stdlib/FreeBSD/lsearch.c

   1 /*
   2  * Initial implementation:
   3  * Copyright (c) 2002 Robert Drehmel
   4  * All rights reserved.
   5  *
   6  * As long as the above copyright statement and this notice remain
   7  * unchanged, you can do what ever you want with this file.
   8  */
   9 #include <sys/types.h>
  10 #include <sys/cdefs.h>
  11 __FBSDID("$FreeBSD: src/lib/libc/stdlib/lsearch.c,v 1.1 2002/10/16 14:29:22 robert Exp $");
  12
  13 #define _SEARCH_PRIVATE
  14 #include <search.h>
  15 #include <stdint.h>     /* for uint8_t */
  16 #include <stdlib.h>     /* for NULL */
  17 #include <string.h>     /* for memcpy() prototype */
  18
  19 static void *lwork(const void *, const void *, size_t *, size_t,
  20     int (*)(const void *, const void *), int);
  21
  22 void *lsearch(const void *key, void *base, size_t *nelp, size_t width,
  23     int (*compar)(const void *, const void *))
  24 {
  25
  26         return (lwork(key, base, nelp, width, compar, 1));
  27 }
  28
  29 void *lfind(const void *key, const void *base, size_t *nelp, size_t width,
  30     int (*compar)(const void *, const void *))
  31 {
  32
  33         return (lwork(key, base, nelp, width, compar, 0));
  34 }
  35
  36 static void *
  37 lwork(const void *key, const void *base, size_t *nelp, size_t width,
  38     int (*compar)(const void *, const void *), int addelem)
  39 {
  40         uint8_t *ep, *endp;
  41
  42         /*
  43          * Cast to an integer value first to avoid the warning for removing
  44          * 'const' via a cast.
  45          */
  46         ep = (uint8_t *)(uintptr_t)base;
  47         for (endp = (uint8_t *)(ep + width * *nelp); ep < endp; ep += width) {
  48                 if (compar(key, ep) == 0)
  49                         return (ep);
  50         }
  51
  52         /* lfind() shall return when the key was not found. */
  53         if (!addelem)
  54                 return (NULL);
  55
  56         /*
  57          * lsearch() adds the key to the end of the table and increments
  58          * the number of elements.
  59          */
  60         memcpy(endp, key, width);
  61         ++*nelp;
  62
  63         return (endp);
  64 }