1 /* $NetBSD: strlcat.c,v 1.3 2007/06/04 18:19:27 christos Exp $ */
2 /* $OpenBSD: strlcat.c,v 1.10 2003/04/12 21:56:39 millert Exp $ */
3
4 /*
5 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND TODD C. MILLER DISCLAIMS ALL
12 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
13 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL TODD C. MILLER BE LIABLE
14 * FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
16 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
17 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19 #include <LibConfig.h>
20
21 #if !defined(_KERNEL) && !defined(_STANDALONE)
22 #if HAVE_NBTOOL_CONFIG_H
23 #include "nbtool_config.h"
24 #endif
25
26 #include <sys/cdefs.h>
27 #if defined(LIBC_SCCS) && !defined(lint)
28 __RCSID("$NetBSD: strlcat.c,v 1.3 2007/06/04 18:19:27 christos Exp $");
29 #endif /* LIBC_SCCS and not lint */
30
31 #ifdef _LIBC
32 #include "namespace.h"
33 #endif
34 #include <sys/types.h>
35 #include <assert.h>
36 #include <string.h>
37
38 #ifdef _LIBC
39 # ifdef __weak_alias
__weak_alias(strlcat,_strlcat)40 __weak_alias(strlcat, _strlcat)
41 # endif
42 #endif
43
44 #else
45 #include <lib/libkern/libkern.h>
46 #endif /* !_KERNEL && !_STANDALONE */
47
48 #ifndef HAVE_STRLCAT
49 /*
50 * Appends src to string dst of size siz (unlike strncat, siz is the
51 * full size of dst, not space left). At most siz-1 characters
52 * will be copied. Always NUL terminates (unless siz <= strlen(dst)).
53 * Returns strlen(src) + MIN(siz, strlen(initial dst)).
54 * If retval >= siz, truncation occurred.
55 */
56 size_t
57 strlcat(char *dst, const char *src, size_t siz)
58 {
59 char *d = dst;
60 const char *s = src;
61 size_t n = siz;
62 size_t dlen;
63
64 _DIAGASSERT(dst != NULL);
65 _DIAGASSERT(src != NULL);
66
67 /* Find the end of dst and adjust bytes left but don't go past end */
68 while (n-- != 0 && *d != '\0')
69 d++;
70 dlen = d - dst;
71 n = siz - dlen;
72
73 if (n == 0)
74 return(dlen + strlen(s));
75 while (*s != '\0') {
76 if (n != 1) {
77 *d++ = *s;
78 n--;
79 }
80 s++;
81 }
82 *d = '\0';
83
84 return(dlen + (s - src)); /* count does not include NUL */
85 }
86 #endif
87