1/*	$OpenBSD: strlcat.c,v 1.8 2001/05/13 15:40:15 deraadt Exp $	*/
2
3/*
4 * Copyright (c) 1998, 2003-2005 Todd C. Miller <Todd.Miller@courtesan.com>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <config.h>
20
21#include <sys/types.h>
22#include <string.h>
23
24#include "missing.h"
25
26/*
27 * Appends src to string dst of size siz (unlike strncat, siz is the
28 * full size of dst, not space left).  At most siz-1 characters
29 * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
30 * Returns strlen(src) + MIN(siz, strlen(initial dst)).
31 * If retval >= siz, truncation occurred.
32 */
33size_t
34strlcat(dst, src, siz)
35	char *dst;
36	const char *src;
37	size_t siz;
38{
39	char *d = dst;
40	const char *s = src;
41	size_t n = siz;
42	size_t dlen;
43
44	/* Find the end of dst and adjust bytes left but don't go past end */
45	while (n-- != 0 && *d != '\0')
46		d++;
47	dlen = d - dst;
48	n = siz - dlen;
49
50	if (n == 0)
51		return dlen + strlen(s);
52	while (*s != '\0') {
53		if (n != 1) {
54			*d++ = *s;
55			n--;
56		}
57		s++;
58	}
59	*d = '\0';
60
61	return dlen + (s - src);	/* count does not include NUL */
62}
63