find_user(atoi(gets(in)));  
                printf("user: %s\n", s ? s->value : "unknown");  
                break;  
            case 4:  
                printf("id?\n");  
                s = find_user(atoi(gets(in)));  
                if (s) delete_user(s);  
                else printf("id unknown\n");  
                break;  
            case 5:  
                delete_all();  
                break;  
            case 6:  
                sort_by_name();  
                break;  
            case 7:  
                sort_by_id();  
                break;  
            case 8:  
                print_users();  
                break;  
            case 9:  
                num_users=HASH_COUNT(g_users);  
                printf("there are %u users\n", num_users);  
                break;  
            case 10:  
                running=0;  
                break;  
        }  
    }  
  
    delete_all();  /* free any structures */  
    return 0;  
}