xref: /f-stack/tools/compat/strlcpy.c (revision df6ad731)
1 /*	$OpenBSD: strlcpy.c,v 1.11 2006/05/05 15:27:38 millert Exp $	*/
2 
3 /*-
4  * Copyright (c) 1998 Todd C. Miller <[email protected]>
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 "compat.h"
20 
21 /*
22  * Copy src to string dst of size siz.  At most siz-1 characters
23  * will be copied.  Always NUL terminates (unless siz == 0).
24  * Returns strlen(src); if retval >= siz, truncation occurred.
25  */
26 size_t
strlcpy(char * __restrict dst,const char * __restrict src,size_t siz)27 strlcpy(char * __restrict dst, const char * __restrict src, size_t siz)
28 {
29 	char *d = dst;
30 	const char *s = src;
31 	size_t n = siz;
32 
33 	/* Copy as many bytes as will fit */
34 	if (n != 0) {
35 		while (--n != 0) {
36 			if ((*d++ = *s++) == '\0')
37 				break;
38 		}
39 	}
40 
41 	/* Not enough room in dst, add NUL and traverse rest of src */
42 	if (n == 0) {
43 		if (siz != 0)
44 			*d = '\0';		/* NUL-terminate dst */
45 		while (*s++)
46 			;
47 	}
48 
49 	return(s - src - 1);	/* count does not include NUL */
50 }
51