netbsd-llist.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <sys/queue.h>
   5 #include <assert.h>
   6
   7 LIST_HEAD(listhead, entry) head;
   8 struct listhead *headp;
   9
  10 struct entry {
  11     LIST_ENTRY(entry) entries;
  12     const char *str;
  13 } *np, *n;
  14
  15 void diep(const char *s);
  16
  17 int main(void)
  18 {
  19     const char *str[] = { "this", "is", "a", "linked", "list" };
  20     unsigned int i;
  21
  22     /* Initialize list */
  23     LIST_INIT(&head);
  24     headp = &head;
  25
  26     /* Populate list with str[] items */
  27     for (i = 0; i < sizeof str / sizeof *str; i++) {
  28         n = malloc(sizeof(struct entry));
  29         if (n == NULL)
  30             diep("malloc");
  31         n->str = str[i];
  32
  33         if (i == 0)
  34             LIST_INSERT_HEAD(&head, n, entries);
  35         else
  36             LIST_INSERT_AFTER(np, n, entries);
  37         np = n;
  38     }
  39
  40     /* Traverse list */
  41     LIST_FOREACH(np, &head, entries)
  42         printf("%s\n", np->str);
  43
  44     /* Delete all elements */
  45     while (LIST_FIRST(&head) != NULL)
  46         LIST_REMOVE(LIST_FIRST(&head), entries);
  47
  48     return EXIT_SUCCESS;
  49 }
  50
  51 void diep(const char *s)
  52 {
  53     perror(s);
  54     exit(EXIT_FAILURE);
  55 }