misc/lsearch.c

   1 /* Linear search functions.
   2    Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <search.h>
  22 #include <string.h>
  23
  24
  25 void *
  26 lsearch (const void *key, void *base, size_t *nmemb, size_t size,
  27          __compar_fn_t compar)
  28 {
  29   void *result;
  30
  31   /* Try to find it.  */
  32   result = lfind (key, base, nmemb, size, compar);
  33   if (result == NULL)
  34     {
  35       /* Not available.  Insert at the end.  */
  36       result = memcpy (base + (*nmemb) * size, key, size);
  37       ++(*nmemb);
  38     }
  39
  40   return result;
  41 }
  42
  43
  44 void *
  45 lfind (const void *key, const void *base, size_t *nmemb, size_t size,
  46        __compar_fn_t compar)
  47 {
  48   const void *result = base;
  49   size_t cnt = 0;
  50
  51   while (cnt < *nmemb && (*compar) (key, result) != 0)
  52     {
  53       result += size;
  54       ++cnt;
  55     }
  56
  57   return cnt < *nmemb ? (void *) result : NULL;
  58 }