1 /* $OpenBSD: strlcpy.c,v 1.16 2019/01/25 00:19:25 millert Exp $ */
2
3 /*
4 * Copyright (c) 1998, 2015 Todd C. Miller <millert@openbsd.org>
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 #define _DEFAULT_SOURCE
20 #include <sys/types.h>
21 #include <string.h>
22
23 /*
24 * Copy string src to buffer dst of size dsize. At most dsize-1
25 * chars will be copied. Always NUL terminates (unless dsize == 0).
26 * Returns strlen(src); if retval >= dsize, truncation occurred.
27 */
28 size_t
strlcpy(char * dst,const char * src,size_t dsize)29 strlcpy (char *dst,
30 const char *src,
31 size_t dsize)
32 {
33 const char *osrc = src;
34 size_t nleft = dsize;
35
36 /* Copy as many bytes as will fit. */
37 if (nleft != 0) {
38 while (--nleft != 0) {
39 if ((*dst++ = *src++) == '\0')
40 break;
41 }
42 }
43
44 /* Not enough room in dst, add NUL and traverse rest of src. */
45 if (nleft == 0) {
46 if (dsize != 0)
47 *dst = '\0'; /* NUL-terminate dst */
48 while (*src++)
49 ;
50 }
51
52 return(src - osrc - 1); /* count does not include NUL */
53 }
54
