1 /* $OpenBSD: strlcpy.c,v 1.15 2016/10/16 17:37:39 dtucker 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 */
27 size_t
strlcpy(char * dst,const char * src,size_t dsize)28 strlcpy(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 }