netbsd-llist.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <sys/queue.h>
   5
   6 LIST_HEAD(listhead, entry) head;
   7 struct listhead *headp;
   8
   9 struct entry {
  10     LIST_ENTRY(entry) entries;
  11     const char *str;
  12 } *np, *n;
  13
  14 int main(void)
  15 {
  16     const char *str[] = { "this", "is", "a", "linked", "list" };
  17     unsigned int i;
  18
  19     /* Initialize list */
  20     LIST_INIT(&head);
  21     headp = &head;
  22
  23     /* Populate list with str[] items */
  24     for (i = 0; i < sizeof str / sizeof *str; i++) {
  25         if ((n = malloc(sizeof(struct entry))) == NULL) {
  26             perror("malloc");
  27             goto CLEANUP_AND_EXIT;
  28         }
  29         n->str = str[i];
  30
  31         if (i == 0)
  32             LIST_INSERT_HEAD(&head, n, entries);
  33         else
  34             LIST_INSERT_AFTER(np, n, entries);
  35         np = n;
  36     }
  37
  38     /* Traverse list */
  39     LIST_FOREACH(np, &head, entries)
  40         printf("%s\n", np->str);
  41
  42  CLEANUP_AND_EXIT:;
  43     /* Delete all elements */
  44     while (LIST_FIRST(&head) != NULL)
  45         LIST_REMOVE(LIST_FIRST(&head), entries);
  46
  47     return EXIT_SUCCESS;
  48 }