1/*	$NetBSD: strlcat.c,v 1.2 2015/01/22 03:48:07 christos Exp $	*/
2/*	$OpenBSD: strlcat.c,v 1.10 2003/04/12 21:56:39 millert Exp $	*/
3
4/*
5 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND TODD C. MILLER DISCLAIMS ALL
12 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
13 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL TODD C. MILLER BE LIABLE
14 * FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
16 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
17 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20#if !defined(_KERNEL) && !defined(_STANDALONE)
21#if HAVE_CONFIG_H
22#include "config.h"
23#endif
24
25#include <sys/cdefs.h>
26#if defined(LIBC_SCCS) && !defined(lint)
27__RCSID("$NetBSD: strlcat.c,v 1.2 2015/01/22 03:48:07 christos Exp $");
28#endif /* LIBC_SCCS and not lint */
29
30#ifdef _LIBC
31#include "namespace.h"
32#endif
33#include <sys/types.h>
34#include <assert.h>
35#include <string.h>
36
37#ifdef _LIBC
38# ifdef __weak_alias
39__weak_alias(strlcat, _strlcat)
40# endif
41#endif
42
43#else
44#include <lib/libkern/libkern.h>
45#endif /* !_KERNEL && !_STANDALONE */
46
47#if !HAVE_STRLCAT
48/*
49 * Appends src to string dst of size siz (unlike strncat, siz is the
50 * full size of dst, not space left).  At most siz-1 characters
51 * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
52 * Returns strlen(src) + MIN(siz, strlen(initial dst)).
53 * If retval >= siz, truncation occurred.
54 */
55size_t
56strlcat(char *dst, const char *src, size_t siz)
57{
58#if 1
59	char *d = dst;
60	const char *s = src;
61	size_t n = siz;
62	size_t dlen;
63
64	/* Find the end of dst and adjust bytes left but don't go past end */
65	while (n-- != 0 && *d != '\0')
66		d++;
67	dlen = d - dst;
68	n = siz - dlen;
69
70	if (n == 0)
71		return(dlen + strlen(s));
72	while (*s != '\0') {
73		if (n != 1) {
74			*d++ = *s;
75			n--;
76		}
77		s++;
78	}
79	*d = '\0';
80
81	return(dlen + (s - src));	/* count does not include NUL */
82#else
83
84	/*
85	 * Find length of string in dst (maxing out at siz).
86	 */
87	size_t dlen = strnlen(dst, siz);
88
89	/*
90	 * Copy src into any remaining space in dst (truncating if needed).
91	 * Note strlcpy(dst, src, 0) returns strlen(src).
92	 */
93	return dlen + strlcpy(dst + dlen, src, siz - dlen);
94#endif
95}
96#endif
97