1/*	$OpenBSD: strlcpy.c,v 1.13 2015/08/31 02:53:57 guenther Exp $	*/
2
3/*
4 * Copyright (c) 1998, 2015 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#include <sys/types.h>
20#include <string.h>
21
22/*
23 * Copy string src to buffer dst of size dsize.  At most dsize-1
24 * chars will be copied.  Always NUL terminates (unless dsize == 0).
25 * Returns strlen(src); if retval >= dsize, truncation occurred.
26 */
27size_t
28strlcpy(char *dst, const char *src, size_t dsize)
29{
30	const char *osrc = src;
31	size_t nleft = dsize;
32
33	/* Copy as many bytes as will fit. */
34	if (nleft != 0) {
35		while (--nleft != 0) {
36			if ((*dst++ = *src++) == '\0')
37				break;
38		}
39	}
40
41	/* Not enough room in dst, add NUL and traverse rest of src. */
42	if (nleft == 0) {
43		if (dsize != 0)
44			*dst = '\0';		/* NUL-terminate dst */
45		while (*src++)
46			;
47	}
48
49	return(src - osrc - 1);	/* count does not include NUL */
50}
51DEF_WEAK(strlcpy);
52