1 /*
2  * Copyright (c) 1998, 2015 Todd C. Miller <millert@openbsd.org>
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 THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <string.h>
19 
20 /*
21  * Copy string src to buffer dst of size dsize.  At most dsize-1
22  * chars will be copied.  Always NUL terminates (unless dsize == 0).
23  * Returns strlen(src); if retval >= dsize, truncation occurred.
24  */
25 size_t
26 strlcpy(char *dst, const char *src, size_t dsize)
27 {
28 	const char *osrc = src;
29 	size_t nleft = dsize;
30 
31 	/* Copy as many bytes as will fit. */
32 	if (nleft != 0) {
33 		while (--nleft != 0) {
34 			if ((*dst++ = *src++) == '\0')
35 				break;
36 		}
37 	}
38 
39 	/* Not enough room in dst, add NUL and traverse rest of src. */
40 	if (nleft == 0) {
41 		if (dsize != 0)
42 			*dst = '\0';		/* NUL-terminate dst */
43 		while (*src++)
44 			;
45 	}
46 
47 	return(src - osrc - 1);	/* count does not include NUL */
48 }