147 lines
3.6 KiB
C
147 lines
3.6 KiB
C
#include <stdio.h> /* printf */
|
|
#include <stdlib.h> /* atoi, malloc */
|
|
#include <string.h> /* strcpy */
|
|
#include "uthash.h"
|
|
|
|
struct my_struct {
|
|
int id; /* key */
|
|
char name[21];
|
|
UT_hash_handle hh; /* makes this structure hashable */
|
|
};
|
|
|
|
struct my_struct *users = NULL;
|
|
|
|
void add_user(int user_id, const char *name)
|
|
{
|
|
struct my_struct *s;
|
|
|
|
HASH_FIND_INT(users, &user_id, s); /* id already in the hash? */
|
|
if (s == NULL) {
|
|
s = (struct my_struct*)malloc(sizeof *s);
|
|
s->id = user_id;
|
|
HASH_ADD_INT(users, id, s); /* id is the key field */
|
|
}
|
|
strcpy(s->name, name);
|
|
}
|
|
|
|
struct my_struct *find_user(int user_id)
|
|
{
|
|
struct my_struct *s;
|
|
|
|
HASH_FIND_INT(users, &user_id, s); /* s: output pointer */
|
|
return s;
|
|
}
|
|
|
|
void delete_user(struct my_struct *user)
|
|
{
|
|
HASH_DEL(users, user); /* user: pointer to deletee */
|
|
free(user);
|
|
}
|
|
|
|
void delete_all()
|
|
{
|
|
struct my_struct *current_user;
|
|
struct my_struct *tmp;
|
|
|
|
HASH_ITER(hh, users, current_user, tmp) {
|
|
HASH_DEL(users, current_user); /* delete it (users advances to next) */
|
|
free(current_user); /* free it */
|
|
}
|
|
}
|
|
|
|
void print_users()
|
|
{
|
|
struct my_struct *s;
|
|
|
|
for (s = users; s != NULL; s = (struct my_struct*)(s->hh.next)) {
|
|
printf("user id %d: name %s\n", s->id, s->name);
|
|
}
|
|
}
|
|
|
|
int by_name(const struct my_struct *a, const struct my_struct *b)
|
|
{
|
|
return strcmp(a->name, b->name);
|
|
}
|
|
|
|
int by_id(const struct my_struct *a, const struct my_struct *b)
|
|
{
|
|
return (a->id - b->id);
|
|
}
|
|
|
|
const char *getl(const char *prompt)
|
|
{
|
|
static char buf[21];
|
|
char *p;
|
|
printf("%s? ", prompt); fflush(stdout);
|
|
p = fgets(buf, sizeof(buf), stdin);
|
|
if (p == NULL || (p = strchr(buf, '\n')) == NULL) {
|
|
puts("Invalid input!");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
*p = '\0';
|
|
return buf;
|
|
}
|
|
|
|
int main()
|
|
{
|
|
int id = 1;
|
|
int running = 1;
|
|
struct my_struct *s;
|
|
int temp;
|
|
|
|
while (running) {
|
|
printf(" 1. add user\n");
|
|
printf(" 2. add or 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");
|
|
switch (atoi(getl("Command"))) {
|
|
case 1:
|
|
add_user(id++, getl("Name (20 char max)"));
|
|
break;
|
|
case 2:
|
|
temp = atoi(getl("ID"));
|
|
add_user(temp, getl("Name (20 char max)"));
|
|
break;
|
|
case 3:
|
|
s = find_user(atoi(getl("ID to find")));
|
|
printf("user: %s\n", s ? s->name : "unknown");
|
|
break;
|
|
case 4:
|
|
s = find_user(atoi(getl("ID to delete")));
|
|
if (s) {
|
|
delete_user(s);
|
|
} else {
|
|
printf("id unknown\n");
|
|
}
|
|
break;
|
|
case 5:
|
|
delete_all();
|
|
break;
|
|
case 6:
|
|
HASH_SORT(users, by_name);
|
|
break;
|
|
case 7:
|
|
HASH_SORT(users, by_id);
|
|
break;
|
|
case 8:
|
|
print_users();
|
|
break;
|
|
case 9:
|
|
temp = HASH_COUNT(users);
|
|
printf("there are %d users\n", temp);
|
|
break;
|
|
case 10:
|
|
running = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
delete_all(); /* free any structures */
|
|
return 0;
|
|
}
|