xref: /freebsd/contrib/tcpdump/missing/strlcat.c (revision 5521ff5a4d1929056e7ffc982fac3341ca54df7c)
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
32 static const char rcsid[] =
33     "@(#) $Header: /tcpdump/master/tcpdump/missing/strlcat.c,v 1.1 2000/01/19 05:34:19 itojun Exp $ (LBL)";
34 #endif
35 
36 #include <config.h>
37 
38 #include <sys/types.h>
39 #include <string.h>
40 
41 #include "interface.h"
42 
43 /*
44  * Appends src to string dst of size siz (unlike strncat, siz is the
45  * full size of dst, not space left).  At most siz-1 characters
46  * will be copied.  Always NUL terminates (unless siz == 0).
47  * Returns strlen(src); if retval >= siz, truncation occurred.
48  */
49 size_t
50 strlcat(dst, src, siz)
51 	char *dst;
52 	const char *src;
53 	size_t siz;
54 {
55 	register char *d = dst;
56 	register const char *s = src;
57 	register size_t n = siz;
58 	size_t dlen;
59 
60 	/* Find the end of dst and adjust bytes left but don't go past end */
61 	while (*d != '\0' && n-- != 0)
62 		d++;
63 	dlen = d - dst;
64 	n = siz - dlen;
65 
66 	if (n == 0)
67 		return(dlen + strlen(s));
68 	while (*s != '\0') {
69 		if (n != 1) {
70 			*d++ = *s;
71 			n--;
72 		}
73 		s++;
74 	}
75 	*d = '\0';
76 
77 	return(dlen + (s - src));	/* count does not include NUL */
78 }
79