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-rw-r--r--src/lib/libc/stdlib/lsearch.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/src/lib/libc/stdlib/lsearch.c b/src/lib/libc/stdlib/lsearch.c
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1/*
2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Roger L. Snyder.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#if defined(LIBC_SCCS) && !defined(lint)
34static char sccsid[] = "@(#)lsearch.c 8.1 (Berkeley) 6/4/93";
35#endif /* LIBC_SCCS and not lint */
36
37#include <sys/types.h>
38#include <string.h>
39#include <search.h>
40
41typedef int (*cmp_fn_t)(const void *, const void *);
42static void *linear_base(const void *, const void *, size_t *, size_t,
43 cmp_fn_t, int);
44
45void *
46lsearch(const void *key, const void *base, size_t *nelp, size_t width,
47 cmp_fn_t compar)
48{
49
50 return(linear_base(key, base, nelp, width, compar, 1));
51}
52
53void *
54lfind(const void *key, const void *base, size_t *nelp, size_t width,
55 cmp_fn_t compar)
56{
57 return(linear_base(key, base, nelp, width, compar, 0));
58}
59
60static void *
61linear_base(const void *key, const void *base, size_t *nelp, size_t width,
62 cmp_fn_t compar, int add_flag)
63{
64 const char *element, *end;
65
66 end = (const char *)base + *nelp * width;
67 for (element = base; element < end; element += width)
68 if (!compar(key, element)) /* key found */
69 return((void *)element);
70
71 if (!add_flag) /* key not found */
72 return(NULL);
73
74 /*
75 * The UNIX System User's Manual, 1986 edition claims that
76 * a NULL pointer is returned by lsearch with errno set
77 * appropriately, if there is not enough room in the table
78 * to add a new item. This can't be done as none of these
79 * routines have any method of determining the size of the
80 * table. This comment isn't in the 1986-87 System V
81 * manual.
82 */
83 ++*nelp;
84 memcpy((void *)end, key, width);
85 return((void *)end);
86}