1 /* $OpenBSD: strlcpy.c,v 1.5 2004/08/07 00:38:33 deraadt Exp $ */
2
3 /*
4 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #if defined(LIBC_SCCS) && !defined(lint)
20 static char *rcsid = "$OpenBSD: strlcpy.c,v 1.5 2004/08/07 00:38:33 deraadt Exp $";
21 #endif /* LIBC_SCCS and not lint */
22
23 #if !defined(_KERNEL) && !defined(_STANDALONE)
24 #include <sys/types.h>
25 #include <string.h>
26 #else
27 #include <lib/libkern/libkern.h>
28 #endif
29
30 /*
31 * Copy src to string dst of size siz. At most siz-1 characters
32 * will be copied. Always NUL terminates (unless siz == 0).
33 * Returns strlen(src); if retval >= siz, truncation occurred.
34 */
35 size_t
36 strlcpy(char *dst, const char *src, size_t siz)
37 {
38 char *d = dst;
39 const char *s = src;
40 size_t n = siz;
41
42 /* Copy as many bytes as will fit */
43 if (n != 0 && --n != 0) {
44 do {
45 if ((*d++ = *s++) == 0)
46 break;
47 } while (--n != 0);
48 }
49
50 /* Not enough room in dst, add NUL and traverse rest of src */
51 if (n == 0) {
52 if (siz != 0)
53 *d = '\0'; /* NUL-terminate dst */
54 while (*s++)
55 ;
56 }
57
58 return(s - src - 1); /* count does not include NUL */
59 }