strlcpy.c revision 86170 
1/*	$OpenBSD: strlcpy.c,v 1.4 1999/05/01 18:56:41 millert Exp $	*/
2
3/*
4 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 *    derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
19 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
20 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
21 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
26 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
27 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#if defined(LIBC_SCCS) && !defined(lint)
31static char *rcsid = "$OpenBSD: strlcpy.c,v 1.4 1999/05/01 18:56:41 millert Exp $");
32#endif /* LIBC_SCCS and not lint */
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD: head/lib/libc/string/strlcpy.c 86170 2001-11-07 19:55:16Z obrien $");
35
36#include <sys/types.h>
37#include <string.h>
38
39/*
40 * Copy src to string dst of size siz.  At most siz-1 characters
41 * will be copied.  Always NUL terminates (unless siz == 0).
42 * Returns strlen(src); if retval >= siz, truncation occurred.
43 */
44size_t strlcpy(dst, src, siz)
45	char *dst;
46	const char *src;
47	size_t siz;
48{
49	register char *d = dst;
50	register const char *s = src;
51	register size_t n = siz;
52
53	/* Copy as many bytes as will fit */
54	if (n != 0 && --n != 0) {
55		do {
56			if ((*d++ = *s++) == 0)
57				break;
58		} while (--n != 0);
59	}
60
61	/* Not enough room in dst, add NUL and traverse rest of src */
62	if (n == 0) {
63		if (siz != 0)
64			*d = '\0';		/* NUL-terminate dst */
65		while (*s++)
66			;
67	}
68
69	return(s - src - 1);	/* count does not include NUL */
70}
71