xref: /minix3/common/lib/libc/string/strlcat.c (revision b6cbf7203b080219de306404f8022a65b7884f33)
1*b6cbf720SGianluca Guida /*	$NetBSD: strlcat.c,v 1.3 2007/06/04 18:19:27 christos Exp $	*/
2*b6cbf720SGianluca Guida /*	$OpenBSD: strlcat.c,v 1.10 2003/04/12 21:56:39 millert Exp $	*/
3*b6cbf720SGianluca Guida 
4*b6cbf720SGianluca Guida /*
5*b6cbf720SGianluca Guida  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
6*b6cbf720SGianluca Guida  *
7*b6cbf720SGianluca Guida  * Permission to use, copy, modify, and distribute this software for any
8*b6cbf720SGianluca Guida  * purpose with or without fee is hereby granted, provided that the above
9*b6cbf720SGianluca Guida  * copyright notice and this permission notice appear in all copies.
10*b6cbf720SGianluca Guida  *
11*b6cbf720SGianluca Guida  * THE SOFTWARE IS PROVIDED "AS IS" AND TODD C. MILLER DISCLAIMS ALL
12*b6cbf720SGianluca Guida  * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
13*b6cbf720SGianluca Guida  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL TODD C. MILLER BE LIABLE
14*b6cbf720SGianluca Guida  * FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15*b6cbf720SGianluca Guida  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
16*b6cbf720SGianluca Guida  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
17*b6cbf720SGianluca Guida  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18*b6cbf720SGianluca Guida  */
19*b6cbf720SGianluca Guida 
20*b6cbf720SGianluca Guida #if !defined(_KERNEL) && !defined(_STANDALONE)
21*b6cbf720SGianluca Guida #if HAVE_NBTOOL_CONFIG_H
22*b6cbf720SGianluca Guida #include "nbtool_config.h"
23*b6cbf720SGianluca Guida #endif
24*b6cbf720SGianluca Guida 
25*b6cbf720SGianluca Guida #include <sys/cdefs.h>
26*b6cbf720SGianluca Guida #if defined(LIBC_SCCS) && !defined(lint)
27*b6cbf720SGianluca Guida __RCSID("$NetBSD: strlcat.c,v 1.3 2007/06/04 18:19:27 christos Exp $");
28*b6cbf720SGianluca Guida #endif /* LIBC_SCCS and not lint */
29*b6cbf720SGianluca Guida 
30*b6cbf720SGianluca Guida #ifdef _LIBC
31*b6cbf720SGianluca Guida #include "namespace.h"
32*b6cbf720SGianluca Guida #endif
33*b6cbf720SGianluca Guida #include <sys/types.h>
34*b6cbf720SGianluca Guida #include <assert.h>
35*b6cbf720SGianluca Guida #include <string.h>
36*b6cbf720SGianluca Guida 
37*b6cbf720SGianluca Guida #ifdef _LIBC
38*b6cbf720SGianluca Guida # ifdef __weak_alias
39*b6cbf720SGianluca Guida __weak_alias(strlcat, _strlcat)
40*b6cbf720SGianluca Guida # endif
41*b6cbf720SGianluca Guida #endif
42*b6cbf720SGianluca Guida 
43*b6cbf720SGianluca Guida #else
44*b6cbf720SGianluca Guida #include <lib/libkern/libkern.h>
45*b6cbf720SGianluca Guida #endif /* !_KERNEL && !_STANDALONE */
46*b6cbf720SGianluca Guida 
47*b6cbf720SGianluca Guida #if !HAVE_STRLCAT
48*b6cbf720SGianluca Guida /*
49*b6cbf720SGianluca Guida  * Appends src to string dst of size siz (unlike strncat, siz is the
50*b6cbf720SGianluca Guida  * full size of dst, not space left).  At most siz-1 characters
51*b6cbf720SGianluca Guida  * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
52*b6cbf720SGianluca Guida  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
53*b6cbf720SGianluca Guida  * If retval >= siz, truncation occurred.
54*b6cbf720SGianluca Guida  */
55*b6cbf720SGianluca Guida size_t
56*b6cbf720SGianluca Guida strlcat(char *dst, const char *src, size_t siz)
57*b6cbf720SGianluca Guida {
58*b6cbf720SGianluca Guida 	char *d = dst;
59*b6cbf720SGianluca Guida 	const char *s = src;
60*b6cbf720SGianluca Guida 	size_t n = siz;
61*b6cbf720SGianluca Guida 	size_t dlen;
62*b6cbf720SGianluca Guida 
63*b6cbf720SGianluca Guida 	_DIAGASSERT(dst != NULL);
64*b6cbf720SGianluca Guida 	_DIAGASSERT(src != NULL);
65*b6cbf720SGianluca Guida 
66*b6cbf720SGianluca Guida 	/* Find the end of dst and adjust bytes left but don't go past end */
67*b6cbf720SGianluca Guida 	while (n-- != 0 && *d != '\0')
68*b6cbf720SGianluca Guida 		d++;
69*b6cbf720SGianluca Guida 	dlen = d - dst;
70*b6cbf720SGianluca Guida 	n = siz - dlen;
71*b6cbf720SGianluca Guida 
72*b6cbf720SGianluca Guida 	if (n == 0)
73*b6cbf720SGianluca Guida 		return(dlen + strlen(s));
74*b6cbf720SGianluca Guida 	while (*s != '\0') {
75*b6cbf720SGianluca Guida 		if (n != 1) {
76*b6cbf720SGianluca Guida 			*d++ = *s;
77*b6cbf720SGianluca Guida 			n--;
78*b6cbf720SGianluca Guida 		}
79*b6cbf720SGianluca Guida 		s++;
80*b6cbf720SGianluca Guida 	}
81*b6cbf720SGianluca Guida 	*d = '\0';
82*b6cbf720SGianluca Guida 
83*b6cbf720SGianluca Guida 	return(dlen + (s - src));	/* count does not include NUL */
84*b6cbf720SGianluca Guida }
85*b6cbf720SGianluca Guida #endif
86