strlcpy.c (1620B)
1 /* $OpenBSD: strlcpy.c,v 1.12 2015/01/15 03:54:12 millert 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 #include "compat.h"
23
24 /*
25 * Copy string src to buffer dst of size dsize. At most dsize-1
26 * chars will be copied. Always NUL terminates (unless dsize == 0).
27 * Returns strlen(src); if retval >= dsize, truncation occurred.
28 */
29 size_t
30 strlcpy(char *dst, const char *src, size_t dsize)
31 {
32 const char *osrc = src;
33 size_t nleft = dsize;
34
35 /* Copy as many bytes as will fit. */
36 if (nleft != 0) {
37 while (--nleft != 0) {
38 if ((*dst++ = *src++) == '\0')
39 break;
40 }
41 }
42
43 /* Not enough room in dst, add NUL and traverse rest of src. */
44 if (nleft == 0) {
45 if (dsize != 0)
46 *dst = '\0'; /* NUL-terminate dst */
47 while (*src++)
48 ;
49 }
50
51 return(src - osrc - 1); /* count does not include NUL */
52 }