lsearch.c revision 105250
1247738Sbapt/*
2247738Sbapt * Initial implementation:
3247738Sbapt * Copyright (c) 2002 Robert Drehmel
4247738Sbapt * All rights reserved.
5247738Sbapt *
6247738Sbapt * As long as the above copyright statement and this notice remain
7247738Sbapt * unchanged, you can do what ever you want with this file.
8247738Sbapt */
9247738Sbapt#include <sys/types.h>
10247738Sbapt#include <sys/cdefs.h>
11247738Sbapt__FBSDID("$FreeBSD: head/lib/libc/stdlib/lsearch.c 105250 2002-10-16 14:29:23Z robert $");
12247738Sbapt
13247738Sbapt#define	_SEARCH_PRIVATE
14247738Sbapt#include <search.h>
15247738Sbapt#include <stdint.h>	/* for uint8_t */
16247738Sbapt#include <stdlib.h>	/* for NULL */
17247738Sbapt#include <string.h>	/* for memcpy() prototype */
18247738Sbapt
19247738Sbaptstatic void *lwork(const void *, const void *, size_t *, size_t,
20247738Sbapt    int (*)(const void *, const void *), int);
21247738Sbapt
22247738Sbaptvoid *lsearch(const void *key, void *base, size_t *nelp, size_t width,
23247738Sbapt    int (*compar)(const void *, const void *))
24247738Sbapt{
25247738Sbapt
26247738Sbapt	return (lwork(key, base, nelp, width, compar, 1));
27247738Sbapt}
28247738Sbapt
29247738Sbaptvoid *lfind(const void *key, const void *base, size_t *nelp, size_t width,
30247738Sbapt    int (*compar)(const void *, const void *))
31247738Sbapt{
32247738Sbapt
33247738Sbapt	return (lwork(key, base, nelp, width, compar, 0));
34247738Sbapt}
35247738Sbapt
36247738Sbaptstatic void *
37247738Sbaptlwork(const void *key, const void *base, size_t *nelp, size_t width,
38247738Sbapt    int (*compar)(const void *, const void *), int addelem)
39247738Sbapt{
40247738Sbapt	uint8_t *ep, *endp;
41247738Sbapt
42247738Sbapt	/*
43247738Sbapt	 * Cast to an integer value first to avoid the warning for removing
44247738Sbapt	 * 'const' via a cast.
45247738Sbapt	 */
46247738Sbapt	ep = (uint8_t *)(uintptr_t)base;
47247738Sbapt	for (endp = (uint8_t *)(ep + width * *nelp); ep < endp; ep += width) {
48247738Sbapt		if (compar(key, ep) == 0)
49247738Sbapt			return (ep);
50247738Sbapt	}
51247738Sbapt
52247738Sbapt	/* lfind() shall return when the key was not found. */
53247738Sbapt	if (!addelem)
54247738Sbapt		return (NULL);
55247738Sbapt
56247738Sbapt	/*
57247738Sbapt	 * lsearch() adds the key to the end of the table and increments
58247738Sbapt	 * the number of elements.
59247738Sbapt	 */
60247738Sbapt	memcpy(endp, key, width);
61247738Sbapt	++*nelp;
62247738Sbapt
63247738Sbapt	return (endp);
64247738Sbapt}
65247738Sbapt