1 /* $OpenBSD: lsearch.c,v 1.7 2021/12/08 22:06:28 cheloha Exp $ */
2
3 /*
4 * Copyright (c) 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Roger L. Snyder.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #include <sys/types.h>
36 #include <string.h>
37 #include <search.h>
38
39 typedef int (*cmp_fn_t)(const void *, const void *);
40
41 void *
lsearch(const void * key,void * base,size_t * nelp,size_t width,cmp_fn_t compar)42 lsearch(const void *key, void *base, size_t *nelp, size_t width,
43 cmp_fn_t compar)
44 {
45 void *element = lfind(key, base, nelp, width, compar);
46
47 /*
48 * Use memmove(3) to ensure the key is copied cleanly into the
49 * array, even if the key overlaps with the end of the array.
50 */
51 if (element == NULL) {
52 element = memmove((char *)base + *nelp * width, key, width);
53 *nelp += 1;
54 }
55 return element;
56 }
57
58 void *
lfind(const void * key,const void * base,size_t * nelp,size_t width,cmp_fn_t compar)59 lfind(const void *key, const void *base, size_t *nelp, size_t width,
60 cmp_fn_t compar)
61 {
62 const char *element, *end;
63
64 end = (const char *)base + *nelp * width;
65 for (element = base; element < end; element += width)
66 if (!compar(key, element)) /* key found */
67 return((void *)element);
68 return NULL;
69 }
70 DEF_WEAK(lfind);
71