1 805e39bf 2021-07-22 op /*	$OpenBSD: strlcat.c,v 1.19 2019/01/25 00:19:25 millert Exp $	*/
 2 805e39bf 2021-07-22 op 
 3 805e39bf 2021-07-22 op /*
 4 805e39bf 2021-07-22 op  * Copyright (c) 1998, 2015 Todd C. Miller <millert@openbsd.org>
 5 805e39bf 2021-07-22 op  *
 6 805e39bf 2021-07-22 op  * Permission to use, copy, modify, and distribute this software for any
 7 805e39bf 2021-07-22 op  * purpose with or without fee is hereby granted, provided that the above
 8 805e39bf 2021-07-22 op  * copyright notice and this permission notice appear in all copies.
 9 805e39bf 2021-07-22 op  *
10 805e39bf 2021-07-22 op  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 805e39bf 2021-07-22 op  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 805e39bf 2021-07-22 op  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 805e39bf 2021-07-22 op  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 805e39bf 2021-07-22 op  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 805e39bf 2021-07-22 op  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 805e39bf 2021-07-22 op  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 805e39bf 2021-07-22 op  */
18 805e39bf 2021-07-22 op 
19 805e39bf 2021-07-22 op #include <sys/types.h>
20 805e39bf 2021-07-22 op #include <string.h>
21 805e39bf 2021-07-22 op 
22 805e39bf 2021-07-22 op #include "compat.h"
23 805e39bf 2021-07-22 op 
24 805e39bf 2021-07-22 op /*
25 805e39bf 2021-07-22 op  * Appends src to string dst of size dsize (unlike strncat, dsize is the
26 805e39bf 2021-07-22 op  * full size of dst, not space left).  At most dsize-1 characters
27 805e39bf 2021-07-22 op  * will be copied.  Always NUL terminates (unless dsize <= strlen(dst)).
28 805e39bf 2021-07-22 op  * Returns strlen(src) + MIN(dsize, strlen(initial dst)).
29 805e39bf 2021-07-22 op  * If retval >= dsize, truncation occurred.
30 805e39bf 2021-07-22 op  */
31 805e39bf 2021-07-22 op size_t
32 805e39bf 2021-07-22 op strlcat(char *dst, const char *src, size_t dsize)
33 805e39bf 2021-07-22 op {
34 805e39bf 2021-07-22 op 	const char *odst = dst;
35 805e39bf 2021-07-22 op 	const char *osrc = src;
36 805e39bf 2021-07-22 op 	size_t n = dsize;
37 805e39bf 2021-07-22 op 	size_t dlen;
38 805e39bf 2021-07-22 op 
39 805e39bf 2021-07-22 op 	/* Find the end of dst and adjust bytes left but don't go past end. */
40 805e39bf 2021-07-22 op 	while (n-- != 0 && *dst != '\0')
41 805e39bf 2021-07-22 op 		dst++;
42 805e39bf 2021-07-22 op 	dlen = dst - odst;
43 805e39bf 2021-07-22 op 	n = dsize - dlen;
44 805e39bf 2021-07-22 op 
45 805e39bf 2021-07-22 op 	if (n-- == 0)
46 805e39bf 2021-07-22 op 		return(dlen + strlen(src));
47 805e39bf 2021-07-22 op 	while (*src != '\0') {
48 805e39bf 2021-07-22 op 		if (n != 0) {
49 805e39bf 2021-07-22 op 			*dst++ = *src;
50 805e39bf 2021-07-22 op 			n--;
51 805e39bf 2021-07-22 op 		}
52 805e39bf 2021-07-22 op 		src++;
53 805e39bf 2021-07-22 op 	}
54 805e39bf 2021-07-22 op 	*dst = '\0';
55 805e39bf 2021-07-22 op 
56 805e39bf 2021-07-22 op 	return(dlen + (src - osrc));	/* count does not include NUL */
57 805e39bf 2021-07-22 op }