xref: /netbsd-src/common/lib/libc/string/strlcpy.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: strlcpy.c,v 1.1 2005/12/20 19:28:52 christos Exp $	*/
2 /*	$OpenBSD: strlcpy.c,v 1.7 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 
20 #if !defined(_KERNEL) && !defined(_STANDALONE)
21 #if HAVE_NBTOOL_CONFIG_H
22 #include "nbtool_config.h"
23 #endif
24 
25 #include <sys/cdefs.h>
26 #if defined(LIBC_SCCS) && !defined(lint)
27 __RCSID("$NetBSD: strlcpy.c,v 1.1 2005/12/20 19:28:52 christos Exp $");
28 #endif /* LIBC_SCCS and not lint */
29 
30 #ifdef _LIBC
31 #include "namespace.h"
32 #endif
33 #include <sys/types.h>
34 #include <assert.h>
35 #include <string.h>
36 
37 #ifdef _LIBC
38 # ifdef __weak_alias
39 __weak_alias(strlcpy, _strlcpy)
40 # endif
41 #endif
42 #else
43 #include <lib/libkern/libkern.h>
44 #endif /* !_KERNEL && !_STANDALONE */
45 
46 
47 #if !HAVE_STRLCPY
48 /*
49  * Copy src to string dst of size siz.  At most siz-1 characters
50  * will be copied.  Always NUL terminates (unless siz == 0).
51  * Returns strlen(src); if retval >= siz, truncation occurred.
52  */
53 size_t
54 #ifdef _LIBC
55 _strlcpy(dst, src, siz)
56 #else
57 strlcpy(dst, src, siz)
58 #endif
59 	char *dst;
60 	const char *src;
61 	size_t siz;
62 {
63 	char *d = dst;
64 	const char *s = src;
65 	size_t n = siz;
66 
67 	_DIAGASSERT(dst != NULL);
68 	_DIAGASSERT(src != NULL);
69 
70 	/* Copy as many bytes as will fit */
71 	if (n != 0 && --n != 0) {
72 		do {
73 			if ((*d++ = *s++) == 0)
74 				break;
75 		} while (--n != 0);
76 	}
77 
78 	/* Not enough room in dst, add NUL and traverse rest of src */
79 	if (n == 0) {
80 		if (siz != 0)
81 			*d = '\0';		/* NUL-terminate dst */
82 		while (*s++)
83 			;
84 	}
85 
86 	return(s - src - 1);	/* count does not include NUL */
87 }
88 #endif
89