bootx.tproj/libclite.subproj/bsearch.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  *  bsearch.c - bsearch from libc.
  27  *
  28  *  Copyright (c) 1998-2000 Apple Computer, Inc.
  29  *
  30  *  DRI: Josh de Cesare
  31  */
  32
  33 #include <libclite.h>
  34
  35 void *
  36 bsearch(const void *key, const void *base, size_t nmemb, size_t size,
  37         int (*compar)(const void *, const void *))
  38 {
  39     int l = 0;
  40     int u = nmemb - 1;
  41     int m;
  42     void *mp;
  43     int r;
  44
  45     while (l <= u) {
  46         m = (l + u) / 2;
  47         mp = (void *)(((char *)base) + (m * size));
  48         if ((r = (*compar) (key, mp)) == 0) {
  49             return mp;
  50         } else if (r < 0) {
  51             u = m - 1;
  52         } else {
  53             l = m + 1;
  54         }
  55     }
  56     return NULL;
  57 }
  58