dlink.c

   1
   2 /* doubly linked lists */
   3 /* This is free software. No strings attached. No copyright claimed */
   4
   5 #include        <unistd.h>
   6 #include        <stdlib.h>
   7 #include        <string.h>
   8 #ifdef __dietlibc__
   9 char *strncpy(char *dest, const char *src, size_t n) __THROW;
  10 #endif
  11 void *xcalloc(size_t num, size_t size);
  12 #include        "dlink.h"
  13
  14
  15 void *dl_head()
  16 {
  17     void *h;
  18     h = dl_alloc(0);
  19     dl_next(h) = h;
  20     dl_prev(h) = h;
  21     return h;
  22 }
  23
  24 void dl_free(void *v)
  25 {
  26     struct __dl_head *vv  = v;
  27     free(vv-1);
  28 }
  29
  30 void dl_init(void *v)
  31 {
  32     dl_next(v) = v;
  33     dl_prev(v) = v;
  34 }
  35
  36 void dl_insert(void *head, void *val)
  37 {
  38     dl_next(val) = dl_next(head);
  39     dl_prev(val) = head;
  40     dl_next(dl_prev(val)) = val;
  41     dl_prev(dl_next(val)) = val;
  42 }
  43
  44 void dl_add(void *head, void *val)
  45 {
  46     dl_prev(val) = dl_prev(head);
  47     dl_next(val) = head;
  48     dl_next(dl_prev(val)) = val;
  49     dl_prev(dl_next(val)) = val;
  50 }
  51
  52 void dl_del(void *val)
  53 {
  54     if (dl_prev(val) == 0 || dl_next(val) == 0)
  55         return;
  56     dl_prev(dl_next(val)) = dl_prev(val);
  57     dl_next(dl_prev(val)) = dl_next(val);
  58     dl_prev(val) = dl_next(val) = 0;
  59 }
  60
  61 char *dl_strndup(char *s, int l)
  62 {
  63     char *n;
  64     if (s == NULL)
  65         return NULL;
  66     n = dl_newv(char, l+1);
  67     strncpy(n, s, l);
  68     n[l] = 0;
  69     return n;
  70 }
  71
  72 char *dl_strdup(char *s)
  73 {
  74     return dl_strndup(s, (int)strlen(s));
  75 }