strlcat.c revision e66460324c0c1d5b6f767afeb6f3d201094156d3 
1/*	$NetBSD: strlcat.c,v 1.5 1999/09/20 04:39:47 lukem Exp $	*/
2/*	from OpenBSD: strlcat.c,v 1.2 1999/06/17 16:28:58 millert Exp 	*/
3
4/*
5 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
6 * All rights reserved.
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. The name of the author may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
20 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
21 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
22 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
23 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
24 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
25 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
26 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
27 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
28 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#ifndef lint
32static const char rcsid[] _U_ =
33    "@(#) $Header: /tcpdump/master/tcpdump/missing/strlcat.c,v 1.5 2003/11/16 09:36:51 guy Exp $ (LBL)";
34#endif
35
36#ifdef HAVE_CONFIG_H
37#include <config.h>
38#endif
39
40#include <tcpdump-stdinc.h>
41
42#include <string.h>
43
44/*
45 * Appends src to string dst of size siz (unlike strncat, siz is the
46 * full size of dst, not space left).  At most siz-1 characters
47 * will be copied.  Always NUL terminates (unless siz == 0).
48 * Returns strlen(src); if retval >= siz, truncation occurred.
49 */
50size_t
51strlcat(char *dst, const char *src, size_t siz)
52{
53	register char *d = dst;
54	register const char *s = src;
55	register size_t n = siz;
56	size_t dlen;
57
58	/* Find the end of dst and adjust bytes left but don't go past end */
59	while (*d != '\0' && n-- != 0)
60		d++;
61	dlen = d - dst;
62	n = siz - dlen;
63
64	if (n == 0)
65		return(dlen + strlen(s));
66	while (*s != '\0') {
67		if (n != 1) {
68			*d++ = *s;
69			n--;
70		}
71		s++;
72	}
73	*d = '\0';
74
75	return(dlen + (s - src));	/* count does not include NUL */
76}
77