strlcpy.c revision 8223e2f2 
1/*
2 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND TODD C. MILLER DISCLAIMS ALL
9 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
10 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL TODD C. MILLER BE LIABLE
11 * FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
13 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
14 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16
17#ifdef HAVE_DIX_CONFIG_H
18#include <dix-config.h>
19#endif
20
21#include <sys/types.h>
22#include <string.h>
23#include "os.h"
24
25/*
26 * Copy src to string dst of size siz.  At most siz-1 characters
27 * will be copied.  Always NUL terminates (unless siz == 0).
28 * Returns strlen(src); if retval >= siz, truncation occurred.
29 */
30size_t
31strlcpy(char *dst, const char *src, size_t siz)
32{
33	register char *d = dst;
34	register const char *s = src;
35	register size_t n = siz;
36
37	/* Copy as many bytes as will fit */
38	if (n != 0 && --n != 0) {
39		do {
40			if ((*d++ = *s++) == 0)
41				break;
42		} while (--n != 0);
43	}
44
45	/* Not enough room in dst, add NUL and traverse rest of src */
46	if (n == 0) {
47		if (siz != 0)
48			*d = '\0';		/* NUL-terminate dst */
49		while (*s++)
50			;
51	}
52
53	return s - src - 1;	/* count does not include NUL */
54}
55