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 #include        "dlink.h"
  12
  13
  14 void *dl_head()
  15 {
  16     void *h;
  17     h = dl_alloc(0);
  18     dl_next(h) = h;
  19     dl_prev(h) = h;
  20     return h;
  21 }
  22
  23 void dl_free(void *v)
  24 {
  25     struct __dl_head *vv  = v;
  26     free(vv-1);
  27 }
  28
  29 void dl_init(void *v)
  30 {
  31     dl_next(v) = v;
  32     dl_prev(v) = v;
  33 }
  34
  35 void dl_insert(void *head, void *val)
  36 {
  37     dl_next(val) = dl_next(head);
  38     dl_prev(val) = head;
  39     dl_next(dl_prev(val)) = val;
  40     dl_prev(dl_next(val)) = val;
  41 }
  42
  43 void dl_add(void *head, void *val)
  44 {
  45     dl_prev(val) = dl_prev(head);
  46     dl_next(val) = head;
  47     dl_next(dl_prev(val)) = val;
  48     dl_prev(dl_next(val)) = val;
  49 }
  50
  51 void dl_del(void *val)
  52 {
  53     if (dl_prev(val) == 0 || dl_next(val) == 0)
  54         return;
  55     dl_prev(dl_next(val)) = dl_prev(val);
  56     dl_next(dl_prev(val)) = dl_next(val);
  57     dl_prev(val) = dl_next(val) = 0;
  58 }
  59
  60 char *dl_strndup(char *s, int l)
  61 {
  62     char *n;
  63     if (s == NULL)
  64         return NULL;
  65     n = dl_newv(char, l+1);
  66     if (n == NULL)
  67         return NULL;
  68     else
  69     {
  70         strncpy(n, s, l);
  71         n[l] = 0;
  72         return n;
  73     }
  74 }
  75
  76 char *dl_strdup(char *s)
  77 {
  78     return dl_strndup(s, (int)strlen(s));
  79 }