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1 b0003f58 2021-03-08 op /* $OpenBSD: strlcat.c,v 1.19 2019/01/25 00:19:25 millert Exp $ */
2 b0003f58 2021-03-08 op
3 b0003f58 2021-03-08 op /*
4 b0003f58 2021-03-08 op * Copyright (c) 1998, 2015 Todd C. Miller <millert@openbsd.org>
5 b0003f58 2021-03-08 op *
6 b0003f58 2021-03-08 op * Permission to use, copy, modify, and distribute this software for any
7 b0003f58 2021-03-08 op * purpose with or without fee is hereby granted, provided that the above
8 b0003f58 2021-03-08 op * copyright notice and this permission notice appear in all copies.
9 b0003f58 2021-03-08 op *
10 b0003f58 2021-03-08 op * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 b0003f58 2021-03-08 op * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 b0003f58 2021-03-08 op * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 b0003f58 2021-03-08 op * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 b0003f58 2021-03-08 op * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 b0003f58 2021-03-08 op * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 b0003f58 2021-03-08 op * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 b0003f58 2021-03-08 op */
18 b0003f58 2021-03-08 op
19 b0003f58 2021-03-08 op #include <sys/types.h>
20 b0003f58 2021-03-08 op #include <string.h>
21 b0003f58 2021-03-08 op
22 b0003f58 2021-03-08 op #include "compat.h"
23 b0003f58 2021-03-08 op
24 b0003f58 2021-03-08 op /*
25 b0003f58 2021-03-08 op * Appends src to string dst of size dsize (unlike strncat, dsize is the
26 b0003f58 2021-03-08 op * full size of dst, not space left). At most dsize-1 characters
27 b0003f58 2021-03-08 op * will be copied. Always NUL terminates (unless dsize <= strlen(dst)).
28 b0003f58 2021-03-08 op * Returns strlen(src) + MIN(dsize, strlen(initial dst)).
29 b0003f58 2021-03-08 op * If retval >= dsize, truncation occurred.
30 b0003f58 2021-03-08 op */
31 b0003f58 2021-03-08 op size_t
32 b0003f58 2021-03-08 op strlcat(char *dst, const char *src, size_t dsize)
33 b0003f58 2021-03-08 op {
34 b0003f58 2021-03-08 op const char *odst = dst;
35 b0003f58 2021-03-08 op const char *osrc = src;
36 b0003f58 2021-03-08 op size_t n = dsize;
37 b0003f58 2021-03-08 op size_t dlen;
38 b0003f58 2021-03-08 op
39 b0003f58 2021-03-08 op /* Find the end of dst and adjust bytes left but don't go past end. */
40 b0003f58 2021-03-08 op while (n-- != 0 && *dst != '\0')
41 b0003f58 2021-03-08 op dst++;
42 b0003f58 2021-03-08 op dlen = dst - odst;
43 b0003f58 2021-03-08 op n = dsize - dlen;
44 b0003f58 2021-03-08 op
45 b0003f58 2021-03-08 op if (n-- == 0)
46 b0003f58 2021-03-08 op return(dlen + strlen(src));
47 b0003f58 2021-03-08 op while (*src != '\0') {
48 b0003f58 2021-03-08 op if (n != 0) {
49 b0003f58 2021-03-08 op *dst++ = *src;
50 b0003f58 2021-03-08 op n--;
51 b0003f58 2021-03-08 op }
52 b0003f58 2021-03-08 op src++;
53 b0003f58 2021-03-08 op }
54 b0003f58 2021-03-08 op *dst = '\0';
55 b0003f58 2021-03-08 op
56 b0003f58 2021-03-08 op return(dlen + (src - osrc)); /* count does not include NUL */
57 b0003f58 2021-03-08 op }