xref: /aosp_15_r20/external/tcpdump/missing/strlcat.c (revision 05b00f6010a2396e3db2409989fc67270046269f)
1*05b00f60SXin Li /*	$NetBSD: strlcat.c,v 1.5 1999/09/20 04:39:47 lukem Exp $	*/
2*05b00f60SXin Li /*	from OpenBSD: strlcat.c,v 1.2 1999/06/17 16:28:58 millert Exp	*/
3*05b00f60SXin Li 
4*05b00f60SXin Li /*
5*05b00f60SXin Li  * Copyright (c) 1998 Todd C. Miller <[email protected]>
6*05b00f60SXin Li  * All rights reserved.
7*05b00f60SXin Li  *
8*05b00f60SXin Li  * Redistribution and use in source and binary forms, with or without
9*05b00f60SXin Li  * modification, are permitted provided that the following conditions
10*05b00f60SXin Li  * are met:
11*05b00f60SXin Li  * 1. Redistributions of source code must retain the above copyright
12*05b00f60SXin Li  *    notice, this list of conditions and the following disclaimer.
13*05b00f60SXin Li  * 2. Redistributions in binary form must reproduce the above copyright
14*05b00f60SXin Li  *    notice, this list of conditions and the following disclaimer in the
15*05b00f60SXin Li  *    documentation and/or other materials provided with the distribution.
16*05b00f60SXin Li  * 3. The name of the author may not be used to endorse or promote products
17*05b00f60SXin Li  *    derived from this software without specific prior written permission.
18*05b00f60SXin Li  *
19*05b00f60SXin Li  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
20*05b00f60SXin Li  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
21*05b00f60SXin Li  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
22*05b00f60SXin Li  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
23*05b00f60SXin Li  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
24*05b00f60SXin Li  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
25*05b00f60SXin Li  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
26*05b00f60SXin Li  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
27*05b00f60SXin Li  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
28*05b00f60SXin Li  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29*05b00f60SXin Li  */
30*05b00f60SXin Li 
31*05b00f60SXin Li #ifdef HAVE_CONFIG_H
32*05b00f60SXin Li #include <config.h>
33*05b00f60SXin Li #endif
34*05b00f60SXin Li 
35*05b00f60SXin Li #include <netdissect-stdinc.h>
36*05b00f60SXin Li 
37*05b00f60SXin Li #include <string.h>
38*05b00f60SXin Li 
39*05b00f60SXin Li #include "netdissect.h"
40*05b00f60SXin Li 
41*05b00f60SXin Li /*
42*05b00f60SXin Li  * Appends src to string dst of size siz (unlike strncat, siz is the
43*05b00f60SXin Li  * full size of dst, not space left).  At most siz-1 characters
44*05b00f60SXin Li  * will be copied.  Always NUL terminates (unless siz == 0).
45*05b00f60SXin Li  * Returns strlen(src); if retval >= siz, truncation occurred.
46*05b00f60SXin Li  */
47*05b00f60SXin Li size_t
strlcat(char * dst,const char * src,size_t siz)48*05b00f60SXin Li strlcat(char *dst, const char *src, size_t siz)
49*05b00f60SXin Li {
50*05b00f60SXin Li 	char *d = dst;
51*05b00f60SXin Li 	const char *s = src;
52*05b00f60SXin Li 	size_t n = siz;
53*05b00f60SXin Li 	size_t dlen;
54*05b00f60SXin Li 
55*05b00f60SXin Li 	/* Find the end of dst and adjust bytes left but don't go past end */
56*05b00f60SXin Li 	while (*d != '\0' && n-- != 0)
57*05b00f60SXin Li 		d++;
58*05b00f60SXin Li 	dlen = d - dst;
59*05b00f60SXin Li 	n = siz - dlen;
60*05b00f60SXin Li 
61*05b00f60SXin Li 	if (n == 0)
62*05b00f60SXin Li 		return(dlen + strlen(s));
63*05b00f60SXin Li 	while (*s != '\0') {
64*05b00f60SXin Li 		if (n != 1) {
65*05b00f60SXin Li 			*d++ = *s;
66*05b00f60SXin Li 			n--;
67*05b00f60SXin Li 		}
68*05b00f60SXin Li 		s++;
69*05b00f60SXin Li 	}
70*05b00f60SXin Li 	*d = '\0';
71*05b00f60SXin Li 
72*05b00f60SXin Li 	return(dlen + (s - src));	/* count does not include NUL */
73*05b00f60SXin Li }
74